Annual Report Jahresbericht 2006/2007

VORWORT | PREFACE

Der Namenspatron des Instituts Heinrich Rudolph Hertz Heinrich Rudolph Hertz, after whom the institute was wurde am 22.Februar 1857, also vor 150 Jahren geboren. named, was born on 22 February 1857, i.e. 150 years ago. Er hat in seinen Arbeiten ganz entscheidend dazu beigetra- His work played a decisive role in explaining electromagnetic gen, die elektromagnetischen Phänomene, wie sie durch die phenomena as put forward in Maxwell’s Equations. In 1889, Maxwellschen Gleichungen theoretisch beschrieben waren, Heinrich Hertz demonstrated the so-called displacement cur- experimentell zu bestätigen. Ihm gelang es, 1889 den soge- rent as an electric wave in the surrounding ether (in the air). nannten Verschiebungsstrom als elektrische Welle im umge- This paved the way for experiments which later resulted in benden Äther (in der Luft) nachzuweisen. Damit war der the use of radio transmission by Guglielmo Marconi (1896), Anfang zu Experimenten gelegt, die später zur Nutzung the birth of the wireless telegraph, radio technology and einer Funkübertragung durch Guglielmo Marconi (1896) hence high-frequency communication technology. In 1886, führten, zur Geburtsstunde der drahtlosen Telegrafie, der Heinrich Hertz also discovered the so-called photoelectric Rundfunktechnik und damit der hochfrequenten Nachrich- effect, i.e. the release of electrons from a metal surface hit tentechnik. Außerdem entdeckte Heinrich Hertz bereits by electromagnetic radiation (for instance light or UV light). 1886 den sogenannten lichtelektrischen Effekt, d. h. das This proved the interaction between light and material Freisetzen von Elektronen aus einer Metalloberfläche, die which must be regarded as one of the foundations of the von elektromagnetischer Strahlung (etwa Licht oder Ultra- laser effect. With his experiments, Heinrich Hertz laid the violettstrahlung) getroffen wird. Damit war ein Beispiel für foundation stone for key areas of research at the institute die Wechselwirkung zwischen Licht und Materie gefunden, that today bears his name. die als eine der Grundlagen des Lasereffekts zu sehen ist. Heinrich Hertz legte mit seinen Experimenten die Grund - steine für wesentliche Forschungsbereiche des Instituts, das seinen Namen trägt.

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Prof. Dr.-Ing. H.-J. Grallert Prof. Dr.-Ing., Dr. rer. nat. H. Boche

Innovationen für die digitale Zukunft! nehmen und überhaupt: ISDN sei ja noch kaum flächende- ckend vorhanden. Heute lächeln wir darüber und sehen in einer In frastruktur, die eine möglichst hohe Bandbreite jedem Es ist die nächste, im gewissen Sinne wichtigste Aufgabe Nutzer zur Verfügung stellt, das Maß aller Dinge in einer mo- unserer bewussten Naturerkenntnis, dass sie uns befähige, dernen Gesellschaft. Erst sie macht die Anwendungen wirk- zukünftige Erfahrungen vorauszusehen, um nach dieser lich verfügbar, die heute in keinem Haushalt fehlen dürfen. Voraussicht unser gegenwärtiges Handeln einrichten zu können. Das HHI hat es sich zur Aufgabe gemacht, die noch beste- aus Heinrich Hertz, „Die Prinzipien der Mechanik“, henden technischen und technologischen Hürden zur voll- Einleitung ständigen Durchdringung der Nutzergemeinschaft mit Band - breitentechnologie überwinden zu helfen und kostengünsti- Wo wir gestern noch den Vorsatz „Mega“ kannten, haben ge Lösungen für den Weltmarkt zu entwickeln. Hierbei wer- wir uns heute bereits an „Giga“ gewöhnt, und schon in den sowohl sehr breitbandige Festnetze vom Core- über den naher Zukunft wird nur noch „Tera“, gar „Peta“ für wirk- Access- bis hin zum Customer-Bereich betrachtet. liche Hochleistung stehen. Die Rede ist von den Bit pro Se - kunde, d.h. von übertragener Bandbreite eines Datenstroms, Die gegenwärtige rasante Entwicklung der digitalen Medien, deren Bestmarke inzwischen bei mehr als 2,56 Tbit/s auf des Internets, der PCs sowie der digitalen Endgeräte wie einer Wellenlänge bzw. 14 Tbit/s verteilt über einen Wellen - DVD-Player, Camcorder und digitales Fernsehen spricht eine längenkamm eines WDM-Systems steht. Auch im Mobilfunk deutliche Sprache und bildet den hochtourigen Motor für hat sich der Leistungspegel deutlich gesteigert und weitere den Ausbau der Breitbandkommunikationsnetze. Rekordmarken bei über einem 1 Gbit/s einer drahtlosen Übertragung gesetzt. Die rasante Entwicklung des Internets, Für die Anbieter der klassischen Medien Fernsehen, Radio das vor nahezu zwanzig Jahren quasi aus dem Nichts kam und Zeitung ist die Präsenz im Internet mit umfassenden und inzwischen im Bewusstsein der Bevölkerung fester ver- Online-Angeboten selbstverständlich geworden. Aber auch ankert ist, als das bei anderen Technologien jemals der Fall unzählige News-Dienste, Diskussionsforen oder die Internet - war, verändert nicht nur ständig unseren geschäftlichen und seiten von Firmen, Institutionen, Verwaltungen und Privat- privaten Alltag, sondern insgesamt unsere Vorstellung leuten tragen dazu bei, dass das Netz der Netze eine uner- davon, wie Kommunikation abläuft. schöpfliche wenn nicht überfließende Quelle von Informationen ist. Erinnern wir uns 30 Jahre zurück: Da schwärmten die einen, meistens Ingenieure vom künftigen Universalnetz Breitband- Das Internet heißt heute nur noch WEB und geht seiner ISDN (BISDN), das jedem Teilnehmer Mega-Bitraten und un - zweiten bzw. dritten Version entgegen. Hier wird dann geahnte neue Kommunikationsmöglichkeiten bieten werde Interaktivität und auch schnelle Interaktivität in digitalen – technologisch sei das bald möglich – man müsse nur wol- Medien unabdingbar sein, denn für Inhalte im Internet soll len und bauen. Andere wiederum waren skeptisch und und will jeder Teilnehmer künftig selber sorgen können. meinten, die „Bandbreiten-Euphorie“ sei unsinnig; der Individuelle Inhalte wirbeln durch die aktuellen Portale wie Mensch könne ohnehin nur wenige Bit pro Sekunde auf - „YouTube“, „MySpace“, „Flickr“ etc. Auch das Fernsehen

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fängt an, sich aus der Rolle des Couch-Potato zu lösen. für DMB besonders erfolgreich entwickelt hat. Weitere wich- Angestrebt werden im Rahmen von Triple-Play-Angeboten tige Themen sind die 2D- und 3D Bildsignalverarbeitung, nicht nur die Versorgung mit allen Diensten über einen Pro - Mixed-Reality-Displays, autostereoskopische 3D-Displays, vider sondern Kombination dreier Dienste. Dies dreifache Mensch-Maschine-Schnittstellen, Informationsmanagement Spiel speist sich aus drei Quellen, die nun auf einmal spru- sowie die Bild- und Videoarchivierung. deln sollen. Die Telefonie, der Internetzugang und der Fern - sehzugang sollen zusammenwachsen und nach Möglichkeit Mit Eintritt in die Fraunhofer-Gesellschaft wurde die Marke - auch mobil sein. ting-Abteilung des HHI noch konsequenter auf die Entwick - lung der Geschäftsfelder ausgerichtet. Heute arbeiten für Das HHI setzt seine Expertise deshalb nicht nur dazu ein, alle Bereiche spezialisierte Marketingbeauftragte zusammen Hardware zur Verbesserung der Übertragungsrate zu ent - mit den Fachabteilungsleitern, um bei neuen und bestehen- wickeln, sondern auch die zu übermittelnden Dienste und den Kunden sowie in öffentlichen FuE-Programmen Aufträ - Inhalte so effektiv zu verpacken und zu komprimieren, dass ge bzw. Projekte einzuwerben, Messeauftritte vorzubereiten auch höchst aufwändige Bilder und Videos zeitgerecht und und die Kundenbeziehungen zu pflegen. Die Kundenorien - mit hoher Qualität zum Nutzer kommen und dies sowohl tierung konnte durch den professionellen Marketingeinsatz über das Festnetz als auch über mobile Kanäle. Mit dem intensiviert werden. kommenden 3D-Internet rücken insbesondere auch 3D- Dienste und Endgeräte in den Mittelpunkt des Interesses. Die Umgestaltungen schlagen sich bereits in den verstärkten Das HHI zählt derzeit sicher zu den wenigen Einrichtungen, Erträgen durch Industrieaufträge nieder. Die Zunahme ist im die einerseits 3D-Bilder stereoskopisch in höchster, nahezu Budgetdiagramm im Jahresvergleich zu erkennen (vgl. Fig. 2). holografischer Qualität darstellen können, ohne auf die Hilfe Das Institut sieht sich deshalb zunehmend auf dem Weg, einer speziellen Brille für den Betrachter zurückgreifen zu den Erfordernissen, die an ein Institut der Fraunhofer-Gesell - müssen und andererseits die gesamten 3D-Technologien von schaft gestellt werden, gerecht zu werden. Dabei ist als der Aufnahme bis zur Wiedergabe beherrschen. Ertrag sicher nicht nur der finanzielle Beitrag zum Budget des Instituts anzusetzen, sondern auch der wissenschaftliche Das Institut hat sich in den vergangenen zwei Jahren inten- Ertrag, der einerseits das Renommee des Instituts und damit siv bemüht, seine Struktur den sich verändernden Märkten die öffentliche Wahrnehmung des Instituts stärkt und ande- und Kunden anzupassen. Dies geschah zum einen durch rerseits als Voraussetzung für künftige Aufträge den finan- eine konsequente Strukturierung des Instituts nach den stra- ziellen Beitrag zu den Budgets der kommenden Jahre sichern tegischen Geschäftsfeldern (Fig. 1). soll. Denn bei allen FuE-Aktivitäten des HHI stehen die Ver - bindung zur Industrie und die Verifizierung einer späteren • Electronic Imaging Realisierbarkeit im Vordergrund. • Communication Networks • Photonic Components Als ein Institut der Fraunhofer-Gesellschaft zur Förderung • Development Services. der angewandten Forschung e.V. ist uns Forschung und Ent - wicklung für industrielle Anwendungen ein selbstverständ - Zum anderen wurden die wissenschaftlichen und technolo- liches Anliegen. Die FuE-Arbeiten werden im Auftrag natio- gischen Kompetenzen des HHI und die Expertise der For - naler und internationaler Großunternehmen und KMU’s, schungs- und Entwicklungsarbeiten gestrafft und stärker Netzbetreibern sowie der öffentlichen Hand, wie Land Berlin, an den Geschäftsfeldern ausgerichtet. Diese Kompetenzen Bund, DFG und EU durchgeführt. Der Erfolg eines Unter- erstrecken sich im Bereich photonische Netze und Systeme nehmens steckt in den Köpfen seiner Mitarbeiter im Wissen vom hochkapazitiven flexiblen Weitverkehrsnetz bis hin über Produkte, Verfahren, Zusammenhänge. Die Leistungs - zum breitbandigen Inhausnetz. Im Mobilfunkbereich von kraft des Instituts beruht auf der Kreativität und dem Opti- Ressourcenzuweisungstechniken für UMTS Erweiterungen mismus unserer Mitarbeiterinnen und Mitarbeiter und der (3GPP LTE) zu MIMO-Systemen bis 1Gbit/s, WPAN Systemen Unterstützung durch unsere zahlreichen Geschäfts partner bis 60 GHz und Ad-hoc-Netzen. Der Bereich der Photo ni - und Förderer. Ihnen allen gilt unser besonderer Dank! schen Komponenten umfasst die Entwicklung und Fertigung von optischen und elektrooptischen Komponenten und Die Institutsleitung im Sommer 2007 Module auf der Basis von Indiumphosphid im Wellenlängen - bereich von 1,1 µm bis 2,0 µm, Polymerlichtwellenleiter und diffraktive optische Elemente. Schwerpunkte liegen außer- dem bei der Video- und Audiocodierung und -übertragung Prof. Dr.-Ing. H.-J. Grallert Prof. Dr.-Ing., Dr. rer. nat. (Video over IP) sowohl für Fest- als auch für Mobilfunknetzte, H. Boche wobei sich der Bereich Mobile TV sowohl für DVB-H als auch

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improving enhancing ensuring broadband and scaling and applications integrating data rates performance components

Electronic Communication Photonic Development Imaging Networks Components Services

Image Processing Mobile Broadband Active Devices Testcenters and Transmission Networks and Systems Passive Devices Measurement Equipment Device and Interactive Media Component Qualification Photonic Networks Integration Human Factors Advanced Training and Systems Technologies

Fig. 1: Businessfields of the Heinrich-Hertz-Institut

Betriebshaushalt / Operating Costs in Mill. €

20 Institutionelle Förderung Institutional Funding

Sonstige (z.B. DFG) Other Projects 15 EU Projekte European Projects

10 Industrieprojekte Industrial Projects

Nationale Projekte National Projects 5

0 2003 2004 2005 2006

Fig. 2: Development of operating costs and sources of funding 2003 – 2006

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Innovations for the digital future! ing force behind the development of broadband communication networks. It is the next, and in a certain sense most important task For providers of classical media, such as television, radio and of our conscious knowledge of nature that enables us to newspapers, Internet presence with comprehensive online forecast future experiences so that we can shape our offers has now become a matter of course. The countless current actions on the basis of these forecasts. news services, discussion forums or the Internet websites of from Heinrich Hertz, “The Principles of Mathematics”, companies, institutions, administrations and private indi- Introduction viduals are helping to transform the network of networks into a sheer endless, if not overflowing, source of informa- Whilst “mega” was the prefix of yesterday, today we have tion. already become accustomed to “giga”, and very soon, “tera” or even “peta” is all that will stand for really high The Internet is now merely referred to as the web and is performance. We are talking about bits per second, i.e. moving towards the second or third version. This is where the transmitted bandwidth of a data stream which at best interactivity and also fast interactivity in digital media will now reaches more than 2.56 Tbps over one wavelength or become indispensable because the participants themselves 14 Tbps distributed over a wavelength comb of a WDM sys- are to – and want to – supply the contents on the Internet. tem. But performance levels have also increased dramatically Individual contents are tumbling through current portals, with mobile radio and have set new record levels of more such as “YouTube”, “MySpace”, “Flickr”, etc. And television than 1 Gbps for wireless transmission. The rapid develop- is also beginning to move away from its couch potato ment of the Internet that came from quasi nothing almost image. The aim pursued here with triple-play offers is not twenty years ago and which is now more firmly established just the provision of all services via one provider but a com- in the minds of the population than any other technology bination of three services. Triple play comes from three before is not only continuously altering our business and pri- sources which are now all to flow at once. Telephone, vate life, it is also changing our concept of how communica- Internet access and television access are to merge and also tions work. be mobile if possible.

Let’s go back 30 years. At that time there was considerable This is why HHI is not only using its expertise to develop enthusiasm, mostly among engineers, about the future hardware designed to improve transmission rates, but also broadband ISDN (BISDN) universal network that would offer to pack and compress the services and contents transmitted each participant megabit rates and unbelievable, new com- so effectively that users receive even the most complex munication possibilities – this would soon be possible in images and videos on time and in high quality, both via the technological terms, all that was needed was determination fixed network and via mobile channels. With the dawn of and work. Others, however, were sceptical and referred to 3D Internet, the focus of attention is shifting, especially the “broadband euphoria” as nonsense; after all, a human towards 3D services and devices. HHI is currently one of the being could only process a few bits per second and besides: few institutes capable of presenting stereoscopic 3D images ISDN was not yet available everywhere. We recall this today in outstanding, almost holographic quality without viewers with a smile whilst looking at an infrastructure that offers having to use special glasses. At the same time, the institute each user high bandwidth – the ultimate in perfection in a has mastered the entire range of 3D technology, from cap- modern society. It is this infrastructure which makes the ture to projection. applications really available which no household today could do without. Over the past two years, the institute has stepped up its efforts to adapt its structure to changing markets and cus- HHI has dedicated itself to overcoming the technical and tomers. This was achieved through persistent reorganisation technological hurdles that stand in the way of complete based on strategic business fields (Fig. 1). penetration of bandwidth technology into the user commu- nity and to developing cost-efficient solutions for the global • Electronic Imaging market. In this context, we focus on very broadband fixed • Communication Networks networks, from the core, to the access and customer area, • Photonic Components as well as very broadband mobile radio systems. • Development Services.

Today’s tremendous pace of development in digital media, Furthermore, HHI’s scientific and technological know-how the Internet, PCs as well as digital devices, such as DVD and the expertise of its research and development work players, camcorders and digital TV, says it all, and is the driv- have been streamlined and orientated more towards the

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business fields. In the field of photonic networks and sys- our staff’s creativity and optimism as well as the support of tems, this competence ranges from high-capacitive, flexible our many business partners and sponsors. We would like to wide-area networks to broadband in-house networks. In the express our thanks to all of them! field of mobile radio, this expertise ranges from resource allocation methods for UMTS expansions (3GPP LTE) to Institute management in summer 2007 MIMO systems up to 1 Gbps, WPAN systems up to 60 GHz and ad-hoc networks. The field of photonic components includes the development and production of indium phosphide-based optical and electro-optical components and Prof. Dr.-Ing. Hans-Joachim Grallert modules in the 1.1 µm to 2.0 µm wavelength range, polymer optical fibres and diffractive optical elements. There is also a focus on video and audio coding and transmission (video over IP), both for fixed and mobile radio networks, Prof. Dr.-Ing., Dr. rer. nat. Holger Boche whilst the field of mobile TV has developed particularly successful for both DVB-H and DMB. Other important topics include 2D and 3D image signal processing, mixed-reality displays, autostereoscopic 3D displays, man-machine-interfaces, information management along with image and video archiving.

When HHI joined Fraunhofer-Gesellschaft, HHI’s marketing department focused more on developing the business fields even further. Today, marketing experts are working in all fields together with the heads of departments in order to solicit contracts and projects with new and existing customers as well as public R&D programmes, to prepare trade show presentations and to foster customer relationships. Customer orientation has been intensified through professional marketing.

The benefits of these reorganisation measures have already been felt in the form of higher revenue from contracts with industry. This increase can be seen in the annual comparison in the budget diagram (refer to Fig. 2). The institute hence sees itself in a good position to meet the demands facing an institute of Fraunhofer-Gesellschaft. However, revenue should not only be seen as the financial contribution to the institute’s budget but also as the scientific gain which strengthens the institutes reputation and hence its public image whilst also securing the financial contribution to future budgets as a precondition for future contracts. After all, ties with industry and verification of implementability are central aspects of all R&D activities pursued by HHI.

In our capacity as an institute of Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V., research and development for industrial applications are our prime and natural concern. R&D work is carried out on behalf of large national and international companies as well as small and medium-sized enterprises, network operators and the public sector, such as the State of Berlin, the Federal Government, DFG and the EU. A company’s success is rooted in the minds of its employees and their knowledge of products, processes and contexts. The institute’s performing power is based on

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LIST OF CONTENTS

VORWORT | PREFACE 1 Photonic Packaging Technology 67 Electron Beam Lithography – A Tool for High Resolution LIST OF CHAPTERS 13 Structures and Maskmaking 68

PHOTONIC NETWORKS AND SYSTEMS 14 Terahertz Technology – Telecom Chips Break Price, Size and Speed 69 Exploiting CWDM in Optical Access Networks 20 Novel Tapered DFB Laser 70 Home and Office Networks 21 Horizontal Cavity Surface Emitting (HCSE) DFB Lasers 71 Optical-Wireless Transmission for Broadband Indoor Communication 22 HHI – A One-stop Shop for Photonic Devices 72 40 Gbps Multimode Trans mission over Distances up to 600m 23 Customized Packaged Devices and Qualification 73 Towards 300 Gbps Data Trans mission for Next Generation Maskless Lithography Tools 24 INTERACTIVE MEDIA – HUMAN FACTORS 74 107 Gbps Transmission Using an Integrated Receiver 25 Advances in Interactive 3D Visualization 81 2.5 Terabit per Second Single Channel Data Transmission over Video-based Man Machine Interfaces 82 160 km Fiber 26 Rollout of Citizen-friendly Mobile Government Services 83 4 Wavelengths Raman Pump Applied to Broadband Raman 3D Amplification over 60 nm Bandwidth 27 Workbench – A Development Tool for Interactive Multi media Applications 84 Optical Multilevel Modulation Systems with Direct and Co her ent Detection 28 Temporal Video Segmentation for Digital Video Analysis 85 TCP over Optical Networks 29 Handheld Photobrowser with Similarity Search 86 Upgrade of Submarine Systems 30 IMAGE PROCESSING 88 GestAvatar – Real-time Animation of Avatars 94 MOBILE BROADBAND NETWORKS AND SYSTEMS 32 Statistical Multiplex for Mobile TV Using DVB-H 95 Spectrally Efficient Bidirec tional Relaying 38 Hardware-accelerated H.264/AVC-Decoding for DVB-H/DMB Multicell MIMO Measurements 39 Terminals 96 Realtime Demonstration of Physical Layer Concepts for 3GPP LTE 40 Multi-source Streaming for Robust Video Transmission in High Data Rate Wireless Inflight Entertainment System 41 mobile Ad-Hoc Networks 97 Temporal Structure of the 60 GHz Wireless Channel 42 A new Approach Based on Texture Analysis and Synthesis Network Calculus for Interference Management 43 for H.265 Video Coding 98 Guaranteeing Quality of Service in OFDM: Towards new A Software Suite for Mobile Broadcasting Product Development 99 Information Theoretic Performance Measures 44 Multi-view Video Coding 100 Cross Layer Optimized Resource Allocation in OFDM Broadcast CineVision 2006 Project 101 Channels 45 Virtual Mirror 102 Distributed Utility-based Power Control for Wireless Networks 46 Fast and high Resolution 3D Face Scanner 103 Impact of MIMO Techniques on Energy Efficiency of Wireless Electronic Components for a Maskless Lithography Data Path 104 Sensor Networks 47 Duality-based Optimization of Multiuser MIMO Systems 48 STRATEGY, NEW PRODUCTS 106

PHOTONIC COMPONENTS 50 COMMUNICATIONS AND EVENTS 110 Laser Diodes for Industrial Spectroscopy Applications 56 Publications 110 Multi-wavelength Diode Laser Pump for Raman Amplification Footnotes 126 in the C Band 57 Patent Applications 127 Mach-Zehnder Modulators for On-off-keying and new Awards 127 Phase-modulation Formats Targeting 100Gbit Ethernet 58 Postdoctoral Theses 128 Highly Linear Travelling Wave Photodetectors for 100 Gbps Applications 59 Doctorate Theses 128 All-polymer Fiber Arrays 60 Diploma Theses / Master Theses 128 Optical Minispectrometer 61 Graduate Theses 130 1.55 µm InP-based QD Lasers 62 Oral Presentations 130 Flip-chip Adapted OEICs for Economic Application Specified Lectures 132 Optical Board Set-ups 63 Workshops Organised 132 Next Generation Microlasers 64 Contributions to Exhibitions 133 40 Gbps directly Modulated Laser 65 Committee Activities 134 Compact 40 Gbps RZ-DPSK Trans mitter Applying a Exchange Program 135 PhaseCOMB Laser as Carved Source 66

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Fig. 3: Organisational chart of the Fraunhofer Institute for Technical Advisory Director s Telecommunications – Heinrich-Hertz-Institut. The various Committee fields of activity are organised into departments. Prof. Dr. Grallert Prof. Dr. Eberspächer Prof. Dr. Dr. Boche

Administration

Photonic Networks Image Processing Strategy, Dipl.-Wirtsch.-Inf. Stohl and Systems New Products

Dipl.-Ing. Walf Dr. Schäfer Dr. Venghaus Business Development/ Marketing Services

Broadband Mobile Interactive Media/ Dipl.-Phys. Schlaak Communication Human Factors Networks Prof. Dr. Dr. Boche Dr. Pastoor Public Services Dr. von Reden Fraunhofer Photonic German-Sino Lab Components for Mobile Communications Dr. Schell Quality Prof. Dr. Dr. Boche Dr. Grote Management Dr. Engel

Fakten und Zahlen Facts and Figures

Insgesamt kann die aktuelle Situation wie folgt zusammen- The current situation can be generally summarized as gefasst werden: follows.

• Das HHI hatte 2006 im Durchschnitt 225 Mitarbeiterinnen • In 2006, HHI employed a staff of 225 on average. und Mitarbeiter. • With around 140 projects, HHI generated revenue of • Mit etwa 140 Projekten wurden im Jahr 2006 Erträge € 10.1 m (refer to Fig. 3) in 2006. The investment volume in Höhe von 10,1 Mio. € (siehe Fig. 3) erwirtschaftet. in 2006 totalled around € 1.1 m. Das getätigte Investitionsvolumen betrug in 2006 etwa 1,1 Mio. € • The institute enjoys a high international reputation in the science and industry communities. • Das Institut genießt hohes internationales Ansehen in Wissenschaft und Industrie. • It boasts technically advanced, sometimes even unique technological resources. • Es verfügt über technisch hochwertige, teilweise einzigartige technologische Ressourcen. • The institute has a well-balanced and highly qualified staff structure and a good working atmosphere with a • Es hat eine ausgewogene und hoch qualifizierte cooperative spirit among the bodies in place. Mitarbeiterstruktur und ein gutes Betriebsklima mit kollegialer Zusammenarbeit der installierten Gremien. • HHI cooperates closely with universities. Some members of the institute teach at universities. Numerous post- • Das HHI kooperiert eng mit Universitäten; einige graduates, pre-graduate students, student assistants and Institutsangehörige nehmen Lehraufträge wahr; interns are involved in its projects. zahl reiche Doktoranden, Diplomanden, studentische Hilfskräfte und Praktikanten werden an den Projekten beteiligt.

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Höhepunkte und Ehrungen Highlights and Awards

Einige wichtige Ereignisse und große Erfolge aus dem • Some important results and major successes from the Berichtszeitraum sollen hier herausgehoben werden: period under review which deserve special mention are reported below. • 2006 erhielt Holger Boche den Vodafone-Innovationspreis • In 2006, Holger Boche was awarded the Vodafone Innov - für Forschungen zur grundlegenden Optimierung von ation Prize for research into fundamental optimisation of Mobilfunksystemen der neuesten Generation. Er hat mit the newest generation of mobile radio systems. His work seinen Arbeiten entscheidende Weichen für die zukünfti- has paved the way for future developments. ge Entwicklung gestellt. • Siegmund Pastoor, René de la Barré and David Przewozny • Siegmund Pastoor, René de la Barré und David Przewozny received the Joseph-von-Fraunhofer 2006 prize worth erhielten den mit 10.000 € dotierten Joseph-von-Fraun- € 10,000 from Fraunhofer-Gesellschaft for outstanding hofer-Preis 2006 der Fraunhofer-Gesellschaft für heraus- scientific work in conjunction with their work on inter- ragende wissenschaftliche Leistungen im Zusammenhang active 3D visualization with gesture interaction. mit ihren Arbeiten zur interaktiven 3D-Visualisierung mit • The display and interaction methods developed by Gesteninteraktion. Siegmund Pastoor’s team were also included in the list of • Die im Team von Siegmund Pastoor entwickelten Display- “German Stars” (50 trailblazing innovations “Made in und Interaktionstechniken wurden zudem durch die Germany”) and nominated for the ICT Prize 2007. Aufnahme in die Liste der „German Stars“ (50 bahn - • The 2006 Literature Prize awarded by Informationstech - brechende Innovationen „Made in Germany“) und durch nische Gesellschaft (ITG) went to Klaus-Dieter Langer for die Nominierung für den ICT Prize 2007 ausgezeichnet. his work titled “Closed-form solutions for key perform- • Den Literaturpreis 2006 der Informationstechnischen ance measures of packet multiplexers with finite capacity Gesellschaft (ITG) erhielt Klaus-Dieter Langer für eine queue”. Arbeit mit dem Titel „Closed-form solutions for key • The ITG also awarded the 2006 “Förderpreis” to Aydin performance measures of packet multiplexers with finite Sezgin for his doctoral thesis titled: “Space-Time Codes capacity queue“. for MIMO Systems: Quasi-Orthogonal Design and • Ebenfalls von der ITG erhielt Aydin Sezgin den Förderpreis Concatenation.” 2006 für seine Dissertation mit dem Titel: „Space-Time • The IEEE Signal Processing Society honoured Holger Boche Codes for MIMO Systems: Quasi-Orthogonal Design and and Eduard Jorswieck with the Best Paper Award for the Concatenation.“ publication titled: “Optimal transmission strategies and • Die IEEE Signal Processing Society hat Holger Boche und impact of correlation in multi-antenna systems with dif- Eduard Jorswieck den Best Paper-Award zugesprochen ferent types of channel state information” für die Publikation: „Optimal transmission strategies • Thomas Wiegand’s team was nominated together with and impact of correlation in multi-antenna systems with the company of Rohde&Schwarz FTK for the Innovation different types of channel state information” Prize Berlin-Brandenburg for their development of a • Das Team von Thomas Wiegand wurde zusammen mit DVB-H playout with static multiplex which makes it pos- der Firma Rohde&Schwarz FTK für den Innovationspreis sible to increase the number of programmes with mobile Berlin-Brandenburg nominiert für die Entwicklung eines TV services by 40 % whilst maintaining the same quality DVB-H-Playouts mit statistischem Multiplex, der es gestat- and hence boosting the value of mobile TV infrastruc- tet, bei Mobile-TV-Diensten die Anzahl der Programme tures considerably. bei gleicher Qualität um 40 % zu steigern und damit den • The ITU (International Telecommunication Union) cele- Wert von Mobile-TV-Infratrukturen erheblich zu erhöhen. brated its 50th anniversary in 2006 and to coincide with • Die ITU (International Telecommunication Union) feierte this called on its members to elect the most influential ihr 50jähriges Bestehen und hat aus diesem Grund 2006 standard that has emerged from the work of the stand- unter den Mitgliedern über den einflussreichsten Standard ardisation committee. The winner by a long distance was abstimmen lassen, der aus der Arbeit des Standardi sie - the video coding standard which was first defined under rungsgremiums entstanden ist. Die Wahl fiel mit großem the name H.262/MPEG2 video and then later under the Abstand auf den Video-Kodierstandard, der erst unter name H.264/AVC. Key parts of the compression code dem Namen H.262/MPEG2-Video und später unter dem which forms the basis for the H.264/AVC standard were Namen H.264/AVC festgelegt wurde. Wesentliche Teile developed at HHI. des Kompressionscodecs, der dem Standard H.264/AVC “incites” reported in July 2007 that, in line with the zu Grunde liegt, wurden am HHI entwickelt. enor mous interest in this standard, the work on this Dem großen Interesse entspricht auch, das die Arbeiten standard by Thomas Wiegand was the most frequently zu diesem Standard von Thomas Wiegand zu einer der cited publication last year among all engineering and

10 Annual Report | Jahresbericht 2006/2007 VORWORT | PREFACE

meistzitierten Publikationen aller ingenieurwissenschaft- scientific disciplines. This and other publications on image lichen Disziplinen im abgelaufenen Jahr gehört wie communication saw the highest percentage rise in the „in-cites“ im Juli 2007 berichtet. Diese und andere Ver- year under review. This evaluation was carried out using öffentlichungen zur Bildkommunikation erzielten den the “Essential Science Indicator”, an instrument operated höchsten prozentualen Anstieg im abgelaufenen Jahr. by the company of Thomson that uses targeted research Die Auswertung erfolgte durch den „Essential Science and analysis of its data to rank scientists, countries as Indicator“, ein von der Firma Thomson betriebenes Instru- well as journals. ment, das durch gezielte Recherche und Auswertung sei- • Highlights in the field of photonics include the demon- ner Daten ein Ranking von Wissenschaftlern, Instituten, stration of a 2.56 Tbps data transmission over one wave- Ländern aber auch Fachzeitschriften vornehmen kann. length through an optical fibre system measuring • Highlights auf dem Gebiet der Photonik sind die Demon - 160 km, 100 Gbps transmission attempts with a view to stration einer 2,56 Tbit/s-Datenübertragung auf einer the future 100 Gb Ethernet standard and the imple- Wellenlänge über eine Glasfaserstrecke mit einer Länge mentation of a photo diode array that demonstrated in von 160 km, 100 Gbit/s-Übertragungsversuche im Hinblick a research satellite its suitability for use in outer space auf den zukünftigen 100 Gbit-Ethernet-Standard und die and which transmitted large volumes of data to the Realisierung eines Photodiodenarrays, das seine Welt - ground station with one wavelength in infrared and a raumtauglichkeit derzeit in einem Forschungssatelliten data rate of 8 Gbps. The satellite’s communication unit unter Beweis stellt und bei einer Wellenlänge im Infra - that contains the diode array was developed by TESAT roten mit einer Datenrate von 8 Gbit/s große Datenmen - GmbH. gen zur Bodenstation übermittelt. Die Kommunikations- • In December 2006, the HHI scientists were able to dem - einheit des Satelliten, die das Diodenarray enthält, wurde on strate at a trade fair in Asia the transmission of data von der Firma TESAT GmbH, entwickelt. based on the basic parameters of a new mobile radio • Im Dezember 2006 konnten Forscher des HHI auf einer standard. Two aerials on the base station and two aerials Messe in Asien die Übertragung von Daten auf der Basis on the mobile terminal device (mobile phone, PDA etc.) von Grundparametern eines neuen Mobilfunkstandards enable usable data rates of up to 100 Mbps in the down- demonstrieren. Zwei Antennen an der Basisstation und ward direction, from the base station to the terminals, zwei Antennen am mobilen Endgerät (Handy, PDA etc.) and 50 Mbps in the in upward direction. This system is ermöglichen nutzbare Datenraten von bis zu 100 Mbit/s designed for ranges of just a few kilometres in cellular in der Abwärtsstrecke, von der Basisstation zu den Termi - mobile radio networks with high user mobility. nals, und 50 Mbit/s in der Aufwärtsstrecke. Dies System • We should not forget to mention the renewed successful ist für Reichweiten von einigen Kilometern in zellularen accreditation of the DIN EN ISO 9001:2000 quality man- Mobilfunknetzen mit hoher Mobilität der Nutzer ausge- agement system in March 2007 for the photonics fields legt. and also for the institute's administration. • Nicht unerwähnt bleiben soll die erneute erfolgreiche Zertifizierung des Qualitätsmanagementsystems DIN EN ISO 9001:2000 im März 2007 für die Photonik-Bereiche, aber auch für die Verwaltung des Instituts.

Annual Report | Jahresbericht 2006/2007 11 VORWORT | PREFACE

Personalia Personal matters

Wissenschaftlichen Rat und Unterstützung findet das Heinrich Hertz Institute receives scientific advice and support Heinrich-Hertz-Institut in seinem Kuratorium, das unter der from its board of trustees which, headed by Professor Leitung von Professor Eberspächer erstmals im März 2007 Eberspächer, met for the first time in March 2007. The zusammentrat. Ihm gehören Personen der Wissenschaft, der board comprises individuals from the worlds of science, Wirtschaft und der öffentlichen Hand an. Durch den business and the public sector. The board was appointed by Vorstand der Fraunhofer-Gesellschaft wurden berufen: the management board of Fraunhofer-Gesellschaft:

• Dr. Volkmar Dietz • Dr. Volkmar Dietz BMBF, Bonn German Federal Ministry of Education and Research, • Prof. Dr.-Ing. Jörg Eberspächer (Vorsitzender) Bonn Lehrstuhl für Kommunikationsnetze der TU München • Prof. Dr.-Ing. Jörg Eberspächer (Chairman) • Dr. Andreas Goerdeler Chair for communications networks at TU München BMWi, Berlin •Dr. Andreas Goerdeler • Prof. Franz Kraus German Federal Ministry of Economics and Technology, ARRI AG, München Berlin • Dr. Christoph Kutter •Prof. Franz Kraus Infineon Technologies AG, Neubiberg ARRI AG, Munich • Bernd W. Lietzau • Dr. Christoph Kutter Senatsverwaltung für Wissenschaft, Forschung und Kultur Infineon Technologies AG, Neubiberg • Wolfgang Lohmann • Bernd W. Lietzau ITCcon, Potsdam Senate Dept. for Science, Research and Culture • Prof. Dr.-Ing. Klaus Petermann • Wolfgang Lohmann Fakultät IV der TU Berlin ITCcon, Potsdam • Dr. Roland Raschke • Prof. Dr.-Ing. Klaus Petermann Fujitsu Laboratories Europe, Langer Faculty IV of TU Berlin • Dr. Fiona Williams • Dr. Roland Raschke Ericsson GmbH Eurolab R&E, Herzogenrath Fujitsu Laboratories Europe, Langer • Dr. Erich Zielinski (stellvertretender Vorsitzender) • Dr. Fiona Williams Alcatel SEL, Stuttgart Ericsson GmbH Eurolab R&E, Herzogenrath • Dr. Erich Zielinski (Deputy chairman) Die wissenschaftlich-technischen Mitarbeiter des HHI haben Alcatel SEL, Stuttgart ihren Vertreter im Wissenschaftlich-Technischen Rat der Fraunhofer-Gesellschaft neu gewählt. Vertreter des HHI im The scientific/technical employees of HHI have re-elected WTR sind jetzt: their representatives in the scientific/technical council of Fraunhofer-Gesellschaft. The HHI representatives in the • Prof. Dr. Ing. Hans-Joachim Grallert (kraft Amtes) scientific/technical council are now: • Wolfgang Schlaak (gewählt). • Prof. Dr. Ing. Hans-Joachim Grallert (ex officio) • Wolfgang Schlaak (elected).

12 Annual Report | Jahresbericht 2006/2007 LIST OF CHAPTERS

Photonic Networks and Systems page 14 – 31

Mobile Broadband Networks and Systems page 32 – 49

Photonic Components page 50 – 73

Interactive Media Human Factors page 74 – 87

Image Processing page 88 – 105

Strategy, New Products page 106 – 109

Annual Report | Jahresbericht 2006/2007 13

PHOTONIC NETWORKS AND SYSTEMS

Photonic Networks and Systems

Photonics is the basis of modern information and communication technology. It was photonics together with electronics which made the triumph of the Internet and global broadband communications possible. Photonics, i.e. the transport of information by means of light, permits the transmission of almost unlimited amounts of information within a short time over unlimited distances. Starting from telecommunications which are today already a traditional application, photonics will make its inroads into all conceiv- able applications, such as life science, traffic and transport as well as production technology and will be used wherever large amounts of information must be transmitted over very long or short distances. Although photonics is already used in a host of applications, we are still at the beginning of a photonics revolution and on course for omnipresent photonics:

• Broadband networking of home and office by photonic networks with data rates between 100 Mbps and 10 Gbps. • Broadband photonic in-house networks from networks in private homes to networks in expanded industrial plants. • Broadband mobile communication systems on the basis of photonic networks. • Broadband photonic information and communication systems in different means of transport, such as vehicles, trains, aircraft, ships and satellite. • Inter-machine and intra-machine communications with data rates even in the terabit range. • Intelligent systems and their photonic networking down to chip level.

As a key technology, comparable with electronics, photonics will thereby attain an outstanding economic importance.

Photonic networks consist of fibre-optical transmission lines and optoelectronic or optical switching nodes. Compared to traditional, copper-based transmission media and to radio systems, optical fibres with a transmission bandwidth of 50 Terahertz offers almost unlimited transmission capacity. Optical fibres enable at very low cost telephone calls to all over the world and the exchange of e-mails, pictures, videos, data, etc. via the Internet with every spot in the world.

Despite the turbulences in the IT industry in recent years, traffic volumes in the networks have been continuously increasing for more than ten years at annual rates of between 30 % and 50 % due to the growing use of the Internet. There is no end to this trend in sight. Instead, the increase will proceed at an even faster pace thanks to new services and applications, such as IPTV, Second Life, You

Annual Report | Jahresbericht 2006/2007 15 PHOTONIC NETWORKS AND SYSTEMS

Tube, Joost … The world-spanning communication networks tion of photonic components as well as nanotechnology are already exclusively based on photonic transmission sys- (nanophotonics) will have a special role to play here. tems. What is at present lacking is the quick, photonic connection of subscribers to the so-called data highway. Quick Since the 1970s, HHI has been intensively researching and access in this context means systems with data rates of at developing photonic transmission systems and networks in least 100 Mbps with the option of up to 10 Gbps. In Asia cooperation projects with industry and network operators. and, above all, in Japan and Korea, the establishment of It is hence one of the few institutions world-wide to have photonic access networks of this kind (fibre to the home, been actively involved in this field from the very beginning FTTH) is being intensively speeded up with the aim of equip- of research in this area and to have contributed greatly ping all households with FTTH by the year 2010. In the US, towards progress in this field. too, developments are strongly gaining momentum at present. In Europe, pilot projects are currently underway in One central aim of current R&D activities is to employ new increasing numbers, especially by new network operators. techniques in order to achieve better utilisation of optical- fibre transmission systems and to boost the performance of This trend will lead to exploding traffic volumes in global photonic networks in order to be able to fulfil the require- wide-area networks and to so far unprecedented demands ments outlined above. All network levels – from the core to on these networks. This will raise some fundamental ques- the access and right through to the in-house area are con- tions: sidered in this context. Besides R&D on purely physical/technical issues, other studies and developments deal with the • How must future photonic networks be designed from design and management of photonic networks as well as the optical subscriber connection to the wide-area the interaction between the protocol layers and the physical networks if all households are equipped with broadband layer. Another R&D activity addresses the use of optical connections with 100 Mbps? transmission methods for high-capacity inter-machine and • How do the technologies for broadband in-house intra-machine communications with total data rates of sev- networks – for buildings, offices and homes – look like eral 100 Gbps to several Tbps forecasted. HHI is working on in order to enable the bandwidth to reach the terminal these issues on behalf of industry and network operators units? and within the scope of research projects by the German • How can the transport costs per bit be drastically federal government, the city of Berlin, and the EU. reduced in order to make broadband access affordable for everybody? Well-equipped laboratories are available for research and development work, permitting experiments that extend to These questions represent challenges to research and devel- the current physical and technical limits. A WDM loop test opment with a view to network structures, network design, bed enables system and network studies with up to 32 network control and management, network security, net- wavelength channels in several wavelength bands (S, C, L) work upgrade, transmission methods, node architectures and a data rate of up to 44 Gbps per channel. A high-speed and key components. This requires consideration of all net- laboratory enables studies and transmission tests in the work levels, from the global wide-area network with trans- direction of several terabits per second. The studies are port capacities in the petabit range via regional networks to accompanied and supported by computer simulations using the optical subscriber connection and broadband in-house complex simulation tools. networks.

Ethernet technology will have a special role to play in this context as a very promising, less costly alternative to existing system technologies. Starting from 10-Gbps Ethernet technology, which is today commonplace, the issue of 100-Gbps Ethernet is currently moving into the focus of interest of research, development and standardisation efforts.

The future networks mean strongly increasing requirements for photonic key components. Their availability is a fundamental precondition for the implementation of such networks. Basically new technological approaches will be necessary in order to meet with the requirements, for example, in terms of speed, signal processing, low cost, etc. The integra-

16 Annual Report | Jahresbericht 2006/2007 PHOTONIC NETWORKS AND SYSTEMS

Photonische Netze und Systeme zunehmende Nutzung des Internets seit über zehn Jahren kontinuierlich zwischen 30 % und 50 % pro Jahr an. Ein Die Photonik ist die Basis der modernen Informations- und Ende dieses Trends ist nicht abzusehen. Vielmehr wird sich Kommunikationstechnik. Erst sie hat zusammen mit der der Anstieg durch neue Dienste und Anwendungen wie IPTV, Elektronik den Siegeszug des Internets und die globale breit- Second Life, You Tube, Joost … noch erheblich verstärken. bandige Kommunikation ermöglicht. Durch die Photo nik, Bereits heute basieren die weltumspannenden Kommunika - d. h. durch den Transport von Informationen mit Hilfe von tionsnetze ausschließlich auf photonischen Übertragungssys- Licht, ist es möglich, nahezu unbegrenzte Informations - temen. Was derzeit fehlt, ist der schnelle, photonische An - mengen in kurzer Zeit über unbegrenzte Entfernungen zu schluss der Teilnehmer an die sogenannte Datenauto bahn. übertragen. Unter schnellem Zugang werden hierbei Systeme mit Daten - raten von mindestens 100 Mbit/s mit der Option von bis zu Ausgehend von der Telekommunikation, dem traditionellen 10 Gbit/s verstanden. Im asiatischen Bereich, speziell in Einsatzgebiet wird die Photonik zukünftig in alle nur denk- Japan und Korea, wird der Aufbau derartiger photonischer baren Anwendungsbereiche vordringen, wie z. B. in die Zugangsnetze (Fiber to the Home, FTTH) intensiv vorange- Bereiche Life Science, Verkehrstechnik und Produktions tech - trieben, mit dem Ziel, bis 2010 alle Haus halte mit FTTH zu nik, und überall dort zum Einsatz kommen, wo große versorgen. Auch in den USA gewinnt zur Zeit die Entwick - Informationsmengen über weite oder aber auch kürzeste lung sehr an Dynamik. In Europa werden derzeit zuneh- Verbindungen übertragen werden müssen. Trotz des bereits mend Pilotprojekte, insbesondere von neuen Netzbetreibern, vielfältigen Einsatzes der Photonik befinden wir uns erst am durchgeführt. Beginn einer photonischen Revolution und auf dem Weg zu einer allgegenwärtigen Photonik: Diese Entwicklung wird zu einer Explosion des Verkehrsauf - kommens in den globalen Weitverkehrsnetzen und zu bisher • Breitbandige Vernetzung von Wohnung und Büro durch ungeahnten Anforderungen an diese Netze führen. Grund - photonische Netze mit Datenraten von 100 Mbit/s bis zu sätz liche Fragen werden aufgeworfen: 10 Gbit/s. • Breitbandige photonische Inhaus-Netze von der • Wie müssen zukünftig die photonischen Netze vom opti- Wohnung bis hin zu ausgedehnten Industrie-Anlagen. schen Teilnehmeranschluss bis hin zu den Weitverkehrs - • Breitbandige Mobilkommunikationssysteme auf der Basis netzen gestaltet werden, wenn alle Haushalte über einen photonischer Netze. breitbandigen Anschluss mit 100 Mbit/s verfügen? • Breitbandige photonische Informations- und Kommuni - • Wie sehen die Techniken für breitbandige Inhausnetze – kationssysteme in Verkehrsmitteln, wie Auto, Zug, Flug - für Gebäude, Büro und Wohnung – aus, damit die Band - zeug, Schiff und Satellit. breite bis zu den Endgeräten geführt werden kann? • Inter- und Intramaschinen-Kommunikation mit Daten - • Wie können die Transportkosten pro Bit drastisch redu- raten bis in den Terabit-Bereich. ziert werden, damit der breitbandige Zugang für alle • Intelligente Systeme und deren photonische Vernetzung bezahlbar wird? bis auf Chipebene. Diese Fragen stellen Herausforderungen an Forschung und Die Photonik erlangt damit als Schlüsseltechnologie – ver- Entwicklung zu den Themen Netzstrukturen, Netzdesign, gleichbar der Elektronik – eine herausragende gesamtwirt- Netzmanagement, Netzsicherheit, Netzupgrade, Übertra- schaftliche Bedeutung. gungsverfahren, Knotenarchitekturen und Schlüsselkompo - nenten dar. Hierbei müssen alle Netzebenen vom globalen Photonische Netze bestehen aus optischen Glasfaserüber tra - Weitvehrkehrsnetz mit Transportkapazitäten im Petabit- gungsstrecken und optoelektronischen oder optischen Ver - Bereich, über die regionalen Netze bis hin zum optischen mittlungsknoten. Im Vergleich zu den traditionellen Übertra- Teilnehmeranschlussnetz und den breitbandigen Inhaus - gungsmedien auf Kupferbasis und zur Funktechnik bietet netzen betrachtet werden. die Glasfaser mit einer Übertragungsbandbreite von 50 Tera- Hertz eine nahezu unbegrenzte Übertragungskapazität. Eine besondere Bedeutung kommt hierbei der Ethernet- Durch die Glasfaser ist es möglich, zu sehr geringen Kosten Technik zu, die eine sehr vielversprechende, kostengünstige- in alle Welt zu telefonieren und per Internet E-Mails, Bilder, re Alternative zu den bestehenden Systemtechniken dar- Videos, Daten usw. mit jedem Punkt der Erde auszutau- stellt. Ausgehend von der mittlerweile etablierten 10 Gbit/s- schen. Ethernet-Technik rückt derzeit massiv das Thema 100 Gbit- Ethernet in den Mittelpunkt des Interesses von Forschung, Trotz der Turbulenzen in der IT-Branche in den vergangenen Entwicklung und Standardisierung. Jahren steigt das Verkehrsaufkommen in den Netzen durch

Annual Report | Jahresbericht 2006/2007 17 PHOTONIC NETWORKS AND SYSTEMS

Die zukünftigen Netze stellen stark steigende Anforde run - gen an die photonischen Schlüsselkomponenten. Ihre Verfügbarkeit ist eine Grundvoraussetzung zur Realisierung derartiger Netze. Es sind grundsätzlich neue technologische Ansätze erforderlich, um z. B. die Anforderungen im Hin- blick auf Geschwindigkeit, Signalverarbeitung, geringe Kos - ten usw. zu erfüllen. Einen besonderen Stellenwert be kom - men hierbei die Integration photonischer Kompo nenten sowie die Nanotechnologie (Nanophotonik).

Das HHI führt seit den 70er Jahren intensive Forschungs- und Entwicklungsarbeiten in Kooperation mit Industrie und Netzbetreibern zu photonischen Übertragungssystemen und Netzen durch. Es gehört damit zu den weltweit wenigen Institutionen, die seit dem Beginn der Forschung auf diesem Gebiet agieren und maßgeblich zum Fortschritt beigetragen haben.

Wesentliches Ziel der derzeitigen F&E-Aktivitäten ist es, mit neuen Techniken eine bessere Nutzung der Glasfaserüber - tragungsstrecken sowie eine Steigerung der Leistungs fähig- keit photonischer Netze zu erreichen, um die oben skizzier- ten zukünftigen Anforderungen erfüllen zu können. Hierbei werden alle Netzebenen – vom Core- über den Access- bis hin zum Inhaus-Bereich – betrachtet. Neben F&E-Arbeiten zu rein physikalisch-technischen Fragestellungen werden Unter - suchungen und Entwicklungen zum Design und Manage - ment photonischer Netze sowie zum Zusammenwirken der Protokollebenen mit der physikalischen Ebene durchgeführt. Eine weitere F&E-Aktivität befasst sich mit dem Einsatz von optischen Übertragungstechniken zur hochkapazitiven Inter- und Intra-Maschine-Kommunikation mit prognostizierten Summendatenraten von mehreren 100 Gbit/s bis zu mehreren Tbit/s. Das HHI bearbeitet die Themen im Auftrag von Industrie und Netzbetreibern sowie im Rahmen von Förder- vorhaben des Bundes, des Landes Berlin und der EU.

Für die Forschungs- und Entwicklungsarbeiten stehen gut ausgestattete Labore zur Verfügung, die Experimente bis an die derzeitigen physikalischen und systemtechnischen Gren - zen erlauben. Mit einem WDM-Loop-Testbett können System- und Netzuntersuchungen mit bis zu 32 Wellenlän - genkanälen in mehreren Wellenlängenbändern (S, C, L) und einer Datenrate von bis zu 44 Gbit/s pro Kanal durchgeführt werden. In einem Hochgeschwindigkeitslabor können Unter - suchungen und Übertragungsversuche in Richtung mehrerer Terabit pro Sekunde erfolgen. Begleitet und gestützt werden die Untersuchungen durch Rechnersimulationen mit komple- xen Simulationswerkzeugen.

18 Annual Report | Jahresbericht 2006/2007 PHOTONIC NETWORKS AND SYSTEMS

Photonic Networks and Systems

Head of Department Godehard Walf Phone +49(0)30/310 02-455 Fax -250 e-mail [email protected]

Secretary Cornelia Kastner Phone -414 e-mail [email protected]

High-Speed TDM-Systems Colja Schubert Phone -252 e-mail [email protected]

WDM-Systems Ronald Freund Phone -652 e-mail [email protected]

Network-Design, Erwin Patzak Phone -514 Modeling e-mail [email protected]

Access- / Inhouse- / Datacom Klaus-Dieter Langer Phone -457 Systems e-mail [email protected]

Inter- / Intra Machine Anagnostis Paraskevopoulos Phone -288 communications e-mail [email protected]

5-10 Tbps long distance traffic

company networks 128 channels x 10 Gbps > 10 Gbps metro ring to the office Implementation of photonic networks in all 30 Mbps 1000 wavelengths to the mobile station 0,1 - 10 Gbps > 1 Gbps to the home to the base communication network areas for broadband station optical transceiver mobile station 1 electrical signals for all: core, metro, access and indoor net- base station mobile station 2 mobile station 3 works.

A 100 Gbps Transceiver demonstrated live at CeBIT 2007 in cooperation with SIEMENS.

transport capacity (Gbps) 0.01 0.1 1 10 4 10 teleworking

3 DVD-9 10

telelearning interactive 2 10 entertainment

response time (ms) response 10 video information exchange, Optical fibres with a nearly unlimited bandwidth of 70 conference retrieval Required network transport capacity as a 0 10 Terahertz are the transmission media for optical broad- 4 5 6 7 8 9 10 function of the information content to be 10 10 10 10 10 10 10 band communication networks. information content (bits) transferred and the needed response time.

Annual Report | Jahresbericht 2006/2007 19 PHOTONIC NETWORKS AND SYSTEMS

EXPLOITING CWDM IN OPTICAL bility of CWDM to serve as an optical efficiently. At short distances, typical in ACCESS NETWORKS transmission platform for different first access networks, this can be simply mile solutions such as VDSL over Optics achieved by exploiting each wave- In fibre optical access networks, (VDSLoO) and fixed wireless access length channel bidirectional, i.e. by Coarse Wavelength Division Mult i - (FWA) have been explored and demon- establishing a full-duplex link, where plexing (CWDM) can be used for strated.2 An outline of such a scenario both transceivers operate at the same different purposes: to provide effi- is depicted in Fig. 2. wavelength. Related issues of bidirec- ciently broadband access to many tional transmission such as limitations subscribers, as a transmission plat- VDSL due to Rayleigh crosstalk and discrete CWDM VDSLoO ONU form for various first-mile solutions, feeder ring reflections at connectors etc. have or to upgrade and extend existing e.g. WiMAX been examined. We have shown that OLT RAP optical access networks. Related FWA transmission supported by Forward scenarios have been investigated ONU Error Correction can cover the de- GbE and demonstrated. distribution ONU mands of access networks with respect ring with protection metro CO feeder distribution home to power budget and reach throughout Wellenlängenmultiplex mit weitem the entire CWDM band.4 Investigations Kanalabstand (CWDM) kann in Fig. 2: Optical platform for different access with channel bit rates up to 10 Gbps faseroptischen Zugangsnetzen für solutions (RAP = radio access point, OLT = are performed in HHI’s CWDM test optical line terminal) verschiedene Zwecke genutzt wer- bed, Fig. 3. den: Zur effizienten Bereitstellung When providing network access to a von Breitbandanschlüssen für viele large number of customers by few Teilnehmer, als Transportplattform commonly shared fibres, it is crucial to für unterschiedliche Lösungen zur protect the links against disruption. Überbrückung der ersten Meile, This can be simply solved by a ring net- oder zur Erweiterung bereits vor- work that inherently provides disjoint handener optischer Zugangsnetze. paths and by a proper access protocol. Entsprechende Szenarien wurden A novel link layer protocol has been untersucht und demonstriert. developed to improve both protocol complexity and restoration time com- One way to use CWDM in a passive pared to well-known Ethernet proto- optical network is illustrated in Fig. 1. cols (like the Rapid Spanning Tree The dual-stage system consists of a Protocol, RSTP). This Fast Access Ring feeder ring which links up to 18 distri- Protection Protocol (FARPP) is tailor- bution rings to a central office (CO) made for Ethernet-based ring networks using optical add-drop multiplexers in the access domain. It supports differ- (OADM). Each CWDM channel carries ent QoS classes and provides path a Gigabit Ethernet (GbE) system that is restoration times below 50 ms for the shared by the subscribers connected to high priority traffic classes, even on a the same distribution ring.1 50-node ring network. These numbers translate for sensitive applications as Fig. 3: CWDM test bed in the lab for optical central office high-end customer Voice-over-IP, IP-TV and Video-on- access networks (dedicated ) Demand to no service disruption in the [email protected] optical network unit 3 (ONU) case of a fibre break. CWDM feeder ring CWDM technology can also be applied 1 K.-D. Langer et al., CWDM access network end-users and prospects for introduction of full-duplex for an upgrade or extension of existing wavelength channels, Proc. NOC 2005, fibre-based access networks. As today’s pp. 68 – 75 remote node distribution rings various FTTx solutions like B-PON, G- 2 K. Habel et al., Broadband access solutions (OADM) (shared channels) on a common CWDM platform, Proc. NOC PON, E-PON and point-to-point links 2006, pp. 157 – 164 Fig. 1: CWDM access ring network occupy several wavelength bands, the 3 S. Chennu et al., QoS-aware traffic number of channels which can be used protection for access rings. Proc. NOC 2006, During the course of the European for a CWDM overlay are quite limited. pp. 165 – 174 4 K.-D. Langer et al., Single-fibre passive opti- Integrated R&D Project MUSE (Multi It is therefore essential that these cal network using full duplex wavelength chan- Service Access Everywhere), the capa- CWDM channels be exploited most nels, ITG Fachbericht 189, pp. 99 – 104, 2005

20 Annual Report | Jahresbericht 2006/2007 PHOTONIC NETWORKS AND SYSTEMS

HOME AND OFFICE NETWORKS networked devices where transport dis- enable high-speed data transmission. tances ≥ 100 m are assumed, Fig. 1. Using electronic dispersion compensa- In the nearest future, modern mul- The bandwidth requirements of ser - tion techniques, data speeds up to timedia applications will require vices depend on both the information 10 Gbps were demonstrated, however broadband home and office net- content to be transferred and the re - at the expense of a smaller core diam - works. In addition, the aim is to sponse time that users will generally eter. At HHI, R&D on specific POF types achieve simplified system installa- accept for a particular service. For for indoor applications is currently tion and low-cost equipment for example, to limit the transfer time of a underway. transmission distances up to 100 m DVD9 file with information content of and network transport capacities 70 Gb to approximately 7 seconds, a Microstructured glass fibers (mGOF) are up to 10 Gbps. The variety of short- network transport capacity of 10 Gbps an attractive option for fiber-based range communication systems cur- would be required, Fig. 2. Such needs broadband home networks with data rently available, based on different are fortified by HD-DVDs (400 Gb) and rates up to ≥ 10 Gbps. Fig. 3 shows an networking media, can hardly meet hard disks for example with 6 Tb which mGOF prototype suitable for home such demands. HHI is investigating are in the making. Altogether, future wiring applications. fiber optic based networks with services need broadband in-house net- data rates of up to 10 Gbps. works.1 HHI is investigating the potential of dif-

transport capacity (Gbps) ferent mGOF types for home network- Moderne Multimediaanwendungen 0.01 0.1 1 10 ing, in-building and access applications 4 benötigen schon bald breitbandige 10 running at speeds of up to 10 Gbps. Heim- und Büronetze. Hierfür sind teleworking Apart from demanding fabrication 3 DVD-9 preiswerte Systeme mit Übertra- 10 issues, a challenging task is the devel- gungslängen bis zu 100 m und Trans - telelearning interactive opment of easy-to-use termination tech- 2 port-Kapazitäten bis zu 10 Gb/s er- 10 entertainment nologies (core diameter of 10 –20 µm). forderlich, sowie eine vereinfachte Installierbarkeit. Die Vielzahl heute 1 core response time (ms) response 10 video information exchange, verfügbarer Kurzstrecken-Kommu - conference retrieval 0 cladding nikationssysteme für verschiedene 10 4 5 6 7 8 9 10 air hole Übertragungsmedien erfüllen kaum 10 10 10 10 10 10 10 die gestellten Anforderungen. Das information content (bits) HHI untersucht faseroptische Netze Fig. 2: Required network transport capacity as a für Datenraten bis zu 10 Gb/s. function of the information content to be transferred and the needed response time 125 µm Performance figures for the short-range Other important requirements for communication networks currently de- home/office networks are low-cost Fig. 3: Cross-section of a microstructured glass fiber with six air holes developed by Hitachi (K. veloped should be in line with the well- components, networking media that Osona et al: Laser Review, 2006) known in-building standards as well as tolerate tight bending radii (≤ 5 mm), the structured cabling standards for transport platforms with Plug & Play In addition to the optical wire-line, HHI residential (home) and office premises. capabilities to link end devices, easy-to- is conducting R&D on radio and optical use media termination technology, Do- wireless techniques especially for indoor It-Yourself installation capabilities and applications. 50 m 50 / 100 m aesthetic appearance of visible cabling. floor gateway / home- [email protected] distributor gateway Fiber optics is a promising technology backbone cabling home network when it comes to meeting such de -

50 / 500 m building mands. POF (plastic optical fiber) core gateway / gateway outside distributor diameters can be much larger than plant those of other fiber types resulting in cabling office a potentially simple termination tech- Fig. 1: In-house network topologies and typical nique, e.g. the use of optical clamps transmission distances instead of connectors. Unfortunately, Here, a centrally located gateway that only relatively low data speeds may be 1 G. Walf: Inhouse Networks-the last Meter to a Broadband World. ITG-Fachtagung Zukunft acts as an interface with the in-build- supported using these techniques. der Netze, Nov. 2006, http://www.comnets.uni- ing’s backbone cabling interconnects all Complex signal processing is needed to bremen.de/typo3site/index.php?id=87

Annual Report | Jahresbericht 2006/2007 21 PHOTONIC NETWORKS AND SYSTEMS

OPTICAL-WIRELESS TRANSMISSION sources are used for illumination and of the related IR transmission channel FOR BROADBAND INDOOR data-transmission. In such a system, it strongly vary, depending on LOS prom - COMMUNICATION would be possible to broadcast various inence. If there is a strong LOS, high broadband information in offices or on transmission rates can be achieved, Optical-wireless (OW) transmission public transport, as well as to use the whereas when LOS is weak or blocked, is especially attractive in environ- internet or a mobile phone, even in air- only signals coming from diffuse reflec- ments where radio communication crafts. Furthermore, one could imagine tions off the room surfaces will arrive is not accepted or desired. Advanced communication between cars or with at the receiver. Al though the transmis- techniques enable high transmis- street hubs, or even between machines. sion rate is limited by ISI, with proper sion speeds of more than 100 Mbps, Bringing these two worlds together equalization these signals can be used without transceiver alignment, e.g. became possible only recently with the to assure link re liability. Orthogonal fre- for office application. Apart from emergence of white-light LEDs which quency division multiplexing (OFDM) is infrared, visible light can be used, offer a considerable modulation band- particularly useful in such a frequency providing at the same time data width (~20 MHz). Moreover, such LEDs selective channel. OFDM offers high transmission and lighting. posses clear advan tages over conven- bandwidth efficiency, inherently deals tional lighting sources, thus making with ISI, thus allowing for the simplest Drahtlose optische Übertragung them a generally strong candidate for equalization at the receiver, and can be ist besonders dort interessant, wo future illumination. entirely realized by standard digital sig- Funk unzulässig oder nicht er- nal processing. In order to efficiently wünscht ist. Fortschrittliche Verfah - In our research, we consider primarily use the channel capacity, an adaptive ren eröffnen z.B. in Büroräumen downlink transmission in a medium- OFDM system is considered where the Möglichkeiten zur ungerichteten size office room where optical sources transmission speed is automatically hochratigen Kommunikation mit are installed at the ceiling and the adjusted to the channel by allocating Bitraten von mehr als 100 Mb/s. receiver is placed on a desktop. In the different orders of modulation on indi- Neben Infrarot kann auch sichtba- case of VL (Fig. 1), large LED panels are vidual subcarriers. In the OW system, res Licht verwendet werden, das needed to provide illumination. Due to subcarrier modulation also offers zugleich den Raum beleuchtet. the power distribution via many strong robust ness against ambient light noise. lines-of-sight (LOS), the transmission Fig. 2 shows the benefits of such trans- The term “wireless” is conventionally channel is flat everywhere at the desk- mission over a non-adaptive system, used as a synonym for radio (RF) com- top surface. Since inter-symbol-interfer- designed to guarantee system perform- munications (frequencies < 100 GHz). ence (ISI) is not present, very high data ance in the worst case where there is OW systems exploit a different part rates can be expected in such systems.1 no LOS. With favourable channel con- of the electromagnetic spectrum This work is being conducted in coop- ditions, rates of more than 100 Mbps (~100 THz). They can use visible light eration with Siemens CT. are expected.2 (VL) or infrared (IR) radiation. Some 1000 advantages which OW communication white LED panel 15 % clipping 2 % clipping offers over RF are: huge, unregulated PTOT = 400mW and available bandwidth, no electromagnetic interference with existing adaptive solution radio systems and possibility to reuse 100 non-adaptive (LOS) solution reflections the same frequencies in adjacent line-of-sight rooms, implying enhanced privacy and security along with simpler network system ca p ac ity (M b /s) design. These unique features make Fig. 1: Broadcasting data with “everyday” light 10 OW technology attractive for high- - 10 0+ 10 + 20 channel state, P / P (dB) speed indoor (short-range) links, espe- In an IR system, a single laser-based LOS DIFF cially in environments where RF sys- transmitter placed at the centre of the Fig. 2: Potential bit rates of an adaptive system tems are not desired, or secure wireless ceiling can provide transmission in the [email protected] transmission is required (medical and whole room. In order to have a simple [1] J. Grubor et. al., „High-Speed Indoor military facilities, aircrafts, banks). optical link, which supports the mobil - Wireless Communication via Visible Light“, in Hence, the two technologies together ity of the terminals (e.g. laptop), optical ITG Fachbericht 198, pp. 203 – 208, 2007. might provide a broad spectrum of sources with wide radiation angles and [2] J. Grubor et. al., „Adaptive-Modulation Technique in Wireless Infrared Indoor capabilities that radio alone would find receivers with wide field of view are Communication“, ITG Fachbericht 193, pp. difficult to meet. With VL, the same considered. Both gain and bandwidth 193 – 200, 2006.

22 Annual Report | Jahresbericht 2006/2007 PHOTONIC NETWORKS AND SYSTEMS

40 GBPS MULTIMODE TRANSMISSION receiver sensitivity and a much lower single-mode- to multimode fiber coupling OVER DISTANCES UP TO 600 M restriction with respect to eye-safety

matters. Tx SM MM Rx Datacom speed in today’s graded Pol up to 600 m GI-MMF index multimode fiber (GI-MMF) To evaluate GI-MMF transmission per- under test based local area networks (LAN) is formance, an optical multimode re- Fig. 3: Schematic of the experimental setup limited to 10 Gbps. To increase the ceiver (Rx) frontend was developed to capacity and speed of LANs, the detect intensity modulated signals up launch (50 µm longitudinal offset SM- transmission performance of 40Gbps to 40 Gbps. A very compact type of MM). In both cases, eye-mask violation NRZ-ASK signals over Draka Comteq’s assembly (see Fig. 1) was developed ratios of zero, zero and 1.2 ×10-4 were optimized GI-MMF was investigated that contains a top-illuminated InGaAs measured for transmission through in the 1300 nm wavelength region. PIN-photodiode (PD) and a lensed GI- 400 m of GI-MMF at wavelengths of For the first time, transmission dis- MMF-taper. The top-illuminated PD 1270 nm, 1290 nm and 1310 nm, re - tances of up to 600 m were experi- with anti-reflection coating can absorb spectively. No significant polarization mentally demonstrated. For these up to + 3 dBm of optical power. The sensitivity was identified. experiments, a special 40 Gbps MMF- diameter of the active region is ≈14 µm receiver-module was developed by and the 3-dB cut-off frequency was HHI.1 measured to be 29 GHz. The lensed GI-MMF-taper (spot size of 10 µm at Die Übertragungsgeschwindigkeit 1300 nm) is used for spot-size conver- von heutigen Gradienten-Multi mode- sion. Back-to-back transmission experi- Faser-basierten Übertragungssys te - ments revealed that the Rx-module is men im LAN-Bereich beträgt 10Gbit/s. suitable for detecting data rates of up Fig. 4: Measured eye diagrams for different lon- Zur Erhöhung der Übertragungska- to 40 Gbps, as can be seen in Fig. 2. gitudinal offsets using radial overfill launching pazität und Übertragungsgeschwin- (ROFL) after transmission through 600 m GI- 25 ps digkeit von LAN wurden die Über- MMF at a wavelength of 1300 nm tragungseigenschaften von 40 Gbit/s To evaluate worst-case transmission NRZ-ASK-Signalen über optimierte performance of the GI-MMF, ROFL was Gradienten-Multimode-Faser (GI- investigated for different longitudinal MMF) der Firma Draka Comteq im offsets at a transmission distance of Wellen längenbereich von 1300 nm Fig. 2: 40 Gbps NRZ-ASK back-to-back eye- 600 m. To the author’s knowledge, this untersucht. Erstmals wurden Über- diagram at 1300 nm was the first real multimode regime tragungsreichweiten von bis zu The experimental setup in Fig. 3 was test on 40 Gbps ever reported. Fig. 4 600 m experimentell demonstriert. employed to investigate the transmis- shows measured eye diagrams for Für die Übertragungsgexperimente sion performance of GI-MMF. The trans- 0 µm, 50 µm, 100 µm, 150 µm longitu- wurde eigens vom HHI ein 40 Gbit/s- mitter consisted of a tunable external dinal offsets, respectively. Up to 100µm, taugliches MMF-Empfängermodul cavity laser (ECL). Its continuous laser clear opened eyes were measured entwickelt.1 light was externally modulated by a which documents large tolerances with Mach-Zehnder modulator, a Lefèvre respect to longitudinal offsets. The de - Within the scope of developing a new polarization controller (POL) for con- tection of higher order modes at longi- 40 Gbps LAN system generation, col- trolling the state of polarization of the tudinal offsets ≥ 100 µm also confirmed laboration with DRAKA focused on transmitter’s output signal. The trans- that the fiber-tapered optical Rx-mod- investigating GI-MMF performance in mitter was pigtailed with standard SMF ule (Fig. 1) works as a real multimode the 1300 nm region which exploits the and FC/PC connector. The extinction receiver frontend. advantages of lower loss, lower differ- ratio and output power were measured ential mode delay (DMD), increased to be ≈ 7 dB and 3 dBm, respectively. The project was subsidised and carried The receiver consisted of the already out in cooperation with Draka Comteq described MMF-Rx-module. Optical Fibre, The Netherlands.

Certain eye-mask measurements at dif- [email protected] ferent wavelengths were performed for different launching conditions, i.e. the 1 P. Matthijsse et al.: “Multimode Fiber Fig. 1: 40 Gbps MMF-Receiver-module (left) and enabling 40 Gbit/s multi-mode Transmission sensitive area of top-illuminated InGaAs PIN- center (0 µm longitudinal offset SM- over Distances > 400 m”, Proc. OFC 2006, photodiode (right) MM, see Fig. 3) and the radial overfill paper OWI13

Annual Report | Jahresbericht 2006/2007 23 PHOTONIC NETWORKS AND SYSTEMS

TOWARDS 300 GBPS DATA TRANS - The project is being carried out by a detectors directly with the CMOS elec- MISSION FOR NEXT GENERATION strong and diversified team from indus- tronics at the receiver side. MASKLESS LITHOGRAPHY TOOLS try, academia and acclaimed European research institutes including Fraunhofer Maskless nanolithography is re- HHI and ISIT, under the leadership of garded as a promising technology the Austrian IMS Nanofabrication that will enable future generation GmbH, an SME with extensive experi- lithography tools with high lateral ence in cutting-edge charged particle resolution and high wafer through- nanofabrication research and technol - put. For this application, HHI is de - ogy. veloping an optical data path with multi-Gigabit/s data throughput. Based on experience from previous, similar projects, HHI’s department of Maskenlose Nanolithografie wird photonic networks and systems is lead- als eine vielversprechende Techno- ing the development of an optical data logie erachtet, die Lithografiean- path bringing together the department’s Fig. 2: Photograph of the 8 x 8 multimode fiber lagen der künftigen Generation mit know-how of photonic networks and array hoher Ortsauflösung und hohem systems with that of the department of Waferdurchsatz ermöglichen wird. image processing (cf. page 104). The The emission of the VCSELs is coupled Für diese Anwendung entwickelt targeted optical data path will allow to multimode fibers. The different das HHI einen optischen Datenpfad for transmission of lithography pattern- fibers from the individual VCSEL transmit multi-Gigabit/s Datendurchsatz. ing data up to a data rate of 300 Gbps mitters are connected to a fiber array from a data server to the aperture plug which serves as the origin of the Within the 6th framework programme plate system which is located within free space transmission section. As an by the European Union, HHI is partici- the high voltage and high vacuum area example, Fig. 2 shows a photograph of pating in the RIMANA1 project which of the electron beam column (Fig. 1). an 8 × 8 multimode fiber array which deals with radical innovation maskless supports the parallel transmission of nanolithography. The research project In order to accommodate for the re - 64 optical beams. The fiber array is addresses the need for maskless nano- quirements of high data throughput, imaged by a 1:1 projection optics onto patterning for the 32 nm node and small footprint and low power con- a photo detector array having the same beyond. The work is focussed on re - sump tion of the receiving optoelec- physical dimensions (2.5 × 2.5 mm) as search into basic, innovative elements tronic components which reside in the the transmitter array. that can demonstrate the feasibility of high vacuum area, the optical data an innovative Projection Mask-Less path is laid out as a highly parallel op - Within the RIMANA project, an optical Lithography (PML2) to address the tical free space transmission link.2 data path test bench will be set up need for fast device development, fast showing the principle operation of the prototyping, flexible low to medium The envisaged data rate per single optical data path. For this purpose, the volume production and, ultimately, for optical beam is about 3 Gbps and will total transmitted data rate will be high volume main stream maskless be provided by directly modulated ver- 30 Gbps which will be realized by lithography. tical cavity emitters (VCSEL) having an means of 10 parallel optical beams. emission wavelength of 850 nm. This allows the integration of the photo Later in the project, the test bench will be interconnected with the aperture plate system and the electron beam electron source column test bench which are being condenser optics developed by the project partners. aperture plate optical data path system 200 x reduction [email protected] electron beam optics scanning wafer stage

Fig. 1: The optical data path as developed by HHI transfers the lithography patterning data to the 1 http://www.rimana.org aperture plate system within the electron beam column. 2 Patent EP1623276B1

24 Annual Report | Jahresbericht 2006/2007 PHOTONIC NETWORKS AND SYSTEMS

107 GBPS TRANSMISSION USING and Siemens AG in a field experiment grated ETDM receiver chip. The demul- AN INTEGRATED RECEIVER in the AT&T network in the US.3 tiplexed 53.5 Gbps tributaries were detected with an error analyzer (EA). Transmission of 107 Gbps data sig- An optical attenuator (att.) was used to nals was demonstrated by FhG-HHI vary the received power Prec. The ex - in cooperation with Siemens AG peri mental results are shown in Fig. 3. using a transmission system with an The bit-error ratio (BER) is plotted as a integrated receiver chip. The system function of Prec for 107 Gbps (word was tested in the laboratory as well length 27-1). The inset shows eye dia- as in a field trial with deployed grams for the 107 Gbps data signal at fiber in the AT&T network in the the PD input and for one 53.5 Gbps US. The receiver chip is a key com- tributary at the receiver chip output. ponent for future 100 Gbps Ether- Each BER curve was obtained by aver- Fig. 1: Micrograph of the chip assembly net systems. aging over all 8 ETDM sub-channels. The receiver chip was based on SiGe Error-free performance (BER < 10-9) was Die Übertragung von 107 Gbit/s and comprised a 1:2-demultiplexer achieved back-to-back and over the Datensignalen wurde vom FhG-HHI (DEMUX) and clock & data recovery 480 km transmission link. in kooperation mit der Siemens AG (CDR).4 A picture of the receiver chip unter Einsatz eines Übertragungs- is shown in Fig. 1. For operation at 3 systems mit integriertem Empfäng - 107 Gbps, an external voltage-con- erchip demonstriert. Das System trolled oscillator (VCO) together with 4 wurde sowohl im Labor, als auch in an external control circuit driven by the Feldversuchen über verlegte Fasern chip-internally generated phase-detec- 5 2

im Netz von AT&T in den USA ge- tor signal was used. - log (BER) 6 tes tet. Der Empfängerchip ist eine 7 107 Gbps back-to-back Schlüsselkomponente für das zu- A schematic of the experimental setup 8 480 km künftige 100 Gbit/s Ethernet. comprising the 107 Gbps optical time 9 10 division multiplexing (OTDM) transmit- - 32- 28 - 24 - 20 - 16 Driven by the rapid growth of Ethernet ter, the 480km fiber link and the received power (dBm) traffic, the next step in transport net- 107 Gbps ETDM receiver is shown in Fig. 3: BER measurements, inset shows eye works is likely to be towards 100 Gb Fig. 2. In the transmitter a 13.375 GHz diagramms for 107 Gbps and 53.5 Gbps Ethernet. Transmission experiments at semiconductor mode-locked pulse 100 and 107 Gbps (expected rate for source (TMLL) emitted short optical The experiments by HHI and Siemens future 100 GbE transport networks pulses which were intensity modulated AG demonstrate the feasibility of a including forward error correction, FEC) (Mod.) and multiplexed to 107 Gbps in 107 Gbps transmission system includ- were recently reported.1,2 For 100 GbE, an OTDM-MUX. The data signal was ing integrated receiver chips. This is electronic components, such as a fast transmitted over a 480 km dispersion- the first step towards future 100 Gbps receiver chip, operating at data rates of managed fiber link composed of Super Ethernet systems. 100 Gbps and above, will be needed. Large Area fiber and Inverse Dispersion Fiber IDF. The fiber link was 100% [email protected] At the HHI a 107 Gbps transmission dispersion and dispersion slope com- experiment using an integrated receiver pensated. In the 107 Gbps receiver, the chip developed by Micram Microelec - data signal was optically pre-amplified, tronics GmbH was carried out in col- filtered (BPF) and detected with a high- 1 G. Raybon et al., OFC’06, PD32 2 R. H. Derksen et al., OFC’06, PD 37 laboration with Siemens AG. The re - speed photodiode (PD). The electrical 3 S. Jansen et al., OFC’07, OWE 3 ceiver chip was also tested by the HHI 107 Gbps signal was fed into the inte- 4 U. Dumler et al., El. Lett. 42 (2006)

107 Gbps transmitter 480 km fiber link 107 Gbps receiver x 6 ETDM receiver chip att. BPF clock 1 : 2 DEMUX TMLL mod. OTDM-MUX PD EA SLA IDF and CDR 13.375 GHz 13.375 Gbps 13.375 107 Gbps 80 km 3 nm data phase detector 107 Gbps Prec 53.5 GHz ext. VCO signal

Fig. 2: Schematic depiction of the transmission experimental setup

Annual Report | Jahresbericht 2006/2007 25 PHOTONIC NETWORKS AND SYSTEMS

2.5 TERABIT PER SECOND SINGLE this is a new record for single wave- including 300 m highly nonlinear fiber CHANNEL DATA TRANSMISSION length channel transmission.1 In a (HNLF) as optical gate. A mode-locked OVER 160 KM FIBER DQPSK modulated signal, each symbol fibre laser (MLFL) provided the control carries 1 out of 4 logical states which pulses and was synchronized by a clock The use of optical time division enables the encoding of two bits into recovery unit which is commercially multiplexing (OTDM) in combina- one transmitted symbol. This enables a available from HHI.2 Within the 80Gbps tion with differential quaternary doubling of the data rate without DQPSK receiver, a delay-line interfero - phase shift keying (DQPSK) modu- changing the symbol rate or reducing meter (DLI) operated as the phase lation enables transmission at ultra- the symbol rate for a given data rate. decoder. high data rates up to the world The latter can be used to increase the 3 record transmission rate of 2.5 Tbps transmission distance which was also back-to-back in a single wavelength channel. demonstrated by error free (bit error 160 km transmission 4 This was demonstrated by HHI in rate BER < 10-9) 1.28 Tbps transmission a 160 km transmission experiment over a record fibre length of 240 km. 5 together with Fujitsu Laboratories 6 2.56 Tbps

Ltd., Japan. Fig. 1 shows the experimental setup - log (BER) 7 alt. pol. comprising the DQPSK transmitter and 8 Der Einsatz der optischen Zeitmulti- receiver as well as the transmission 1.28 Tbps 9 alt. pol. plextechnik (OTDM) in Verbindung link. In the transmitter, a 10GHz mode- 10 mit differentieller vierstufiger Pha- locked solid state laser (MLSL) and a - 20 - 10 0 + 10 senmodulation (DQPSK) ermöglicht pulse compression unit provided a received power (dBm) die Übertragung mit extrem hohen 10 GHz optical pulse train with a pulse Datenraten bis zur Welt kord-Daten- width of 0.42 ps. The pulse compres- Fig. 2: Bit error rate measurement results rate von 2,5 Tbit/s auf einem einzel- sion unit was a soliton compressor nen Wellenlängen kanal, die vom based on highly-nonlinear dispersion Fig. 2 shows the BER measurements of HHI in einem 160 km Übertragungs- decreasing fibre followed by a disper- 2.56 Tbps and 1.28 Tbps transmission experiment zusammen mit Fujitsu sion imbalanced loop mirror for pedes - over 160 km DMF. Coherence crosstalk Laboratories Ltd., Japan, demon- tal suppression. An optical bandpass from overlapping pulse tails of the striert wurde. filter (BPF) defined the final pulsewidth slightly broadened pulses after trans- for transmission. The 10GHz pulse train mission resulted in performance vari- Traffic in telecommunication networks was DQPSK modulated to 20 Gbps by ations (indicated by the dashed area). is increasing by more than 50 % each pseudo random bit sequences (PRBS) At 2.56 Tbps, a best BER value of < 10-5 year. A corresponding upgrade of net- and finally multiplexed by optical PRBS- was achieved which is sufficient to work capacity and thus better utiliza- multiplexer stages (MUX). The last obtain a BER < 10-12 using standard for- tion of the optical fibre links will be stage up to 2.56 Tbps was a bit-inter- ward error correction (FEC) codes. mandatory in the future. One way leaved polarization multiplexing stage. towards better exploitation is to in - The signal was transmitted over up to [email protected] crease the data rates that are trans- three 80 km spans of dispersion man- ported by one optical carrier (wave- aged Ultrawave™ Fibre (DMF) provided length) in the optical fibre. Recently, by OFS Denmark. The receiver com- HHI performed 2.5 Tbps data transmis- prised a polarization demultiplexer 1 Weber et.al., Electron. Lett. 42 (3) sion over a single wavelength channel (PBS, polarization beam splitter) and a pp. 178 – 179 (2006) using the DQPSK modulation format; nonlinear optical loop mirror (NOLM) 2 www.hhi.fraunhofer.de/OTDM

DQPSK transmitter (up to 2.56 Tbps) DQPSK receiver (up to 2.56 Tbps) 160 / 240 km ultrawave fiber link clock recovery optical TM HNLF 10 GHz BPF att. amplifier 20 Gbps MLSL + MUX MUX 40 GHz MLFL DQPSK pulse x 4 x 32 SLA IDF TE = 1532 nm modulator BPF compression 1556 80 km PBS 80 Gbps nm 80 Gbps received DQPSK DQPSK x 2 or x 3 power NOLM receiver OTDM demultiplexer 6 nm

Fig. 1: Experimental set-up

26 Annual Report | Jahresbericht 2006/2007 PHOTONIC NETWORKS AND SYSTEMS

4 WAVELENGTHS RAMAN PUMP stabilized BH lasers and a fiber-based + 20 APPLIED TO BROADBAND RAMAN wavelength combiner to feed the laser sprectra + 10 1426.6 nm AMPLIFICATION OVER 60 NM power of the lasers into one fiber. The 1435.7 nm 1444.8 nm 0 BANDWIDTH emission spectrum of the 4 lasers is 1480.8 nm depicted in Fig. 2. The lasers have a - 10 Raman amplification is used in long- power of 260 mW (1427 nm), 160 mW haul transmission systems, submar- (1436 nm), 280 mW (1445 nm), and - 20 ine systems and high-speed systems 400 mW (1481 nm), respectively.

fi b er output power (dBm) - 30 (≥ 40 Gbps) to improve transmission - 40 distances and bandwidth and to To verify the usability of the pump 1420 1440 1460 1480 reduce noise and signal distortions. source, broadband Raman amplifi - wavelength ( nm) A 4 wavelengths C-band Raman cation experiments were performed pump source has been designed using alternatively a white light source Fig. 2: Emission spectrum of the pump source and fabricated by the Fraunhofer or 60 WDM channels (-3 dBm/channel, Institutes HHI, ILT and IAF. Pump non-modulated) distributed over 60nm. 0 tests show a total output power of The Raman-amplified signals and the signal spectrum after 52.8 km SMF - 10 1.1 W, flat gain bandwidth of 60 nm, gain spectrum after 53 km SMF trans- gain of 11 dB, and OSNR of 43 dB mission, using backward pumping with - 20 using 53 km SMF, 60 channels and the 4 wavelengths pump, are shown in - 30 -3 dBm signal power/channel. Fig. 3 and 4. With an on/off-gain of 11 dB, a gain ripple of 1.6 dB, and an - 40 sign a l power (dBm) In Weitverkehrs- und Unterseeka - OSNR of 43 dB the accomplished 4 - 50 bel-Übertragungssystemen sowie in wavelengths pump source represents a ≥ - 60 hochratigen Systemen ( 40 Gb/s) very good Raman pump for broadband 15201530 1540 15501560 1570 findet die Raman-Verstärkung zur WDM applications. wavelength (nm) Erhöhung der Reichweite und Bandbreite und zur Verringerung Raman Pump Source Specifications Fig. 3: Raman amplified signal spectrum (60 channels, 1nm spacing, -3 dBm/channel) des Rauschens und der Signalver- zer rungen Anwendung. Eine C- • 4 Wavelengths pump Band-Raman-Pumpquelle mit vier (diode laser based) 12

Wellenlängen wurde von den 1427 nm (≤ 260 mW) 10 Fraunhofer-Instituten HHI, ILT und 1436 nm (≤ 160 mW) IAF entwickelt und hergestellt. 1445 nm (≤ 280 mW) 8 Pumptests zeigen eine Gesamt- 1481 nm (≤ 400 mW) 6 ausgangsleistung von 1,1 W, ein 4

ebenes Verstärkungsband von • Gain bandwidth - g a in (dB) on / off 60 nm mit 11 dB Verstärkung und 1520 – 1580 nm, rippel 1.6 dB, 2

43 dB OSNR für 53 km SMF, 60 11 dB gain and 43 dB OSNR for 0 Kanäle und -3 dBm Signalleistung/ 53 km SMF and -3 dBm signal 15201530 1540 15501560 1570 Kanal. power per channel at 1550 nm wavelength (nm)

Fig. 4 : Broadband Raman gain spectrum Multi-wavelength pumps used for • Fiber Output broadband Raman amplification in SMF 28, FC/APC or E2000 WDM networks can be based on diode [email protected] lasers or Raman fiber lasers, but diode laser pumps offer the advantage of lower relative intensity noise and in general easier adjustment of the individual wavelength powers to obtain a flat gain bandwidth.

The pump source, built by the Fraun - hofer Institutes, is shown in Fig. 1. 1 M. Haverkamp et al., OFC’07 (accepted It comprises 4 fiber-coupled and FBG- Fig. 1: 4 wavelengths pump source paper)

Annual Report | Jahresbericht 2006/2007 27 PHOTONIC NETWORKS AND SYSTEMS

OPTICAL MULTILEVEL MODULATION The transmitters for high-order modu- PD SYSTEMS WITH DIRECT AND CO- lation formats can be composed of dif-

2 x 4 BD HER ENT DETECTION ferent structures which show different 3 dB 90°- 3 dB

chirp and transmission characteristics. TS hybrid BD The growth of the Internet and the As an example, Fig.1 shows a novel EDE & 2 x 4 BD provision of new services are leading optical IQ transmitter with consecutive ph ase 90°- A/D estim a- to increasing bandwidth de mands Mach-Zehnder-modulators (MZM) and hybrid BD tion and have recently enhanced interest phase modulators (PM) in each branch LO in multilevel modulation for optical which can be used to generate optical fiber transmission. To be able to Square-QAM signals. Fig. 3: Direct detection receiver for Star-QAM increase spectral efficiency, novel formats (top), coherent receiver with digital phase estimation (bottom), PD: photodiode, LO: transmitter and receiver concepts MZM PM local oscillator, A/D: analog to digital converter are being tested, and the question CW 3 dB 3 dB -90° MZM PM arises as to how optical high-order Within the coherent receiver, transmis- differential phase shift keying (M- sion impairments can be compensated Fig. 1: Novel optical transmitter for DPSK) and quadrature amplitude Square-QAM effectively by electronic distortion modulation (M-QAM) formats per- equalization (EDE). form during transmission. As an Compared to the conventional IQ alternative to direct detection, co- transmitter, this structure has the To determine the system performance herent receivers are coming back advantage that the electrical driving of various modulation formats and into the focus of re search and can signals for Square-16QAM are binary, structures, different system configur- make use of the advantages offered but shows a more critical behaviour at ations were implemented in simulation by high-speed digital signal pro - the symbol transitions for non-return- software and analyzed by extensive cessing now available. to-zero (NRZ) pulse shape, see Fig.2. Monte Carlo simulations and by calcu- lating eye opening penalties (EOP). Das stetige Internetwachstum und Semi-analytic BER estimation methods die Bereitstellung neuer Dienste were extended to high-order modu - führen zu steigenden Bandbreite- lation formats to be able to determine anforderungen und mehren aktuell the BER by fast calculations. In this das Interesse an höherwertigen way, the dispersion and self phase Modulationsverfahren für die op - modulation tolerances as well as the Fig. 2: Symbol transitions for Square-16-QAM tische Glasfaserübertragung. Mit NRZ when using a conventional IQ transmitter linewidth and OSNR requirements, dem Ziel der Erhöhung der spektra- (left) and the novel transmitter structure (right) shown as examples in Fig.4, can be len Effizienz werden neue Sender- determined for a wide range of modu- und Empfänger-Konzepte getestet, At the receiver end, direct detection lation formats. und es stellt sich die Frage nach der receivers as well as coherent receivers 1E-3 Übertragungscharakteristik opti- can be used to detect DPSK and Star- scher Systeme mit höherwertiger QAM signals. To be able to detect opti- 16 DPSK differentieller Phasentastung (M- cal Square-QAM signals, coherent 1E-5 DPSK) und Quadraturampli tu den - detection has to be employed. Both Star

BER DQPSK modulation (M-QAM). Als Alterna - types of receivers are shown in Fig.3. 16 QAM 1E-7 8 DPSK tive zum Direktempfang rücken DPSK Überlagerungsempfänger wieder in The optical core of both receivers can den Fokus der Forschung. Diese comprised 2 × 4 90° hybrid followed by 1E-9 profitieren von neuerdings verfüg- two balanced detectors (BD). The entire 12 16 20 24 28 barer digitaler Hochgeschwindig - optical frontend has the potential to be required OSNR (dB) keits-Signalverarbeitung. integrated into one chip. Fig. 4: OSNR requirements of various modulation formats when using direct detection High-order modulation formats are To combat phase noise in the coherent receivers, calculated by semianalytic BER estimation (solid lines) and Monte Carlo simulations widely used in electrical and wireless receiver, a digital phase estimation mod - (stars) -bitrate: 40 Gbit/s, line code: NRZ systems. For optical systems, however, ule based on digital signal pro cessing the transmission characteristics of most technology can be used. Approriate al- [email protected] high-order M-DPSK and M-QAM for- gorithms are developed to enable phase mats are largely unknown. estimation for Square-QAM formats. [1] M. Seimetz, NFOEC´06, Anaheim, NWA4

28 Annual Report | Jahresbericht 2006/2007 PHOTONIC NETWORKS AND SYSTEMS

TCP OVER OPTICAL NETWORKS In order to evaluate the performance Fig. 3 shows an example with the of TCP over an OBS network, two download times of a fixed size data file TCP is one of the key transport layer scenarios regarding contention reso - depicted against the network load. protocols of the Internet. For the lution methods were investigated: Increasing download times mean per- rollout of new network concepts, 1) Only wavelength conversion is used. formance degradation. The results are such as optical burst or packet Contending bursts are dropped, shown for wavelength conversion with switching, the compatibility of TCP leading to TCP segment losses. 8 wavelengths and with 16 wave- is mandatory. 2) Wavelength conversion and deflec- lengths as well as wavelength conver- tion routing are used. sion with 8 wavelengths and additional TCP ist eines der Schlüsselprotokolle Contending burst are not dropped but deflection routing. This comparison auf der Transportschicht des Inter- sent on an alternative path, leading to shows that doubling the number of nets. Für die Einführung von neuen reordering of TCP packets. wavelengths outperforms the deploy- Netzkonzepten, wie optisches Burst ment of deflection routing. oder Packet Switching, ist die Kom- To model all the details for a large net- 45 patibilität von TCP zu diesen Kon- work containing several tenths of OBS M = 8 wc zepten zwingend erforderlich. switches connected to a high number 40 M = 16 wc of TCP sources and receivers would 35 M = 8 wc + dr TCP is the dominant transport protocol result in prohibitively high computation 30 in the Internet. More than 90 % of the times. But a valid OBS network model 25 IP traffic is using TCP on the transport must at least include the OBS edge func - 20 layer. For networks with new purely tions burst assembly and disassembly

a nsfer Time in s File Tr 15 optical network switching concepts – and must provide realistic loss and like Optical Burst Switching (OBS) or delay statistics of the bursts on a path 10 Optical Packet Switching (OPS) – new through the network. 0.0 0.2 0.40.6 0.8 questions with respect to the behav- Offered Load iour of TCP occur. The simulation setup used is illustrated Fig 3: File transfer times vs. offered load – com- in Fig. 2 parison of doubling the number of wavelengths The absence of flexible optical memory with the deployment of deflection routing makes it difficult to handle contention 2 core network 3 1 of burst/packets. Contention leads to a 4 0 5 One major result of the analysis is that – 6 7 loss of burst/packets. There are three deflection path C 8 deflection path B 9 due to interplay between OBS conten - 10 11 major possibilities for avoiding con- shortest path A tion resolution and TCP congestion 12 13 tention in optical networks. These pos- edge router edge router avoidance mechanism – the effective 16 15 18 17 sibilities are wavelength conversion, 20 19 throughput is limited to a value de - fibre delay lines and deflection routing. pending on the efficiency of the con- access networks access networks tention resolution scheme. For instance Especially in the case of deflection Fig 2: Simulation Setup the maximum effective network util- routing, this leads to some interaction ization in our simulations ranges from between OBS and TCP which is caused The OBS network in this scenario com- 0.237 with 8 wavelengths and wave- by the reordering of bursts.1 Besides prises edge devices providing access to length conversion to 0.583 with 64 this, TCP congestion control influences the OBS core and optical (WDM) paths wavelengths and with wavelength the network load. Fig. 1 shows inter- through the OBS network. The OBS conversion and deflection routing. action between TCP and the behaviour network model includes three paths: of the network. shortest path A, deflection path B and This work was partly funded by the deflection path C. The paths are char- European Commission within the scope network TCP acterized by a path delay, the number of the IST NOBEL 2 project. congestion of hops per path and the number of avoidance load wavelengths. It was assumed that the [email protected] flow control node contention probability is equal in all nodes of a path. The computation losses loss recovery of the contention probabilities of shortest path A and deflection path B differ [1] M. Schlosser et al., “Impact of Deflection Fig 1: Interaction between TCP and Network due to the different number of hops Routing on TCP Performance in Optical Burst per path. Switching Networks”, IEEE ICTON, July 2005.

Annual Report | Jahresbericht 2006/2007 29 PHOTONIC NETWORKS AND SYSTEMS

UPGRADE OF SUBMARINE SYSTEMS upgrades by replacing or adding optic - using commercial 40 Gbps technology, al channels on a fibre already carrying one ASK modulated channel was Due to the steadily increasing band- traffic.1 As an example, results are pre- replaced by a channel modulated with width demand on ultra long-haul sented on how to add capacity to a 42.8 Gbps RZ-DPSK. After 6000 km, a trans-oceanic communication sys- third generation submarine system BER value of ~ 5 × 10-4 was measured tems, currently installed fibre-optic operating with N × 10.7 Gbps RZ-ASK which is above the desired value of undersea links are approaching channels over transatlantic distances. 1 × 10-6 for operation using Forward their capacity limits. Upgrading Error Correction (FEC) with enough sys- such systems beyond their original For the purpose of experimenting, a tem margins. Numerical simulations design capacity is an attractive recirculating twin-loop testbed with showed that this performance can be alternative to deploying new cables. non-slope matched submarine fibres slightly improved using in-band slope Recently available advanced modu- was set up, replicating the typical compensation. lation formats enable the use of dispersion and OSNR maps of trans- 1E-2 1 x 42.8 Gb/s RZ-DPSK & higher bit rates per channel and/or oceanic fibre links (Fig. 1) 15 x 10.7 Gb/s reduced WDM channel spacing RZ-ASK EDFA EDFA 1E-4 com pared to the original design, TX AOM coupler RX 3x3 1 x 19.9 Gb/s RZ-DPSK & leading to an increased spectral effi- 1E-6 AOM BER 15 x 10.7 Gb/s ciency and overall system capacity. LEAF / NZDSF RZ-ASK 45.7 km AOM Different scenarios for upgrading a EDFA 1E-8 16 x 10.7 Gb/s typical transatlantic fibre link were outer inner loops RZ-ASK loops 1 ... 8, 10 ... 17, ... PS experimentally investigated with 9, 18, ... coupler 1E-10 EDFA 3 dB 5000 5500 60006500 7000 the recirculating loop-testbed of GEQ EDFA distance (km) the HHI WDM laboratory; this re- EDFA MZ-EQ Fig. 2: Measured BER vs. distance for different search was commissioned by Azea SSMF 30 km SSMF 43 km upgrade scenarios for 100 GHz channel spacing Networks Ltd. Fig. 1: Experimental twin-loop configuration with doubly-periodic dispersion map In an alternative approach, one 10Gbps Der stetig steigende Bandbreiten- channel was upgraded to 20 Gbps RZ- bedarf bei der transozeanischen In the WDM transmitter (TX), sixteen DPSK (Fig. 2). Without in-band slope Datenkommunikation bringt die channels are launched in the worst- compensation this channel showed derzeit verlegten Untersee-Glasfa- case co-polarised state. Four Erbium much less severe performance degrad- serkabelsysteme an ihre Kapazitäts - Doped Fibre Amplifiers (EDFA) were ation and sufficient margins at 6000km. grenzen. Das Aufrüsten solcher used to compensate for fibre attenu - Systeme über ihre Designkapazität ation and loop loss. Two Fibre Bragg The maximum spectral efficiency with hinaus ist eine kostengünstige Gratings (FBG) suppressed the ASE 20 Gbps RZ-DPSK was investigated by Alternative zum Verlegen neuer noise peaks of the EDFAs. Different reducing the channel spacing of the 3 Kabel. Inzwischen verfügbare fort- NZDSF types, including large effective channels around 1553.33 nm, leaving geschrittene Modulationsformate area fibre (LEAF) and low-slope fibre, the other 13 channels as CW loading gestatten dabei eine Erhöhung der were used to reflect a typical third channels in this experiment. Kanaldatenrate bzw. eine Verringe- generation system. The channels were rung des WDM-Kanalabstandes, equalised by a channel-based Gain The results show that channel separ - was zur Steigerung der spektralen Equaliser (GEQ) as well as a Mach- ation can be reduced to 50 GHz (spec- Effizienz und zur Erhöhung der Zehnder gain Equalizer (MZ-EQ). Po - tral efficiency of 0.4 bps/Hz) until the System-Übertragungskapazität larisation scrambling (PS) was applied onset of severe performance degrad - führt. Mit dem WDM-Ringtestbett to mitigate polarisation effects. Within ations, emphasizing the 20 Gbps RZ- des HHI wurden im Auftrag von the receiver (RX), the bit error ratio DPSK format as a strong candidate for Azea Networks Ltd. verschiedene (BER) was measured. dark-fibre upgrades and various overlay Varianten zur Aufrüstung eines scenarios. typischen transatlantischen Unter- As a baseline, the transmission of see-Glasfaserkabels untersucht. 16 × 10.7 Gbps RZ-ASK channels with [email protected] a spacing of 100 GHz was evaluated System upgrades can be carried out using a proprietary 10 Gbps submarine either as dark fibre upgrades, i.e. light- transponder. A BER of ~10-8 was [1] R. Freund et al, “Mixed Bitrate and Modulation Format Upgrades of Non-Slope ing previously unused fibre pairs in a obtained after 6000 km (Fig. 2). To Matched Submarine Links”, proc. ECOC 2006, submarine cable, or as overlay emulate an overlay upgrade scenario paper Th1.6.5

30 Annual Report | Jahresbericht 2006/2007 PHOTONIC NETWORKS AND SYSTEMS

Annual Report | Jahresbericht 2006/2007 31

MOBILE BROADBAND NETWORKS AND SYSTEMS

Mobile Broadband Networks and Systems

Networks will be under substantial expansion pressure in the years to come. Forecasts suggest that the number of mobile communication customers will double to five billion by the end of 2015 and that the volume of data transmitted will be a hundred times higher – corresponding to an annual increase of around 60 to 70 percent. This is becoming possible thanks to the use of new technologies – around 50 percent of today’s data communications in mobile networks are handled by HSDPA. The 3GPP long-term evolution (LTE) of UMTS, which is currently undergoing stand - ardisation and which is based on OFDM and MIMO, will enable another ten-fold increase in data rates compared to HSDPA. Although mobile networks currently handle just one percent of data communications in fixed nets, forecasts indicate that the share of mobile networks will increase even faster.

In the strategic business field of mobile broadband networks and systems, we develop solutions within the entire range, from information theory via channel measurement, design of detection algorithms, system- and network simulation right through to the implementation of algorithms in the demonstrator with a focus on the following elements:

• Multi-antenna systems (MIMO) up to 1GBps • 3GPP LTE test bed @ 2.6GHz • Technologies beyond 3GPP LTE • Resource management for cellular and WPAN systems up to 60 GHz • New cross-layer optimisation approaches for QoS enhancement • Wireless ad-hoc networks • Vehicle-to-vehicle communications • Multi-standard baseband signal processing platform • Heterogeneous access management • Meshed networks and wireless sensor systems

Today, there is a wish to guarantee a certain quality of ser - vice even in mobile radio communications. In view of the time variance of the radio channel, this poses a challenge if no further measures are implemented especially for realtime applications which are susceptible to delay. In order to consider the delay sensitivity, the delay-limited capacity (DLC) parameter is hence introduced as a new performance measure in information theory. The Rayleigh fading channel, for example, features a DLC of zero which directly pinpoints the fundamental problem of mobile radio communications. Diversity is often the remedy because channels with more than one degree of freedom typically have a delay-limited capacity greater than zero. Orthogonal frequency-division multiplex (OFDM) systems, as will be shown, have several advantageous properties to offer in this context.

Annual Report | Jahresbericht 2006/2007 33 MOBILE BROADBAND NETWORKS AND SYSTEMS

In scenarios for cellular and mobile systems, the number of range is seen to be a promising method in order to meet users located within the range of the base station can be with the demanding requirements of future WPAN systems very high and is usually time-variant. Efficient allocation of with regard to increasing data rates. The use of millimetre- resources, taking channel quality into consideration in terms wave techniques at 60 GHz offers many advantages for of time, frequency and space (for multi-antenna base sta- short-range systems compared to radio methods at lower tions), is a fundamental precondition for all future systems. frequencies. The main advantages of this frequency band This allocation of resources – usually also referred to as are, on the one hand, the large (license-free) bandwidth multi-user scheduling – can be used to optimise system which permits high data rates and in the short wavelength and/or cell load and throughput with additional parameters on the other which leads to small antenna dimensions even for the quality of service (such as delay, average rates, BER) with multi-antenna systems. Furthermore, there is no inter- so that the network operator can operate the system as an ference with existing radio systems. In view of the high optimised, controllable cost function. One key advantage for radio field attenuation and the high transmission losses of multi-subscriber MIMO systems is the fact that the downlink walls, the radio cells are small, but interferences by other transceiver optimisation problem can be formulated and millimetre-wave systems and neighbouring radio cells are solved as a virtual uplink problem due to the duality theory. small as well. One immediate application is, for example, wireless multimedia supply in aircraft cabins. In this respect, A paradigm change in mobile communications enables the the properties of the broadband 60-GHz indoor channels transition to cooperative systems. Research here focuses on are examined and a system concept as well as first results of cooperative communication strategies for distributed anten- an experimental system are presented. nas. Permitting cooperation between several distributed antennas offers advantages from the spatial structure of the Wireless ad hoc networks are characterised by the absence wireless propagation medium. Significant increases in spec- of a fixed infrastructure. This distinguishes them from trad- tral efficiency can be achieved by making use of spatial itional mobile wireless networks and makes them interesting diversity and reducing interference. We have hence de - for an ever-increasing range of applications, such as vehicle- veloped a theory for modelling and optimising interference- to-vehicle communications, emergency services, etc. Vehicles coupled ratio networks. Multi-cell MIMO channel measure- which are capable of communicating with other vehicles ments then enable the determination of how large gains and their environment not only contribute towards avoiding will be in reality. accident situations and saving lives on the road, but can also increase driving comfort and efficiency. On the other hand, Cooperative strategies are of primary importance for users however, ad hoc networks also pose an enormous technical at the cell boundaries which have a very low capacity due to challenge for the administration and management of scarce propagation loss. One promising way of dealing with this wireless resources, especially due to the lack of central co - problem is the use of distributed relays which relay informa- ord ination. Our work covers all aspects related to the design tion via several hops. This not only increases the range and of the physical layer, the medium access control layer and reduces the – usually high – infrastructure costs, but add - the network layer, and explores coupling and interaction itionally leads to an extraordinary reduction in interferences between these layers in order to ensure optimum network between cells. We develop protocols and algorithms for performance. These research activities also cover different adaptive relay systems in conjunction with multi-antenna types of fixed and mobile wireless meshed networks. techniques and resource allocation. A wireless sensor network is a collection of sensor nodes In a joint project, Siemens AG, Fraunhofer HHI and IAF which is capable of capturing different physical phenomena GmbH have developed transmission concepts for the 3GPP and/or of acting on the environment. Sensor nodes have the long-term evolution (LTE) of UMTS. The LTE transmission potential for wireless communications and sufficient artificial techniques are based on a combination of OFDM and multi- intelligence for signal processing and networking of the antenna techniques which are also referred to as MIMO data captured. Thanks to their self-organisation capability, (Multiple-Input Multiple-Output). The base system with wireless sensor networks can be used almost everywhere orthogonal frequency-division multiple access (OFDMA) in and hence offer enormous potential for a host of applica- the downlink and single-carrier (SC) FDMA in the uplink was tions. Energy restriction is one of the central design criteria successfully presented to the general public by Siemens for wireless sensor networks and since the energy required Networks GmbH & Co. KG at ITU Telecom World 2006, and, for data transmission accounts for the largest share of en- in a version amended by the link adaptation, at the 3GSM ergy consumption in most practical applications, there is a World Congress 2007 in Barcelona. strong interest in energy-efficient communication algorithms in order to make the idea of a ubiquitary sensor network a Broadband millimetre-wave transmission in the 60-GHz reality. Our research activities include work on distributed

34 Annual Report | Jahresbericht 2006/2007 MOBILE BROADBAND NETWORKS AND SYSTEMS

coding for correlated sources and the development of ener- Orthogonale Frequenzmultiplex (OFDM) Systeme bringen, so gy-efficient communication algorithms and protocols. wird gezeigt, in diesem Kontext vorteilhafte Eigenschaften mit sich. Mobile Breitbandnetze und -Systeme In Szenarien für zellulare und mobile Systeme kann die Zahl In den nächsten Jahren stehen die Netze unter hohem Aus - der sich in Reichweite der Basisstation befindenden Nutzer baudruck. Den Prognosen zufolge wird sich die Zahl der sehr hoch sein und ist in der Regel zeitvariant. Ein effiziente Mobilfunkkunden bis Ende 2015 auf fünf Milliarden verdop- Ressourcenallokation, die die Kanalqualität hinsichtlich Zeit, peln und die übertragene Datenmenge etwa verhundertfa- Frequenz und Raum (für Mehrantennen-Basisstationen) chen, was einer Steigerung um etwa 60 bis 70 Prozent pro berücksichtigt, ist eine grundlegende Voraussetzung für alle Jahr entspricht. Ermöglicht wird das durch den Einsatz neuer zukünftigen Systeme. Diese Ressourcenallokation, die ge - Technologien – schon heute werden 50 Prozent des Daten - meinhin auch als Mehrnutzer-Scheduling bekannt ist, kann ver kehrs in den Mobilfunknetzen über HSDPA abgewickelt. genutzt werden, um die System- bzw. Zelllast oder den Die zurzeit in der Standardisierung befindliche 3GPP long- Durchsatz mit zusätzlichen Dienstgüteparametern (z.B. Ver- term evolution (LTE) von UMTS, die auf OFDM und MIMO zögerung, Durchschnittsraten, BER) zu optimieren, so dass beruht, wird gegenüber HSDPA eine weitere Verzehnfach - der Netzbetreiber das System als optimierte, kontrollierbare ung der Datenrate ermöglichen. Derzeit tragen die Mobil - Kostenfunktion fahren kann. Von großem Vorteil für Mehr - funknetze nur ein Prozent des Datenverkehrs der Festnetze, teilnehmer MIMO Systeme ist hierbei, dass das Downlink der Anteil werde hier den Vorhersagen zufolge aber schnel- Transceiver Optimierungsproblem aufgrund der Dualitäts - ler steigen. theorie als virtuelles Uplink Problem formuliert und gelöst werden kann. In dem strategischen Geschäftsfeld Mobile Breitbandnetze und -Systeme erarbeiten wir Lösungen innerhalb der gesam- Ein Paradigmenwechsel in der Mobilkommunikation ermög- ten Spanne von Informationstheorie über Kanalmessung, licht den Übergang zu kooperativen Systemen. Der For - Entwurf von Detektionsalgorithmen, System- und Netzsimu - schungsschwerpunkt liegt hier auf kooperativen Kommu- lation bis hin zur Algo rithmenimplementierung im Demon- nikationsstrategien für verteilte Antennen. Indem man Ko - strator mit folgenden Schwerpunkten: operation zwischen mehreren verteilen Antennen zulässt, kann man Vorteil aus der räumlichen Struktur des drahtlo- • Multi-Antennen Systeme (MIMO) bis 1GBit/s sen Ausbreitungsmediums ziehen. Man kann beachtliche • 3GPP LTE Testbett @ 2,6GHz Steigerungen in der spektralen Effizienz durch die Nutzung • Techniken jenseits von 3GPP LTE räumlicher Diversität und durch Reduktion von Interferenz • Ressourcenmanagement für zellulare und WPAN Systeme erzielen. Wir haben daher eine Theorie zur Modellierung bis 60 GHz und Optimierung interferenzverkoppelter Funknetzwerke • Neue Cross-layer Optimierungsansätze zur QoS entwickelt. Aus Mehrzellen MIMO Kanalmessungen lässt Verbesserung sich dann ableiten, wie hoch die Gewinne in der Realität • Drahtlose Ad-hoc Netzwerke sein werden. • Fahrzeug zu Fahrzeug Kommunikation • Multi Standard Basisbandsignalverarbeitungsplattform Kooperative Strategien sind vor allem für die Nutzer an den • Heterogenes Access Management Zellgrenzen entscheidend, die bedingt durch den Ausbrei - • Vermaschte Netze und drahtlose Sensor Systeme tungsverlust eine sehr niedrige Kapazität haben. Ein vielver- sprechender Weg, um dieses Problem zu bewältigen, ist die Heutzutage besteht der Wunsch, auch in Mobilfunkverbin - Nutzung von verteilten Relais, die die Information über meh- dungen eine bestimmte Dienstgüte zu garantierten. Ange - rere Hops weiterleiten. Dies erhöht nicht nur die Reichweite sichts der Zeitvarianz des Funkkanals ist das ohne weitere und reduziert die üblicherweise hohen Infrastrukturkosten, Maßnahmen insbesondere für Echtzeitanwendungen, die sondern führt zusätzlich zu einer außerordentlichen Redu - sensibel auf Verzögerungen reagieren, eine Herausforde - zierung der Interferenzen zwischen den Zellen. Wir entwi- rung. Zur Berücksichtigung der Verzögerungssensitivität wird ckeln Protokolle und Algorithmen für adaptive Relais-Sys - daher in der Informationstheorie die verzögerungsbeschrän - teme in Verbindung mit Mehr-Antennen-Techniken und kte Kapazität (DLC) als neues Performanz-Maß eingeführt. Ressourcen Allokation. Z.B. hat der Rayleigh Fading Kanal eine DLC gleich null, was das grundsätzliche Problem von Mobilfunkverbindungen In einem gemeinsamen Projekt haben die Siemens AG, das sofort aufzeigt. Abhilfe bringt hier meist Diversität, da Ka- Fraunhofer HHI und die IAF GmbH Übertragungskonzepte näle mit mehr als einem Freiheitsgrad üblicherweise eine für die 3GPP long-term evolution (LTE) von UMTS entwickelt. verzögerungsbeschränkte Kapazität größer Null haben. Die Übertragungstechniken von LTE beruhen auf einer

Annual Report | Jahresbericht 2006/2007 35 MOBILE BROADBAND NETWORKS AND SYSTEMS

Kombination von OFDM und Mehrantennentechniken, die Ein drahtloses Sensornetzwerk ist eine Ansammlung von auch als MIMO (Multiple-Input Multiple-Output) bekannt Sensorknoten, die in der Lage sind unterschiedliche physika- sind. Das Basis-System mit orthogonal frequency-division lische Phänomene zu erfassen und/oder auf die Umgebung multiple access (OFDMA) in der Abwärtsstrecke und single- einzuwirken. Sensorknoten haben das Potential zur drahtlo- carrier (SC) FDMA in der Aufwärtsstrecke wurde erfolgreich sen Kommunikation und ausreichend künstliche Intelligenz von der Siemens Networks GmbH & Co. KG auf der ITU für die Signalverarbeitung und Vernetzung der gesammelten Telecom World 2006, sowie erweitert um die Linkadaption Daten. Wegen ihrer Fähigkeit zur Selbstorganisation, können auf dem 3GSM World Congress 2007 in Barcelona der brei- drahtlose Sensornetzwerke fast an jedem Ort eingesetzt ten Öffentlichkeit vorgestellt. werden und haben damit ein enormes Potential für zahlrei- che Applikationen. Die Energieeinschränkung ist eines der Die breitbandige Millimeterwellen-Übertragung im 60 GHz- zentralen Designkriterien für drahtlose Sensornetzwerke und Bereich gilt als aussichtsreiches Verfahren, um den hohen da die bei der Datenübertragung benötigte Energie bei den Anforderungen zukünftiger WPAN-Systeme bezüglich stei- meisten praktischen Anwendungen den Hauptteil des ge - gender Datenraten gerecht zu werden. Für Systeme mit samten Energieverbrauchs ausmacht, besteht ein starkes kurzer Reichweite bietet der Einsatz von Millimeterwellen - Interesse an energie-effizienten Kommunikationsalgo rith- tech niken bei 60 GHz viele Vorteile gegenüber Funktech - men, um die Idee eines ubiquitären Sensornetzwerkes zu niken bei niedrigeren Frequenzen. Die Hauptvorteile dieses verwirklichen. Unsere Forschungsaktivitäten schließen Arbei - Frequenzbandes liegen zum einen in der großen (lizenz- ten zu verteilter Kodierung für korrelierte Quellen und die freien) Band breite, die hohe Datenraten ermöglicht, und Entwicklung von energie-effizienten Kommunikationsalgo - zum anderen in der kurzen Wellenlänge, die zu geringen rithmen und Protokollen ein. Antennenabmes sungen auch für Multi-Antennen Systeme führt. Weiterhin gibt es keine Interferenzen zu bestehenden Funksystemen. Aufgrund der hohen Funkfelddämpfung und der hohen Transmissionsverluste von Wänden sind die Funk - zellen klein, aber damit sind auch die Störungen anderer Millimeterwellensysteme und benachbarter Funkzellen gering. Eine direkte Anwendung ist z.B. die drahtlose Multi - mediaversorgung in Flugzeugkabinen. Hierzu werden die Eigen schaften des breitbandigen 60 GHz Indoor-Kanals untersucht und ein Systemkonzept sowie erste Ergebnisse eines Experimentalsystems präsentiert.

Drahtlose Ad hoc Netzwerke, sind charakterisiert durch das Fehlen einer festen Infrastruktur. Das unterscheidet sie von traditionellen mobilen drahtlosen Netzwerken und macht sie interessant für einen immer breiter werdenden Anwen - dungs bereich wie z.B. Fahrzeug zu Fahrzeug Kommunika - tion, Katastrophenschutz, etc. Autos, die die Fähigkeit haben mit anderen Autos und mit ihrer Umgebung zu kom- munizieren, können nicht nur dazu beitragen, Unfallsitu - ationen zu vermeiden und Leben auf unseren Straßen zu retten, sondern können auch den Komfort und die Effizienz beim Fahren steigern. Andererseits stellen Ad hoc Netzwer - ke, gerade wegen der fehlenden zentralen Koordinierung, eine große technische Herausforderung an die Verwaltung der knappen drahtlosen Ressourcen dar. In unseren Arbeiten decken wir alle Aspekte ab, die sich auf das Design der physikalischen Schicht, der Medium Access Control Schicht und der Netzwerkschicht beziehen und untersuchen die Kopp - lung und Interaktion zwischen diesen Schichten, um die bestmögliche Netzwerk-Performance zu gewährleisten. Diese Forschungsaktivitäten umfassen auch unterschiedliche Arten der festen und mobilen drahtlosen vermaschten Netze.

36 Annual Report | Jahresbericht 2006/2007 MOBILE BROADBAND NETWORKS AND SYSTEMS

Mobile Broadband Networks and Systems

Head of Department Holger Boche Phone +49(0)30/310 02-540 Fax -609 e-mail [email protected]

Secretary Susanne Müller Phone -399 e-mail [email protected]

Katharina Schweers Phone -541 e-mail [email protected]

LTE, LTE+ real time implementation Volker Jungnickel Phone -768 e-mail [email protected]

Wireless Gigabit PAN at 60GHz Wilhelm Keusgen Phone -639 e-mail [email protected]

Wireless Sensor networks Slawomir Stanczak Phone -875 Ad hoc networks e-mail [email protected]

Network Calculus Martin Schubert Phone -870 Interference management e-mail [email protected]

New air interface Gerhard Wunder Phone -872 Heterogenous access management e-mail [email protected]

Car to car communication Slawomir Stanczak Phone -875 e-mail [email protected]

Andreas Kortke Phone +49(0)30/31 42 83 11 e-mail [email protected]

Ad-hoc car-to-car communication.

After digital postprocessing, which comprises complex down conversion, noise filtering and correlation, a set of coherent channel impulse responses (CIRs) can be obtained. Such a small-scale set of 100 CIRs under line-of-sight (LOS) conditions inside a conference room is shown.

In December, 2006 the next milestone for mobile communication could be demonstrated on the ITU Telecom World in Hong Kong, the largest fair for Telecommu- nikations in Asia in 2006. An experimental setup was presented transferring data using the basic parameters 64-QAM Signals, received spatially of the future LTE-Standard. multiplexed in downlink constellations.

Annual Report | Jahresbericht 2006/2007 37 MOBILE BROADBAND NETWORKS AND SYSTEMS

SPECTRALLY EFFICIENT BIDIREC - should be specified in the IEEE 802.20 mal coding for the classical information TIONAL RELAYING standard. theoretic multiple access channel. In the succeeding broadcast phase (BC), We study the achievable rate region Here, we consider a three-node net- the relay broadcasts the previously of a spectrally efficient bidirectional work where one node acts as a relay to received messages. The relay node relaying decode-and-forward proto- enable bidirectional communication of superimposes the code words for node col. In the second (broadcast) phase, the others. In practice, it is difficult to 1 with portion 0 ≤ q ≤ 1 and for node the receiving nodes exploit their isolate the signal received from the 2 with portion 1 − q of the relay trans- own information about the inter- own transmit signal. Therefore, we mit power. Therefore, nodes 1 and 2 ference to improve their decoding assume that the relay node cannot receive their own message as interfer- capabilities. transmit and receive at the same time ence. Since each node knows the chan- using the same frequency which is nel and the codebooks used, before Wir untersuchen die erreichbare called a half-duplex relay. Because of decoding the unknown message each Ratenregion einer spektral effizien- this, in most cooperative communica- node subtracts the interference caused ten bidirektionalen Relais übertra - tion protocols additional resources in by its own message, i.e. effectively gung basierend auf dem Dekodier - time or frequency are allocated, i.e. interference-free reception is achieved. und-Weiterleit-Protokoll. In der they suffer from an inherent loss in zweiten Phase nutzen die Empfangs- spectral efficiency. This spectral loss can R stationen ihre vorhandenen Infor - be avoided with a bidirectional relaying mationen über die Interferenz, um protocol.1 There is a conceptual rela- die eigene Dekodierfähigkeit zu tionship to the network coding ap- verbessern. proach2 which also deals with efficient information transfer respectively rou- Future communication systems should ting in a network. Network information offer access to wireless services with theory concepts will be essential for 1 high data rates almost everywhere. developing new techniques for future Fig. 2: The achievable rate region of the bidirec- This objective represents an enormous communication systems. For this rea- tional relay channel (BRC) is given by the intersection of the MAC and BC achievable rate engineering challenge for years to son, we are approaching the problem region come, especially in scenarios where the with a view to information theory and direct link does not have the desired assume a perfectly synchronized net- Here, we assume equal time division quality, e.g. due to shadowing or dis- work with flat-fading AWGN channels between the MAC and BC phase. tance. Therefore, there has been a between the relay node and nodes 1 Furthermore, we assume that the infor- recent increase in interest in co-opera- and 2. Each node has an individual mation received in the MAC phase has tive protocols for wireless systems transmit power constraint and has to be immediately forwarded in the BC where one or more relay nodes realize perfect channel knowledge. phase. The achievable rate region of range extension by way of multi-hop the bidirectional relaying scheme is communication. PHY and MAC tech- then given by the intersection of the niques which enable mesh networking MAC and BC achievable rate region. in wireless networks are currently being discussed for wireless personal area One fundamental question left is how networks by the Task Group 5 of the to share the transmit power at the relay R 2 IEEE 802.15 standard, for wireless local node which we have examined along area networks in extension IEEE Fig. 1: In the MAC phase node 1 and 2 transmit with an additional relay communica- 802.11s, and for wireless metropolitan the blue and green message to the relay node. tion.1 area networks in amendment IEEE Both messages will be decoded at the relay node and simultaenously retransmitted in the 802.16j – mobile multi-hop relay. succeeding broadcast (BC) phase. [email protected] Thereby, one allows every subscriber station to function as a backhaul, for- Bidirectional communication is per- 1 T. J. Oechtering and H. Boche, “Optimal Resource Allocation for a Bidirectional warding traffic until it arrives finally at formed in two phases. In the first Regenerative Half-duplex Relaying,” in IEEE the intended destination. Such meshed phase, the multiple access phase International Symposium on Information Theory network principles will be indispens- (MAC), nodes 1 and 2 transmit their and its Applications, Seoul, Korea, 2006 able for a future wireless global area messages for each other with rates R1 2 R. Ahlswede, N. Cai, S.-Y. R. Li, and R. W. Yeung, “Network information flow,” IEEE network which should implement net- and R2 to the relay node. Encoding Transactions on Information Theory, vol. 46, no. work access across the country and and decoding are exactly like the opti- 4, 2000.

38 Annual Report | Jahresbericht 2006/2007 MOBILE BROADBAND NETWORKS AND SYSTEMS

MULTICELL MIMO MEASUREMENTS Heinrich-Hertz-Institut MATH. In total, there are six strong DoF z y HHI as observed on the right side of Fig. 3. We report broadband multicell x MIMO measurements in an urban HFT Institut für Fernmelde- macrocell deployment. Interference 1 und Hochfrequenztechnik c df c df can be reduced and capacity can be 2 3 multiplied by factors using cooperative multicell processing of antenna ILR 5 10 15 5 10 15 Institut für Luft- signals. und Raumfahrt 5 4 singular values singular values N Fig. 3: Left: Singular value statistics for classical Wir haben erstmals Messungen in frequency reuse (left) and for cooperative base einem Multizell MIMO Mobilfunk - stations (right) netz mit mehreren Basisstationen MATH CU Institut für Mathematik und Terminals durchgeführt. Die MATH ILR MATH ILR Fig. 1: Multicell measurement scenario Interzellinterferenz kann durch Ko- resource resource resource 1 2 1 operation der Basisstationen redu- LOS + pos. 5 pos. 2 pos. 5 pos. 2 ziert werden, und die Kapazi tät pro NLOS c df Zelle vervielfacht sich. Fig. 4: Left: Frequency reuse. Right: When coop- 246108 12 eration is enabled in a central unit (CU) The capacity of the cellular access net- singular values work is limited by interference. Future NLOS Finally, the capacity gain of base sta- networks intend to reduce interference c df tion cooperation is quantified in Fig. 5 in order to increase capacity. The cur- 246108 for a full scenario. In order to compare, rent long-term evolution (LTE) reduces singular values the mean capacity of isolated cells is intracell interference. But interference narrow band shown. With frequency reuse, capacity LOS broadband NLOS remains from adjacent cells. c df is reduced since bandwidth is shared. 20 25 30 35 By means of cooperation, capacity can Intercell interference can be reduced by spectral effciency (bps/Hz) @ 10 dB SNR be enhanced by a factor of 5 and it is using an advanced wired signalling Fig. 2: Singular value statistics in single cells even higher than in isolated cells due network behind the wireless access to the enhanced channel rank. network. In uplink, antennas of active while channel statistics are similar to Our results verify that cellular network terminals in adjacent cells can be inter- Rayleigh and have typically more DoF. capacity can be enhanced significantly preted as inputs and antennas of sur- The capacity distribution indicates a with advanced multicell processing and rounding base stations as outputs of a higher capacity in NLOS scenario at the novel backbone architectures. generalized multiple-input multiple- same SNR. The cumulative distribution output (MIMO) system. Over the sig- function (cdf) of broadband compared nalling network, signals received can to narrowband capacity is steeper since (a)(b)(c) be brought to a joint spatial processor multipath diversity can be exploited.

where interference is reduced. c df Fig. 3 shows that DoF (or the channel A scenario with four base stations and rank) are enhanced in the cooperative 5 terminals is investigated (see Fig.1). multicell scenario, i.e. more data Each terminal has 10 antenna ele- streams can be transmitted parallel. 0105 1520 25 30 ments, while base stations have 16. capacity per cell (bps / Hz) Channels between all terminals and Intuition is given in Fig. 4. Frequency Fig. 5: Left: 4-cell 5-user capacity using frequen- base stations are recorded at 5.2 GHz reuse assigns different resources in cy reuse (a), mean capacity of isolated cells (b) with 120 MHz bandwidth using the adjacent cells. There are two times 2 and capacity with cooperation (c) MEDAV Rusk-HyEff channel sounder. DoF, since the LOS is free in each cell. With cooperation in a central unit [email protected] Fig. 2 (top) illustrates that polarized (CU), the same resource can be as - antennas create two similarly strong signed. Now the intercell “interference” spatial degrees of freedom (DoF) due channels enhance the capacity. In the V. Jungnickel, S. Jaeckel, L. Thiele, U. Krueger, A. Brylka, C. von Helmolt, “Capacity measure- to the line-of-sight (LOS). In the non- measured scenario, all links have free ments in a multicell MIMO system,” Proc. IEEE LOS scenario (centre), power is reduced LOS except the link between ILR and Globecom, 2006, San Francisco, CA

Annual Report | Jahresbericht 2006/2007 39 MOBILE BROADBAND NETWORKS AND SYSTEMS

REALTIME DEMONSTRATION OF PHYSICAL LAYER CONCEPTS FOR 3GPP LTE

Transmission based on the 3GPP long-term evolution (LTE) has been demonstrated for the first time at ITU Telecom World 2006 in Hong Kong. Core components of baseband signal processing have been made at HHI.

Es wurden erstmals Mobilfunküber- tragungen mit dem Nachfolger des UMTS Standards demonstriert. Kern- komponenten der Echtzeitsignalver- arbeitung wurden am HHI erstellt.

The long-term evolution of cellular access networks is currently defined in the 3GPP standardization. Orthogonal frequency multiplexing (OFDM) is used to reduce both intracell interference and complexity. OFDM enables efficient solutions for smart multiantenna and Fig. 1 Top: LTE Demonstration at the Siemens booth during ITU Telecom World 2006 in Hong Kong. link adaptation techniques. Bottom: Received 16-QAM uplink constellation,(left) , frequency-division duplex spectrum (centre), received spatially multiplexed downlink constellations (64-QAM, right).

Multiple-input multiple-output (MIMO) ters are the same. Potential operators Modulation in downlink supports techniques are used in downlink in can match the system to the spectrum QPSK, 16-QAM and 64-QAM. Spatial combination with orthogonal fre quency- regulations. Cross-polarized antennas are multiplexing of two streams and code division multiple access (OFDMA) while used at the base station and terminal. rate ¾ are used to achieve a peak single-carrier (SC) FDMA is agreed for throughput of 100 Mbps in 20 MHz uplink. Note that SC transmission re - For real-time implementation, a hybrid mode. In uplink, BPSK, QPSK and duces the power dynamics at the ter- FPGA/DSP platform is used, similar to 16 QAM are supported. Cyclic delay minal transmitter. Both schemes allow the recent 1Gbps trial in.1 Processing in diversity and maximum ratio combining space-frequency (SF) adaptive schedul- each link is implemented in 4 XILINX are used to form a very robust uplink ing of user data in the medium access Virtex2Pro/100 FPGAs. Transmit and with more than 50 Mbps. control (MAC) layer where both trans- receive chains are pipelined and data mission frequency and bandwidth are are passed through continuously. SC Uplink and downlink are operated in best adapted to channel conditions waveforms are synthesized using DFT full-duplex mode to minimize latency. and traffic demands. precoding with variable bandwidth, Measured round-trip delay between and detection is based on IDFT. input and output of a simplified MAC Frequency-division duplex (FDD) is used, layer is less than 5 ms enabling real- 2.53GHz for uplink and 2.68GHz for Four DSPs are operated parallel in the time applications such as voice over IP downlink. OFDM parameters are suit- downlink receiver. They interpolate the (VoIP) and mobile online games. able for mobile users at a range of channel frequency response from the some km. According to the LTE study sparse pilot grid and adapt MIMO- [email protected] item, sampling rate is 30.72 MHz and OFDM equalizer weights once per TTI to 1.200 out of 2.048 subcarriers are the time-selective and frequency-selec- used. The cyclic prefix is 4.7 µs, and tive channel. Signals received are 1 V. Jungnickel, A. Forck, T. Haustein, C. Juch - radio frame length is 10 ms with 0.5 buffered for ≈1ms before equalization. ems, W. Zirwas, Gigabit Mobile Communi - ms transmit time intervals (TTI). System So the moment of processing is in time cations using Real-Time MIMO-OFDM Signal Processing, in: MIMO System Technology for bandwidth can be selected as 1.25, 5, with delayed results of weight calcula- Wireless Communications, Francis & Taylor, 10 and 20 MHz, while other parame- tion. Buffering has an impact on latency. 2006.

40 Annual Report | Jahresbericht 2006/2007 MOBILE BROADBAND NETWORKS AND SYSTEMS

HIGH DATA RATE WIRELESS multimedia distribution networks at multiple access per cell is realized in INFLIGHT ENTERTAINMENT SYSTEM 60 GHz is well suited for aircraft: The the time and frequency domain. Uplink extremely high user density of up to a and downlink operate in the frequency Today the application of millimetre- thousand passengers results in a re - division duplex. waves for high data rate wireless quired sum data rate of several Gbps. transmission systems attracts much Moreover, the system can be inte - To cope with multipath propagation as interest. We are examining the grated in the passenger seats and a well as with high free space attenu - employment of 60 GHz for wireless worldwide interference-free and license- ation, the frequency and spatial selec- multimedia distribution systems in free operation is provided. The required tivity of the milimeterwave channel has aircrafts and present a possible sys- downlink data rate of such a system is to be exploited by means of multicar- tem concept and first implement- 10 Mbps per user which is sufficient for rier signals and multiantenna tech- ation results. high-definition video standards. In the niques. Therefore, each access point uplink, 1 Mbps should be provided. and each terminal is equipped with Zurzeit erfährt der Einsatz von The advantages of a wireless system two antennas which allow the applica- Milli meterwellen zur breitbandigen compared to a wired solution are the tion of space-time codes in the trans- Funkkommunikation große Beach - weight and cost reductions, the ease of mit case and of maximum ratio com- tung. Im Folgenden wird der Ein - installation and maintenance and the bining in the receive case. satz von 60 GHz für die drahtlose higher flexibility regarding cabin layout. Multimediaversorgung von Flug - zeugkabinen untersucht und ein Systemkonzept sowie erste Ergeb- nisse eines Experimentalsystems präsentiert.

It is expected that in future wireless communication systems the data rates Fig. 3: Developed transceiver board transmitted will increase strongly. The use of millimetre-waves at 60 GHz is To prove the concept, a realtime de - very promising for short range trans- monstrator is developed. Fig. 3 shows mission. The main advantages of this the prototype of a stacked transceiver Fig. 1: Cellular system architecture for wireless frequency band are the large license- inflight entertainment system board. The lower board contains FPGA free bandwidth available, resulting in a circuits for broadband signal proces - very high achievable data rate, and the The Fig. 1 shows the proposed system sing, the middle board the AD-convert- short wavelength, which leads to small architecture: A number of passenger ers and DA-converters and the small antenna dimensions even for multi- seat terminals are supplied by an ac - upper boards the high frequency com- antenna systems. Due to the high free cess point which builds up a radio cell. ponents at an intermediate frequency space attenuation and the strong pen- The whole cabin is covered by several (IF) of 2.4 GHz. Broadband transmission etration losses through walls, coverage access points, whereas adjacent cells experiments at the IF have been very of a 60 GHz system is relatively small are separated by different carrier fre- promising and first results at 60 GHz whilst on the other hand interference quencies as illustrated in Fig. 2 for the are expected within a short time. with other wireless systems and adja- Airbus A380 aircraft. The user links are cent radio cells is also very low. allocated to the access points dynam - This research is carried out in coopera- ically, depending on the current chan- tion with Airbus Deutschland. With respect to these specific proper- nel state. The system supports a max - ties, the implementation of wireless imum of 32 links per access point and [email protected]

Fig. 2: Radio cells with frequency reuse factor of eight for Airbus A380 aircraft

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TEMPORAL STRUCTURE OF THE investigations are measurements in impulse responses (CIRs). Such a small- 60 GHZ WIRELESS CHANNEL application-oriented environments scale set of 100 CIRs under line-of- under realistic propagation conditions. sight (LOS) conditions inside a confer- Broadband millimetre wave trans- ence room is shown in Fig. 2. To assess mission in the 60GHz band is a For this purpose, an experimental meas- the small-scale variations of the chan- promising technique when it comes urement setup with an operation band- nel, the receive antenna was mounted to meeting the high demands of width of 1 GHz was built up, the sche - on a positioning device and moved on future WLAN and WPAN systems. matics of which is illustrated in Fig. 1. a linear track over a distance of 20 To provide a basis for theoretical An arbitrary waveform generator wavelengths during the measuring pro- investigations and system design, it (AWG) serves as a source for the base- cedure. The illustrated example refers is important to analyse and charac- band signal which is derived from an to an omnidirectional transmit antenna terise the underlying wireless chan- optimised multitone sequence or a and an aligned Vivaldi antenna at the nel. We present exemplary results of maximum length sequence. receiver with a gain of about 12 dBi. a measurement campaign regard ing Both were vertically polarised. the 60GHz broadband indoor channel which was performed using a The small-scale sets are the basis for modular measurement setup. further analysis. By averaging over all snapshots within a set, we obtain an Die breitbandige Millimeterwellen- averaged power delay profile (APDP) Übertragung im 60 GHz-Bereich gilt which indicates the decay of arriving als aussichtsreiches Verfahren, um multipath power with respect to the den hohen Anforderungen zukünf- excess delay, discounting the small- Fig. 2: Measured small-scale set of CIRs under tiger WLAN- und WPAN-Systeme LOS conditions scale fading effects (Fig.3). gerecht zu werden. Um eine Basis für theoretische Untersuchungen By means of a 5 GHz IF, the baseband und das Systemdesign bereitzustel- signal is mixed up to 60 GHz. At the len, ist es wichtig, den zugrunde receiver side, a mixer converts the sig- liegenden Funkkanal zu untersu- nal to the IF-frequency. Afterwards, it is chen und zu charakterisieren. Wir sampled in the IF domain by a digital präsentieren exemplarische Ergeb- sampling oscilloscope (DSO). Since the nisse einer Messkampagne bezüg- oscilloscope is triggered by the second lich des breitbandigen 60 GHz channel of the AWG, the setup allows Indoor-Kanals, die mit Hilfe eines snapshots of the received signal to be modularen Messaufbaus durchge- taken with an adjustable rate. führt wurde. Fig. 3: APDP corresponding to the small-scale set in Fig. 2. After digital postprocessing, which The aim of our work is to gain insight comprises complex down conversion, In order to determine the number of into the channel’s propagation mech - noise filtering and correlation, we multipath components, several ap pro - anisms. The starting point for our obtain a set of coherent channel aches were investigated. The methods involve the Akaike information criterion (AIC) and the minimum description length (MDL). They are based on the eigen-decomposition of the channel covariance matrix. Multiple signal classification (MUSIC) was applied to de ter mine the excess delays of the components. The results are very useful when it comes to deriving a stochastic model for the 60 GHz broadband channel and evaluating existing ones.

[email protected]

Fig. 1: Schematic of the time-domain measurement setup

42 Annual Report | Jahresbericht 2006/2007 MOBILE BROADBAND NETWORKS AND SYSTEMS

NETWORK CALCULUS FOR in a competitive situation, where all under channel uncertainty. For ex - INTERFERENCE MANAGEMENT users try to compensate for interfer- ample, the evolution of current 3G ence by increasing their own transmis- standards, like High-Speed Downlink The control and reduction of multi- sion power and this in turn increases Packet Access (HSDPA) and High-Speed user interference is a fundamental overall interference in the system. A Uplink Packet Access (HSUPA), will problem in wireless communica- transmission strategy which neglects include signal processing strategies for tions. But most established commu- these interdependencies is likely to interference reduction, like MIMO or nication techniques are optimized cause uncontrollable and excessive beamforming. In order to ensure for point-to-point links. MCI has interference which means a waste of smooth inter-operation with medium developed an analytical framework overall system efficiency. It therefore access control, good knowledge of the for modelling and optimizing inter- makes sense to find a suitable equilib - quality-of-service (QoS) region is reference-coupled wireless networks.1 rium that optimally exploits the re - quired. Such knowledge can be used sources available. This requires joint to design efficient resource allocation Kontrolle und Reduktion von Mehr - optimization of all communication algorithms. nutzerinterferenz ist ein fundamen- links. It is generally not sufficient to tales Problem für die Funkkommu- regard the system as a collection of In1 different interference models are ni kation. Aber die meisten etablier- point-to-point communication links. studied. The models are general ten Techniken sind für Punkt-zu- enough to be valid for a wide range of Punkt Verbindungen optimiert. system designs, but they are also spe- Das MCI hat eine Theorie zur Mo- cific enough to facilitate efficient algo- dellie rung und Optimierung inter- rithmic solutions. One important class ferenz-verkoppelter Funknetz werke of interference functions is based on entwickelt.1 axioms, which characterize the impact of the power allocation of the interfer- The traditional way of handling multi- ence received by the individual users. user interference is to assign all links Another class of interference functions Fig. 1: Wireless Networks are coupled by orthogonal resources in time (TDMA), interference, so spectrally efficient transmission is based on non-negative coupling frequency (FDMA), or code space requires a joint optimization approach matrices which may be parameter-de- (CDMA). This considerably simplifies pendent in order to model the possible the system design since the links are MCI has derived a general framework impact of receive strategies. no longer coupled by interference. for modelling and optimizing interfer- However, reserving each link a fixed ence-coupled multiuser systems.1 The It is shown how convexity and concav- resource often comes at the expense theory is based on interference func- ity of the interference functions can be of sacrificing spectral efficiency. The tions and can be applied to many prac- exploited in order to obtain iterative bandwidth available is generally best tical signal-to-interference ratio (SIR) algorithms with super-linear conver- exploited by letting transmitted signals related measures, like data rates, delay, gence. Also, we study the geometry of interfere with each other in a con- BER, etc. Optimization can be per- the QoS region for log-convex interfer- trolled way. Also, orthogonality may be formed with respect to various design ence functions. Conditions are pro - lost because of system imperfections goals, like the overall efficiency, max- vided under which the region is a con- and the effects of the time-varying min fairness, proportional fairness, net- vex set. This is closely related to the multipath channel. So it can be said work utility maximization. All these problem of proportionally fair resource that interference and power constraints strategies aim at finding a suitable allocation, which aims at finding a are the main hurdle in achieving a high operational point in the QoS feasible good trade-off between ideal fairness per-user throughput in heavily loaded region (the set of jointly achievable and optimum system efficiency. multiuser networks, as will be required QoS). in the future. [email protected] The proposed framework offers an Interference plays a central role in the analytical tool for system-wide “cross- optimal exploitation of the given band- layer” optimization which is able to width. The quality-of-service (QoS) of incorporate signal processing tech- each link depends on its own transmis- niques, power allocation, and other sion power, but also on the power networking aspects. Some well-known 1 Martin Schubert and Holger Boche, QoS- based resource allocation and transceiver opti- levels of the other links which are ex - examples are multiuser beamforming, mization. Foundation and Trends in Commu - perienced as interference. This results CDMA designs, or robust transmission nications and Information Theory, 2(6), 2006.

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GUARANTEEING QUALITY OF current time varying channel condi- Interestingly, simple suboptimal stra - SERVICE IN OFDM: TOWARDS NEW tions. Given the fading characteristics tegies such as allocating the same INFORMATION THEORETIC PERFOR- of the channel (i.e. its probability dens- amount of power or rate on each sub- MANCE MEASURES ity function), the DLC characterizes carrier at any time yield very tight lower which rate is achievable at each time bounds achieving nearly the entire A new performance measure in - instance under a long term power con- DLC. This fact is illustrated in Fig. 1. On corporating delay sensitivity called straint. Very high power consumption the other hand, the DLC of an OFDM delay limited capacity is presented. may compensate arbitrary bad chan- system depends on the number of in- Orthogonal frequency division nels – as long as they do not occur too dependent propagation paths; as ex - mult iplexing (OFDM) systems are often. Fading distributions offering a pected, the DLC increases as the num- studied in this context showing the delay limited capacity strictly greater ber of independent paths (and thus the advantageous properties of OFDM. than zero are called regular fading dis- diversity of the channel) increases. tributions. Interestingly, a very import - Simple lower bounds can be provided Die verzögerungsbeschränkte Kapa- ant and common fading channel, the for this behaviour as well. zität ist ein neues Performanz-Maß, Rayleigh fading channel, has a DLC of das Verzögerungssensitivität berück- zero. This means that an arbitrary big Fig. 2 depicts this behaviour. Further - sichtigt. Orthogonal frequency div - power budget cannot compensate for more, it was possible to show that the ision multiplexing (OFDM)-Systeme bad channel conditions. In contrast, DLC converges towards traditional bringen, so wird gezeigt, in diesem channels with more than one degree Shannon capacity as L goes to infinity. Kontext vorteilhafte Eigenschaften of freedom usually offer a DLC greater mit sich. than zero. This is the case for multiple- input multiple-output (MIMO) channels Today’s wireless communication sys- and frequency selective channels. The tems call for hard Quality of Service diversity offered in the form of multiple constraints. Calls may drop or services propagation paths prevents channel may fail if at a certain time a necessary conditions from becoming too bad. rate cannot be provided. This could be disastrous, especially for time-critical OFDM systems have become the object applications. Unfortunately, the wire- of much interest in recent years due to less channel varies heavily in time. This extremely simple signal processing and fact causes significant problems for the robustness against inter-symbol inter- provision of secure rates which have to ference. And OFDM has emerged as a Fig. 2: Delay limited capacity of an OFDM be guaranteed for the above-men- core technology used by nearly all cur- system at low SNR and its dependence on the tioned reasons. rent wireless communication standards. number of propagation paths (L) Exploiting the frequency selectivity of The underlying fundamental analysis of the underlying channel, OFDM systems This work was supported by the wireless channels with a view to infor- offer a DLC depending on the long Bundes ministerium für Bildung und mation theory suffers from this recent term SNR. Forschung (BMBF) under grant FK 01 development. The traditional notion of BU 350. capacity introduced by Shannon implies an infinite decoding delay exploiting [email protected] the time variations of the channel. This means that very bad and good channel conditions can be averaged out in the long run. However, this may take a while. The need for certain rates within a very short time interval prohibits the use of Shannon capacity as a relevant 1 G. Wunder and T. Michel, “Delay-limited OFDM broadcast capacity region and impact of measure. system parameters”, IEEE Information Theory Workshop, Punta del Este, March 2006. Instead, the so-called delay limited cap - Fig. 1: Delay limited capacity of an OFDM 2 G. Wunder and T. Michel, “Approaching the acity (DLC) has attracted reasonable system and simple suboptimal resource delay-limited OFDM broadcast capacity region allocation strategies with OFDMA”, IEEE Workshop on Signal Pro - interest recently. This measure reflects cessing Advances in Wireless Communications, the need for rates independent of the Cannes, July 2006.

44 Annual Report | Jahresbericht 2006/2007 MOBILE BROADBAND NETWORKS AND SYSTEMS

CROSS LAYER OPTIMIZED orating the restriction of exclusive sub- designed aiming at different QoS re - RESOURCE ALLOCATION IN OFDM carrier assignment and the fact that quirements: First, the resource alloca- BROADCAST CHANNELS only quantized feedback is available. tion problem is transformed into a Furthermore, only certain rates are weighted sum rates maximization prob- OFDM is considered to be a promis- achievable since only a finite set of lem. The weight factors are chosen ac - ing technology for next generation coding and modulation schemes can cording to the QoS requirements con- wireless communication systems. be used. The optimization problem cerned. In the next step, the weighted Resource allocation strategies are then results in a non-convex problem sum of rates is maximized using the being developed to realize the per- over discrete sets which is much more algorithm introduced. formance gain of OFDM in practical difficult to solve. systems. Follwing this concept, a special re - An iterative algorithm is developed to source allocation strategy is developed OFDM ist eine erfolgversprechende tackle the problem.1 It maximizes a minimizing the averaged delay and Technologie für die nächste Gene - weighted sum of rates, if quantized maximizing the possible offered load of ration drahtloser Kommunikations- feedback is available and minimum the system at the same time. It can be sys teme. Ressourcenmanagement- rates have to be guaranteed. The algo- shown that if the current channel state strategien werden entwickelt, um rithm is motivated by a weight match- information and the statistical know- den Performanzgewinn von OFDM ing strategy stemming from a Lagran - ledge of the channel are known at the in praktischen Systemen zu realisie- gian approach. It is easy to implement transmitter, this strategy minimizes the ren. and can be proven to converge to an average waiting time of each bit in the excellent suboptimal solution. It is buffer. In order to support high data rate ser - shown that the algorithm has low com - 2 vices over wireless channels, radio re - putational complexity and superior per- 10 LQHPR sources in the OFDM system, i.e. trans- formance. QPS mission power and subcarrier, should proposed scheduler be dynamically allocated according to time-varying channel conditions and service requirements.

1 10 Since the resource allocation problem a ver ged b it del y (ms) involves physical conditions such as channel fading state, individual and 3 4 5 6 7 8 9 sum power constraints, as well as ser- (Mbits/s) vice requirements, such as service rate Fig. 2: Delay comparison between introduced and maximum waiting time, the strat- scheduling strategy, Queue Proportional egy solving the problem covers both scheduling (QPS) and Longest-Queue-highest- the physical layer and MAC layer in the Possible-Rate (LQHPR) scheduling classic layered structure. It becomes a so-called cross layer optimization prob- [email protected] lem. In general, the resource allocation problem can be described as maxi - mizing a benefit (e.g. throughput) or minimizing a cost measure (e.g. transmission power) while considering system constraints on the physical layer, service specific quality of service (QoS) requirement on the MAC layer and the overall system state. Numerous theoretical studies were carried out in this Fig. 1: Sum rate (top) and failure rate (bottom) context. comparison between introduced algorithm 1 C. Zhou, G. Wunder, and T. Michel, Proc. and Hungarian algorithm2 IEEE Int. Conf. on Communications (ICC), A crucial challenge when it comes to Glasgow, June 2007, to appear. 2 H. Yin and H. Liu, “An efficient multiuser making these theoretical concepts us - Based on this result, scheduling and loading algorithm for OFDM based broadband able for real systems involves incorp - resource allocation strategies are wireless systems,” IEEE Globecom, 2000.

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DISTRIBUTED UTILITY-BASED solution. The computational effort re- nodes. Therefore, the use of classical POWER CONTROL FOR WIRELESS quired to solve such a problem by the flooding protocols to exchange this NETWORKS best known numerical methods grows information leads to relatively high prohibitively fast with the dimension of costs in terms of wireless resources. In We have developed an iterative dis- the problem. In wireless mesh net- contrast, our scheme is based on the tributed gradient projection algo- works that operate without a central use of an adjoint network to efficiently rithm for power control. The scheme network controller, the problem is fur- distribute some locally measurable uses the so-called adjoint network ther aggravated due to the need for quantities to other logical transmitters. to allow each transmitter to esti- decentralized schemes. For these rea- One may call the procedure coopera- mate its current update from some sons, we identified a class of utility tive flooding as nodes cooperate by local variables. This mitigates the measures that allow a convex formu- transmitting their local information to problem of global coordination of lation of the power control problem. other nodes. More precisely, instead of the transmitters when carrying out For a large family of modulations each node sending its message separ - the algorithm in distributed wire- determining the relationship between ately as in the case of classical flooding less networks. data rates attainable on wireless links protocols, nodes transmit simultan- and the signal-to-interference ratios eously over the adjoint network so that Ein iterativer verteilter Algorithmus (SIR) at the outputs of fixed linear re - each node can estimate its gradient zur Leistungskontrolle wurde ent- ceivers, the utility functions are increas- component from the received power. wickelt. Das auf der Verwendung ing, strictly concave functions of the This parallelizes the computation of the des sogenannten adjungierten data rate. Moreover, our definition of gradient vector without resorting to Netzes basierende Verfahren er- fairness includes an arbitrarily close extensive internode communication. laubt eine verteilte Schätzung des approximation of max-min fairness. This parallelization can be seen as sep- Gradienten von lokalen Variablen. arating the algorithm into local algo- We proposed a novel power control rithms operating concurrently at differ- The objective of utility-based power con - scheme based on gradient-projection ent transmitter-receiver pairs. trol is to coordinate transmit powers in methods as well as on the use of a so- every frame so as to provide MAC layer called adjoint network. Using methods The price for parallelization are possible fairness. The notion of MAC layer fair- of the optimization theory, we can estimation errors that appear simply by ness is defined along similar lines as establish global convergence of the virtue of limited estimation time. There - end-to-end fairness for elastic traffic, gradient projection algorithm and pro- fore, the algorithm was analyzed in the except that instead of network flows, vide sufficient conditions for a geomet- more general framework of stochastic MAC layer flows are considered, being ric (or linear) convergence rate. An approximation. We modified the algo- one-hop flows between neighbouring essential advantage of the algorithm is rithm to obtain weak and almost sure nodes. MAC layer fair strategies can be its amenability to efficient implement - convergence under some conditions on coupled with hop-by-hop congestion ation in distributed networks. Indeed, the estimation noise process. We also control to achieve network-wide end- although much more powerful algo- proposed using adaptive estimation to-end fairness. Potential applications rithms (in terms of convergence rate) times and methods for averaging the of the power control scheme presented can be devised to solve the problem, iterates in order to improve the con - in this paper are envisaged in wireless the significance of simple algorithms vergence rate. mesh networks to control transmit that allow an efficient distributed im - powers of base stations (mesh routers). plementation cannot be emphasized [email protected] These base stations create a wireless enough in the case of wireless net- backbone via multi-hop ad-hoc networks. In particular, given the limited working and have practically unlimited and costly nature of wireless resources, energy supply. In contrast, if the energy minimizing the control message over- supply is a bottleneck, then the through - head for each iteration step must be a put and fairness performance should high priority. In the case of the gradi- be balanced against power consump- ent-based power control algorithm, the 1 S. Stanczak, M. Wiczanowski, and H. Boche. tion to prolong battery life. major challenge is a distributed compu- Distributed utility-based power control: tation of the gradient vector. Due to Objectives and algorithms. IEEE Trans. Signal The power control problem in the pres- the mutual dependence of logical links, Processing, January 2007 (accepted). ence of interference is in general not this computation generally involves the 2 S. Stanczak, M. Wiczanowski, and H. Boche. Theory and Algorithms for Resource Allocation convex. General-type non-convex prob- coordination and exchange of global in Wireless Networks. Lecture Notes in Com - lems are too difficult for numerical information between all network puter Science (LNCS). Springer, Berlin, 2006.

46 Annual Report | Jahresbericht 2006/2007 MOBILE BROADBAND NETWORKS AND SYSTEMS

IMPACT OF MIMO TECHNIQUES ON sensor nodes may dominate energy multiple antenna systems to save ENERGY EFFICIENCY OF WIRELESS consumption. power in a sensor network scenario. SENSOR NETWORKS The results show that classical tech- In traditional wireless networks with niques including space time coding, In wireless sensor networks, where high data rates, multiple antenna tech- antenna selection and beamforming energy consumption is the main niques such as space time coding, may be suboptimal compared to SISO concern, traditional multiple an - beamforming and MIMO schemes are systems. Nevertheless, they do offer tenna techniques may offer limited used to decrease power and energy some essential advantages. More pre- performance. Therefore, new MIMO consumption. In wireless sensor net- cisely, the classical MIMO strategies schemes need to be de veloped. works, however, the benefit of using pro vide a higher robustness in the these techniques is not obvious since sense that they can support better Eine entscheidende Größe beim the energy expenditure for additional quality-of-service re quirements. Besides, Ent wurf drahtloser Sensornetze ist hardware components may be signifi- they achieve a lower outage probability der Energieverbrauch. Es wurde die cant. In other words, the additional under the same quality-of-service re- Energieeffizienz verschiedener energy expenditure may exceed the quirements. This makes sense in net- MIMO-Übertragungsverfahren potential energy savings which can be works where applications require high untersucht. achieved by means of multiple antenna reliability. techniques. Wireless sensor networks are attractive for a wide range of applications. This So far, we have investigated the prob- includes surveillance, environmental lem in a homogeneous wireless sensor monitoring, home automation, logistics network in which each sensor node is as well as applications in industrial equipped with the same number of automation and control. Although antenna elements. On each link, a strict energy constraints are not inher- transmission is assumed to be success- ent to all sensor networks, some of the ful if some common quality-of-service most exciting applications for wireless requirement (QoS) is satisfied. The re - sensor networks require that sensor quirement is expressed in terms of a nodes be powered by batteries or by strictly increasing function of the sig- Fig. 1: Energy consumption over QoS (SIR) for the SISO case and an adaptive MIMO strategy environmentally scavenged energy with nal-to-interference ratio. The investiga- or without battery backup. For this rea- tions are carried out under the assump- Sophisticated MIMO schemes enable son, when designing wireless sensor tion of optimal power control in the the transmission of multiple data networks, the focus is on minimizing sense that each transmitter attempts streams and thus require less transmis- the energy consumption associated to satisfy the quality-of-service require- sion time to transmit the same packet. with both signal processing (hardware) ment with the minimum transmit At the same time they enhance their and data transmission in order to power. sleeping period. Thus, when energetic achieve long lifetime of the network. optimality in the above sense is desired, First, we analyzed the effects of differ- both transmission time and transmit While the hardware components are ent transmission strategies for multiple- power should be optimized jointly. We within reach, communication protocols antenna systems on the network-out- proposed an algorithm to calculate the and algorithms tailoring the compon- age probability. This probability de - energy-optimal power allocation which ents into a working network are far pends on network setup issues like uniquely determines the energy-optimal from being technically mature. The lack stochastic channel properties as well as number of data streams per link. The of suitable algorithms and protocols is on the transmission strategy. Our focus results show that with increasing QoS one of the major obstacles in realizing has been on the effects of simple orth- requirements, the number of data the dream of ubiquitous wireless sen- ogonal space time codes on the per- streams decreases (see Fig. 1). sors everywhere. In wireless networks, formance of the network. Analytical the power demand rapidly increases results for some simple networks give Finally, we conclude that to achieve the with the distance between two sensor insights that help us to understand and best performance in terms of energy nodes. Therefore, although the power explain the simulated performance for consumption one has to apply adaptive consumption associated with signal more complex networks. techniques that switch between differ- processing cannot be neglected, the ent strategies. transmit power associated with data Then, we examined the capability of transmission and coordination between different transmission strategies for [email protected]

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DUALITY-BASED OPTIMIZATION OF Fortunately, it has been discovered that than a joint optimization approach, MULTIUSER MIMO SYSTEMS “dual” properties exist between the since one of the variables is optimized uplink and downlink channels. Re - while the others remain fixed. An HHI proposes a fundamentally new cently, in1, an uplink-downlink MSE application example can be found in.3 way to investigate the problem of duality is established which shows that downlink transceiver optimization the achievable MSE region of MIMO The significance of this duality-based based on uplink-downlink Mean- downlink is exactly the same as that of framework is even more far-reaching. Square-Error (MSE) duality. This the dual MIMO uplink, under the It is not limited to the MSE transceiver duality shows that the uplink and assumption of the same sum power optimization problems discussed here. downlink have the same achievable constraint in both links. This extends In fact, HHI shows duality for the MSE region under a total sum the previous result of SINR duality2 and whole MSE feasible region, so the power constraint. Via a duality- also provides a better general under- analysis of any other design goal (such based framework, downlink MMSE standing of the duality phenomenon. as min-max fairness, utility optimi- transceiver optimization can be zation, etc.) can be based on this frame- carried out by focusing on an The most important application of MSE work as well. Therefore, the results will equivalent uplink problem or by duality is that it provides conceptionally be of further importance for combining alternating optimization between new approaches for downlink trans- transceiver optimization with resource the virtual uplink and downlink ceiver optimization. Instead of investi- allocation strategies, like medium ac- channels. gating the downlink structure, the cess control and scheduling. problem can be solved indirectly via Das HHI hat grundlegende Beiträge MSE duality between uplink and down- This work was supported in part by the zum Problem der Downlink-Trans- link channels. One example is the prob- Federal Ministry of Education and ceiver Optimierung für Mehrnutzer lem of downlink transceiver sum-MSE Research under grant 01BU350. MIMO-Systeme geleistet. Der An- optimization which has been studied satz basiert auf einer Dualität zwi- for a decade. Based on MSE duality, [email protected] schen Uplink und Downlink Mean- the optimum downlink solution is Square-Error (MSE) Regionen. Es derived by focusing on the equivalent wurde gezeigt, dass beide Kanäle uplink problem.1 die gleichen MSE Region unter einer Summenleistungsbeschrän kung However, in some cases, the uplink besitzen. Dies ermöglicht eine indi- problem itself is not easier to be rekte Optimierung der Downlink handled than the downlink problem. Transceiver durch einen virtuellen For ex ample, for the problem of min- Uplink-Kanal. max user-MSE, the situation is not better for the uplink channel since the In multiuser MIMO systems, the base downlink user-MSEs are coupled by station and mobile terminals are the choice of transmit filters and as equipped with multiple antennas. well as the uplink MSEs. By exploiting Unlike single user MIMO systems, MSE duality result, HHI proposes an transmission over the link from the alternating optimization framework for mobiles to the base station (uplink or MMSE transceiver design which is suit- Multiple Access Channel) and over the able for problems of this kind. The reversed link – from the base station basic idea is as follows: if we want to 1 S. Shi, M. Schubert and H. Boche, ”Down - to the mobiles (downlink or Broadcast optimize a downlink channel, then the link MMSE transceiver optimization for multiuser MIMO systems: duality and sum-MSE mini- Channel) differ greatly. In the uplink, virtual uplink channel only serves the mization”, accepted by IEEE Trans. on Signal the base station can perform joint purpose of optimization, and vice Processing. reception of all signals received in versa; additionally, MSE duality ensures 2 M. Schubert and H. Boche, ”Solution of the order to obtain the diversity or multi- that the same MSEs can be achieved in multi-user downlink beamforming problem with individual SINR constraints“, IEEE Trans. on plexing gain. However, joint transmis- both links. This makes it possible to Vehicular Technology, vol. 53, no. 1, pp. 18– 28, sion in the downlink leads to a more optimize the powers and filters in an Jan. 2004. complicated mathematical structure alternating manner by switching be- 3 M. Schubert, S. Shi, and H. Boche, than in the uplink, since the signals tween the virtual uplink channel and ”Iterative transceiver optimization for linear multiuser MIMO channels with per-user MMSE transmitted to all mobiles are coupled downlink channel. In most cases, this requirements”, EUSIPCO, Florence, Italy, Sep by the transmit filters and powers. alternating approach is less complex 2006, (invited).

48 Annual Report | Jahresbericht 2006/2007 MOBILE BROADBAND NETWORKS AND SYSTEMS

Annual Report | Jahresbericht 2006/2007 49

PHOTONIC COMPONENTS

Photonic Components

The years 2006 and 2007 have shown a significant recovery of the datacom and telecom component industry. Prior to this period, the market was nearly completely dominated by cost reduction, resulting in a strong growth of Asian or Asian manufacturing companies and a significant consoli- dation in the industry. Nowadays, in parts of the installed fiber plant the first bottlenecks are already showing up, and the performance of optics and its improvement has become more important relative to the pure cost position once again. As a sustainable growth of the data traffic with 50 % to 100 % per year can be expected over the next 10 to 15 years, mainly driven by Video Over IP, network operators continue to invest in capacity growth. To avoid the costly installation of new fibers, multiplication of equipment, or additional regeneration stations in long distance links, a new set of optics is required with significantly better performance. This trend is opening up extremely good opportunities for technologically driven companies or institutions. HHI has always been at the forefront of optical component technologies. Over the past two years, we have introduced the world's first 100 Gbps detector, we have improved the performance of our 40 – 80Gbps modulator, and we had first results with direct modulation of a semiconductor laser at 40 Gbps.

A second trend is the decline of large optic component companies in Germany and Europe. Many component ac tivities have been closed, merged with US companies, or sold to US companies. HHI Photonic Components has responded to this trend: Our non-European revenue has increased to above 30 %, we have initiated partnerships to increase marketing of our products and development services outside Europe, we are presenting our latest component results not only at scientific conferences but also to industry standard bodies like the IEEE High Speed Study Group for 100 Gbps, and, for example, we have introduced our latest photodetector together with a US sampling scope manufacturer during the OFC.

As a third trend, most of the activities on opto chip level have declined drastically, been spun out, or discontinued by the worldwide optics component industry. With the rising demand for high performance optics, this is opening up excellent new possibilities for the scientific power focused at HHI, but also poses a new challenge: the requirement for industrialization. Especially in the high performance chip segment, even with a record product introduction, product volumes are likely to stay below 2 to 5 wafer starts per week during the first three years. This low volume does not justify the transfer to a volume fab and requalification of a new chip design. Hence the design fab must be able to support also initial volumes, and to supply them in product quality,

Annual Report | Jahresbericht 2006/2007 51 PHOTONIC COMPONENTS

with all quality and process monitoring and stabilization re - quirements fulfilled. HHI Photonic Components has taken up this challenge: Since 2007, we have been ISO 9001 ac - credited, not only for Research and Development, but also for Production. We are continuously investing in aging, burn- in, and qualification equipment to supply long-term stable opto chips. We have received first, very promising results on the aging of our polymer platform and the optical functions implemented on it.

In addition to these three major trends, the past two years have also seen some minor changes, resulting in a reorienta- tion of the research portfolio of HHI Photonic Components. The increase of performance of electronic ICs and the growing importance of phase sensitive transmission formats have postponed the likely introduction of all optical switching and all optical clock recovery and regeneration to future years. We have reduced our activities in this field. The Terahertz spectrum has opened up new possibilities: Telecom technologies will bring a typical THz setup from the lab table to the suitcase. We have initiated work here, with first promising results on the receiver side at 1.5 µm. We have also strengthened our collaboration with non-telecom customers, focusing on single mode lasers with up to 700 mW output power between 1300 and 1550 nm, and on DFB lasers for sensor applications.

Please enjoy reading the next pages which deal with our work in more detail. Do not hesitate to contact the respect- ive author or me at [email protected], if we can assist you with additional information.

52 Annual Report | Jahresbericht 2006/2007 PHOTONIC COMPONENTS

Photonische Komponenten dukteinsatz zu genügen. Vor allem im Bereich der hochper- formanten Chips bleibt selbst bei optimaler Produktein füh - In den Jahren 2006 und 2007 war ein bedeutsames Wieder - rung das Volumen in den ersten drei Jahren in der Größen - erstarken der Kompontenindustrie im Datacom- und Tele - ord nung von zwei bis fünf Wafern pro Woche. Diese gerin- komsektor festzustellen. Während in den Jahren zuvor der gen Volumina rechtfertigen keine Verlagerung zu einer Markt nahezu vollständig durch Maßnahmen zur Kostensen - anderen Chip-Fab mit der dann notwendigen erneuten kung wie z. B. die Verlagerung von Produktion und Teilen Qualifizierung. Deshalb muss die Design-Fab auch in der der Entwicklung in den asiatischen Raum bestimmt war, Lage sein, initiale Volumina in Produktqualität zu liefern. Der zeigen sich heute bei den installierten Glasfasernetzen die Bereich der photonischen Komponenten des HHI hat sich ersten Engpässe, und die Leistungsfähigkeit der Optik und dieser Herausforderung gestellt. Seit 2007 sind wir erneut ihre technische Verbesserung wird erneut wichtiger im Ver- nach DIN EN ISO:9001:2000 zertifiziert, und dies nicht nur gleich zur reinen Kostenposition. In den nächsten 10 bis 15 in Bezug auf unsere Forschungs- und Entwicklungsprozesse Jahren ist eine jährliche Zunahme des Datenverkehrs – vor sondern auch für die Technologie. Um optische Kompo nen - allem verursacht durch Video over IP – von 50 – 100% zu ten mit beweisbar stabilem Langzeitverhalten zu entwickeln erwarten. Netzwerkbetreiber müssen daher stetig in den investieren wir weiter in Anlagen für Alterungs- und Burn- Ausbau von Übertragungskapazitäten investieren. Um die In-Prozesse und Qualifizierungsmessungen. Zusätzlich haben kostspielige Verlegung neuer Fasern, die Multiplizierung von wir vielversprechende Ergebnisse insbesondere bei der Alte - Equipment, oder zusätzliche Regenerator-Stationen zu ver- rung unserer Polymerplattform und den darauf implemen- meiden ist eine neue Generation von photonischen Kompo - tierten optischen Funktionselementen erhalten. nenten mit wesentlich besseren Eigenschaften unabdingbar. Dies eröffnet exzellente Möglichkeiten für technologisch Neben diesen Haupttrends gab es einige kleinere Verände - orientierte Unternehmen und Institutionen. Das HHI war rungen, die zu einer Neuorientierung des Forschungsport - immer an der vordersten Technologiefront bei der Photonik. folios der Abteilung Photonische Komponenten führten. Die In den vergangenen zwei Jahren haben wir den weltweit Leistungs- und Qualitätssteigerung der elektronischen ICs ersten 100 Gbit/s-Detektor entwickelt; wir haben die Leis- und die zunehmende Bedeutung phasenempfindlicher Über- tung unseres 40 – 80Gbit/s-Modulators verbessert, und wir tragungsformate hat die lang erwartete Einführung rein können erste Ergebnisse bei der direkten Modulation von optischen Schaltens und einer rein optischen Takt-Rückge - Halbleiterlasern mit 40 Gbit/s vorweisen. win nung und Signalregeneration auf einen späteren Zeit - punkt verschoben. Deshalb haben wir unsere Anstrengungen Ein zweiter Trend ist der Niedergang der großen Unter - in diesem Themenkomplex reduziert. Die Terahertz-Seite des nehmen für optische Komponenten in Deutschland und elektromagnetischen Spektrums hat hingegen neue Mög - Europa. Viele Komponentenaktivitäten wurden geschlossen, lichkeiten eröffnet. Telekommunikationstechnologie wird es mit amerikanischen Firmen zusammengelegt, oder an Fir - ermöglichen, Terahertz-Messplätze oder Analysegeräte so men in den USA verkauft. Wir haben uns auf diesen Trend kompakt aufzubauen, daß ihr Einsatz vom Labortisch in eingestellt und unsere aussereuropäischen Erträge auf über einen Aktenkoffer verlagert werden kann. Wir haben die 30 % gesteigert. Außerdem haben wir Partnerschaften Arbeit in diesem Sektor aufgenommen und die ersten hoff- geschlossen, um das Marketing für unsere Produkte und nungsvollen Ergebnisse auf der Empfängerseite bei 1,5 µm unsere Angebote zur Unterstützung bei Entwicklungen erreicht. außerhalb Europas zu verbessern. Wir präsentieren unsere neuesten Produkte und Ergebnisse nicht nur auf wissen- Darüber hinaus haben wir unsere Zusammenarbeit mit schaftlichen Konferenzen sondern auch in industriellen Kunden aus dem Nichttelekommunikationsbereich verstärkt. Standardisierungsgremien wie der IEEE High Speed Study Dabei konzentrierten wir uns auf Single-Mode-Laser mit Group für 100 Gbit/s und haben beispielsweise unseren einer Ausgangsleistung von 700 mW im Wellenlängenbe - neuesten Photodetektor auf der OFC gemeinsam mit einem reich zwischen 1300 und 1500 nm und DFB-Lasern für Sen - amerikanischen Hersteller von Messgeräten eingeführt. soranwendungen.

Als dritten Trend hat die weltweite Industrie für optische Bitte genießen Sie die Lektüre der nächsten Seiten, die Datenübertragungskomponenten ihre Aktivitäten auf der unsere Arbeit etwas detaillierter darstellt. Zögern Sie bitte Ebene der optischen Chips aufgegeben, drastisch verringert, auch nicht, mit dem jeweiligen Autor oder mir unter oder ausgelagert. Der wachsende Bedarf an hochqualitativer [email protected] Kontakt aufzunehmen. Optik in diesem Bereich eröffnet deshalb ausgezeichnete Wir helfen Ihnen gerne mit zusätzlichen Informationen. neue Möglichkeiten für die wissenschaftliche und innovative Kraft des HHI, setzt aber auch die neue Herausforderung, den Anforderungen einer qualifizierte Herstellung für Pro -

Annual Report | Jahresbericht 2006/2007 53 PHOTONIC COMPONENTS

Polymer based low-cost FTTH Transceiver developed for Berlin Access, a public project in cooperation with several companies located in Berlin (Merge Optics, VPIsystems, FOC Fibers Optical Components GmbH, Berliner Glas, ELBAU, AVM Computersysteme)

Surface emitting BH-Laser: Full waver processing for minimum costs, ideal for laser-to-waveguide coupling

43 Gbit/s NRZ operation of a packaged modulator with Vpp = 2.8 V has been successfully demon- – All in one hand, from wafer to module – strated over 30 nm tuning range in the C-band We run a complete line of epitaxy, processing, and assem- and a temperature between 20 C and 70 C as well bly technologies to develop photonic components for as error free transmission (bit error rate: 10-10) optical communication systems over 320 km fiber at 1550 nm

54 Annual Report | Jahresbericht 2006/2007 PHOTONIC COMPONENTS

Photonic Components

Head of Department Martin Schell Phone +49(0)30/310 02-703 e-mail [email protected]

Deputy Head Norbert Grote Phone -431 e-mail [email protected]

Secretary Iphigenia Janne Phone -557 Fax -558 e-mail [email protected]

High-Speed Photodetectors Heinz-Gunter Bach Phone -503 e-mail [email protected]

Planar Photodiodes Detlef Schmidt Phone -704 e-mail [email protected]

Semiconductor Lasers Martin Möhrle Phone -724 e-mail [email protected]

High Bitrate Modulators Karl-Otto Velthaus Phone -645 e-mail [email protected]

Polymer Devices Norbert Keil Phone -590 e-mail [email protected]

Terahertz Generation and Detection Bernd Sartorius Phone -508 e-mail [email protected]

Diffractive Optics Margit Ferstl Phone -430 e-mail [email protected]

Technology / Epitaxy Harald Künzel Phone -546 e-mail [email protected]

Technology / Processing Detlef Schmidt Phone -704 e-mail [email protected]

Technology / Backend Klemens Janiak Phone -574 e-mail [email protected]

Technology / Electron-Beam Lithography Ralf Steingrüber Phone -236 e-mail [email protected]

Technology / Module Assembly Thomas Rosin Phone -221 e-mail [email protected]

Annual Report | Jahresbericht 2006/2007 55 PHOTONIC COMPONENTS

LASER DIODES FOR INDUSTRIAL tility concerning header types and/or emitting lasers (HCSEL, s. page 71). SPECTROSCOPY APPLICATIONS module design is required. Our lasers When fabricated as DFB lasers, these are provided either as chips-on-header devices can also provide an interesting Optical sensor systems are becom- (Fig. 1) or as miniature self-supported alternative to VCSEL diodes in the ing increasingly important in vari- TE-cooled modules (Fig. 2). 1.3 – 1.7 µm wavelength range in the ous fields of industry. DFB lasers sensing area. tailored to specific wavelengths are crucial devices for applications such as gas sensing, pollution control, process control involving gaseous reactions, etc.

Optische Spektroskopie spielt eine zunehmend wichtige Rolle bei un - ter schiedlichen industriellen An - wen dungen. Unser Engagement in diesem Bereich wird durch maßge- schneiderte DFB Laser in unter- schiedlichen Konfektionierungs for - men demonstriert. Fig. 2: DFB Laser mounted on a compact TO- Fig. 4: Planar photodiodes with up to 3 mm module with integrated TE cooler diameter are equally crucial for the development of sensing equipment Based on its many years of experience Due to the coming into effect of the with InP-based optoelectronic semicon- new European Directive on the Re - Last but not least, HHI also has a long ductor devices, driven by the evolution striction of Hazardous Substances tradition in manufacturing InGaAs- of optical communication systems, HHI (RoHS) in mid-2006, we have adapted based photodiodes. Thanks to our is extensively involved in this evolution. our technology and are now providing excellent material quality, we are able These activities are performed in inten- so-called RoHS-compliant devices and to provide up to 3 mm wide photo- sive cooperation with R&D teams from modules. detectors. Also worth mentioning for various manufacturers of sensing specific sensing applications are highly equipment. sensitive photodetectors (typical responsivity 1.22 A/W, quite near the Our lasers were initially designed for theoretical limit). the 1250 – 1650 nm range featuring specific wavelengths with an accuracy [email protected] of ± 1 nm. In recent years we were able to expand these limits, first to 1750 nm and most recently to 1850 nm.

Fig. 3: Fibre-pigtailed (“butterfly”) DFB laser module for spectroscopy applications In order to address customers using fibre-pigtailed laser modules in their equipment, we have also recently ex - panded our module series with a single-mode fibre coupled version (Fig. 3). It is worth mentioning that these modules fulfil the stringent Telcordia criteria Fig. 1: DFB Laser mounted on a SOT-type and, thus, provide high reliability for header sensing applications. Customer experience shows that for this particular type of application, On the laser chip front, we have where the laser diode is implemented recently demonstrated a novel laser into a sensing equipment, high versa - structure: horizontal-cavity surface-

56 Annual Report | Jahresbericht 2006/2007 PHOTONIC COMPONENTS

MULTI-WAVELENGTH DIODE LASER 0 signal spectrum after 52.8 km SMF PUMP FOR RAMAN AMPLIFICATION - 10 IN THE C BAND - 20 InP-based InGaAsP buried-het- - 30 erostructure Fabry-Perot (BH-FP) pump laser diodes developed at - 40

HHI have been combined in a com- sign a l power (dBm) - 50 pact and easy-to-control four-wavelength pump source. The source for - 60 Raman amplification in the C band Fig. 2: 1470 nm BH-FP power laser on copper 1520 15401560 158 heatsink was developed in a joint project wavelength (nm) together with the Fraunhofer Fig. 5: Spectrum of 60 ECL signals after 52.8 km SMF transmission under distributed institutes ILT and IAF. Raman amplification, single signals at 3 dBm level (measured at HHI’s dept. ON) Die im HHI entwickelten InP-basierten InGaAsP BH-FP (Buried-Hetero- [email protected] structure Fabry-Perot) Pump-Laser- dioden wurden zu einer kompakten und leicht zu steuernden Pump - quelle kombiniert. Die Quelle für Raman-Verstärkung im C-Band Fig. 3: Four-wavelength pump source wurde in einem gemeinsamen Pro- (developed and assembled at FhI-ILT) jekt mit den Fraunhofer-Instituten ILT und IAF entwickelt. The power contribution of each of the four lasers can be controlled independ- 2.0 0.8 50 ently as opposed to multi-wavelength BH-laser 1470 nm Q-cladding fibre lasers. An example spectrum of L = 2.85 mm 40 1.5 w = 5 µm 0.6 the optical output at 1.1 W of total

30 CW power is shown in Figure 4. 1.0 0.4 + 20 20 WPE ( % ) power (W) volt a ge (V) laser- spectrum 0.5 0.2 + 10 1426.6 nm 10 90 % / 1 % 1435.7 nm CW 20 °C 0 1444.8 nm 0.0 0.0 0 1480.8 nm 0.0 1.0 2.0 - 10 current (A) F - 20 Fig. 1: PI-UI characteristics of 1470 nm BH-FP

re-output power (dBm) fi b re-output - 30 power laser diode - 40 The HHI laser diodes exhibit CW optical 1420 1440 1460 1480 power exceeding 0.7 W (fundamental wavelength (nm) mode operation) when bonded p-side Fig. 4: Spectrum of four-wavelength pump down with AuSn solder on AlN sub- source at 1.1 W CW power mounts (Fig. 1). A robust implementation on a copper heatsink is shown in A Raman amplification experiment was Figure 2. conducted with 60 ECL lines of 1 nm spacing which were switched-on one Using four such laser diodes with at a time. The resulting spectra can be wavelengths of between 1426 nm and seen in Figure 5, demonstrating a very 1481 nm, a compact multi-wavelength flat envelope. The underlying gain pump source (Fig. 3) was constructed spectrum shows a variation of less than for Raman amplification in the C band +/- 1 dB which is quite near the theor - (~1530 – 1570 nm). etically predicted value of +/- 0.45 dB.

Annual Report | Jahresbericht 2006/2007 57 PHOTONIC COMPONENTS

MACH-ZEHNDER MODULATORS stable operation over time. The modu- in Fig. 4. With a necessary driving volt-

FOR ON-OFF-KEYING AND NEW lator operates in a series push-pull con- age of 5.5 V the actual 3 dBeo band- PHASE-MODULATION FORMATS figuration for low-chirp while the width (on chip) is 63 GHz which is only TARGETING 100 GBIT ETHERNET Mach-Zehnder-Interferometer concept a few GHz below the 70 GHz limit allows operation with a variety of dif- which is required for 100 Gbps oper- The ongoing evolution of the Inter - ferent modulation formats such as on- ation. net to an integrated information off-keying, DPSK and duobinary. platform for data, voice, and video applications is leading to an in - creased demand for high speed data links. A future 100 G Ethernet standard shows a great potential for cost savings since it can be extended from local area (LAN) to wide area network (WAN) interconnects. A key-component on the Fig. 4: Electro-optical (EO) response of a high speed modulator transmitter side is a long range, Fig. 1: 43 Gbps MZI-Modulator module high speed modulator, based on a Detailed high frequency simulations of Mach-Zehnder-Interferometer (MZI) the current device layout reveal a pos - -structure. This powerful design is sible bandwidth of up to 80 GHz not only suited for standard on-off- achievable with several distinct design keying modulation but also for changes. With this adapted design enhanced new modulation formats concept 100 Gbps on-off-keying oper - Fig. 2: Schematic layout of an MZI based modu- like DPSK, DQPSK and duobinary. ation with a driving voltage Vpp <3V lator with capacitively loaded travelling wave will be possible in the near future. electrodes (TWEs) Die stetige Entwicklung des Inter- nets zu einer allgegenwärtigen To achieve high data rates, the modu- Another approach to realise 100 G Informationsplattform für Daten-, lator is equipped with capacitively Ethernet applications is the use of an Sprach- und Video-Dienste führt zu loaded travelling wave electrodes advanced integrated IQ-Modulator einem immer größer werdenden (TWE) (cf. Fig. 2), which are designed which consists of two parallel MZIs Bedarf an extrem schnellen Daten- as microstrip lines with an overall (Fig. 5) that operate as phase modu - verbindungen. Ein zukünftiger impedance of 50 Ω. 43 Gbps NRZ oper- lators. Differential Quadrature Phase 100 Gbit Ethernet-Standard bietet ation (cf. Fig. 3) of a packaged modu- Shift Keying (DQPSK) at 2 × 50 Gbps ein hohes Einsparpotential, wenn lator with Vpp = 2.8 V has been success- enables this complex modulator struc- dieser von der lokalen Netzwerk- fully demonstrated over 30 nm tuning ture to use standard 50 G electronics Infrastruktur (LAN) in den Bereich range in the C-band and a temperature while achieving 100 Gbps data rates. der Weitverkehrsnetzwerke (WAN) between 20 °C and 70 °C as well as ausgedehnt wird. Eine senderseitige error free transmission (bit error rate: Schlüsselkomponente hierfür ist ein 10-10) over 320 km dispersion compen- schneller Modulator, welcher auf sated fiber at 1550 nm. einer Mach-Zehnder-Interferometer (MZI)-Struktur basiert. Aufgrund seines Arbeitsprinzips ist er nicht nur für die aktuellen Standardmo - dulationsverfahren, sondern auch Fig. 5: Schematic layout of the IQ-modulator for DQPSK modulation für höherwertige Modulationsver- fahren wie DPSK, DQPSK und No matter which modulation format Duobinary einsetzbar. will be chosen for the 100 G Ethernet standard, the Heinrich-Hertz-Institut The modulator is based on InP and will be able to deliver an adequate integrated with an optical spot size Fig. 3: 43 Gbps eye-diagram of the modulator high speed modulator for the specific at 1550 nm (PRBS 231 -1) converter (SSC) for low insertion loss. needs of our customers. It has a 30 nm optical bandwidth, low The electro-optical (EO) response of a driving voltage, small footprint, and highest frequency modulator is shown [email protected]

58 Annual Report | Jahresbericht 2006/2007 PHOTONIC COMPONENTS

HIGHLY LINEAR TRAVELLING WAVE Four of the optimized micro-pin PDs rent of 10 mA (Fig. 4). The traveling PHOTODETECTORS FOR 100 GBPS were monolithically integrated with an wave detector exhibits a bandwidth of APPLICATIONS 1 × 4 MMI coupler which is fed by a 75 GHz, but its high-frequency decay is tapered input waveguide. Fig. 1 gives a much better flattened compared to the Both fiber-based ultra high-bit rate partial view of the traveling wave lumped element 5 × 20 µm2 detector. transmission like 100 G Ethernet detector chip /1/. The o/e-converted TWPD: 4 PDs with 4 x 7 µm2 and W-band free space communica- signals are summed up by a coplanar 40 single PD with 4 x 7 µm2 0.31 A / W tions demand photodetectors with (CPW) transmission line; the electrical 0.37 A / W 30 bandwidths of around 100 GHz. output signal is provided by the 50 Ω In addition to the high bandwidth, pads in the ground-signal-ground con- 20 these detectors should operate lin- figuration. 10 early up to high optical input (mA) D C photo c urrent electrical signal Vbias = -3 V powers. For these applications, a 0 novel traveling wave detector struc- SIG 0 40 80 120 ture with 40 mA output current optical power (mW) R capability was developed that is 50 Fig. 4: DC photocurrent vs. optical input power: comparison of single PD and TWPD V based on the 100 GHz waveguide- h bias C integrated photodiode previously bias Fig. 4 shows that the traveling wave presented. detector is linear up to 40 mA. Fig. 5 Fig. 2: Travelling wave detector circuitry shows the achievable RF output power integrated monolithically on the TWPD chip Die Hochbitraten-Übertragung über levels of a single and a traveling wave Weitverkehrs-Glasfaserstrecken, das Fig. 2 explains the equivalent circuit pin structure, the latter delivering 100 Gbit/s Ethernet und W-Band- diagram of the traveling wave detector +10 dBm into 50 Ω at 10 GHz. The Freiraumverbindungen benötigen chip, including a 50 Ω termination. This traveling wave detector chips showed einerseits Photodetektoren mit termination, together with an opti- single pulse amplitudes as high as Bandbreiten im 100 GHz-Bereich; mized impedance of the transmission 0.55 V with a pulse width of 8 ps andererseits sollen diese Detekto- line, leads to an ultra-broad band elec- (FWHM) accompanied by very low ren bis zu hohen Leistungen linear trical output reflection lower than undershoot ringing of 4 %. Chips have arbeiten. Hierfür wurde auf Basis -13 dB up to 110 GHz. been packaged and tested successfully der früher vorgestellten Wellenlei - at bit rates of up to 80 Gbps so far. ter-integrierten 100 GHz Photodi - 0 PD 4 x 7 µm2 To the best of our knowledge, this is ode eine fortgeschrittene Wander - the highest power linear operation up wellendetektorstruktur entwickelt, 5 to 75 GHz demonstrated for a 1.55 µm die Photoströme bis zu 40 mA abge- TWPD traveling wave detector with a respon- 10

ben kann. (dB) a tive response sivity higher than 0.3 A/W. rel PD 5 x 20 µm2 15 + 20 TWPD: 4 PDs with 4 x 7 µm2 The size of the photodetector mesa 2 + 10 single PD with 4 x 7 µm was down-sized from typ ical 5 × 20 µm2 0 50 100 150 200 frequency (GHz) dimensions to 4 × 7µm2.1 In order to 0 Fig. 3: Measured frequency responses of - 10 keep responsivity high, the buried lumped element PDs and a TWPD with n-contact layer was enlarged in the d = 110 µm. All devices stem from the same - 20 RF power (dBm) waveguide direction to support proper wafer with dabs = 200 nm. The measurements - 30 f = 10 GHz, V = -3 V absorption steering. were done at a DC photocurrent of 2 mA and sig bias Vbias =-2V. - 40 0.1 1 10 100 BCB layer bias pad The DC responsivity of the traveling DC photocurrent (mA) p-i-n PDs wave detector amounts to 0.31 A/W at Fig. 5: Comparison of single PD and TWPD: MMI splitter detected output power vs. the DC photocurrent 1.55 µm. The frequency response of (both devices without R50) electrical the photodetector was measured with from optical output an optical heterodyne measurement [email protected] input d R50 output CPW setup up to 170 GHz (Fig. 3). [1] Beling A., H.-G. Bach, G. G. Mekonnen, Fig. 1: Partial view of the fabricated TWPD chip. R. Kunkel, D. Schmidt in: IEEE Journal of While the single micro-pin PD (4×7µm2) The input signal is fed from the left via the Selected Topics in Quantum Electronics, special spot-size converter and rib waveguide (not shows the broadest frequency response, issue on High-Speed Photonic Integration, shown) into the MMI splitter. it is limited to an electrical output cur- Vol. 13, No. 1 (2007), pp. 15 – 21.

Annual Report | Jahresbericht 2006/2007 59 PHOTONIC COMPONENTS

ALL-POLYMER FIBER ARRAYS

Single-mode fibre-arrays made on polymer material have been de - veloped for connecting polymer chips to optical fibres. This CTE- matched fibre-array is fabricated using low-cost techniques that allow for large volume production.

Es wurden optische Faser-Arrays auf Polymerbasis hergestellt, mit denen eine thermo-mechanisch angepasste Ankopplung von Faserbändchen an optische Polymerwellenleiter- Fig. 1: A fibre-array with 8 fibres on polymer substrate Chips möglich ist. Dank der einfachen Herstellungstechnologie ist formed in polymer material as well is eine kostengünstige Massenferti - advantageous. gung möglich. 125 µm single mode fiber Figure 1 shows the photograph of a Polymer-based planar lightwave circuits polymer fibre-array with eight fibres. (PLCs) are considered to offer advan- The fibres are inserted and guided in tages in terms of costs and flexibility in V-grooves that are formed by microfabrication. A wide range of optical machining in the polymer substrate, devices have been demonstrated on as shown in Figure 2. polymer substrate this platform, including waveguides for Fig. 2: V-grooves in polymer substrate optical interconnections, static routers, The simple fabrication procedure such as couplers, taps, splitters, multi- allows for very low fabrication costs. polymer cover plexers, demultiplexers and OADM The core-to-core pitch is 250 µm. The (Optical Add-Drop Multiplexer), cover plate is made of polymer material thermo-optic switches, VOA (Variable too, as shown in Figure 3. The end SMF ( 125 µm) Optical Attenuator), and tuneable fil- face of the fibre-array is polished to ters. Polymer-based PLCs can also be ensure low-insertion loss. CTE of the hybridly integrated with optoelectronic fibre-array and of the polymer wave- devices, such as lasers and photo guide device is perfectly matched if diodes, in order to create complex the same polymer substrate is used. polymer substrate active/passive components. Fig. 3: Fibre-array with polymer top cover Figure 4 shows an example of a mod- Polymer AWGs fabricated on polymer ule which contains an all-polymer AWG substrates were recently introduced by chip. The input and output fibres are HHI. This all-polymer approach offers connected to this chip using the poly- the possibility to control the tempera- mer fibre-arrays described above. ture and polarization behaviour of the AWG. It is possible, for instance, to [email protected] achieve negative or positive temperature tuning behaviour.

When an AWG structure on a polymer Fig.4: All-polymer AWG module with all-polymer substrate is connected to a fibre-array fibre-arrays commonly made on silicon, the mis- match in the values of thermal expansion coefficient (CTE) of polymer material and silicon may cause excess coupling loss. Therefore, a fibre-array

60 Annual Report | Jahresbericht 2006/2007 PHOTONIC COMPONENTS

OPTICAL MINISPECTROMETER

optical PD array An optical, miniaturized spectrom - motherboard (InP) eter has been fabricated by hybridly (polymer) integrating an arrayed-waveguide grating (AWG) and an array of photodetectors on a polymer chip. This device may be used as an op- 45° mirror tical channel performance monitor, as a wavelength meter, or as an optical sensor for IR applications. miniature spectrometer Auf Basis eines Polymerchips wurde ein miniaturisiertes Spektrometer Fig.1: Miniature spectrometer hybrid integrated on a polymer waveguide platform hergestellt, das ein sog. „Arrayed- waveguide grating“ als optisches The optical input signals are coupled to fiberarray AWG detector LED P Filter und eine integrierte Photodi- the polymer AWG via a fibre-array opt P odenzeile enthält. Das mögliche again implemented in polymer material opt P opt P Anwendungsspektrum reicht von (cf. page 60). The output signals are opt DEMUX der Überwachung optischer Kanäle vertically deflected to the PD array via Popt in optischen Übertragungssystemen sawn 45° mirrors. Figure 1 shows block diagram bis hin zu Sensoranwendungen im microscopic pictures of three detectors Fig. 2: Operation principle of the spectrometer IR-Bereich. of the PD array, and the cross-section of a 45° mirror. fiberarray AWG detector LED Integrating multiple optical functions (polymer) (polymer) (InP) into a single device is considered to be Figure 2 illustrates the operation prin - a key step towards lowering the costs ciple of the spectrometer. The input of optical components. This is because light consists of different wavelengths. packaging costs can be reduced. The polymer AWG acts as a demulti- in out Device performance may be improved, plexer and spectrally separates the and last but not least integration offers input signals into the different output schematic layout a viable route for further miniaturizing ports (channels). For reasons of simpli- Fig. 3: Schematic layout of the spectrometer components and eventually instru- city, an AWG with only four channels is ments. Using a hybrid integration depicted in Figure 2. Depending on the scheme, one can choose discrete elem - specific application, the number of ents, thus exploiting the best-suited channels can be easily adapted. Eight material technology, whilst yield man- channels were employed in our demo agement is facilitated due to testing of prototype. The electrical output signals the individual devices at an early stage of the PD are coupled to a circuit board of fabrication. including electronic amplifiers and an array of LEDs in order to display the We have developed a miniaturized 8- optical power in the corresponding channel spectrometer that incorporates channel (Fig. 3). an arrayed-waveguide grating (AWG) formed in special polymer films. Con - This spectrometer can be implemented taining an array of waveguides with as an optical channel performance constant length difference, the AWG monitor in optical WDM networks, as spectrally separates the incoming sig- a wavelength meter, and may find vari- nals. The polymer AWG itself is fabri- ous applications for sensing applica- cated on a polymer substrate, and an tions in the IR spectral range. array of InP photodetectors is mounted onto the polymer chip as shown in [email protected] Figure 1.

Annual Report | Jahresbericht 2006/2007 61 PHOTONIC COMPONENTS

1.55 µm INP-BASED QD LASERS (Tg) in combination with stacking a Devices with a length ranging from high number of QD layers. A maximum 200 µm to 800 µm and widths of be- In recent years, quantum dot (QD) density of up to 8 × 1010 cm-2 was tween 50 µm and 100 µm were made materials have been primarily de- reached at Tg = 470 °C where the onset with a high degree of uniformity. veloped on the basis of the GaAs of formation of quantum dashes was Device characteristics taken on repre- material system. At Fh-HHI, a re- observed. More than 10 layers could sentative devices under pulsed oper - search project is being conducted to be stacked virtually without inducing ation are shown in Figure 3 and Figure adopt QD technology to InP-based defects. Above Tg = 500 °C stable emis- 4. Excellent linearity of laser emission materials relevant for fibre-based sion from the QDs was obtained when and comparatively low threshold values 1.55 µm optoelectronics and to exposing the QDs to thermal treatment are obtained. Plotting threshold density assess its potential for innovative or InP cladding growth, irrespective of versus inverse length and extrapolating photonic components. the conditions used. Based on this pro- to 1/L = 0 threshold densities per dot cedure, laser structures with seven QD layer of 80 Acm-2 were achieved which, Quantenpunktmaterialien wurden layers and 5 × 1010 cm-2 dot density to our knowledge, are record values bisher vorwiegend in GaAs-Halb - were grown. Reproducible emission for such devices and are quite close to leitersystemen entwickelt. Am Fh- wavelength was obtained. the values of comparable MQW laser HHI wird ein Forschungsprojekt devices. With the present design, durchgeführt, die QD-Technologie quantum efficiencies of 65 % and an auch für auf InP basierende Materi- internal absorption of 4 cm-1 were z (nm) alien zu entwickeln und ihr Poten - obtained. The differential efficiency 20 tial für die Realisierung innovativer amounted to 0.23 W/A per uncoated Kom ponenten zu untersuchen. y (nm) facet.

800 3.0 0.16 Present optoelectronic components es - # 2MOE 5228 2 A = 400 x 50 µm sentially rely on band-band transitions 400 R = 0.71 s 2 0.12 (emission, absorption) in bulk and QW x (nm) Jth = 1.86 kA / cm 800 2.0 U = 0.86 V layers. Aiming to achieve improved 400 th ex = 0.23 W / A device characteristics, additional mater- 0 0.08 ial options and physical mechanisms Fig. 1: AFM image of MOVPE QD-layer volt a ge (V) 1.0 are currently under investigation world- 0.04 light output (W) wide. The most prominent develop- 300 K ment in this field may be the imple- 1.0 0 0.00 mentation of quantum dot (QD) mater- 0.0 0.2 0.4 0.6 0.8 1.0 ials offering complete spatial quan - drive current (A) tisation of free carriers. Besides broader 220 nm Fig. 3: U/I- and L/I-characteristics of a broad- 0.5 2 optical gain spectra due to statistic size 70 nm area device (400 × 50 µm ) incorporating seven QD-layers grown at 500 °C

distribution, superior static laser char- norm. PL-intensity acteristics, such as low-threshold dens - 3 ity and high-characteristic temperature, 410• 0.0 # 3MOE 5228 or promising high frequency properties, # 3MOE 5229 13001400 1500 1600 1700 (W = 100 µm) such as reduced chirp, have been pre- wavelength (nm) 2 dicted. Real InAs QDs (rather than 3 Fig. 2: Comparison of 300K PL of 1.55 µm 210• quantum dashes) on InP, as shown in emitting QDs (red) and QWs (blue) th Figure 1, are deposited at Fh-HHI using J (A / c m) 3 MOVPE equipped with conventional Up to now, the international status of 10 sources. The QDs were grown in a InP-based QD laser development is 600 A / cm22 80 A / cm per QD layer GaInAsP matrix to achieve a 1.55 µm generally not competitive to conven- 05010 20 30 40 emission as demonstrated in Figure 2. tional quantum-well-based technology. -1 1 / L (cm) Besides improving deposition param - Our work has led to an improvement eters for achieving the highest PL inten- in 1.55 µm QD laser development in Fig. 4: Device length dependence of threshold sities, special emphasis was placed on terms of growth and device-related density of 100 µm wide devices with (3MOE5229) and without (3MOE5228) implementing a high density of dots by properties. Broad-area laser devices p-doping in the upper waveguide layer decreasing the deposition temperature were fabricated using the standard fabrication processes of MQW lasers. [email protected]

62 Annual Report | Jahresbericht 2006/2007 PHOTONIC COMPONENTS

FLIP-CHIP ADAPTED OEICS FOR Wavelength Division Multiplexing) The alignment accuracy is in the range ECONOMIC APPLICATION SPECIFIED system. of ± 1 µm. The laser performance is not OPTICAL BOARD SET-UPS affected by the soldering process. Vertical and lateral alignment stops and An essential cost reduction in the a backside lithography are the final As an integration demonstrator, Figure set-up of optical modules and optic - steps of laser fabrication. A precise 4 shows the output spectrum of an SOI al boards demands the application cleaving of the front facet is essential transmitter board with five flip-chip- of self-aligning, flip-chip mounting for mounting. The footprint of the mounted lasers. The laser signal is of optoelectronic ICs (OEICs) on the cleaved laser chip is 500 µm square combined via an onboard AWG to a optical platform. 1.3 µm and 1.5 µm with a height of 200 µm (cf. Fig. 1). single output waveguide. The CWDM CWDM lasers suitable for this channels of the S, C and L band are mounting technology have been matched and side-mode suppression fabricated. (SMSR) is better than 30 dB.1

Eine entscheidende Kostenreduk- 0 tion in der Fertigung von optischen - 10 Modulen und von optischen Boards - 20 setzt den Einsatz der selbstjustie- renden Flip-Chip-Montage der - 30 optoelektronischen ICs (OEICs) auf - 40 der optischen Leiterplatte voraus. Fig. 1: Coupling interface between laser (left) a tive intensity (dB)

rel - 50 1,3 µm und 1,5 µm CWDM Laser and optical platform geeignet für Art der Montage - 60 wurden hergestellt. Multiple solder bumps fabricated by 15101530 1550 1570 1590 using sputter deposition of the accur - wavelength (nm) Optical modules and optical boards for ate eutectic Au80Sn20 alloy establish the Fig. 4: Output spectrum of SOI transmitter Giga-scale data communication de- electrical, thermal and mechanical con- board with AWG combiner onboard. SMSR is mand single-mode operation of the tact between the OEIC and the board. better than 30 dB and four of five lasers show devices. The economic set-up of such a homogenous signal. units requires reliable optical inter - facing of the planar hybridly mounted This work was supported by the Fed - laser and detector OEICs with micro - eral Ministry of Education and Research meter accuracy. under grant 01 BP 281. Partners in the project consortium were Technical The 1.3 µm and 1.5 µm buried hetero- University of Berlin and Merge Optics structure (BH) λ/4 phase-shifted DFB GmbH. lasers implemented are based on the InGaAsP/InP material system with inte- [email protected] grated spot-size converter for self- 1 mm aligning passive flip-chip mounting. Fig. 2: Photograph of four lasers mounted on an optical platform with flip-chip process The flip-chip capable DFB laser diodes are designed to be butt-coupled to a silicon waveguide within an SOI optical board with a near-field spot size extension of about 5 µm resulting in a small far-field angle.

The laser diode consists of a 300 µm 1 T. Mitze, M. Schnarrenberger, L. Zimmer - λ/4 phase shifted DFB section and a mann, J. Bruns, F. Fidorra, K. Janiak, J. Kreissl, separate 200 µm spot size converter S.Fidorra, H. Heidrich, and K. Petermann, “CWDM Transmitter Module Based on Hybrid region. The components have the Fig. 3: SEM picture of the same devices Integration”, IEEE Journal of Selected Topics in potential for up to 10 Gbps direct Quantum Electronics 5, September/October modulation in a CWDM (Coarse 2006, pp. 983 – 987.

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NEXT GENERATION MICROLASERS couplers. The concept provides the in - forming an inverted signal pattern at a tegration of an optical transparent pas- wavelength determined by the lateral Photonic integration is a key issue sive bus waveguide vertically coup led laser cavity. in achieving low-cost, reliable and to the active ring laser(s). After the fab- high-speed photonic components. rication of the first waveguide level, The reflectors of the GC cavity are HHI is tackling the miniaturization the InP-wafer is waferbonded upside formed by deeply etched Bragg grat- of OEICs in order to be able to com- down on a GaAs-substrate using BCB ings. Threshold lasing condition at pete for the next and the next-but- as an intermediate layer. After removal 1.5 µm emission was demonstrated at one component generations. Ex - of the InP-substrate by wet chemical 40 mA for a cavity length of 20 µm (see amplarily, we sketch recent results etching, the second waveguide level, photograph in Figure 3). on microring laser and wavelength including all the necessary electrical incoming signal converter devices. Both activities contacts, are defined as shown 1 are performed in projects within schematically in Figure 1. the scope of the 6th EU Framework Programme for Technological p-contact aplification Re search and Development (see n-contactn-contact below). MMI zone

Photonische Integration ist ein Weg, BCB um kostengünstige, zuverlässige GaAs substrate photonische Komponenten für hohe Fig. 1: Cross-section of vertically coupled Datenraten zu realisieren. Das HHI microring/ bus waveguide structure (schematic) verfolgt diesen Weg konsequent, clamping + um für die nächste und über nächste Exemplarily, Figure 2 shows a processed conversion Komponenten generation konkur- 3-wavelength transmitter microring renzfähig zu bleiben. Als Beispiel laser source coupled to a single bus outgoing signal werden aktuelle Ergebnisse zu waveguide. 2 Mikroring-Laser- und Wellenlängen- 100 µm konverter-Komponenten skizziert. Beide Aktivitäten werden innerhalb von Projekten des 6. Europäischen Rahm enprogramms durchgeführt (s.u.). Fig. 2: WDM microring laser source Vertically coupled microring laser: Semiconductor-based microring res- Wavelength converter: Optical wave- onators have become attractive due length conversion is becoming more to their potential for multiple function- and more important for improving the Fig. 3: Schematic architecture of the wave- alities. Relevant applications include capacity and flexibility of photonic net- length converter and SEM picture of an ultra compact gain clamping/converter section lasers, wavelength converters, optical works. In the novel concept, wave- modulators and sensors. length conversion (CV) is achieved via This kind of wavelength converter amplification in a laterally gain-clamped offers cost advantages compared to Miniaturization is here not only a pre- (GC) semiconductor optical amplifier state-of-the-art set-ups, such as Four requisite for low costs, due to tiny section (SOA). The architecture of the Wave Mixing (FWM) approaches which footprint, but also to assure high bit- wavelength converter device is shown require additional pump lasers or large rate application due to the photonic schematically in Figure 3. Wavelength footprint Mach-Zehnder interferometer lifetime in the resonator. Optimum conversion of an incoming signal, devices with integrated SOA-sections. coupling conditions of the microrings which is amplified via an input wave- can be achieved by applying a vertical guide and an MMI section – both with This work has been partly funded by coupling concept where a submicro - SOA functionality, is performed in a EU contract FP6-2003-IST-2-004073/ meter coupler gap can be precisely GC/CV section. This ultra-short cavity WAPITI and EU contract FP6-2003-IST- controlled with epitaxial growth accur - path is designed to operate above 2-004582/FUNFOX. acy performed in a single run. This lasing threshold (GC). The lasing signal allows the fabrication of ultrashort is modulated by the incoming signal, [email protected]

64 Annual Report | Jahresbericht 2006/2007 PHOTONIC COMPONENTS

40 GBPS DIRECTLY MODULATED Experimentally, the bit patterns and bit LASER error rates (BER) were measured on bar level using a high frequency probe Directly modulated lasers operating head (Figs. 3, 4). Well-opened eyes at 40 Gbps are attractive candidates with an extinction ratio of 6 dB at for compact and low-cost transmit- 40 Gbps are observed. Further analysis ters in high-speed VSR optical links. on the chirp characteristic and width of We have a novel high-speed laser the operation windows verified the for wavelengths of 1.55 µm with an quality of this very cost-efficient laser enhanced 3 dB optical modulation concept. Error-free operation allows Fig. 1: SEM photograph of a two section bandwidth of 30 GHz. The laser en- passive feedback laser (PFL) structure showing transporting 40 Gbps signals over up to ables error-free, high-speed oper- the laser ridge and electrical contacts 2 km of standard single mode fibre. ation under 40 Gbps NRZ signals with an extinction ratio of 6 dB. Our device (Fig. 1) is a passive feedback laser (PFL) consisting of a 1.55 µm Direkt modulierte Laser für Daten- emitting GaInAsP distributed feedback 4 raten von 40 Gbit/s sind als kompak- laser (DFB) which is monolithically inte- te und kostengünstige optische grated with a short passive feedback 6

Sender gefragte Komponenten in section (IFB). The feedback from a -log (BER) 8 VSR-Übertragungsstrecken. Wir highly reflecting IFB facet is electrically 10 ver fügen über einen neuartigen phase controlled. schnellen Laser für Wellenlängen 12 um 1,55 µm mit einer optischen - 25 - 20 - 15 no feedback received optical power (dBm) Modulationsbandbreite von 30 GHz. optimum feedback Der Laser erlaubt die fehlerfreie Fig. 4.: Results of back to back BER Übertragung von 40 Gbit/s NRZ 0 measurements Signalen und zeichnet sich durch ein hohes Extinktionsverhältnis von We have achieved the first-time imple- 6 dB aus. - 10 mentation of direct laser modulation norm. response (dB) norm. response at 40 Gbps. Up to now, this high bit High-bit rate 40 Gbps transmission sys- rate – one of the key targets for the tems are the way to handle the grow- 0310 20 0next generation of photonic communi- ing popularity of the Internet. For very- modulation frequency (GHz) cation systems – required external short-reach (VSR) optical links and modulation for both long-range and Fig. 2: Feedback enhanced small signal optical metro application, the direct modu- modulation bandwidth in two section laser (DFB short-range applications. Our laser pro- lation of lasers provides low cost and injection current: 40 mA) vides a modulator-free, low-cost trans- compact transmitters. mitter solution in 40 Gbps VSR optical The feedback enhances the modulation links. Whereas 10 Gbps directly modulated bandwidth by about a factor of three lasers are commercially available for over the typical carrier photon reson - The work has been partly funded by 1.3 µm and 1.5 µm emission wave- ance frequency limit. A 30 GHz band- the EFRE-programme of the European lengths, high-speed lasers for bit rates width is achieved even at low DFB bias Union under contract 10125597 of of up to 40 Gbps suffer from the limit- currents (Fig. 2). the IBB. ed modulation bandwidth of standard single section semiconductor lasers. [email protected]

One way to increase the modulation bandwidth is to use novel gain mater - 1 U. Troppenz, J. Kreissl W. Rehbein, C. Born - ials, short laser cavities and/or high bias holdt, T. Gaertner, M. Radziunas, A. Glitzky, U. currents. We succeeded with a differ- Bandelow, and M. Wolfrum: “40 Gb/s Directly ent approach and have speeded up our Modulated InGaAsP Passive Feedback DFB 40 Gbit/s NRZ laser deploying the longitudinal dy - Laser”, Proc. European Conference on Optical Communication (ECOC’2006), 24 – 28 Sept. namics in a specially designed two sec- Fig. 3: Large signal characteristic of directly 2006, Cannes (France), post deadline paper tional structure. modulated laser Th4.5.5.

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COMPACT 40 GBPS RZ-DPSK TRANS- Tx MITTER APPLYING A PHASECOMB Pattern generator DPSK RZ eye 31 LASER AS CARVED SOURCE clock data data 40 Gb/s 2 -1 el. dc dc el. amp Differential Phase Shift Keying amp (DPSK) is increasingly becoming the opt. communication format of choice for DFB1 phase DFB2 amp modulator future optical networks. However, 800 µm robust, compact and low-cost solu- PhaseCOMB laser tions for transmitter and receiver components are required to pave Fig. 1: Simplified approach for an optical RZ-DPSK transmitter the way towards DPSK field deployment. In a 160 km transmission laser device, the electrically synchron - experiment, we demonstrated a ized self-pulsating PhaseCOMB laser simplified approach for 40 Gbps (Phase Controlled Mode Beating). RZ-DPSK transmitter where a The PhaseCOMB laser is a compact PhaseCOMB laser is applied as an (length of 800 µm), three-section laser optical pulse carver. with two detuned DFB gratings and an integrated phase tuning section. The Die differenzielle Phasenumtastung pulsation frequency of the device is (DPSK) ist als Modulationsformat electrically tuneable to various data der Kommunikationstechnik tech- rates via the dc biases covering bit-rate nisch die erste Wahl für zukünftige flexible operation, e.g. at 40/43 Gbps. Fig. 2: Compact pulse source with integrated optische Netze. Um auch den öko- Two beating laser modes generate a bias network nomischen Durchbruch des DPSK- sinus-shaped output signal with high Formats im Feldeinsatz zu sichern, spectral efficiency, hence meeting the - 4 back to back werden robuste, kompakte und demands of DWDM systems. The beat- 160 km transmission kostengünstige Sender und Emp- ing pulsation frequency is synchronized fängerlösungen benötigt. Wir by an electrical 40 GHz signal with a - 6 haben für die Entwicklung eines typical rf-power of 8… 10 dBm. The 40 Gbit/s RZ-DPSK Transmitters optical output power of the present - 8 log (BER) einen einfachen Ansatz erfolgreich device (no spot size converter inte - in einem 160 km Übertragungsexpe- grated) exceeds + 1.5 dBm. - 10 riment demonstriert, bei dem ein - 12 PhaseCOMB Laser als optischer The PhaseCOMB laser chip was pack- - 40 - 38 - 36 - 34 - 32 - 30 Pulsschneider zum Einsatz kommt. aged by the company u2t into a sur- received power (dBm) face-mountable butterfly module The conventional RZ-DPSK transmitter shown in the photograph in Fig 2. Fig. 3: BER - and eye analysis scheme requires a series of optical For electrical synchronization of the components, consisting of a cw laser PhaseCOMB laser, a bias-network is [email protected] and two modulators, each followed by integrated into the module and the an optical amplifier, in order to com- corresponding electrical interface is pensate for the modulator insertion designed for 40/43 GHz operation. losses. The first modulator, driven by an electrically amplified clock signal, is The system performance at 40 Gbps used as an RZ carver. The second was evaluated in a 160 km transmis- modu lator is driven in push-pull oper- sion experiment. The results are de - ation by the electrically amplified NRZ picted in Figure 3. Error-free operation and inverse NRZ pattern, encoding the (BER < 10-13), a penalty of 1 dB and a data information as ± π phase modu - clearly opened eye after 160 km trans- lation on to the carved pulses. In our mission demonstrate the excellent simplified approach (Fig. 1), we re - system performance of our simplified placed the cw laser, the first modulator DPSK-transmitter concept that employs and an optical amplifier by only one a PhaseCOMB laser as a carved source.

66 Annual Report | Jahresbericht 2006/2007 PHOTONIC COMPONENTS

PHOTONIC PACKAGING In the case of the InP-based pump laser Connecting 100 GHz signals is a diffi- TECHNOLOGY (1480 nm), it makes sense to use cult task, even for ultra-fast HHI-InP- aspherical lenses for high-fiber cou- based photodiodes (>100 GHz). But It is the goal of the photonic pack- pling efficiency of more than 80 %. HHI has extensive experience in de - aging technology group to continu- signing, manufacturing and bonding ously increase capability, power CPW or MS (microstripline) connections out put and high frequency limits in µm dimensions with low signal of packaged devices in a small damping (e.g. MS with 0.43 dB/mm at series production. The offer for 110 GHz). external and internal customers is enhanced and continuously im - Fig. 2: Lensholder for aspheric lens with proved. Ex amples include the HCSE quadratic contour on fibre tip laser in TO-Can, butterfly modules for pump laser or 40 Gbps lasers and FC-mounted photodiodes with 110 GHz connector.

Es ist das Ziel der Gruppe für photonische Aufbau- und Verbindungs- Fig. 5: Packaged InGaAs/InP-photodiode (PD) in Technologie, Leistungsfähigkeit, housing with 110 GHz connector Ausgangsleistung und Hochfre - quenzgrenze der verpackten Bau- The PD module in Figure 5 is butt- Fig. 3: Quadratic aspheric lens on fibre, teile in einer Kleinserienproduk tion NA = 0.55 and 0.29 mm focus distance coupled to the fibre and has a 110 GHz kontinuierlich zu verbessern. Das connector as the output. RF measure- Angebot für externe und interne A lensholder (see Figure 2., prepared ments (refer to Fig. 6) with an optical Kunden wird ständig verbreitert for laser welding, sitting on a single heterodyn setup demonstrate the und verbessert. Beispiele sind HCSE mode fibre tip) was designed for a power1 available within encouraging Laser in TO-Can, Butterfly-Module quadratic lens with NA = 0.55 and 3 dB limits of up to 107 GHz. für Pump- oder 40 GHz Laser, und 0.29 mm focus distance (see Fig. 3), FC montierte Photodioden mit making laser coupling as easy as The results of a joint project by Fraun - 110 GHz-Anschlußstecker. adjusting a tapered lensed fibre. hofer HHI and IZM enable the future flip-chip mounting of the PD. The HCSE DFB laser (horizontal cavity A directly modulated laser (see DML in surface emitting laser, see page 71) this report) was packaged in a cooled simplifies the packaging for sensor ap - butterfly housing with lateral RF-input. plication in TO-Can. Mounting is carried A coplanar waveguide (CPW) on quartz out simply by soldering the laserdiode led the signal from V-type connector to onto the surface of the TO-socket. the bond pad of the laser. This enabled Wire bonding is also performed in this short-wire bonds between the CPW orientation, see Figure 1. A 90° rota- and laser, resulting in a 40 Gbps stream tion is not necessary. The freedom of in the fibre. In Figure 4, the module is wavelength choice is combined with fixed in a modified butterfly socket. the ease of VCSEL mounting and coup - Fig.6: Frequency response of PD module with ling. 110 GHz connector (1 mm, W-typ); -3 dB power at 107 GHz

[email protected]

1 M. Töpper, Th. Rosin, T. Fritzsch, R. Jordan, G. Mekonnen, C. Sakkas, R. Kunkel, K. Scher - pinski, D. Schmidt, H. Oppermann, L. Dietrich, A. Beling, Th. Eckhardt, H.-G. Bach, and H. Reichl: “Thin Film Substrate Technology and Fig. 4: Directly modulated Laser (DML) in FC Interconnection for Very High Frequency Fig. 1: HCSE DFB Laser on TO-socket, left after modified butterfly module and socket with Applications”, 56th ECTC, 30.05 – 02.06.2006, bonding, right with ball lens in cap lateral RF input San Diego, USA

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ELECTRON BEAM LITHOGRAPHY – Photonic Bandgap structures (Fig. 2) high contrast resist, the fabrication of A TOOL FOR HIGH RESOLUTION which are commonly fabricated in 3 dimensional structures, such as com- STRUCTURES AND MASKMAKING direct write mode. puter-generated DOEs, multi-level zoneplates or other microoptical de- With more than 42 man-years of vices, can be carried out in a flexible experience, electron beam lithog - manner using our tool. Up to 256 raphy is an important key technol- height levels have been implemented. ogy for microfabrication at the FhI HHI. The current system is a new In order to minimize so-called stitching state-of-the-art e-beam tool that errors, which cause problems to almost successfully fulfils both the require- every EBL tool, a process technology ments for the highly precise and was invented that evidently reduces flexible generation of micro- and Fig. 1: SEM image of a DFB grating etched in InP the stitching error to fractions of the nanostructures as well as the de- specifications.1 mands for fast and repetitive photomask and reticle production. To meet the requirements of sub-nano - meter addressing when fabricating Mit mehr als 42 Mannjahren Erfah- chirped gratings an exposure strategy rung ist die Elektronenstrahllitho - was invented already in the mid-1990s graphie eine wichtige Schlüssel tech - to realize grating pitch variations of nologie für die Mikrostrukturierung distinctively less than a few 10 pico - im FhI HHI. Die auf dem neuen meters.1 Stand der Technik basierende An- lage erfüllt erfolgreich die Anfor - To meet the requirements of fast and derungen an hochpräziser und cost-effective production the system is flexibler Strukturierung von Mikro- supplied with a 10 position airlock to und Nanometerstrukturen als auch automatically handle and expose sub- die Ansprüche zur schnellen und strates. The system is capable to load Fig. 2: AFM image of a Photonic Bangap reproduzierbaren Herstellung von structure in resist and to address all semi-standard sizes Photomasken und Reticles zu. up to 6 inch. Furthermore we have a The extreme overlay accuracy and high lot of experience to use customer spe- Electron beam lithography (EBL) is one precision of the system is for instance a cific substrates of various dimensions, of the most widely used and proven requirement for generating T gate thicknesses, and materials. technologies for the generation of structures, especially if a two-step EBL micro- and nanostructures. Direct-write process is applied in order to achieve Among both national and international EBL directly on the substrate combines sub-100 nm gatelengths. Figure 3 pres- customers, HHI’s e-beam services are the advantages of high resolution and ents a gate-profile after etching the known as a centre of excellence for the maskless lithography. It is accepted as a ‘foot’ layer in SiNx and a subsequent generation of micro- and nanostruc- potential candidate for the Next Gener- EBL step to generate the ‘head’ layer tures for research and development ation Lithography tools by the Semi - prior to evaporating the gate metal. activities as well as for the fabrication con ductor Industry Association (SIA). of photomasks and reticles. We fabricate measuring standards for a major At FhI HHI, EBL has been the technique supplier of 45 nm lithography optics, of choice for more than 24 years. The DFB gratings for an international chip new Vistec EBPG5000plus system foundry, computer-generated holo- installed in 2003 is a modern Gaussian grams for an international optics sup- beam vector scan system. Three differ- plier and various photonic microstruc- ent accelerating voltages (20 kV, 50kV tures for leading research institutions. and 100 kV) are provided. The system is 1.2 µm equipped with a thermal field emitter [email protected] Fig. 3: SEM image of an embedded Gate-profile source that creates Gaussian beam pro- (foot etched in SiNx, head in resist) files down to 10 nm in diameter which 1 Proc. of SPIE, Vol. 4343, 2001, pp 317 – 322 are necessary to fabricate Bragg grat- Although high resolution lithography 2 Microelectr. Engineering, vol. 61-62, pp. ings for semiconductor lasers (Fig. 1) or directly on substrates commonly uses a 331 – 335, 2002

68 Annual Report | Jahresbericht 2006/2007 PHOTONIC COMPONENTS

TERAHERTZ TECHNOLOGY – A very promising concept pursued at replace the slow and bulky mechanical TELECOM CHIPS BREAK PRICE, FhG-HHI is based on interference of delay lines used in conventional homo- SIZE AND SPEED two lasers with different wavelengths dyne systems. Thus, this master-chip which results in a beating signal at THz represents a milestone towards ultra- Terahertz waves, safe for humans, frequencies (Fig. 2). fast data acquisition for video rate facilitate penetration of clothes, applications. photomixer packages and plastics. Applications THz generation cover security (detection of hidden laser 1 The second chip contains the photo- weapons and explosives), inspection mixer. The well-established, low tem- of materials (isolation of space perature grown (LT) GaAs cannot be THz THz detection shuttle tank), and spectroscopic beating applied, because the material is not laser 2 homodyn signal analysis (biological materials, can- sensitive at 1.55 µm wavelength. cer). Present THz transmitters and Fig.2: Scheme of beating and photomixing Instead, we have developed a LT detectors are expensive and bulky, InGaAs MQW heterostructure. The but chips matured for telecom ap- Using a nonlinear photomixer, the excellent operation of the new photo - plications can pave the way towards beat ing can be converted into THz mixer at 1.55 µm has already been cheap and compact systems. radiation. Vice versa, irradiating the demonstrated. In addition, the material photomixer with the THz wave, and was also operated at 800 nm, and Terahertz-Wellen durchdringen using the optical beating as a local when compared to LT-GaAs devices, at Klei dung, Verpackung und Plastik, oscillator, one can apply homodyne least similar performance was found. und sie sind dabei unschädlich wie techniques and derive a down-con - This photomixer for 1.55 µm wave- die Strahlung einer Heizung. An - verted signal indicating the THz power. length turns out to be the key for wen dungen erstrecken sich von At HHI, we are implementing this transferring mature telecom technolo- Sicherheit (Erkennen versteckter concept using mature telecom devices gies to THz applications. Waffen oder Sprengstoffe) über and technologies. Ma terial-Inspektion (Isolierung A complete THz system can thus be Space Shuttle Tanks) bis zu spek- The system presently developed (Fig. 3) assembled using compact modules, troskopischen Analysen (biologische is based on two InP chips: The first connected by flexible fibres, measuring Stoffe, Krebs). Derzeitige THz-Sen - comprises a tuneable two-colour laser ultra-fast without mechanical delay der und Detektoren sind groß und source, defining the THz beating fre- lines. Such cheap, compact and fast teuer, aber Chips aus der Tele kom- quency. With the lasing wavelengths systems will open up new applications Entwicklung können zukünftige close to 1550 nm, the use of EDFAs as and markets for THz technology. Systeme billig und kompakt verfüg- booster amplifiers becomes feasible. bar machen. Via electrical tuning of wavelength, [email protected] one can sweep the THz frequency. The new chip also contains integrated electronic photonic phase modulators. These electrically devices THz gap devices radio visible and high-frequency driven modulators light waves 10 GHz 1 THz 100 THz 100 GHz 10 THz tunable time delay LT-InGaAs 1.5 µm laser modulator photomixer Fig.1: Electromagnetic spectrum and THz gap object transmitter t 1 EDFA The THz regime in the electromagnetic spectrum (Fig. 1) totals between 0.3 THz (λ= 1 mm, 1.2 meV) and 30 THz 2 (10 µm, 120 meV). Such frequencies are flexible fibres THz EDFA beyond pure electronics, and the photon energy is too small for room-temperature operated semiconductor lasers and detectors. Thus, practicable technologies are needed for the generation homodyne receiver and detection of radiation in this “THz gap” between electronics and optics. Fig.3: HHI concept with fibre-connected InP chips

Annual Report | Jahresbericht 2006/2007 69 PHOTONIC COMPONENTS

NOVEL TAPERED DFB LASER The fabrication of this laser, named eliminate an optical isolator in specific CSDFB laser, relying on a buried hetero- applications. Tapered 1550 nm DFB lasers have structure (BH), does not involve any 50 been introduced to feature not additional processing steps compared AR / HR only small optical far-field patterns, to standard non-tapered BH-DFB-lasers, 40 AR / cleaved but also high single-mode yield, and standard DFB-gratings without an as-cleaved high slope efficiency, large optical implemented λ/4 phase shift are re - 30 output power and reduced feed- quired. Only the bending of the active back sensitivity. stripe leads to a tilted front facet and 20

thus to a strong reduction of the front 10 Neuartige 1550 nm DFB-Laser mit facet reflectivity. Fabricated CSDFB C W output power (mW) integriertem optischen Taper zei- lasers emitting at 1550nm showed high 0 gen ein schmales Fernfeld, eine yield single-mode operation even in as- 0 50 100 150 hohe Single-Mode-Ausbeute, große cleaved configuration (1 and Fig. 2). current (mA) optische Ausgangsleistung und 25 L = 400 µm reduzierte Rückwirkungsempfind - 60 20 AR / cleaved lichkeit. 50 20 / 50 / 70 / 90 °C 15 40 DFB lasers are key components in fibre- based optical transmission systems to 30 10

provide single wavelength light sources. SMSR (dB) 20 5 With state-of-the-art DFB structures, it C W output power (mW) is hardly possible to simultaneously ful- 10 417 laser 89 % yield 0 fil the range of parameters required or 0 0 20 40 60 80 100 desired for such devices. We have 0 100 200 300 400 current (mA) introduced a novel DFB laser design laser number Fig. 3: Optical output power of 1550 nm CSDFB that largely overcomes these restric- lasers in dependence of facet coating and tem- Fig. 2: Single-mode yield of 417 as-cleaved perature tions. These lasers not only exhibit high 1550 nm CSDFB lasers chips measured on bar yield and stable-single mode operation, level: red (I = 20 mA), blue (I = 50 mA, black they also demonstrate high slope effi- (I = 100 mA) The superior features of the CSDFB ciency. Inherent to the design is a laser structure invented as outlined tapered active region re sulting in low Due to the tapered active layer, the above will help to substantially lower beam divergence. The devices also optical output power of the front facet the laser chip as well as transmitter show enhanced immunity to optical is higher than that of the back facet, module costs. feedback. resulting in a high slope effciency at the front facet (Fig. 3). The tilted out- [email protected] The main design feature of the DFB put facet leads to an emission angle of laser developed is a curved and tapered about 30°. active stripe incorporating an uniform (non-chirped) DFB grating (Fig. 1). Measured in this direction the FWHM values of the optical farfield in the lateral and vertical direction have been

laser stripe determined to be around 17°. n-contact The modulation bandwidth at

Ith + 20 mA amounts to about 10 GHz 1 M. Möhrle, A. Sigmund, A. Suna, L. Mörl, at 20 °C and 7.5 GHz at 90 °C. These W. Fürst, A. Dounia, W.-D. Molzow,“High values are virtually identical to those Single-Mode Yield, Tapered 1.55 µm DFB Lasers p-contact for CWDM Applications”, Proc. 31th Europ. of similar ordinary DFB lasers. Optical Conf. on Optical Communications (ECOC feedback measurements revealed that 2005), Glasgow (UK), paper Tu 4.5.4. the CSDFB lasers show increased stabil- 2 L. Mörl, M. Möhrle, W. Brinker, A. Sigmund, ity with respect to the optical feedback and N. Grote, “Tapered 1550 nm DFB Lasers with Low Feedback Sensitivity”, 32th Europ. Fig. 1: Microscopic view of a CSDFB-laser power in comparison to standard DFB- Conf. on Optical Communications (ECOC lasers.2 This behaviour may suffice to 2006), Cannes (F), paper Mo 3.4.3

70 Annual Report | Jahresbericht 2006/2007 PHOTONIC COMPONENTS

HORIZONTAL CAVITY SURFACE 0 both facets are effectively AR-coated, T = 20 °C EMITTING (HCSE) DFB LASERS l = 50 mA the single-mode yield of these devices L = 300 µm is very high. - 20 Vertically emitting DFB lasers have as-cleaved + 30 been developed involving an inte- 1.0 grated 45° deflection mirror. This - 40 + 20 0.9 0.8

type of laser combines the advan- a tive intensity (dB) 0.7 tages of ordinary DFB lasers and of rel + 10 - 60 0.6 common vertical cavity surface 0 0.5 emitting lasers (VCSEL). Y (deg) 0.4 1285 1290 1295 1300 - 10 0.3 wavelength (nm) 0.2 DFB-Laser mit horizontalem Laser- - 20 0.1 °C = 20 50 70 90 resonator und vertikaler Emission 0 10 - 30 mittels eines integrierten 45°-Spie- - 30 - 20 - 10 0 10 20+ + 30+ gels zeigen stabilen Single-Mode- 8 X (deg) Betrieb und hohe Ausgangs leis - Fig. 3: Optical farfield in vertical direction of 6 tung. 1300 nm HCSE DFB lasers

4 The fabrication costs of conventional The present devices have been realized edge emitter DFB lasers are to a large output power (mW) 2 L = 300 µm with an emission wavelength of around extent dominated by the facet coating as-cleaved 1300 nm.1 Output power, temperature process, characterization and selection 0 behavior and optical farfield are identi- of the devices on bar-level. 0 4080 120 cal to that of traditional edge emitting current (mA) DFB-BH lasers (Fig. 2 and Fig. 3). The

On the other hand, with conventional Fig. 2: Emission spectra (top) and optical maximum modulation bandwidth of VCSELs this problem is avoided be - output power characteristics of 1300 nm the devices was determinded to be cause all these steps are conducted on HCSE DFB laser about 11GHz at 20 °C and 7.5 GHz at wafer-level. However, for a lot of appli- 90 °C which should enable at least cations VCSELs cannot provide enough The fabricated HCSE-DFB laser consists 4.25 Gbps of uncooled operation over single-mode optical power, especially of a buried heterostructure (BH) based that temperature range. at elevated temperatures in uncooled horizontal DFB laser structure with an operation. Furthermore, it may be integrated 45°-deflection mirror on Summing up, the developed HCSE-DFB almost impossible to achieve the wave- each side as shown in Figure 1. The lasers enable full on-wafer processing length accuracy required for DWDM or mirrors have been implemented by a and testing. They demonstrate high CWDM systems with high yield. single chemically assisted ion beam single-mode yield, good temperature

light- etching step. The size of the devices behaviour and high modulation band- emission amounts to 300 µm × 250 µm and are width. The flexible concept of these 45°-mirror p-contact comparable with the chip size of surface emitting DFB lasers can be VCSELs. An index-coupled DFB grating extended to all wavelengths in the with a λ/4 phase shift was employed. 1200… 1670 nm range. At the front facet, the laser light is coupled out vertically, whereas it is The devices may be used to replace active layer backside 45°-mirror with DFB-grating n-contact deflected at the back facet into the VCSELs in applications where particu- Fig. 1: Schematic view of a horizontal cavity substrate, thereby effectively reducing larly high wavelength accuracy and surface emission (HCSE) DFB-laser the reflectivity of this facet. high optical output power are needed.

We have developed the so-called hori- The emission window at the front facet [email protected] zontal cavity surface emitting (HCSE)- is AR-coated by full wafer deposition DFB laser that provides most of the of a suitable AR-coating layer. This advantages of VCSEL whilst main - means that the lasers are fully pro - taining the well-known benefits of or - cessed on-wafer and this also applies dinary DFB structures, especially high to characterization, screening and se- 1 M. Möhrle, A. Sigmund, A. Dounia, L. Mörl, “1300nm Horizontal Cavity Surface Emitting output power, precise wavelength lection, thus warranting the same be - BH-DFB-Lasers for uncooled operation”, Photon. adjustment and integration options. nefits as VCSLs. Due to the fact that Techn. Letters, vol. 18, pp. 962– 964, 2006

Annual Report | Jahresbericht 2006/2007 71 PHOTONIC COMPONENTS

HHI – A ONE-STOP SHOP FOR writing on wafers. The new Vistec PHOTONIC DEVICES EBPG5000plus system installed in 2003 is a modern Gaussian beam vector Relying on its many years of experi- scan. The system is capable of loading ence and expertise in developing and addressing all semi-standard sizes and manufacturing photonic com- of up to 6 inches. A lot of experience ponents, HHI offers a wide range of has been gained in the use of cus- Fig.3: 16-level off-axis DOE generating the services to external customers in- tomer-specific substrates of various FhG-HHI logo: section of DOE-pattern (left), cluding epigrowth, e-beam litho - dimensions, thicknesses, and materials. simulated intensity distribution (right) graphy and processing as well as E-beam compatible CAD is available for design and measurement jobs. transferring device designs to masks for a wide range of applications. Aufbauend auf seiner langjährigen Erfahrung in der Entwicklung und Herstellung photonischer Bauele - mente bietet das HHI externen Kunden eine Vielzahl von Dienst - leistungen an, von der Technologie bis zu Design- und Messaufgaben.

For the growth of epi-wafers, different Fig. 4: 300 µm deep hole etched in InP MOVPE reactors (Aixtron) are in oper - ation focusing on InP related materials Fig. 2: Section of an e-beam written grey tone meet customers’ needs is provided, (InGaAsP, InGaAlAs). Epi-growth on mask along with complete or partial process- 3 × 2 “wafers or 2 – 4” single wafers The e-beam machine is particularly use- ing of wafers and chips. Using CAIBE, can be carried out, supported by real- ful for the fabrication of tailored micro- for instance, dedicated processes have time optical growth monitoring. There structures and micro-optical compon- been elaborated for creating involved is extensive know-how in regrowth ents for customers in research and structures like underetched mirrors for processes and selective area growth, industry. The elements are mainly made lasers, vertical tapers and holes in InP semi-insulating Fe doping, in-situ Cl on quartz glass and silicon for wave- with a depth of even 300 µm. etching and in-situ post growth Zn lengths ranging from the DUV to the diffusion, amongst others. Besides IR region and include binary gratings, conventional material characterization high frequency gratings, refractive tools, secondary ion mass spectroscopy micro-lenses, and Fresnel zone lenses (SIMS) is available, not just for ana - and lens arrays. Further-more, HHI lyzing III-V compounds but also for boasts considerable expertise in de - other materials of interest. signing and structuring special com-

5 puter-generated diffractive optical 10 Q 1.06 MQW elem ents (DOEs) such as beam splitters, 190 nm InP 393 nm 4 beam formers and pattern generators. 10 675 nm Q 1.15 The Iterative Fourier Transform Algo- InGaAs + Q 1.3 186 nm Q 1.15 78 nm 94 nm Fig.5: Automatic wafer probe station for opto- 1000 rithm (IFTA ) is used to design DOEs. electronic devices As 75

c ountr a te ( ps) P 31 100 When it comes to device fabrication, a Last but not least, HHI boasts is a broad complete process line for InP as well as spectrum of measurement equipment 10 for polymer devices is available, includ- available, ranging from back-end test- 0400 800 1200 1600 ing RIE and CAIBE dry etching ma - ing (e.g. wafer probe stations, bar level depth (nm) chines equipped with in-situ moni - laser testing) to high-end measure- Fig. 1: Precise layer thickness calibration of a toring tools, evaporation, sputtering, ments in the electrical and optical do - MQW structure by means of SIMS and CVD deposition processes for main. Equipment for burn-in and aging At HHI, electron beam lithography has metals and insulating films, AR/HR tests will be expanded in the near been the technique of choice for more coating, selective Zn diffusion, depos - future. than 20 years when it comes to gener- ition of AuSn bumps and solder layers, ating lithography masks and for direct- and others. Process development to [email protected]

72 Annual Report | Jahresbericht 2006/2007 PHOTONIC COMPONENTS

CUSTOMIZED PACKAGED DEVICES no warm-up time. Chip fabrication is strength, temp. cycling and accelerated AND QUALIFICATION carried out at HHI, while commercial aging, typically for submounts as an distribution is performed at u2t Pho- assembly “level” for lasers. Further- Some of the advanced components tonics, Berlin. more ESD tests are carried out. developed at HHI have geometrical, electrical, optical or thermal param- The OptoClock 40 GHz contains a eters that surpass the capabilities of packaged, three-section DFB laser of standard packages. Here, novel so- the PhaseCOMB type (phase controlled lutions are developed that can be mode beating, invented at HHI). The qualified by the Telcordia standard device acts as a dc driven optical oscil- for photonic devices. lator, continuously tunable in frequency e.g. from 35 to 50 GHz, and even Für neuartige Devices, deren geo- higher. The oscillation synchronizes to L metrische, elektrische, optische oder an optically or electrically injected PRBS thermische Parameter über die Ver - RZ data signal and delivers a stable P wendbarkeit vorhandener, genorm- clock pulse trace even for strongly ter Gehäuse, hinausgehen, werden degraded input signals. Fig. 4: Chamber for temp. cycling /accelerated aging, LI measurement sphere im HHI spezifische Packages entwickelt, die nach dem Telcordia-Stan - dard für photonische Bauelemente qualifiziert werden können.

sat. absorber gain

gain Fig. 2: Photograph of 40 GHz OptoClock module

phase Ultra-fast synchronization within less heater then 3 ns and bit-rate flexible operation make the OptoClock an attractive solu- Fig. 5: Melt bond wire connection caused by 40 GHz / 1.55 µm tion for optical clock recovery in future; SIPBH DBR SA-MMLD chip an Electrostatic Discharge Test (ESD) DBR flexible burst/packet switched networks. Fig. 1: SEM picture of a monolithic 1.55 µm / 40 GHz mode-locked laser chip (footprint: 150 2000 1.3 mm2, SEM: Scanning Electron Microscope) 1500 1000 120 RT volt a ge (mV) 500 1765 h 30 °C 1000 h 50 °C High performance monolithic 1158 h 80 °C 90 0 0 100 200300 400 500 mode-locked 1.55 µm laser chips for current (mA) 40/43/50 GHz pulse generation, suit- 60 Fig. 3: Pulse stream of injected data and Oh RT 1765 h 30 °C able for different applications in 30 recovered clock opti ca l power (mW) 1000 h 50 °C advanced high speed OTDM/WDM 1158 h 80 °C 0 tele- & data-communications systems Qualification 1 were previously developed ( , Fig. 1). Device samples are selected randomly 0 100 200300 400 500 from a minimum of three wafers and Fig. 6: Light-Current Curves after Accelerated For customers not willing or able to subjected to the standard burn-in step. Aging by different temperatures handle the bare chip, we package The laser diodes, detectors, or modu - these chips into modules. Key charac- lator chips are then tested for optical Both our packaging and our qualifica- teristics are: A very compact chip & and electrical characteristics (Optical tion services are offered to interested module design, generation of short Spectrum, Light-Current and Voltage- customers. and low noise optical pulses (≤ 2 ps), Current Curve, Modulated Output, high pulse-to-pulse phase stability (for FarField Pattern). [email protected] applications of advanced phase modulation formats (D(Q)PSK)!), wavelength The reliability tests for the laser diodes 1 R. Kaiser, B. Hüttl: “Monolithic 40- GHz tunability, low RF power consumption, include mechanical/physical tests, as Mode-Locked MQW DBR Lasers for High-Speed Optical Communication Systems”, IEEE J. Select. long-term, stable and robust operation, well as endurance tests: Mechanical Topics Quantum Electron., Vol. 13, No.1 , no time-consuming adjustments, and shock, vibration, die shear, wire bond pp. 125 – 135, Jan./Feb. 2007.

Annual Report | Jahresbericht 2006/2007 73

INTERACTIVE MEDIA HUMAN FACTORS

Interactive Media – Human Factors

“Being digital” is significantly changing our role as users in the information age. We are rapidly moving from the role of ‘classical’ consumers of media content towards interacting and even content providing users. Interactivity is becoming the key concept of future media.

Broadband networks and novel devices for end users provide access to a sheer endless source of multimedia content – at work, at home and on the move. Formally placing the letter “e” in front of old terms transforms traditional services into eGovernment, eCommerce, and eLearning, offering a completely new level of qualities and possibilities. In addition, the rapidly growing sector of interactive software is delivering new solutions for the individual user. Software packages for creating and managing databases containing text, digital music, photos and videos are part of almost every new PC.

For the pacesetters of the digital future it is essential to recognise new potentials at an early stage and to utilise them in the best possible way. Providing tools and methods that empower users to smoothly interact with the emerging media technologies is a continuous challenge.

Compared to other innovations, interactive media are ex - ceptional. We are confronted with extremely inhomoge- neous groups of users – ranging from professional power users to novices and from kids to the “silver generation”. The rate of innovation is high while standardisation is rather limited.

In close collaboration between partners from science and industry, we are creating solutions for the interactive multimedia systems of the future. Our task is to design next generation man-machine-interfaces, services and applications, providing attractive and user-friendly access to multimedia information.

One of our core competences lies in the creation of novel 3D displays and multimodal sensing devices allowing intuitive, smooth, and rich interaction between users and technology.

In this context we have implemented a set of at-a-distance, non-intrusive interfaces to sense people and to recognise non-verbal inputs through eye movement and hand gestures. Our remote stereo Video Head Tracker detects the 3D position of the eyes at a rate of 120 Hz. Interactive applications including 3D visualisation with motion parallax as well as optical systems can be adapted to the user’s current vantage point without noticeable delay.

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Our patented Video Gaze Tracker is particularly user- awarded the Joseph-von-Fraunhofer-Prize in 2006 and have friendly, since it works without individual calibration. This been nominated for the ICT Prize 2007. means that in interactive applications it is possible to evaluate the user's current point of interest and to anticipate the eGovernment services have been developed in cooper - user's wishes. Moreover, users can directly select interactive ation with the Senate of the Interior of Berlin. Our mobile objects on the screen by simply looking at them. terminal brings government services to citizens – when and where they are needed – in shopping centres, in hospitals, With our multiple-baseline stereo Hand Gesture Tracker and in homes for the elderly. Sensitive personal data are we achieve precise measurements in large interaction spaces transferred via secured wireless interfaces. A queue manage- by cascading sets of inexpensive chip cameras. In Mixed ment system generates information available online about Reality applications users can touch and grab virtual objects how many people are waiting at a particular site, and it floating in front of the 3D screen like they are used to doing sends SMS messages to waiting citizens when they are next with real objects. This new user interface technology has in the queue. been integrated in the Telekom “3D Center” and the adidas “mi Innovation Center”. The “iPoint Explorer”, a large- In order to handle the increasing amount of multimedia screen gesture-based tourist information system showing data we are developing methods for image and video points of interest and travel details (maps, videos, images analysis and annotation. Novel search, filter and visual - and related text) is under development. ization techniques for multimedia data allow users to intuitively browse and search in large video and photo archives. Our sensing people interfaces can be tailored to all rele- The descriptions used were derived from the MPEG-7 stand - vant parameters including range, precision, speed, operating ard. A fast algorithm detects shot boundaries in video foot- conditions and costs. Beyond that, special procedures age, such as hard cuts, dissolves, fades and wipes. This extract and describe personal features and data in digital means that extended video material is automatically sub- video. Such sensing people functionalities are fundamental divided into basic temporal units and each extracted shot is to a range of intelligent-camera applications used in surveil- represented by a key frame in the video asset management lance, biometric-based personal identification and ver- system. Our solution is used as a reference model in the ification, as well as off-line description of video contents. international TRECVID contest. Other features include intui- These technologies are further developed and marketed by tive video-summarization and a camera detection and inter- our spin-off company, the VISaPIX GmbH. pretation method.

We are developing 3D technologies that enable users to In a related project, we are developing security management watch stereoscopic video and 3D computer graphics without and archiving software for event-controlled, MPEG-4 video- special stereo glasses. Our displays outperform competing over-IP applications together with an industrial partner. technologies since they perfectly separate the stereo chan- Events generated e.g. by bar scanners, RFID devices and nels and provide extremely clear, high-resolution pictures automatic licence-plate recognition software are used to (2 × 1600 × 1200 RGB pixels on 30 inch screen). index the MPEG-4 data stream. The software tool allows very fast retrieval in huge datasets containing, for example, At the same time the patented optical system solves the video data captured by thousands of cameras over a period accommodation conflict when users interact with virtual of 30 days and more. objects. This system enables a perfectly seamless mixture of virtuality and reality in Mixed Reality applications. Our In professional cinematographic applications, high demands special 3D flat-screen displays show interactive content in are placed on the quality of the camera view finding photo-realistic quality for desktop and kiosk applications system, which must provide a reliable and comfortable (1600 × 1200 RGB pixels on 21.3 inch LCD screen). evaluation of framing, focus and aesthetic composition under all viewing conditions. For this reason, optical reflex In combination with the Hand Gesture Tracker, users can viewfinders are still preferred over electronic monitors. press virtual keys floating in front of the display (“touch-less On the other hand, electronic viewfinders have their own touch screen”). Moreover, a movable Mixed Reality display advantages: greater flex ibility for remote operation, multi- with integrated video-based object tracking has been devel- viewer capability or display of additional data. To make oped. these advantages available to professional cinematog - raphers, we are working with ARRI to conceive a high defin - “Partners for Innovation” features our display and inter- ition full colour view finder that is based on reflective micro action technology as a “German Star” (one of the 50 most display technology, which can be used as an alternative to groundbreaking innovations “made in Germany”); we were optical viewfinder systems.

76 Annual Report | Jahresbericht 2006/2007 INTERACTIVE MEDIA HUMAN FACTORS

Products in information technology should be adapted to spiel von Mensch und Technik unmittelbar betreffen. the needs and abilities of their future users. Because successful marketing depends on user-friendly products, it is Im Vergleich zu anderen technischen Neuerungen nehmen important to consider human factors when developing new die interaktiven Medien eine Sonderstellung ein, hat man products. Even at the earliest stages of conception and es doch hier mit einer ausgesprochen inhomogenen Nutzer - design, user-centred design helps create products that are gruppe zu tun, die z.B. professionelle Poweruser, absolute user-friendly and marketable. Our Human Factors Test Laien, Kinder und die „Silver Generation” umfasst; die Center (HFTC) offers tests and consultation for all phases of Geräte und Anwendungen sind äußerst vielfältig; die In no - developing information technology services, systems, and vationsrate ist hoch – gleichzeitig gibt es nur wenige devices. Our main goal is the fine-tuning of technology to Standards, auf die man aufbauen kann. the needs of the user, in order to provide easy to use and satisfactory products. In enger Zusammenarbeit mit Partnern aus der Industrie und Wissenschaft entwickeln wir Lösungen für die multimediale Our services include the analysis of user requirements, Interaktion und Kommunikation der Zukunft. Unser Ziel ist experts’ assessment for the usability of products and proto- die Schaffung von Endgeräten, Systemen und Anwendung - types, usability tests, design studies, accessibility of web en, die einen attraktiven und nutzerfreundlichen Zugriff auf content for people with disabilities, and consultation in multimediale Daten und interaktive Dienste ermöglichen. strategic decisions concerning future product lines. Eine unserer Kernkompetenzen liegt auf dem Gebiet neuar- In addition, the HFTC supports developers in designing web- tiger 3D-Displays und multimodaler Interaktions sys te - sites which meet with the special requirements of handi- me, die ein intuitives, reibungsloses Zusammenspiel von capped users (Web Accessibility). Mensch und Technik ermöglichen.

In 2006 we tested the functionality and efficiency of a In diesem Zusammenhang entwickeln wir eine umfassende German version of a filter developed by the Internet Con- Palette von Technologien zur berührungslosen Erfassung von tent Rating Association (ICRA) to protect children from nicht-verbalen Eingaben des Anwenders, z.B. durch Blick - potentially harmful material on the Internet. bewegungen und Handgesten. Unser Video Head Tracker ortet die Augen des Menschen (3D-Koordinaten) mit einer Interaktive Medien – Human Factors Messrate von 120 Hz. Damit lassen sich sowohl interaktive Anwendungen als auch optische Systeme verzögerungsfrei Die Digitalisierung der Medien verändert mit Macht unsere und präzise an den aktuellen Blickwinkel des Betrachters Rolle als Nutzer: Wir werden von schlichten Konsumenten anpassen. eines weitgehend vorgefertigten Medienangebots mehr und mehr zu aktiven Anwendern, die selbst Beiträge erstellen Unser patentiertes Verfahren zur Messung der Blickrichtung und mit anderen austauschen. Die Interaktivität entwickelt erfordert keine individuelle Kalibrierung und ist daher sich zum alles bestimmenden Merkmal künftiger Medien. besonders nutzerfreundlich. In interaktiven Anwendungen kann damit auf den aktuellen Interessenschwerpunkt des Breitbandige Netze und neuartige Endgeräte verschaffen uns Betrachters geschlossen werden. Interaktive Objekte können Zugang zu den schier unerschöpflich sprudelnden multime- durch einfaches Anblicken ausgewählt werden. dialen Informationsquellen des Internet – am Arbeitsplatz, am heimischen PC und unterwegs. Traditionelle Dienste Mit unserem Stereo Hand Tracker erreichen wir durch bekommen durch das vorangestellte kleine „e” (wie in Kas ka dierung einfacher Chipkameras eine hohe Messge - eCommerce, eLearning, eGovernment) völlig neue Quali- nauig keit in einem großen Erfassungsbereich. In Mixed- täten und Möglichkeiten. Hinzu kommt die nicht minder Reality-Anwen dungen können damit virtuelle Objekte, die rasant wachsende Vielfalt interaktiver Softwareanwendun- dank stereoskopischer Verfahren scheinbar vor dem Display gen. Programme zur Erstellung eigener Datenbanken mit schweben, wie Realobjekte mit der bloßen Hand „berührt” selbst gestalteten Texten, digitaler Musik, Urlaubsbildern und werden. Diese neue Technologie wird bei der Interaktion mit Videos gehören inzwischen zur Bonussoftware bei jedem dem Telekom „3D Center” und dem adidas „mi Innovation PC-Kauf. Center” eingesetzt. Mit dem „iPoint Explorer”, einem gesten- basierten Reiseführer, können Touristen die Umgebung be - Für die Schrittmacher der digitalen Zukunft gilt es, Potentiale liebter Reiseziele auf einem Großbildschirm erkunden. Diese frühzeitig zu erkennen und in der bestmögliche Weise nutz- Informationen werden mittels multimedialer Inhalte (Videos, bar zu machen. Als besondere Herausforderung stellen sich Bilder, Geo-Daten, 3D-Stadtmodelle) vermittelt. dabei die Bereiche heraus, die das reibungslose Zusammen -

Annual Report | Jahresbericht 2006/2007 77 INTERACTIVE MEDIA HUMAN FACTORS

Unsere Tracking-Technologien können hinsichtlich aller Um die zunehmende mediale Datenflut zu bewältigen, ent- relevanten Parameter wie Erfassungsbereich, Präzision, wickeln wir ein Bild- und Video-Retrieval-System der Ge schwindigkeit, Einsatzbedingungen und Kosten maßge- nächsten Generation. Neuartige Such-, Filter- und Visualisie - schneidert werden. Darüber hinaus ermöglichen spezielle rungsverfahren ermöglichen eine wesentlich einfachere Verfahren eine automatisierte Beschreibung von Personen - Sichtung und Nutzung von großen Video-Datenbanken, daten in digitalen Bild- und Audioquellen hinsichtlich des ohne dass dabei auf manuell erstellte Annotationen zurück- Aufenthaltsorts, der Aktivität und Identität und sonstiger gegriffen werden muss. Die Beschreibungen der Bild- und personenbezogener Informationen. Sensing-People- Tondaten sind vom MPEG-7 Standard abgeleitet. Ein schnel- Funktionalitäten mit intelligenten Kameras bilden so unter ler Algorithmus erkennt Szenenübergänge wie z.B. harte anderem die Grundlage künftiger sicherheitstechnischer Schnitte und verschiedene Arten von Überblendungen in Systeme. Diese Technologien werden von unserer Ausgrün - Videofilmen. Auf diese Weise wird umfassendes Videoma - dung, der VISaPIX GmbH, weiter entwickelt und vermarktet. terial automatisch in Szenen zerlegt. Jede einzelne Szene wird durch ein repräsentatives Bild in der Datenbank des Wir entwickeln 3D-Technologien, die das Betrachten von Video-Verwaltungssystem dargestellt. Im internationalen stereoskopischen Videobildern und 3D-Computergrafiken TRECVID Wettbewerb wird unsere Lösung als Referenzmo - ohne spezielle Stereobrille ermöglichen. Unsere Displays dell eingesetzt. Unser System verfügt zudem über eine zeichnen sich durch eine brillante und besonders augenver- intuitive Methode zur Video-Zusammenfassung und ein trägliche Stereowiedergabe aus. Beispielweise ermöglicht Verfahren zur Kamera-Analyse und Interpretation. unser Verfahren eine perfekte Trennung der Stereokanäle bei extrem hoher Bildauflösung (2 × 1600 × 1200 RGB-Bild- In einem verwandten Projekt entwickeln wir gemeinsam mit punkte auf einem 30 Zoll Bildschirm). einem Industriepartner eine Sicherheits-Management und Archivierungs-Software für ereignis-gesteuerte MPEG-4- Das patentierte optische System löst zugleich den Akkom - Video-Over-IP-Anwendungen. Dabei werden Ereignisse, die mo dationskonflikt bei der Interaktion mit virtuellen Objekten z.B. von Bar-Scannern, RFID-Geräten oder einer automati- und bietet so eine perfekte, nahtlose Mischung von Virtu - schen Erkennungssoftware für Kfz-Kennzeichen erzeugt alität und Realität in Mixed-Reality-Anwendun gen. werden, zur Indizierung eines MPEG-4-Datenstroms verwen- Spezielle 3D-Flachbildschirme können als Arbeitsplatz display det. Die Software ermöglicht eine schnelle Suche und Navi - oder 3D-Kiosk gestaltet und interaktive Inhalte in fotorealis- gation in riesigen Datensätzen (z.B. in Videodaten, die von tischer 3D-Qualität dargestellt werden (1600 × 1200 RGB- tausenden von Videokameras über einen Zeitraum von 30 Bildpunkte auf einem 21,3 Zoll Bildschirm). Tagen aufgezeichnet wurden).

In Verbindung mit unserem Hand Tracker kann der Anwen - Bei der professionellen Aufnahme von Kinofilmen werden der virtuelle Auswahltasten betätigen, die vor dem Display sehr hohe Anforderungen an die Qualität des Kamera- schweben („touch-less touch screen”). Darüber hinaus Suchersystems gestellt: der Sucher muss unter allen Be- wurde ein bewegliches Mixed-Reality-Display mit integrier- trachtungsbedingungen eine zuverlässige und komfortable tem videobasierten Objekt-Tracking entwickelt. Be wertung des Bildrahmens, der Schärfe und der ästheti- schen Komposition ermöglichen. Aus diesem Grund werden Unsere Display und Interaktionstechniken wurden durch die optische Sucher immer noch gegenüber elektronischen Aufnahme in die Liste der „German Stars” (50 bahnbre- Sucherdisplays bevorzugt. Andererseits bieten elektronische chende Innovationen „Made in Germany”), mit dem Sucher eine Reihe von Vorteilen – unter anderem eine grö- Joseph-von-Fraunhofer-Preis 2006 und durch die ßere Flexi bilität bei der Fernbedienung, die Möglichkeit zur Nominierung für den ICT Prize 2007 ausgezeichnet. Aus wer tung durch mehrere Betrachter und die Anzeige zusätzlicher Daten. Wir arbeiten daher gemeinsam mit ARRI Unter Beteiligung der Berliner Senatsverwaltung für Inneres an der Entwicklung eines hochauflösenden vollfarbigen haben wir ein Endgerät entwickelt, mit dem mobile Bürger - Suchersystems, das auf einer reflektiven Mikrodisplay-Tech - berater eGovernment-Dienstleistungen in Einkaufszen - nologie basiert, um diese Vorteile für den professionellen tren, in Krankenhäusern und Altenheimen erbringen kön- Einsatz nutzbar zu machen. nen. Dabei werden auch sensible personenbezogene Daten über entsprechend gesicherte Luftschnittstellen transportiert, Produkte der Informationstechnik lassen sich umso besser bargeldlose Zahlungen abgewickelt und Dokumente erstellt. vermarkten, je mehr sie auf die Bedürfnisse und Fähigkeiten Ein integriertes Warteschlangen-Managementsystem zeigt ihrer zukünftigen Nutzer zugeschnitten sind und je mehr die über das Internet die momentane Zahl der Kunden an den menschlichen Aspekte (human factors) berücksichtigt wer- verschiedenen Standorten an. Eine SMS benachrichtigt die den. Bereits bei der Konzipierung neuer Produkte erhöht ein Wartenden, sobald sie an der Reihe sind. nutzerzentriertes Vorgehen die Chance der späteren erfolg -

78 Annual Report | Jahresbericht 2006/2007 INTERACTIVE MEDIA HUMAN FACTORS

reichen Vermarktung. Unser Human Factors Test Center (HFTC) bietet als einen besonderen Service Tests und Bera - tung in allen Phasen der Entwicklung von Diensten, Sys te - men und Endgeräten der Informationstechnik.

Unser Leistungsangebot umfasst die Analyse von Nutzeran - forderungen, die Evaluierung von Produkten und Prototypen durch Human Factors Experten, sowie Usability Tests mit Versuchspersonen, Designstudien und die Beratung bei strategischen Entscheidungen über Produktlinien.

Darüber hinaus unterstützt das HFTC Anbieter von Web an - geboten bei der Erstellung barrierefreier Websites, die auch den erhöhten Anforderungen von Behinderten gerecht werden.

In 2006 haben wir die Funktionalität und Wirksamkeit der deutschen Version einer Filtersoftware getestet, die von der Internet Content Rating Association (ICRA) zum Schutz von Kindern vor potentiell schädlichem Material aus dem Internet entwickelt wurde.

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Interactive Media – Human Factors

Head of Department Siegmund Pastoor Phone +49(0)30/310 02-210 Fax -212 e-mail [email protected]

Secretary Regina Kiesewetter Phone -211 e-mail [email protected]

Marketing Klaus Schenke Phone -675 e-mail [email protected]

Media Management Thomas Meiers Phone -218 e-mail [email protected] eGovernment, Human Factors Test Center Lothar Mühlbach Phone -237 e-mail [email protected]

Advanced Displays René de la Barré Phone -345 e-mail [email protected]

Man Machine Interaction Klaus Hopf Phone -581 e-mail [email protected]

Computer Graphics Sylvain Renault Phone -274 e-mail [email protected]

Computer Vision David Przewozny Phone -629 e-mail [email protected]

The novel Free2C_digital 3D display technology (implemented in a Medical Display of ACL GmbH) features user tracking without mechanical devices. The multiplex scheme is digitally switched at subpixel level, in order to adapt the stereoscopic “sweet-spot” to the user's current viewing position.

The 3D Media Center supports, among else, life-size video communications in 3D. The applications are controlled intuitively and without physical contact via the hand-gesture recognition system integrated below the display.

Our Handheld Photobrowser allows content-based similarity search for images. Using a few example images selected with The iPoint Explorer is an interactive travel information the pointing device, the browser retrieves images with similar system for public places, such as train stations or airports. colour and textural features. The system employs our contact-free gesture interaction technology, allowing users to virtually explore popular We have developed a programmable hardware interface for travel areas by just pointing at a large screen from a 3D displays which accepts the most commonly used stereo 2 distance. The current prototype provides multimedia signals (separate left and right-eye video as well as time- content like geographical data, photorealistic 3D models, sequential stereo) and delivers the display-specific multiplexed videos and pictures of interesting sights and tours in output signals via DVI. Via USB, the multiplexing scheme can Berlin. be adapted to the user’s viewing position.

80 Annual Report | Jahresbericht 2006/2007 INTERACTIVE MEDIA HUMAN FACTORS

ADVANCES IN INTERACTIVE 3D channel the left and right-eye views to order to adapt the stereoscopic “sweet- VISUALIZATION the appropriate eye. The Free2C dis- spot” to the user’s viewing position. plays allow free 3D viewing with the The Free2C 3D display is one of the naked eye since the optical elements Interactive Applications most advanced developments in for selective addressing of the two eyes Figure 2 shows an interactive system autostereoscopic (glasses-free) 3D are integrated in the display device. developed for Deutsche Telekom. The technologies available on the mar- This type of display is hence much prototype services offer 3D video ket. This special head-tracking more comfortable for the viewer than telephony, 3D video show, and 3D lenticular-screen display principle conventional stereo techniques. shopping. To the user, the control ele- allows free head movements in ments (virtual buttons, changeable three dimensions at unprecedented The displays employ special micro- objects) seem to hover in front of the image quality. The digital Free2C optical plates mounted in front of the display. A computer-vision system concept introduced in 2006 applies imaging screen. For example, small which recognises hand gestures is inte- a special pixel-shift technology for lenticular lenses, each of them covering grated below the display. Hence, the head tracking. This approach pro- two pixel columns, guide the light applications are controlled intuitively vides almost symmetrical resolution beams to the viewer's left and right and without physical contact via the in landscape format and is easier eye, respectively. The left and right virtual user interface. and cheaper to produce than a dis- views are displayed on alternate pixel play with moving parts. The Free2C columns. This means that the viewer’s displays are available for desktop left eye will see pixels of the left view and information-kiosk applications. only whilst the right eye sees the right view only. Das Free2C 3D Display definiert einen Meilenstein in der Entwick - A dual-axes voice-coil tracking system lung autostereoskopischer Displays adjusts the lens plate at a precision of (3D ohne Stereobrille). Mit einer about 10 µm allowing both lateral and Auflösung von 1600 × 1200 RGB frontal head movements while watch- Bildpunkten zählt es nicht nur zu ing the stereo images. The integrated den höchstauflösenden 3D-Displays; video tracker senses the viewer’s eye Fig. 2: The Telekom 3D Center demonstrates fascinating communications experiences in 3D mit Free2C gelang es darüber hin- positions at 120 Hz. (with courtesy of Deutsche Telekom) aus, dem Betrachter einen freien Bewegungsspielraum in drei Dimen - sionen zu ermöglichen. Die in 2006 eingeführte Pixelshift-Technologie liefert eine nahezu symmetrische Auflösung im Querformat und ist einfacher und billiger zu fertigen als ein Display mit bewegten Teilen. Das Free2C Display ist als Desktop- Monitor und als Infoterminal ver- fügbar.

Fig. 3: The Free2C Kiosk combines innovative 3D displays provide different perspec- 3D display and gesture recognition technologies tive views to the left and right eye. Like with elegant terminal design in natural vision, the differences in perspective are immediately used by the Kiosk systems must stand out by offer- visual system to create a vivid, compel- ing simple intuitive handling and eye- ling and efficient sensation of depth in Fig. 1: The novel digital Free2C 3D technology catching design. The Free2C Kiosk natural and computer-generated implemented in a display of ACL GmbH shown in Figure 3 is an eye-catching scenes. attraction for any museum, convention The most recent implementation (see hall, airport, trade show, shopping mall Special user-worn devices like stereo Figure 1) operates without mechanical or store. glasses or head-mounted miniature dis- tracking. Instead, the multiplex scheme plays are usually required to optically is digitally switched at subpixel level, in [email protected]

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VIDEO-BASED MAN MACHINE identifying the spatial relations of INTERFACES multiple objects in a three-dimensional scene. In normal communications, the Interaction with digital media gaze direction signals special interest in should be as easy, convenient and the object or the person being looked intuitive as possible. We have de- at. veloped a family of non-intrusive, video-based devices that allow Our non-intrusive and marker-less video- users to interact in a very natural based devices sense, track and interpret way. The devices sense and recog- such gestures. The software is designed Fig. 1: In the adidas “mi Innovation Center”, nise hand gestures (pointing, push- for a variety of cameras ranging from users select video objects of the adidas Info - space and costumize the shoe aestetics by ing and grabbing), the user’s head low-cost to high-end devices, allowing simply pointing a finger to the screen. The movements and the point of gaze. users to find the best compromise be- gesture interface is mounted above the user, Another technology recognises tween performance and price. The allowing unhindered interaction (with courtesy of adidas AG). objects and estimates the relative devices communicate via established viewing position and angle. These protocols and software interfaces. technologies can be combined to create multi-modal interfaces. The head tracking interface accepts simple USB or fire-wire cameras. For Die Interaktion mit digitalen Me- applications where tracking latencies dien sollte einfach, angenehm und and speed are an issue, a special intuitiv sein. Wir haben eine Familie 120 Hz high-speed camera is available. von berührungsfreien video basier- The high-end stereo version allows pre- ten Geräten entwickelt, die sehr cision measurements (in the millimetre natürliche Formen der Interaktion range) in three-dimensions. A multi- ermöglichen. Die Geräte erfassen user head tracker is currently under Handgesten, Kopfbewegungen und development. den Blickpunkt. Eine weitere Tech - nologie erkennt Objekte und schätzt Pointing with the fingertip is an easy die relative Betrachtungsposition and natural way to interact with und den Blickwinkel. Diese Techno - objects shown on a (3D) display. Our logien lassen sich zu multimodalen hand gesture interface measures the Schnittstellen kombinieren. 3D position of the user’s fingertip at a Fig. 2: The object tracker camera on top of the monitor captures the real scene. The software rate of 50 Hz (Fig. 1). Simple gestures is recognizing the position and orientation of A major objective in advanced man- intuitively used to start and stop an a known object (in this examle a loudspeaker) machine-interface design is to supple- action, to select, move and rotate an and correctly matching the edges and a virtual texture. All procressing is done in realtime. The ment or even replace traditional input object are recognized in real-time. user can freely move the articulated monitor. devices such as keyboards and mice Several trackers can be daisy-chained, with more natural interaction systems. in order to in crease the tracking range. speech recognition engine can infer the This includes the use of speech input context and react more reliably. as well as machine-vision techniques The gaze tracking interface applies a capable of sensing people and inter- special cornea reflex method. It senses The video-based object tracker com- preting their gestures. the user’s current gaze point (the inter- putes the position and orientation of section of the lines-of-sight of both known, geometrically defined objects. For example, hand gestures can be eyes) at a rate of 50 Hz with a single Markers on the object are not required. useful for selecting interactive objects stationary camera. Due to the wide- These data are used in mixed-reality on a display by pointing to them (de- angle optics, the user may move in a applications to overlay 3D graphical ictic indications) or touching them with range of 30 × 30 × 30 cm. Gaze tracking objects and to annotate information a finger, for moving irrelevant objects can be used to trigger context sensitive about the scene on live video (Fig. 2). aside, and for indicating the direction applications (e.g. when looking re - The object tracker can also be used as of simulated ego-motion in interactive peatedly at certain screen elements) as a flexible interacting device to manipu- scene walkthroughs. Head movements well as in usability re search, in order to late virtual objects with real tools. are a natural means of inspec ting an study the visual reaction of test sub- object from different perspectives or of jects. Knowing the user’s gaze vector, a [email protected]

82 Annual Report | Jahresbericht 2006/2007 INTERACTIVE MEDIA HUMAN FACTORS

ROLLOUT OF CITIZEN-FRIENDLY as recreational centres, public libraries, Some municipalities have ordered a MOBILE GOVERNMENT SERVICES hospitals, homes for the elderly, and “mobile citizen services case” at HHI, also shopping malls. similar to that one developed within After successfully completing the the framework of the MoBüD project “Mobile Citizen Services (MoBüD)” (e.g. Köln, Bremen and Bergisch project, HHI is now supporting the Gladbach). rollout of mobile government (mGovernment) services. Among other things, this is accomplished by providing municipal administrations with HHI’s know-how and expertise. In some cases, local governments ordered a customized version of the Fig. 1: Sample of a mobile office of citizen special case for carrying all the nec- services essary mobile equipment that had been developed by HHI within the The technology and services were framework of the MoBüD project. tested within the framework of field An EU project that aims at analysing trials in the cities of Berlin and Magde - the market perspectives for intro- burg. More than 3,000 citizens partici- ducing similar mGovernment ser- pated in these trials. The results of the vices in other European countries accompanying scientific analysis per- has started. formed by HHI showed a high accept- ance of mobile citizen services among Nachdem das Projekt „Mobile Bür- customers (citizens) as well as among gerdienste (MoBüD)“ erfolgreich users of the equipment (mobile citizen abgeschlossen wurde, treibt nun consultants). Fig. 2: The mobile office of citizen services case das HHI die Einführung von mobilen Verwaltungsdiensten (mGovern- One of the essential technological con- The marketing of HHI’s technological ment) voran. Dies wird u.a. dadurch ditions for mobile citizen consultancy and Human Factors expertise in terms erreicht, dass das HHI sein Know- was secure access to Berlin’s MAN. The of mGovernment is supported – how und Fachwissen öffentlichen project used a VPN for this purpose. In among other things – by Vodafone, Verwaltungen anbietet. In einigen addition, a security concept/protection which recommends it to their public Fällen haben Verwaltungen eine profile was generated in which all authorities customers. angepasste Version des Spezial-Kof - potential security threats and counter- fers zum Transport der notwendi- measures to be taken were listed in The dissemination of the MoBüD con- gen mobilen Komponenten bestellt, detail. GPRS, WLAN and UMTS were cept on an international level was sup- der vom HHI im Rahmen des MoBüD- used for wireless communication be- ported by various means, such as pre- Projekts entwickelt wurde. Ein EU- tween the mobile terminals and the sentations and demonstrations of the Pro jekt zur Analyse der Marktpers - servers in Berlin’s MAN. Three versions mobile citizen services case at various pek tiven für die Einführung ähn- of the mobile terminal (“office of citi- conferences and fairs – for example, in licher mobiler Verwaltungsdienste zen ser vices cases”, containing a lap- South Africa. in an deren europäischen Ländern top computer, a printer, a payment ter- wurde begonnen. min al etc.) were developed and tested Negotiations with the European Com - in user trials in terms of their usability. mission have led to a project that aims HHI was a partner in (and during the at marketing analyses for the introduc- second phase the leader of) a project Since the end of the project, the dis- tion of mGovernment services similar dealing with mobile citizen services semination and rollout of mGovern- to MoBüD in other European countries. (German acronym: MoBüD). The pro - ment services in general and mobile HHI is the project co-ord inator of this ject enabled a spectrum of governmen- citizen services in particular have been project. tal services for citizens in Berlin and on HHI’s agenda. As an example, HHI Magdeburg by means of mobile equip- has provided various other German [email protected] ment and technologies. With the help cities and municipalities with consult - of mobile terminals, citizen consultants ancy in terms of mobile governmental offered their services at locations such services and technologies.

Annual Report | Jahresbericht 2006/2007 83 INTERACTIVE MEDIA HUMAN FACTORS

WORKBENCH3D – A DEVELOPMENT (API) that bridges the gap between Tele kom 3D Center (page 81) use these TOOL FOR INTERACTIVE MULTI - novel or unconventional input devices features of Workbench3D. MEDIA APPLICATIONS and various multimedial output technologies, including sound, voice, 3D The Workbench3D scenegraphs describe Workbench3D is a development visualization, and force feedback. The the 2D/3D multimedial environments tool which helps software designers various input signals are managed by which are then rendered in arbitrary create interactive multimedia appli- the software in a consistent way to windows in realtime. Elements such as cations with the Microsoft Visual form a multimodal user interface. cameras, lights, geometric primitives, Studio® 2005 environment. It sup- enhanced interactive objects and exter- ports the latest DirectX® technol - The Workbench3D API consists of nal model files can be dynamically ogies as well as multiple (mixed) 2D a .NET library written in C# and a managed including all appending attri - and 3D display systems and video- corresponding core application which butes like transformations, colours and based man-machine-interface tech- manages the plugins and drivers. In textures. An event and animation sys- nologies. this way, interactive systems (including tem helps the developer to define new virtual and mixed reality systems) can interactions. The application can like- Workbench3D ist ein Entwicklungs- be created for a variety of fields in wise appear playful or functional. werkzeug für Softwaredesigner science, industry, culture and entertain- zum Erstellen von interaktiven ment (Figures 2 and 3). It is especially The simple manner to write new appli- Multimedia-Anwendungen unter easy to write experimental applications cations with integrated 3D technologies der Microsoft Visual Studio® 2005 (for example in usability research) and provides the designer and ergonomist Umgebung. Es unterstützt die neu- demonstrators which can be used at with more room for creating user- esten DirectX®-Technologien sowie trade shows. friendly, experience orientated and 2D- und 3D-Mehrfachbildschirm- forward-looking computer systems. Systeme und video-basierte Mensch- Workbench3D supports visualization on Maschine-Interaktionstech nologien. mutliple displays (multiview, combined 2D / 3D displays), communication be - Recent advances in 2D and 3D display tween computers via Microsoft .NET technologies along with the increasing Remoting, animation techniques, real- power and performance of computer time editing of model attributes, envir- graphics processing units are allowing onmental sound as well as voice input multimedia communications designers and output using an avatar and the to create fascinating visual experiences. force feedback device PHANToMTM Moreover, novel video-based control from SensAble Inc. The inheritance devices sensing, for example, hand methods of the .NET Framework make gestures, head movements and even it possible to enhance the API with other Fig. 2: Plugin for managing, viewing and the user’s eye gaze offer completely technologies. The API includes state-of- rotating 3D models new ways of interacting with the con- the-art components like scenegraphs, tents displayed. 3D objects with inheritance, event systems and multitasking / multithreading.

The graphical elements to be used in a multimedia application can be de - signed with well-known computer graph ics programs like 3ds MAX, Corel Draw and Visual Studio tools. 3D models must use a DirectX readable format (the X-file format). It is possible to create textual, graphical as well as Fig. 3: Plugin for a molecular designer which is capable of loading any PDB file, modifying it photo and video objects (including live and then saving it Fig. 1: The Workbench3D API bridges the gap stereocamera streams) which can be between novel multimodal input and multi- mapped in real time onto animated 3D [email protected] media output technologies surfaces. For example, the Infospace As shown in Figure 1, Workbench3D is application of the adidas mi Innovation an Application Programming Interface Center shown on page 82 and the

84 Annual Report | Jahresbericht 2006/2007 INTERACTIVE MEDIA HUMAN FACTORS

TEMPORAL VIDEO SEGMENTATION FOR DIGITAL VIDEO ANALYSIS

Video is a rich source of information. But when it comes to search and retrieval applications, video is inherently more difficult to handle, for example, than text. In the same way as text is organized in a nat - ural hierarchy of characters, words, sentences, paragraphs and chapters, etc., video is organized into frames, sub-shots, shots and scenes of a film or programme. For video visualization, abstraction, navigation, search and retrieval, automatic discovery Fig. 1: Example frames for a hard cut and a dissolve shot transition and a shot with camera of the temporal video structure on motion (top to bottom row) different hierarchical levels is an We have built a temporal video segmen- used as the reference system providing important prerequisite. The units to tation system for intermediate sub-shot, the mas ter shot reference for different be used in indexing, search and shot and scene levels. It currently pro- TRECVID search and retrieval tasks. retrieval are not marked until tem- vides segmentation algorithms for shot A schematic overview of the shot poral video segmentation has been and sub-shot levels and will be extend- detection system is shown in Figure 2. carried out. Using the hierarchical ed to include scene segmentation. structure, it is possible for users to For some applications in video analysis, video file browse through video in the same search and retrieval, the segments on way as they can browse text in shot level may be too coarse because video books or magazines. detector shots with camera motion, for example, may contain diverse visual con-

Ein Video enthält eine Fülle von In - calculation of tent. See the bottom row in Figure 1. global pixel, formationen. Aber beim Suchen edge and A finer segmentation into sub-shots is und Wiederfinden von Videoma te - histogram necessary as this allows indexing and difference rial ist Video deutlich schwieriger statistics finding of all different and relevant zu handhaben als z.B. Text. So wie parts of a video sequence. We have für Text verschiedene Hierarchiestu - hard cut dissolve and wipe implemented and successfully tested fen wie Buchstaben, Wörter, Sätze, detector fade detector detector algorithms based on visual content Absätze und Kapitel existieren, gibt similarity and on motion analysis. es für Video Einzelbilder, Sub-Shots, results Shots und Szenen innerhalb eines program Fig. 2: Overview of the shot detection system level news feature film commercials feature film Films oder einer Sendung. Für An- wendungen der Visualisierung, A shot is the sequence of frames taken scene scene scene scene scene scene level 1 2 3 4 5 Navi gation und Suche in Videos ist by one camera act. It basically consists shot eine automatische Erkennung der of the frames recorded between hitting shot 1 shot 2 shot 3 zeitlichen Struktur auf den unter- the Record and Stop button on a cam- level schiedlichen hierarchischen Ebenen era. We have developed a fully auto- sub-shot sub-shot sub-shot sub-shot sub-shot sub-shot eine wichtige Voraussetzung. Durch matic and fast-shot detection system level 1 2 3 4 5 die zeitliche Videosegmentierung that can be used for video archiving frame frames werden die Einheiten für Analyse, and retrieval applications. The system level Indizierung und Suche festgelegt. can detect hard cuts as well as gradual Fig. 3: Hierarchy for temporal video Die hierarchische Struktur ermög- transitions like dissolves, fades and segmenation licht es dem Nutzer, Video zu sich- wipes. In the international TRECVID ten und sich einen Überblick zu ver- shot detection contest, it proved to be The final hierarchy for temporal video schaffen, wie er es von Text in Bü- one of the fastest systems and demon- segmentation is shown in Figure 3. ch ern und Magazinen gewohnt ist. strated excellent detection performance. In 2005, 2006 and 2007 it was [email protected]

Annual Report | Jahresbericht 2006/2007 85 INTERACTIVE MEDIA HUMAN FACTORS

HANDHELD PHOTOBROWSER WITH SIMILARITY SEARCH

The Handheld Photobrowser is a software tool for managing large image sets on handheld devices (such as PDAs and camera phones) running on Microsoft Windows Mobile OS. A special feature of this programme is content-based similarity search for images. Using a few example images selected by the user, the programme retrieves images with similar colour and textural features. Fig. 2: Visual Search, left: selected query images, right: search result from a 7.000 images database

Der Handheld-Photobrowser ist ein albums and search the images in terms The Image Dialog box allows an image Programm zur Archivierung großer of various criteria: name, creation date to be displayed in its original size. The Bildbestände auf mobilen Geräten and time and – especially – visual simi- user may zoom in and out of the (PDA, Kamera-Handy). Eine Beson - larity. For visual searches, the user can image displayed and browse one after derheit dieses Programms ist die directly select images for a Query-by- the other through the images currently inhaltsbasierte Suche, bei der an Example search from thumbnail lists loaded in the thumbnail view. The pro- Hand von Beispielbildern nach ähn- displayed or can use complete albums gram runs on all devices that use MS lichen Bildern (hinsichtlich Farbe to search for album similarity. Windows Mobile Operating Systems, und Textur) gesucht werden kann. like e.g. the current Windows Mobile In order to find visually similar images, 5.0. the user selects one or more query images which share similarities with We are developing a special web ser - the search goal he or she has in mind. vice for content-based image retrieval. One does not need to think in terms of With this service, the handheld device image parameters, such as colour, but (as well as any other device connected in more semantic terms (e.g. select a to the Internet) will be used for visu- ship, if you want to look for other alization and interaction only, while the ships and you have a suitable ship image collections will be stored on a image available). Then press the visual server. A face-finding algorithm will be search button in the search bar. The integrated into this service, counting first page of the resultant list of images the number of faces in each image and is loaded into the thumbnail view imme- allowing the user to retrieve facial diately after the search is finished. You images. can subsequently refine your search by choosing more images from the result In connection with our video shot list or deselecting others. boundary detection software, the search algorithms of the photo browser Albums are collections of images which can also be used for content-based Fig. 1: Graphical User Interface of the Handheld can – but do not necessarily have to – video retrieval. Photobrowser showing thumbnails of the images contained in the database be located within the same file folder. Our software tool offers the possibility [email protected] The program is capable of managing to create, save, load and delete huge amounts of images, limited only albums, to add and remove images by the size of the storage space avail- from existing albums. The “Album able. Search” functionality also allows the user to use complete albums as input The Handheld Photobrowser allows the for visual searches. user to view images, group them in

86 Annual Report | Jahresbericht 2006/2007 INTERACTIVE MEDIA HUMAN FACTORS

Annual Report | Jahresbericht 2006/2007 87

IMAGE PROCESSING

Multimedia services for all, no matter where, no matter when

Information Technology (IT) is the driving force behind the Information Society of the 3rd millennium. It is penetrating almost all areas of business and private life. Digital technologies help people in their business and private affairs, and digital technologies are being used more and more to entertain people.

Multimedia is one of the key elements in Information Technology, because video, images, speech, sound and ancillary data are needed for a growing number of services in the office, at home and in public areas.

The vision of Multimedia services for all, no matter where, no matter when is the driving force behind the R&D developments of the Image Processing Department. This department has built up key competencies and an internationally recognized reputation in the following areas:

• Image and video coding • Multimedia transmission (IP, mobile, DVB) • 3D image and video processing • Image and video analysis, computer vision • Image and video synthesis, computer graphics • Hardware design and implementation of multimedia systems (video, audio, graphics) • ASIC and IP design • Image and video enhancement

One of the main activities was the development of the new video coding standards SVC (Scalable Video Coding) and MVC (Multi View Coding), for which the proposals submitted by HHI have been selected as the basis for stand - ardization within ISO/MPEG and ITU-T. For both SVC and MVC, extensions of H.264/AVC are used. HHI has played an important role in the development of this standard.

SVC allows the generation of a scalable video stream, from which partial streams with lower temporal and/or spatial resolution or lower quality can be extracted. Such a scheme can be used at the transition from a broadband fixed network to a narrowband mobile network or for the distribution of video to terminals with different resolutions (e.g. TV and HDTV).

On the other hand, MVC is used to encode video signals from camera arrays, where each camera looks at the same scene from a different viewing point. Such coding schemes will be used in future 3D video and TV systems.

Following the successful introduction of H.264/AVC as the most advanced and efficient video coding standard, which

Annual Report | Jahresbericht 2006/2007 89 IMAGE PROCESSING

has been deployed worldwide for applications ranging from A special highlight was the presentation of a 5 k multi-pro- mobile TV up to HDTV, the next generation in video coding jection system developed by HHI with a horizontal resolution is under preparation. The target of H.265 is cutting the data of 5000 pixels during the 2006 football World Champions - rate by half whilst keeping image quality constant. First hip. Football scenes were recorded using two Arri D20 digit - promising approaches towards H.265 using analysis/synthe- al film cameras (one camera for each half of the stadium) sis coding have been presented by HHI. and stitched together to a wide screen panorama. As the cameras were completely fixed, the scenes contained no In addition, the implementation of real time systems for camera motion and this created a completely different mobile TV was one of the main activities in the department. viewing experience on the 20 m screen. It was similar to A number of very successful cooperations with industrial sitting in a stadium and following the match by turning the partners on the transmission side (audio/video streaming head. The projection system is based on the CineCard and server for DVB-H and DMB) as well as on the receiving side Cinebox which allow the decoding, smooth blending and (decoder/player for DVB-H/DMB) have been carried out. cascading of an arbitrary number of video streams with up The highlight of these activities was the development of a to HD resolution, so that almost unlimited resolution can be DVB-H playout with statistical multiplex in cooperation with obtained. Rohde&Schwarz which allows the number of programs per TV channel to be increased by 40 %. HHI has been nomin - 3D modelling of objects, persons or head and shoulders is ated for the Innovation Award Berlin Brandenburg 2006 for now a mature technology that permits the development of this development. The joint product has currently no compe- new services. Thanks to 3-dimensional computer models, tition on the world market and is used in the world’s first video clips can be transmitted to mobile phones or pocket commercial DVB-H service in Italy where the number of pro- PCs even over low speed network connections. Different grams was increased from 9 to 16. Meanwhile HHI’s tech- technologies to capture and model 3D scenes and objects nology is used in many countries all over the world. have been developed using single or arrays of still or video cameras with or without structured light. One of the appli- Based on HHI’s encoder/server system, a crypting framework cations using these technologies is a virtual mirror which (IsmaCryp + Simulcrypting) has been developed which sup- allows the user to exchange his real shoes captured with a ports a number of proprietary key providers. This system is camera for virtual shoes which the user can design himself. also in operation in many parts of the world. This system has been exhibited in a newly opened shopping center of Adidas at the Champs-Élysées in Paris. Further in - Another activity is research into video streaming methods stallations are planned in Beijing and San Francisco in 2007. for ad-hoc networks. HHI has developed a method based on SVC in connection with Unequal Error Protection which Free Viewpoint Video (FVV) is one of the long-term, vision- shows excellent performance and robustness even under the ary research topics in the Image Processing Department. In most severe transmission conditions. a FVV system, scenes are captured with an array of cameras and the user can interactively navigate through the scene, With these activities combined, HHI can offer its customers selecting his preferred viewing point. However, a number of a diverse portfolio in compression technologies, ranging challenging innovations in the fields of multi-view scene from software implementations to hardware architectures, capturing, scene analysis, 3D scene representation, multi- complete transmission systems and a number of applications view postproduction, multi-view coding, multi-view trans- such as wireless and wired video streaming or video surveil- mission and multi-view rendering are required for such a lance. system. During the reporting period, first technical work has begun and several processing steps have been implemented. Computer graphics and image processing technologies have Several camera arrays and capture devices as well as a com- reached a state that allows the development of novel multi- plete camera dome have been installed. media applications and services. The new challenge in the field of television, electronic cinema and multimedia is called In the area of hardware development three important mile- immersive telepresence with which users should feel that stones have been reached. On the one hand, a H.264/AVC they are immersed in the scene. Large displays with high decoder system for mobile applications has been imple- resolution similar to cinema, IMAX or CAVE projections in mented on a FPGA platform and has then been further VR applications are required. In this context, there are a developed as an ASIC. This ASIC has extremely low power number of activities in the Image Processing Department in - consumption whilst offering high computational power. On cluding applications like 3D videoconferencing, Digital Cin - the basis of these components, a complete DVB-H terminal ema, ultra-high resolution projection systems, 3D-TV, and has been developed in order to demonstrate performance in Free Viewpoint Video. a realtime application.

90 Annual Report | Jahresbericht 2006/2007 IMAGE PROCESSING

On the other hand, the development of a realtime, FPGA- SVC erlaubt die Generierung eines skalierbaren Videostroms, based system for format conversion has been completed. aus dem Teilströme extrahiert und decodiert werden kön- It is based on the format conversion algorithm HiCON devel- nen, so dass ein Video geringer örtlicher und/oder zeitlicher oped at HHI. With this system, the realtime conversion from Auflösung bzw. geringerer Qualität entsteht. Dies kann z.B. TV to HDTV with simultaneous change of the frame rate beim Übergang von einem breitbandigen Festnetz auf ein from 50 to 60 Hz can be demonstrated. schmalbandiges Mobilfunknetz oder bei der Verteilung von Video auf Terminals unterschiedlicher Auflösung (z.B. TV A third activity concerns maskless lithography. The develop- und HDTV) eingesetzt werden. Hingegen erlaubt MVC die ment of three boards has been completed for which two effiziente Codierung von Videosignalen, die mit Kamera- ASICs have also been developed. One board carries a data Arrays aufgenommen werden, wobei jede Kamera von buffer with throughput rates of up to 10 Gbps, another einem anderen Blickwinkel auf die gleiche Szene schaut. contains optical receivers and the third is used to demultiplex Solche Verfahren sollen in zukünftigen 3D-Video und TV- the mask data. With these three components, the basis for Systemen zum Einsatz kommen. a maskless lithography process has now been created. Nach der erfolgreichen Einführung von H.264/AVC als z. Z. Multimedia-Dienste für jeden an jedem Ort und leistungsstärkstem Videocodierstandard, der sich bei Appli - zu jeder Zeit ka tionen von Mobil-TV bis hin zu HDTV als weltweit durchgesetzt hat, befindet sich nun der nächste Schritt der Video- Die Informationstechnologie (IT) ist die treibende Kraft hinter co dierung in der Vorbereitung. H.265 soll eine Halbierung der Informationsgesellschaft, IT zieht in fast alle Gesell- der Datenrate bei gleicher Bildqualität ermöglichen. Ein viel schaftsber eiche, die geschäftlichen und in die privaten ein. versprechender Ansatz hierfür ist die Analyse-Synthese Digitale Technologien unterstützen uns im Beruf und zuhau- Codie rung, wofür das HHI erste Ergebnisse präsentiert hat. se und tragen immer mehr zu unserer Unterhaltung bei. Darüber hinaus war die Implementierung von Echtzeitsys - Multimedia ist eine der Schlüsselkomponenten in der Infor - temen für mobile TV-Systeme einer der Schwerpunkte der mationstechnologie, da Bilder, Video, Sprache, Ton und Arbeiten. Hierbei gab es sehr erfolgreiche Kooperationen Zusatzdaten für eine steigende Zahl von Diensten im Büro, mit mehreren Industriepartnern sowohl für die Sendeseite im Haushalt und in öffentlichen Bereichen verwendet wer- (Audio-Video-Streaming-Server für DVB-H und DMB) als den. auch für die Empfangsseite (Decoder/Player für DVB-H/DMB). Als Highlight kann die gemeinsam mit Rohde&Schwarz Die Vision Multimedia-Dienste für jeden an jedem Ort und (R&S) durchgeführte Entwicklung eines DVB-H Playouts mit zu jeder Zeit ist auch die treibende Kraft hinter den F&E- statistischem Multiplex angesehen werden, die es gestattet, Aktivitäten der Abteilung Image Processing. Diese verfügt eine um 40 % höhere Anzahl von DVB-H-Programmen in über Kernkompetenzen und international anerkanntes einem Fernsehkanal zu übertragen. Für diese Entwicklung Renommée in den folgenden Bereichen: wurden das HHI und R&S für den Innovationspreis Berlin- Brandenburg 2006 nominiert. Dieses auf dem Weltmarkt • Bild- und Videocodierung konkurrenzlose Produkt wurde auch erfolgreich im weltweit • Multimedia-Übertragung (IP, mobil, DVB) ersten kommerziellen DVB-H-Dienst in Italien eingesetzt, • 3D-Bild- und Videoverarbeitung wobei die Anzahl der Programme bei gleicher Qualität von • Bild- und Videoanalyse, Computer Vision 9 auf 16 erhöht werden konnte. Inzwischen konnte das • Bild- und Videosynthese, Computer-Grafik System weltweit vermarktet werden. • Hardware-Entwurf und Implementierung von Multimedia-Systemen (Video, Audio, Grafik) Darauf aufbauend wurde ein Verschlüsselungssystem für • IP-Design für ASICS, FPGAs und „embedded“ DVB-H implementiert (IsmaCryp + Simulcrypting), das unter- Prozessoren schiedliche Provider von proprietären Verschlüsselungsverfah - • Bild- und Videoverbesserung ren unterstützt. Auch dieses System befindet sich in vielen Ländern im kommerziellen Einsatz. Eine der Hauptaktivitäten im Berichtszeitraum war die Ent- wicklung der neuen Videocodierstandards SVC (Scalable Als weitere Aktivität in diesem Bereich sind Video-Streaming- Video Coding) und MVC (MultiView Coding), bei denen sich Verfahren über ad-hoc-Netze zu nennen. Hierfür hat das jeweils die Vorschläge des HHI als Basis für die Standardi sie - HHI ein auf SVC basierendes Verfahren in Verbindung mit rung bei ISO/MPEG bzw. der ITU-T durchgesetzt haben. Für ungleichförmigem Fehlerschutz entwickelt, das durch seine beide Verfahren werden Erweiterungen des vom HHI maß- Robustheit auch bei schwierigsten Übertragungsbedingun- geblich mit entwickelten Standards H.264/AVC verwendet. gen besticht.

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Mit diesen Aktivitäten kann das HHI seinen Kunden ein brei- selbst entworfenen Schuhe auszutauschen, so dass sich der tes Portfolio an Videocodierungs- und -übertragungstechno- Betrachter mit diesen Schuhen im Display sieht. Dieses Sys - logien bieten. Diese reichen von Software-Implementie run - tem wurde 2006 erstmals in einem neu eröffneten Verkauf- gen über Hardware-Architekturen bis hin zu kompletten Center von Adidas auf den Champs-Élisées in Paris gezeigt Übertragungssystemen und einer Anzahl von Anwendungen und soll in 2007 u.a. in Peking und San Francisco installiert wie dem drahtlosen und drahtgebundenen Video-Streaming werden. oder wie der Videoüberwachung. Free Viewpoint Video (FVV) ist eines der visionären Fernziele Computer-Grafik und Bildverarbeitungstechnologien haben der Arbeiten in der Abteilung. Bei FVV werden Szenen mit einen Stand erreicht, der die Entwicklung neuartiger Multi- vielen Kameras aufgenommen und der Nutzer soll langfristig media-Anwendungen und Dienste ermöglicht. Die neue die Möglichkeit erhalten, interaktiv durch diese Szenen zu Herausforderung in den Bereichen Fernsehen, elektronisches navigieren. Hierfür ist eine Vielzahl von technischen Inno- Kino und Multimedia heißt immersive Telepräsenz. Immersiv vationen in den Bereich Videoaufnahme mit Kamera-Arrays, bedeutet in diesem Zusammenhang, dass der Nutzer das der Szenenanalyse, der 3D-Szenrepräsentation, der Multi - Gefühl hat, sich in der Szene zu befinden. Große Displays view-Postproduktion, der Multiview-Codierung, der Multi- mit sehr hoher Auflösung, ähnlich wie im Kino, im IMAX view-Übertragung als auch der Multiview-Darstellung oder bei CAVE-Projektionen in VR-Anwendungen werden (Rendering) notwendig. Im Berichtszeitraum wurden erste hierfür benötigt. In diesem Kontext gibt es in der Abteilung technische Voraussetzungen für die verschiedenen Arbeits - Image Processing verschiedenste Aktivitäten, die 3D-Video - schritte geschaffen. So wurden mehrere Kamera-Arrays und konferenzsysteme, digitales Kino, ultra-hochauflösende ein kompletter Kamera-Dome im HHI installiert. Projektionssysteme, 3D-TV und Free Viewpoint Video ein- schließen. Im Bereich der Hardware-Entwicklungen wurden drei wichtige Meilensteine erreicht. Zum einen wurde ein H.264/AVC Ein besonderes Highlight war dabei die Präsentation eines Decoder-System für mobile Anwendungen erfolgreich auf am HHI entwickelten 5k-Multiprojektionssystems mit einer einer FPGA-Plattform implementiert und dann zu einem horizontalen Auflösung von 5000 Bildpunkten während der ASIC weiterentwickelt. Dieses ASIC zeichnet sich durch sei- Fußballweltmeisterschaft 2006. Hierbei wurden Fußball - nen sehr geringen Stromverbrauch bei gleichzeitig hoher szenen gezeigt, die mit zwei parallelen digitalen Kinoka - Rechenleistung aus. Auf dieser Basis wurde auch ein kom- meras Arri D20 (je eine Kamera für eine Stadionhälfte) auf- plettes DVB-H-Terminal entwickelt, um die Leistungsfähig - genommen und zu einem Breitbildpanorama verrechnet keit der entwickelten Komponenten in Echtzeitan wendun - wurden. Da die Kameras fest installiert waren, weshalb es gen zu demonstrieren. keinerlei Kamerabewegung gab und die Szenen auf eine 20m Leinwand projiziert wurden, ergab sich ein völlig neues Andererseits wurde die Entwicklung eines FPGA-basierten Seherlebnis, das dem Live-Erlebnis im Stadion entspricht. Echtzeitsystems zur Formatkonversion abgeschlossen. Dieses Basis dieses Multiprojektionssystems sind die am HHI entwi- basiert auf dem im HHI entwickelten bewegungskompensie- ckelten CineCard und CineBox, die die Decodierung, das renden Videokonversionsalgorithmus HiCON. Mit diesem weiche Überblenden und die Kaskadierung von beliebig System konnte u. a. die Echtzeitkonversion von TV nach vielen Videosignalen mit bis zu HD-Auflösung erlauben, HDTV bei gleichzeitiger Wandlung der Videorate von 50 wo durch prinzipiell beliebige Auflösungen erreicht werden nach 60 Hz demonstriert werden. können. Eine dritte Aktivität betrifft die maskenlose Lithographie. Die 3D-Modellierung von Umgebungen, Objekten, Personen Hierfür wurde die Entwicklung von drei Boards abgeschlos- oder Kopf- und Schulteransichten ist eine Technologie, die sen, wofür auch zwei ASICs entwickelt wurden. Dabei han- mittlerweile ihren Kinderschuhen entwachsen ist und nun delt es sich um einen Datenpuffer mit Durchsatzraten von die Entwicklung völlig neuer Dienste ermöglicht. So können 10 Gbit/s, ein Board mit optischen Receivern und eine z.B. dank 3-dimensionaler Computer-Modelle Videoclips mit Demultiplexeinheit für die Maskendaten. Somit wurden extrem geringen Datenraten auf Handys und Pocket-PCs wesentliche Grundlagen für den Aufbau eines maskenlosen übertragen werden. Es wurden verschiedenste Technologien Lithographieprozesses geschaffen. zur Aufnahme und Modellierung implementiert, die mit einer oder mehreren Einzelbild- oder Videokameras und ggf. mit strukturiertem Licht arbeiten. Eine mit solchen Techno- logien entwickelte Anwendung ist ein virtueller Spiegel, der es gestattet, mit einer Kamera aufgenommene Schuhe an den Füßen des Betrachters auf einem Display durch andere,

92 Annual Report | Jahresbericht 2006/2007 IMAGE PROCESSING

Image Processing

Head of Department Ralf Schäfer Phone +49(0)30/310 02-560 Fax +49(0)30/392 72 00 e-mail [email protected]

Secretary Andrea Semionyk Phone +49(0)30/310 02-561 e-mail [email protected]

Image Communication Thomas Wiegand Phone -617 e-mail [email protected]

Computer Vision & Graphics Peter Eisert Phone -614 e-mail [email protected]

Immersive Media & 3D-Video Peter Kauff Phone -615 e-mail [email protected]

Embedded Systems Benno Stabernack Phone -661 e-mail [email protected]

Architectures & Implementations Maati Talmi Phone -293 Fax -692 e-mail [email protected]

Marketing Martin Hahn Phone -393 Fax -213 e-mail [email protected]

Software Engineering & Support Jens Güther Phone -606 e-mail [email protected]

At the adidas performance store in Paris, customers can try on sports shoes virtually – without first having to ask for the correct size or the other shoe.

Video services and video based information systems in the vehicle. Live performance of a multi projection system for Digital Camera (5k projection) during the FIFA- Worldcup 2006 in a cinema theatre.

Video codecs and streaming solutions for mobile communications.

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GESTAVATAR – REAL-TIME ANIMA- TION OF AVATARS operator avatar animation customer parameter (FAP’s, BAP’s)

New video communication applica- video analysis filter tions, such as virtual chat rooms or handsegmentation video in and tracking web-based customer-care-services, 2D feature network player display become reality where the user is feature point conversion tracking replaced by an artificial representa- character tive, a so-called avatar. The avatar viseme viseme generator conversion is animated by the user’s hand and network interf ac e network interf ac e audio in head motion which are registered audio grabber speaker by a web-camera mounted on the display. The system presented runs Fig. 1: Block diagram of the customer care application robustly on a standard PC in real- time in any environment.

Neue Videokommunikationsanwen- dungen, wie virtuelle Chat-Räume oder Internet-basierte Kundenbera- tungsdienste, bei denen der Nutzer durch eine künstliche Figur, dem sog. Avatar, dargestellt wird, gewin- nen zunehmend an Realität. Der Avatar wird dabei durch die Hand- und Kopfbewegung des Benutzers Fig. 2: Animated avatar and related video image showing a recognized gesture animiert, die mittels einer auf dem Diplay montierten Web-Kamera laps or self-occlusions of skin-color avatar (Fig.3). The focus of the com- registriert wird. Das hier vorgestell- regions or in the case of hand that dis- plete system is oriented towards user te System ist echtzeitfähig und läuft appear partly or completely. Speech is friendliness and usability. This is why robust auf einem gewöhnlichen PC also analyzed and visual representa- no specific calibration or initialization und in beliebiger Umgebung. tions of lip movements, so-called are required. The user can behave visemes, are extracted. These visemes normally without any restrictions. Real-time video analysis leads to many are used to provide a realistic and syn- new applications, such as video surveil- chronous animation of the avatar’s lip lance, person identification or motion movements. capture for the entertainment industry but also embodied systems where the Hand positions, head rotation and user interacts through human-machine- visemes are expressed as body anima- interfaces with interactive applications. tion parameters (BAP) as defined in the MPEG-4 video standard (Part 2 (Visual)) In the novel video communication sys- (refer to Fig.1). The resulting animation tem presented, an avatar is animated parameters are sent to the receiving on the basis of the live motion and the side with very low bandwidth require- speech of the operator. Due to this, ments compared to full video transmis- communication is enhanced by visual sion. Fig. 2 shows the animated avatar cues without transmitting live video (left) and the related input video (right). Fig. 3: Segmented silhouette of a victory streams. The latter is often not desired gesture including black lines assigning the for privacy protection reasons. The system also provides additional finger orientation features, such as gesture recognition The main features for segmenting and due to the high quality segmentation [email protected] tracking hands and head are skin-color results based on skin color. A set of ten and motion. This provides robust and different gestures from the American temporarily stable recognition results, Sign language set are currently recog- even in critical situations such as over- nized and immediately shown by the

94 Annual Report | Jahresbericht 2006/2007 IMAGE PROCESSING

STATISTICAL MULTIPLEX FOR uncompressed StatMux inter modul burst side MOBILE TV USING DVB-H audio and video communication information (digital / analog) (TCP / IP) (UDP / TCP / IP)

The efficiency of television broad- StatMux master cast systems scales with the number RTP / RTCP StatMux encoder AAC audio + of programs that can be transmit- H.264 / AVC video MPEG2 TS ted for a given video quality. One key element for efficient transmis- c e sour sion is the use of the most ad - R&S DIP010 vanced video coding standard a udio & video H.264/AVC to which HHI has made R&S NV7000 Fig. 1: DVB-H statistical multiplex system with Rohde&Schwarz TS-multiplexer and sender substantial contributions. When used in a multi-program environ- The bit rate for a video signal that is HE AAC (high efficiency advanced ment, the efficiency of H.264/AVC- encoded at a fixed level of quality audio coding) encoder with a constant based transmissions can be in - typically varies depending on the video bit rate. The video signal is compressed creased using a statistical multiplex content. These variations of video con- by an H.264/AVC encoder with a vari- system. HHI has implemented such tent and with that bit rate appear over able bit rate controlled by the statistical a system for DVB-H playout as a time within one program and also multiplex master. In order to meet real- real time encoder cluster with up among programs. Ideally, all programs time constraints with a maximum of to 32 video and audio (HE AAC) should be delivered to the viewer at a rate-distortion performance, the video encoder units, by which savings of constant and acceptable quality at all encoder is equipped with dynamic up to 40 percent of the bit rate times. Hence, the approach of a statis- complexity control. With respect to the compared to constant bit rate en- tical multiplex is to share the overall bit CPU resources available, this control coding can be achieved. The single rate in such a way that a constant scales the complexity of the most time encoder units are controlled by a max imum level of quality is achieved consuming video encoder algorithms central unit called StatMux Master. for all programs. The statistical multi- (motion estimation and mode decision) plex system for a DVB-H play-out parti- to gain a maximum CPU load. The Die Effizienz von Fernsehsendesys- tions a fixed bit rate into several vari- compressed video and audio elemen- temen steigt mit der Anzahl der able bit rate channels, according to the tary streams are put into RTP packets Pro gramme die bei einer vorgege- content of the input signals, gaining a and sent via UDP/IP to an MPEG2 benen Qualität übertragen werden max imum of subjective video quality transport stream (TS) multiplexer. können. Ein Schlüssel zur effizien- for all services. ten Video-Übertragung ist die Ver - DVB-H compliant transport streams wendung des modernsten Video- The statistical multiplex system is or- contain timing information that con- Encoders H.264/AVC, zu dessen gan ized as a three stage synchronous trols an essential power saving standby Entwicklung das HHI substantielle pipeline process. In the first stage, the mode at the receivers. A DVB-H trans- Beiträge geliefert hat. Bei simulta- content of each video signal is ana- port stream multiplexer typically extracts ner Übertragung mehrerer Program- lyzed by the encoder units and the this timing information by collecting me kann die Leistungsfähigkeit results are sent to the statistical multi- incoming RTP-packets in a special input H.264/AVC-basierter Systeme durch plex master. In the second stage, the buffer which introduces a significant ein statistisches Multiplexsystem master calculates a bit rate distribution additional delay. In our system, the gesteigert werden. Das HHI hat ein depending on the analysis results of statistical multiplex master sends side solches System für DVB-H in Form the first stage in order to achieve max - information about the RTP streams to eines Echtzeit-Encoder-Verbundes imum subjective quality for all services the DVB-H transport stream multiplexer mit bis zu 32 Video- und Audio- and the bit rate allocations are sent in order to completely remove this Encoder Einheiten entwickelt, das back to each of the encoder units. In delay. With this side information, a im Vergleich zu einem Encodersys - the third and final stage, the encoder DVB-H transport stream multiplexer tem mit konstanten Bitraten eine units compress the video signals at the can determine the required timing in - Reduzierung der Bitrate um bis zu bit rates provided by the statistical formation without extra buffering and 40 Prozent erzielt. Die Encoder wer- multiplex master. can construct the transport stream den durch eine zentrale Einheit, immediately. den StatMux Master gesteuert. The video and audio source signals are grabbed with professional input de - [email protected] vices. The audio signal is encoded by a

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HARDWARE-ACCELERATED H.264/ To solve the problems of broadcasting the software can be identified and AVC-DECODING FOR DVB-H/DMB A/V content to small portable devices, optimized. This method can be used, TERMINALS the new DVB-H standard has been for instance, to reduce the execution developed and also considers aspects time of some software modules by The new DVB-H standard allows of power consumption aspects at the up to 30 % merely by reducing the broadcasting of audio/video (A/V) RF-front end in mobile devices. DVB-H amount of memory accesses. In order content to mobile terminals. Such applies H.264/AVC for compressing to boost system efficiency further, devices are subject to severe restric- video data. The high coding efficiency hardware acceleration can be applied. tions concerning computational of H.264/AVC places high demands on power and power consumption. computational power, data transfers A specialized hardware architecture has The most demanding part in this and hence means high power con- been derived from the profiling results respect is the H.264/AVC decoding sumption. This does not cause any for a system-on-chip implementation of of video content. Software opti- prob lems for processors used in cur- the DVB-H terminal. For the decoder mizations and hardware acceler- rent PC platforms. However, mobile modules with the highest computa- ations for the H.264/AVC decoder DVB-H terminals will be built around tional complexity, coprocessors have have been developed with this embedded processors which may not been designed, namely for the de - restriction in mind. fulfill these requirements. blocking filter, the interpolation filter within the motion compensation and Der neue DVB-H Standard ermög- for the inverse integer transformation. licht die Rundfunkübertragung von A special processor has been devel- digitalem Audio/Video-Material auf oped for the algorithmic parts of the mobile Empfangsgeräte. Diese Ge - decoder which require only a small rä te sind bzgl. ihrer Rechenleis tung portion of control flow but are not und der zulässigen Verlustleistung suitable for implementation as copro- stark eingeschränkt. Die kritische cessors. It is based on a RISC architec- Komponente in dieser Hinsicht ist ture and is extended by SIMD instruc- der H.264/AVC Decoder zur Ver- tions tailored to video processing. arbeitung der Videodatenströme. Furthermore, a DMA controller has Software Optimierungen und Hard- Fig. 2: Companion chip for H.264 decoding been added for efficient data transfer warebeschleuniger helfen diesen with HW-accelerators and a SIMD-processor to the coprocessors and a video output Beschränkungen gerecht zu werden. interface for direct connection of a dis- When implementing a pure software- play device. Mobile multimedia became a popular based DVB-H receiver using a typical topic using mobile phones, PDAs or embedded processor, e.g. Intel’s similar devices, see Fig. 1. One of the PXA270, the required frequency for major drawbacks of such systems is H.264/AVC decoding totals about that content is delivered in a point-to- 420 MHz (320 × 240 pixels, 384 kbps). point configuration (e.g. UMTS) which Such a high frequency leads to high is not efficient in terms of the band- power consumption and therefore to width required of the network cell. short battery runtimes. In order to create a lowpower device, methods must be applied, either for optimizing the software or by employing special hard-

ware architectures. Depending on the Fig. 3: Prototype platform for a DVB-H terminal, processor architecture, different mech- tested in a field-trial in Berlin anisms are available for this and are mainly based on SIMD (Single Instruc - This H.264/AVC companion chip (Fig. 2) tion Multiple Data) instructions. The has been manufactured as an ASIC in a thus inherent data parallelism can be UMC 0.18 µm process with ~500 k exploited and memory accesses can be gates and a maximum clock frequency reduced. Based on extensive profiling of 120 MHz, whereas for the DVB-H of instruction count and data transfers, scenario only ~50 MHz are required. Fig. 1: Mobile DVB-H reception with a PDA and which have been performed by an in- an external RF-frontend on an SD-IO card house profiling tool, the hot spots in [email protected]

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MULTI-SOURCE STREAMING FOR which is based on Raptor forward error high path outage probability makes it ROBUST VIDEO TRANSMISSION IN correction codes. While the reception impossible to reliably transmit a video MOBILE AD-HOC NETWORKS of a single stream in the presented stream by simply applying known tech- approach guarantees base quality only, niques from the wired or cellular trans- This contribution presents a multi- the combined reception enables play- mission environment. Therefore, this source streaming approach which back of video at full quality and/or work proposes a robust multi-source increases the robustness of real- lower error rates. Network types like video streaming protocol for reliable time video transmission in non wireless networks based on the real-time video streaming, which main- infrastructure-based Mobile Ad-Hoc Wireless LAN (WLAN) 802.11 a,b,g – ly solves the route-loss problem in case Networks (MANET). By combining specifications are becoming increasing- of real-time streaming over MANETs. Scalable Video Coding (SVC) with a ly popular and suitable for real time The basic approach is to enhance reli - rateless channel coding techniques transmission. These network types ability by using different sources at the on the application layer, the pro- allow very high data rates, but usually same time with different, independent posed transmission scheme allows only if the distance between receivers representations of the media layers, for source and path diversity to and senders is sufficiently short. Longer resulting in a network multiple descrip- cope with the route loss problem ranges can be achieved, for example, tion approach (Fig.2). To realize this in MANETs. by multi-hop transmission: In contrast property, the video stream is divided to the inefficient case where many into different layers using SVC. SVC Wir zeigen einen Ansatz für robus- nodes are available in a certain area provides layers with different import- te Videoübertragung in infrastruk- with a plain access point or hot-spot- ance for video reconstruction and a turlosen Mobilen Ad-Hoc Netz - based network structure, the Ad-Hoc different percentage of the complete werken (MANETs) basierend auf mode of WLAN nodes can increase stream bit-rate. SVC is used in connec- Scalable Video Coding (SVC) und coverage and may save costs for infra- tion with a novel UPLP scheme based einem ratenlosen vorwärts gerich- structures. MANETs (an example is on recently proposed Raptor Forward teten Fehlerkorrekturcode. Die shown in Fig.1) make use of all nodes Error Correction (FEC) codes for pro- hohe Pfadverlustwahrscheinlichkeit in a mobile network as routers in order tecting different layers with different in MANETs wird durch eine Diver- to build up short-time dynamic net- importance. By combining SVC with sität in Quellen und Netzwerkpfa- work infrastructure. a Raptor code-based Unequal Packet den abgefedert. Loss Protection, a distribution of linear- source source ly independent representations of the A 6 Emerging non infrastructure-based net- 8 D video stream among servers can be 1 9 work types like MANETs are becoming 3 achieved. By receiving independent suitable platforms for exchanging / streams from the different sources, 10 sharing real-time video streams thanks 4 7 the layer-wise reconstruction of the to recent progress in routing algo- 2 scalable video is realized. The more rithms, throughput and transmission source 5 client source network streams are received from E bit-rate. MANETs are characterized by C independent sources, the better the highly dynamic behavior of the trans- Fig. 1: Mobile ad-hoc network playable video quality is at the re - mission routes and path outage prob - ceiving client. abilities. This contribution presents a multi-source streaming approach which [email protected] increases the robustness of real-time UPLP-stream video transmission in MANETs. For this transmitter 1 UPLP-stream transmitter 2 purpose, video coding as well as chan- UPLP-stream nel coding techniques on the applica- receiver tion layer are introduced, exploiting UPLP-stream the multi-source representation of the transferred media. Source coding is based on the Scalable Video Coding transmitter L transmitter 3 (SVC) extension of H.264/MPEG4-AVC Fig. 2: Multi source transmission – principal with different layers for assigning importance for transmission. Channel The dynamic behavior of MANETs T. Schierl, et al, “SVC-based multisource streaming for robust video transmission in mobile ad coding is based on a new Unequal means some additional challenges for hoc networks”, IEEE Wireless Communications Packet Loss Protection (UPLP) scheme high quality video transmission: The Magazine, Vol. 13, No. 5, IEEE; October 2006.

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A NEW APPROACH BASED ON a fallback option. The synthesized pic- the area to synthesize is typically sur- TEXTURE ANALYSIS AND tures are submitted to the video quality rounded by one or more textures, SYNTHESIS FOR H.265 VIDEO assessment unit (VQA) for detection of which complicates the synthesis task CODING possible spatial or tem poral impair- even more, as the motion in the recon- ments in the reconstructed video. In structed sequence must appear natu- Future content-based video coding the subsequent iterations, the degrees ral. Rigid texture synthesis yields very frameworks will provide significant- of freedom of the system are explored compact side information and works ly higher compression gains than by a state machine (SM) for SI opti- remarkably well. Non-rigid texture syn- known efficient, block-based, hy - mization. thesis is more complex and based on brid video codecs such as H.264/ computer graphics approaches. It is AVC. New methods like Analysis/ applicable to generic video sequences V TA Q TS VQA SI Synthesis coding strategies may find including sequences with significant their way into the next codec gen- camera motion. eration, namely H.265, provided SM that a mature concept is at hand. The quality of the reconstructed video Over the past five years, HHI’s Fig. 1: Principle of the generic closed-loop sequence is evaluated based on a per- Image Processing department has analysis-synthesis approach ceptual measure developed at HHI. The been actively involved in providing measure performs significantly better the proof-of-concept for the afore- The TA yields regions that can be re - than PSNR at a slightly increased com- said technology. The expertise produced with reduced accuracy at the plexity (factor ~ 2) and than stand- gained has yielded a generic, con- decoder without noticeable quality ardized counterparts at significantly tent-based video coding approach degradations. Spatio-temporal tools are reduced complexity (factor ~ 10-4). The with a closed-loop texture analysis/ used that allow identification and efficiency of the new VQ assessor relies synthesis algorithm. tracking of textures. Spatial tools ini- on the fact that feature points are tialize picture partitions that typically carefully selected in the video in order Künftige inhaltsbasierte Videoco- provide the subsequent motion analysis to have a predominant influence on dierverfahren werden wesentlich with valuable hints. Motion analysis is the quality evaluation outcome. höhere Kompressionsgewinne er- carried out based on dense motion möglichen als gängige effiziente, fields on which robust, iterative, max- Fig. 2 shows the evaluation results of blockbasierte, hybride Codecs wie imum-likelihood methods are applied the closed-loop analysis/synthesis H.264/AVC. Neue Kompressions ver - to extract textures with homogeneous method. Two sequences (“Concrete”, fahren wie die Analyse/Synthese- properties. “Flower Garden”) featuring rigid tex- Codierung werden Einzug in die tures are used, while the third test nächste Codec-Generation (H.265) sequence shows a swimming pool 40 flowers halten können, sofern es gelingt, concrete filled with water and with an orca in it. hierfür tragfähige Konzepte zu prä- whale The whole system is integrated into an 30 sentieren. In der Abteilung Image H.264/AVC codec. It can be seen that,

Processing des HHI wurde in den 20 compared to the genuine H.264/AVC vergangenen fünf Jahren an der g a in ( % ) video codec, bit rate gains of up to Entwicklung solcher Technologien 10 41.4 % can be achieved using HHI’s gearbeitet. Die daraus resultieren- framework. den Ergebnisse wurden in einen 0 generischen, inhaltsbasierten 01,000 2,000 3,000 4,000 [email protected] Videocodieralgorithmus überführt. bit rate (kbps) Fig. 2: Bit rate gains obtained with closed-loop Fig. 1 depicts a block diagram of the analysis/synthesis approach for three test closed-loop analysis-synthesis algo- sequences rithm. The incoming video sequence (V) is analyzed by the texture analyzer The The texture synthesizers developed (TA) and synthesized by the texture for the given framework handle both synthesizer (TS), given the (quantized) rigid textures as flowers, grass, sand side information (SI) generated by the etc. and non-rigid textures such as TA. The remaining regions are currently water, smoke etc. Texture synthesis is coded using H.264/AVC that serves as constrained in the given system since

98 Annual Report | Jahresbericht 2006/2007 IMAGE PROCESSING

A SOFTWARE SUITE FOR MOBILE force enables maintainable software Team members are trained and follow BROADCASTING PRODUCT development. It has been applied to a state-of-the-art work-flow as well DEVELOPMENT products in the field of mobile broad- as adhering to a common coding style- casting and is explained below. guide. Fig. 1 depicts the most import- A software product suite in the ant strategies applied in the develop- mobile broadcasting application The requirements mentioned in the ment process. area has been developed at HHI. abstract apply to all product develop-

Successful product development ments. Library re-use is one key to cop- stable requires a short time to market, ing with several developments. Indi- software products maintainability, copy protection, vidually tested libraries for each func- common automated work-flow document. protection of IPs, documentation, tional block with an easy-to-use object- version software automated platform-independency and high oriented interface (C++) guarantee management libraries selftests stability. State-of-the-art software high stability. Libraries endorse quick unification through automation: increased efficiency, development technologies have application development and lead to a consistency, stability, maintainability, ... been applied to fulfill these needs. short time to market. Protection of Fig. 1: Supporting pillars for professional This article explains the technical IPs is achieved when only the inter- product development aspects of the development. faces of the libraries are exposed to the user and the main code is delivered in Fraunhofer HHI offers a variety of com- Am HHI wurde eine Software Pro- binary form only. While components mercial software products in the field duktpalette für den Bereich des developed as libraries lead to main- of mobile broadcasting. Among these mobilen Rundfunks entwickelt. tainability, this must be further sup- are: Erfolgreiche Produktentwicklung ported by means of version manage- • DVH-H encoder erfordert schnelle Markteinfüh- ment and revision control. Subversion, • Statistical multiplex for DVB-H rung, Wartbarkeit, Kopierschutz, a version management tool, is a major • T-DMB encoder Schutz der IPs, Dokumentation, key for making the software maintain- • IsmaCryp Scrambler hohe Stabilität und Plattformunab - able. Libraries are developed with auto- • SimulCrypt Synchronizer hängigkeit. Am HHI kamen hierfür mated self-tests that ensure that the to name only the most important ones. Softwareentwicklungsmethoden, expected functionality is preserved with die dem neuesten Stand der Tech - each new version. Applications as well These products took great advantage nik entsprechen, zum Einsatz. as libraries and their documentation of the applied methodology. Many of Dieser Artikel erläutert die tech- are managed in databases (repositories) them share the same functional blocks, nischen Aspekte der Entwicklung. that are accessible for all members of including A/V grabbing, A/V encoding, the development team. Sub version dongle-based copy protection and IP- The Image Processing department has sup ports the important feature of based streaming. Fig. 2 shows the hier- carried out cutting edge research in the managing multi-repository versioning archy of libraries that support platform area of image compression and is a which keeps the databases of libraries independency. major player in the standardization and applications fully consistent. An process for image coding technologies. applications automated process is applied to gener- DMB DVB-H StatMux scrambler SCS Consequently, companies world-wide ate documentation of the software specific libraries have asked FhG-HHI for support and components. Doxygen is the tool that H264 encoder AAC encoder MPEG-4 sys. solutions for the in-time introduction is used to generate consistent hyper- generic libraries of the related new technologies espe- linked documentation for each new dongle prot. A/V capture packet lib cially with a view to the emerging software version within a few minutes. multiple operating systems library (MSysLib) mobile broadcasting market. linux operating system windows operating system Platform independency (Windows, Fig. 2: Applications built on reusable libraries For several years now, FhG-HHI has Linux) is another important require- pushed a strategic initiative for soft- ment. A library has been developed The development time has been short ware management (SoMan) in order to that provides an object-oriented inter- and the systems have proven to be develop reusable software libraries and face to operating system (OS) resources stable and maintainable. Their commer- key technologies to quickly respond to like threads and sockets. This library cial success is the best proof of the product requests and to transform hides OS specific implementation de - convenience of the applied software research results into products with a tails from users who no longer need to management efforts. short time to market. The infrastruc- concern themselves with operating sys- ture that has been set up in this task tem specific details. [email protected]

Annual Report | Jahresbericht 2006/2007 99 IMAGE PROCESSING

Fig. 1: Example of a multi-view video sequence with eight linearly arranged cameras

MULTI-VIEW VIDEO CODING turing the video streams of several encoder receives N temporally synchron- cameras. This is often referred to as ized video streams and generates one For multi-view video applications, multi-view video and Fig. 1 shows a bitstream. The multi-view decoder such as 3D television or free view- typical example with eight views of receives the bitstream, decodes and point video, a real world scene is one scene. outputs the N video signals. captured simultaneously by multiple cameras. Multi-view video Since multi-view video causes a vast To ensure interoperability between coding deals with compressing the amount of data to be stored or trans- different systems, standardized formats several video streams. The method mitted to the user, efficient com- for data representation and com - presented achieves a significantly pression techniques are essential for pression are necessary. Therefore, ISO/ greater coding efficiency by jointly implementing such applications. The MPEG is developing a new standard for exploiting both temporal and inter- straight-forward solution for this would MVC. In this context, the multi-view view correlations and has the be to encode all the video signals inde- video coding approach presented out- advantage of complying with the pendently with H.264/AVC. However, performed any other algorithm investi- H.264/AVC video coding standard. multi-view video contains a large gated by MPEG. It performed particu- amount of inter-view statistical de- larly well in a Call for Proposals on Für Multi-view Video Anwendun - pendencies, since all cameras capture MVC technology and was therefore gen wie 3D Television oder Free the same scene from different view- adopted as the basis for the new Viewpoint Video wird eine reale points. These can be exploited for stand ard. Szene mit mehreren Kameras simul- combined temporal/inter-view predic- tan erfasst. Multi-view Video Kodie- tion, where images are not only pre- Our algorithm achieved the highest rung befasst sich mit der Kompres- dicted from temporally neighboring compression efficiency in terms of both sion mehrerer Video Streams. Die images but also from corresponding objective and subjective quality for a hier vorgestellte Methode zur images in adjacent views referred to as wide variety of evaluated multi-view Kodierung von Multi-view Video multi-view video coding (MVC). Fig. 2 video sequences. In some cases, gains erzielt eine deutlich höhere Ko- illustrates how this approach is used to of more than 3 dB, corresponding to diereffizienz, indem die Korrela - efficiently compress a multi-view video bit-rate savings of up to 50 %, are tionen zwischen benachbarten sequence by combining the advantages obtained by using the multi-view video Bildern nicht nur in zeitlicher, son- of temporal prediction with hierarchical coding approach presented. dern auch in räumlicher Dimension B pictures with prediction from inter- genutzt werden, und ist zugleich view reference pictures. The multi-view [email protected] konform zum H.264/AVC Standard für Videokodierung. time

3D television and free viewpoint video camera 1 I B B B B B B B BI are new types of visual media that expand the sensation to the third camera 2 B B B B B B B B BB dimension. While 3D television offers a three dimensional depth impression of the scene observed, free viewpoint camera 3 P B B B B B B B BP video allows for interactive selection of viewpoint and view direction in relation camera 4 B B B B B B B B BB to the scenery presented. One common characteristic of many of these systems is that they use multiple cam- camera 5 P B B B B B B B BP era views of the same scene. This is Fig. 2: Coding structure for multi-view video using temporal (black arrows) and inter-view implemented by simultaneously cap- (red arrows) reference pictures for prediction

100 Annual Report | Jahresbericht 2006/2007 IMAGE PROCESSING

CINEVISION 2006 PROJECT

On June 14, 2006 the German “CineVision 2006” research project organized a “New Media Day” event during the FIFA World Cup. The objective was to demonstrate to an international audience the benefits of digital cinema and Fig. 2: The CineCard PCI board projection technologies made in In order to create such a panoramic tion described (see Fig. 1). Such high Germany. The event was held at view, the sports event was captured by quality applications require seamless the Berlinale premiere theatre at two ARRIFLEX D-20 “film-style” digital transitions between the sub-images Berlin’s Potsdamer Platz. cameras. Using sophisticated image and highly accurate frame synchron- processing algorithms, these two sep- isation. Am 14.06.2006 hat das deutsche arate views were stitched together to Förderprojekt „CineVision 2006“ im form a complete panorama of around For this purpose, we have developed Rahmen der FIFA-Fußball-WM einen 5000 × 1400 pixels. This acquisition a modular, PC-based multi-projection „Tag der neuen Medien“ ausgerich- technique allows for a wide field of system. The key component is the so- tet. Vor internationalem Publikum view of more than 100° and provides called CineCard, a PCI board with dedi- wurden im Berlinale-Premierenkino an image quality that cannot be cated hardware for MPEG-decoding, am Potsdamer Platz in Berlin die achieved with a single state-of-the-art Transport Stream synchronisation and Vorzüge von digitaler Kino- und D-cinema camera. real-time processing of the required Projektionstechnik aus Deutschland photometric corrections such as alpha demonstriert. The same holds true for the projection blending, black level adjustment and side. Current digital cinema projectors gamma correction (see Fig. 2). One highlight of this event was an like state-of-the-art 2K DLP-projectors immersive 5K projection providing a or Sony’s 4K projector are limited to a horizontal resolution of more than horizontal resolution of 2048 and 4096 5,000 pixels. The content presented pixels, respectively. Obviously, this is shows a sports arena with a football not sufficient for panorama projections match underway. In contrast to con- of large-scale sports events or other ventional sports coverage, it contains applications using panoramic views. no pans, zooms and scene cuts, but instead shows a static long-shot of the This is why there is a growing demand entire football ground and the sur- for higher resolutions by combining rounding arena including the stands multiple projections. Such multi-projec- Fig. 3: Multi projection system and spectators. Thus, the viewer has tion systems are already available on the impression of really being present the market and in use today. However, The CineCard is able to process two in the stadium and watching the game their quality is insufficient for D-cinema independent HD streams and, thus, to from the very best seat (see Fig. 1). applications like the 5K football projec- serve two HD projectors. The host system for the CineCard, the so-called CineBox, is capable of supporting up to four CineCards. Several CineBox systems can be merged to PC clusters with a maximum of eight HD project - ors per PC. The whole system is hence fully cascadable and the maximum number of projectors is practically unlimited. Fig. 3 shows the application example that was used for the 5K football projection described.

[email protected] Fig. 1: 5K projection of sports arena with ongoing football match

Annual Report | Jahresbericht 2006/2007 101 IMAGE PROCESSING

VIRTUAL MIRROR design and colors of a shoe model at a shoes that were designed just a few special terminal and add individual minutes earlier. A Virtual Mirror has been de - embroideries and decorations. In order veloped that enhances the visu - to give the customer an impression of alization of customized sports what the shoes will finally look like shoes. Instead of viewing yourself after being manufactured, the user can in a real mirror, highly sophisticated step in front of the Virtual Mirror. 3D image processing techniques are used to verify the appearance of new shoe models. A camera captures the person and outputs the mirrored images onto a large display which replaces the real mirror. The 3D motion of both feet are tracked and computer graphics models of the shoes are augmented into the video such that the person seems to be wearing the virtual shoes. Fig. 1: Installation of the Virtual Mirror in the adidas store, Champs Elysées, Paris Ein Virtueller Spiegel wurde entwickelt für die Visualisierung indivi- A camera then captures the customer Fig. 2: Upper: Part of the original scene duell gefertigter Sportschuhe. An- wearing fitting boots with a standard captured with a single camera; Lower: Virtual statt sich selbst in einem realen design. A display replaces a real mirror Mirror output augmented with customized Spiegel zu betrachten, werden hoch and outputs the horizontally flipped shoes. entwickelte 3D Bildverarbeitungs- camera image. The display is mounted technologien eingesetzt, um das such that the person appears at the The framework uses high-end aug- Aussehen der neuen Schuhmodelle same position, where the user would mented reality techniques that com- zu überprüfen. Eine Kamera nimmt expect to see himself when looking bine real video content with computer- dabei die Person auf und stellt des- into a real mirror. In order to enhance generated material in real-time. The sen gespiegeltes Bild auf einem the virtual feeling of the framework, concept of a mirror realizes the aug- großen Display dar, das den realen the background is segmented and mentation without the need for the Spiegel ersetzt. Die 3D Bewegungen replaced by a synthetic environment. A customer to wear glasses, but the user der beiden Füße werden verfolgt novel 3D motion tracker estimates the can move freely just like in front of a und Computer Graphik Mo delle so position and orientation for each foot real mirror. No additional equipment in die Videoszene integriert, dass using a model-based approach that is has to be used but you can just step die Person die virtuellen Schuhe zu very robust and can easily be adapted into the application. This significantly tragen scheint. to new shoe models. Once the exact enhances the acceptability and im - foot position in 3D space is known, the mersiveness and reduces the effort for The Virtual Mirror developed by the computer graphics models that have supervising such an application. The Image Processing Department is a sys- been configured and colored according system has been designed and opti- tem for visualizing customized shoes to the customer’s wishes are rendered mized to show customized shoes, but that a person can try on and look at in and integrated into the video stream can also be generalized to visualize front of a mirror although they do not such that the real shoes are replaced other clothes or a new hairstyle. In exist in reality. The system shown in by the virtual ones. Special care has to contrast to existing approaches, the Fig. 1 has been created for adidas and be taken for this augmentation since system works three-dimensionally and runs in their new store which was the real scene in the 2D video can shows all virtual equipment from the opened in October 2006 on the occlude parts of the virtual 3D scene. correct viewing direction and pose. Champs Elysées, Paris, France. In this Therefore, visibility for all parts of the The output is not restricted to a fixed innovation center, a customer can not shoe must be computed for a given frontal view as in other 2D systems, only chose shoes from the shelf but position. Since all algorithms have been giving the user a much greater feeling can also design personalized models. implemented with real-time constraints, of being present in a real environment. Besides particular fitting of the left and the customer can move freely and right foot, the client can change the watch himself/herself with the new [email protected]

102 Annual Report | Jahresbericht 2006/2007 IMAGE PROCESSING

FAST AND HIGH RESOLUTION 3D pondences between the lines in the FACE SCANNER picture with the ones in the pattern.

A 3D face scanner has been developed to capture 3D models of faces in high resolution with low computational load. The system cap - tures only two pictures of the face, one illuminated with a colored stripe pattern and one with regular Fig. 2: The structural setup of the 3D face white light. The former is needed scanner for the depth calculation, the latter as texture. Using these two images, In the given case, the cost function re - a combination of specialized algo- Fig. 1: The 3D face scanner device presents the quality of all the assign- rithms is applied to generate a 3D ments and Dynamic Programming is model. The results are shown in dif- Every stripe in the picture must have an chosen for the minimization procedure. ferent views: simple surface, wire assigned stripe in the pattern. The es - frame or textured 3D surface. tab lishment of these correspondences From these correspondences, the 3D and the detection of the colors is one points are calculated by triangulation Es wurde ein 3D Gesichtsscanner of the main challenges of this approach. using calibration data from the setup. ent wickelt, der hochaufgelöste 3D The triangle mesh model is generated Modelle von Gesichtern mit gerin- The color of a pixel is difficult to guess by exploiting the regular pixel grid gem rechnerischen Aufwand er- because of the reflection properties of from the input images. Finally, the wire zeugt. Dieses System nimmt nur the skin. Additionally, ambient light of frame model is textured using a picture zwei Bilder des Gesichts auf, eines the environment and the distortions of taken with regular white light. mit einem Streifenmuster und eines the lenses in the projector and camera mit normalem weißen Licht beleu- worsen the measurements. Sophisti - The simple setup and its easy usage chtetes. Ersteres wird für die Be- cated image preprocessing and color make the system presented ideally rech nung der Tiefeninformation estimation have been developed to suited for various 3D model creation benötigt, letzteres dient als Textur. overcome this problem. scenarios, e.g. virtual environments like Zur Erzeugung des 3D Modells wer- 3D games or human machine inter- den auf diese zwei Bilder speziali- For the assignment of stripes, a typical faces. sierte Algorithmen angewandt. Die combinatorial optimization problem Ergebnisse werden in verschiedenen (COP) has to be solved by minimizing a [email protected] Sichtweisen präsentiert: einfache cost function with a suitable method. Oberflä che, Drahtgitter oder tex- turierte 3D Oberfläche.

The 3D face scanner developed at the Image Processing Department is a system for creating high resolution 3D models of faces. The system shown in Fig. 1 consists of regular consumer hard ware: a digital camera and a DLP projector. For shape reconstruction, it uses a structured light method where the 3D data is extracted from a picture of the face illuminated by a special pattern. The depth information is calculated by triangulating the setup of projector and camera. The pattern we use consists of unicolored horizontal lines which eases the search for corres- Fig. 3: Results of 3D face scanner

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ELECTRONIC COMPONENTS FOR chosen, combining two 64-bit memory plete data stream was split into 4 A MASKLESS LITHOGRAPHY DATA modules in parallel per FPGA. A high- Demux chips, each performing an iden- PATH speed input interface allows for data tical subset, handling 8 data input rates of 10 Gbps. Optoelectronic con- channels plus several control channels. In the context of a maskless litho - version is carried out directly on-board The Demux features a dedicated graphy application, large data sets using four 12-channel PAROLI2 trans- deskewing circuit with adaptable delay have to be transmitted rapidly to mitters. The High-Speed Buffer archi- chains with up to 20 ps resolution to an exposure unit inside a high-volt- tecture is capable of handling transmis- compensate the skew of the input age vacuum area. High-perform- sion rates of up to 51 Gbps. An up- channels and real-time error detection. ance electronic components have grade to DDR2-SDRAM may yield trans- All input channels are deskewed, de - been developed for that purpose mission rates that exceed 100 Gbps. coded and demultiplexed with a ratio since there are no off-the-shelf High - Speed Buffer optical free-space transmission OptRX Demux components that provide the required functionality and bandwidth.

Im Rahmen einer Maskenlose-Litho- graphie-Applikation müssen große

Datenmengen zu einer im Hoch- 2070µm spannungs-Vakuumbereich be find - lichen Belichtungseinheit übertra- gen werden. Zu diesem Zweck wur- 5090µm den leistungsfähige elektronische • 2 Xilinx Virtex-II Pro XC2VP70 •5× 8 photodiode array • quarter scale design • Multi-Gigabit transceiver • 36 parallel channels • 8 data channels per chip Komponenten entwickelt, da die • double buffer structure • backchannel support • demux factor 1:4: • DDR-SDRAM (400 MTs) • differential design of photodiodes • 1 Gbps / 250 Mbps erforderliche Funktionalität und • max. memory transfer rate 51 Gbps • integrated TIA and LIA • input deskewing circuit Bandbreite nicht durch Standard - • 10 Gbps input channel • LOP indication circuit • real-time error detection • 36 parallel output channels (36 Gbps) • 0.6 µm BiCMOS technology • 0.18 µm CMOS technology bau steine bereitgestellt werden • 16 layer FR4 board • pin count 92 • pin count 122 • approx. 600 mW power consumption • approx. 250 mW power consumption kann. Fig. 1: Data path structure and in-house designed components The transmission of skew-sensitive An optical free-space transmission sys- of 1:4 and then delivered to the aper- high-speed data requires appropriately tem, designed by HHI’s PN department, ture plate system at 250 Mbps. The designed data path components. By connects the buffer to the Optical Re- Demux is fabricated in a 0.18 µm proper physical design and the use of ceiver (OptRX) and the Demux inside CMOS technology and has been de- desk ewing techniques, data transmis- the vacuum area. Both components are signed in cooperation with the Tech - sion of 36 Gbps over 36 parallel chan- implemented as full-custom ASICs. nical University of Berlin. nels (1 Gbps each) has been accomplished. A block diagram of all data The OptRX features a highly parallel Due to the vacuum environment, the path components including a feature structure of 36 channels, provided by main emphasis with the receiver ICs list is shown in Fig 1. means of an integrated 5 × 8 photo - was on low power consumption and diode array. The signal path is followed small area. It was possible to take full The High-Speed Buffer is used to tem- by transimpedance and limiting amp- advantage of the low-power CMOS porarily capture a subset of the input lifiers. A loss-of-power (LOP) indication technology, achieving a power con- data in order to generate a continuous circuit, as well as two VCSEL drivers for sumption of approx. 600 mW for the data stream for the lithography appli- backchannel connection are added. OptRX and 250 mW for the Demux at cation. It is designed as a double- After converting the optical input data data rates of 1 Gbps (per channel). buffer structure providing read / write to electrical signals, the data is trans- accesses simultaneously. mitted via differential low-power inter- Both, the PCB buffer board and the faces to the Demux chip. The OptRX is ASICs allow for the modularity and The Buffer is implemented as a 16- based on a 0.6 µm BiCMOS technology scalability required for higher data rates. layer printed circuit board (PCB) and and has been designed in cooperation To maximize the throughput of infor- features two high-pincount Xilinx with Vienna University of Technology mation, the additional appliance of Virtex-II Pro FPGAs as core elements. To and A3PICs. effective data compression is possible. achieve the desired throughput, a 128- bit interface to the DDR SDRAM was The demultiplexing task for the com- [email protected]

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Annual Report | Jahresbericht 2006/2007 105

STRATEGY, NEW PRODUCTS

Strategy, New Products

Device developments based on HHI’s Indiumphosphide (InP) technology line were refocused after HHI became a member of the Fraunhofer Society: Parallel to striving for scientific excellence, significant progress has been made towards meeting industrial standards with respect to performance, overall quality, long-term reliability and statistical process control for example. Components operating in the 1.3 to 1.5 µm wavelength range have achieved commercial pro - duct status and offer application potential in areas other than telecommunications which has been their genuine market so far. The characteristics of these devices, such as small dimensions, high mechanical stability and low cost, enable the replacement of classical lasers in various sub - systems, and the devices can be used for completely new applications as well. Fostering such developments and opening new market opportunities are the key objectives of the ‘New Products’ department.

R&D projects, which support the process of entering new fields and applications, are frequently carried out in close cooperation with universities, other Fraunhofer partner institutes or even companies. Identifying such partners, including opportunities to acquire funding on a national or European level, is another objective of the ‘New Products’ department.

The first new topic chosen in 2006 for future activity at HHI was Terahertz (THz) technology (see p. 69). THz technology is considered to be particularly promising worldwide, and application areas of specific interest include security, drugs or materials analysis. The different technical approaches, which enable access to the THz regime (0.3 … 30 THz), have been comprehensively assessed, and finally it has been decided that HHI will de velop cw systems based on 1.5µm emitter and receiver structures. Key characteristics of corresponding THz systems will be wide and simple tuneability, high sensitivity due to coherent detection, and a useful frequency range of up to about 2 THz. HHI has already secured funding by the German Research Council (‘DFG’) for a joint research project with the THz group at the university of Frankfurt/Main (Prof. H. Roskos), and additional cooperation with German and European partners is in preparation.

Another field with bright future prospects is Silicon pho - tonics, and HHI has decided to significantly ramp-up its past activities related to this topic. Emphasis will be on the hybrid integration of optoelectronic InP-based active devices with CMOS-compatible silicon structures. It is expected that this approach will lead to components with significantly better performance than existing solutions or even completely new functionalities.

Annual Report | Jahresbericht 2006/2007 107 STRATEGY, NEW PRODUCTS

Neue Strategien, neue Produkte

Mit dem Übergang in die Fraunhofer-Gesellschaft haben die auf der InP-Technologielinie des HHI basierenden Arbeiten eine Neuorientierung erfahren: Neben der Erzielung von wissenschaftlichen Spitzenleistungen wurden wesentliche Fortschritte erreicht bei der Industrialisierung, z. B. bei der Qualitätssicherung, bei der Lebensdauersicherung, und bei der Prozeßkontrolle. Komponenten für den 1,3 – 1,5µm Wellenlängenbereich haben mittlerweile einen kommerziellen Reifegrad erreicht, auf dessen Basis es möglich ist, neue industrielle Arbeitsgebiete fernab der Telekommunikation zu erschließen. Vorteile der Telekom-Technologien wie Klein - heit, mechanische Stabilität und niedrige Kosten können klassische (Laser-) Lösungen ersetzen oder vollkommen neue Anwendungen ermöglichen. Der Innovationsprozeß zur Eröffnung solcher Marktchancen ist eine der wesentlichen Aufgaben der Abteilung ‘Neue Produkte, Strategien’.

Die Erschließung neuer Arbeitsgebiete beginnt in der Regel mit entsprechenden F&E-Arbeiten, die in vielen Fällen be son - ders effizient in Kooperation mit Hochschulen, anderen FhG- Instituten oder auch Industriefirmen durchgeführt werden können. Die Identifikation solcher Partner, ggf. in Kombi na - tion mit Förder-Möglichkeiten sowohl auf nationaler wie auf internationaler Ebene, gehört ebenfalls zu den Zielsetzungen der Abteilung NP.

Im Jahre 2006 wurde als erstes neues Arbeitsgebiet die Tera - Hertz-Technologie ausgewählt (0,3... 30 THz), der ge gen - wär tig ein großes Entwicklungspotential eingeräumt wird mit Anwendungen z. B. in den Bereichen Sicherheit, Drogen/ Medi kamente oder Werkstoffprüfung (s. Seite 69). Nach eingehender Ana lyse der verschiedenen technologischen Ansätze und ihrer speziellen Einsatzmöglichkeiten wurde entschieden, am HHI auf 1,5 µm InP-Sender- und Empfän - ger-Strukturen ba sierende cw-Systeme zu entwickeln. Wesentliche Merkmale sind: kontinuierliche Abstimmung der THz-Emission, hohe Emp fangsempfindlichkeit durch kohärente Detektion und Fre quenzen bis zu etwa 2THz. Die Arbeiten am HHI werden bereits im Rahmen eines DFG- Projektes gefördert, das zu sam men mit der THz-Gruppe der Universität Frankfurt/Main (Prof. H. Roskos) durchgeführt wird, weitere Kooperationen auf nationaler und europäi- scher Ebene sind in Vorbereitung.

Ein weiteres aussichtsreiches Zukunftsfeld ist die Silizium- Photonik. Auf diesem Gebiet beabsichtigt das HHI, neuar - tige optoelektronische Strukturen zu entwickeln, bei denen aktive InP-Bauelemente mit CMOS-kompatiblen Silizium- Strukturen hybrid integriert werden, so daß neue Funktio- nalitäten oder Bauelementlösungen mit verbesserten Leis - tungsmerkmalen möglich werden.

108 Annual Report | Jahresbericht 2006/2007 STRATEGY, NEW PRODUCTS

Strategy, New Products

Head of Department Herbert Venghaus Phone +49(0)30/310 02-555 Fax -551 e-mail [email protected]

Secretary Ramona Reichold Phone -554 e-mail [email protected]

monolithic EDFA optical photo homodyne 2-laser chip booster fibre mixer receiver

THz 1.55 µm

1.55 µm THz-Setup based on low-cost telecom components developed for long-term operation.

An upcoming topic is heterogeneous integration of functional materials on silicon. The implementation of a wide range of photonic components opens the way to enhanced optical functionality (light emission, New products, innovations are always a kind of a optical amplification, Gigascale modulation, all-optical jigsaw. signal processing …) with improved performance.

Annual Report | Jahresbericht 2006/2007 109 COMMUNICATIONS AND EVENTS

PUBLICATIONS* S. Chennu, K. Habel and K.D. Langer, QoS- R. Freund, L. Molle, C. Caspar, J. Schwartz12, aware traffic protection for access rings, S. Webb12 and S. Barnes12, Mixed bitrate and Photonic Networks and Systems Proc. 11th Europ. Conf. on Networks & Optical modulation format upgrade of non-slope Communications (NOC 2006), pp. 165 – 174. matched submarine links, Proc. 32nd Europ. C. Arellano1, C. Bock1, M. Seimetz, K.-D. Langer Conf. on Optical Communication (ECOC 2006), and J. Prat1, Crosstalk mitigation using sub- L.D. Coelho5, L. Molle, D. Gross, N. Hanik5, Cannes (FR), paper Th1.6.5, vol. 4, pp. 65 – 66. carrier multiplexing and forward error R. Freund, C. Caspar and E.-D. Schmidt6, correction in reflection-mode ONU systems, Numerical and experimental investigation R. Freund, L. Molle, F. Raub, C. Caspar, M. Karkri Proc. 10th Europ. Conf. on Networks & Optical of the effect of dispersion on nonlinear and Ch. Weber, Triple-(/S/C/L)-band WDM Communications (NOC 2005), London (UK), phase noise in RZ-DPSK, ECOC 2007. transmission using Erbium-doped fibre pp. 271 – 276. amplifiers, Proc. 31st Europ. Conf. on Optical A. Demircan2, M. Kroh, U. Bandelow2, B. Hüttl Communication (ECOC 2005), Glasgow (UK), C. Arellano1, C. Bock1, K.-D. Langer and J. Prat1, and H. G. Weber, Compression limit by third- paper Mo4.2.3, pp. 69 – 70. Optical network units based on semicon - order dispersion in the normal dispersion ductor optical amplifiers in single-wave- regime, IEEE Phot. Tech. Letters, Nov. 2006, vol. R. Freund, L. Molle, C. Caspar, J. Schwartz12, length single-fiber access networks, ITG- 18, no. 22, pp. 2353 – 2355. S. Webb12 and S. Barnes 12, Higher bitrates Fachbericht 189, Breitbandversorgung in and advanced modulation formats facilitate Deutschland – wie schaffen wir den Anschluss, A. Demircan2, M. Kroh, B. Hüttl and U. overlay upgrades of installed submarine Berlin (DE), Oct. 2005, pp. 63 – 68. Bandelow2, Generation of new frequencies systems, 8. ITG-Fachtagung Photonische Netze, by pulse splitting, ECOC 2007. 2007. C. Arellano1, C. Bock1, J. Prat1 and K.-D. Langer, RSOA-based optical network units for R.H. Derksen7, G. Lehmann7, C.-J. Weiske7, F. Futami13, R. Okabe13, S. Ono13, S. Watanabe13, WDM-PON, Proc. Optical Fiber Communication C. Schubert, R. Ludwig, S. Ferber, C. Schmidt- C. Schubert, R. Ludwig and C. Schmidt-Lang - Conf. (OFC 2006), paper OTuC1. Langhorst, J. Lutz8 and M. Möller8, Integrated horst, All-optical amplitude noise suppres- 100 Gbit/s ETDM receiver in a transmission sion of both 160-Gb/s OOK and DPSK data C. Arellano1, J. Prat1 and K.-D. Langer, On the experiment over 480 km DMF, Proc. Optical signals by parametric fiber switch, Proc. influence of ONU-gain on transmission in Fiber Communication Conf. and National Fiber Optical Fiber Communication Conf. (OFC 2007) centrally seeded-light WDM-PONs, Proc. Optic Engineers Conf. (OFC/NFOEC 2006), and National Fiber Optic Engineers Conf. Optical Fiber Communication Conf. (OFC 2007), Anaheim (CA, USA), postdeadline paper PDP (NFOEC 2007), paper OthB3. Paper OTuG4. 37. M. Galili14, B. Hüttl, C. Schmidt-Langhorst, U. Bandelow2, M. Radziunas2 A. Vladimirov2, G.J. Eilenberger9, A. Gladisch10, U. Kohn11, A. Gual, R. Ludwig and C. Schubert, 320 Gbit/s B. Hüttl and R. Kaiser, Harmonic mode-locking P. Leisching7 and G. Walf, Netz der Zukunft – DQPSK all-optical wavelength conversion in monolithic semiconductor lasers: Theory, BMBF-Förderschwerpunkt EIBONE, Jahrbuch using four wave mixing, Proc. Optical Fiber simulations and experiment, Optical and Elektrotechnik 2007, vol. 26, pp. 169 – 176. Communication Conf. (OFC 2007) and National Quantum Electronics 38, 2006, pp. 495 – 512. Fiber Optic Engineers Conf. (NFOEC 2007), G.J. Eilenberger9, A. Gladisch10, U. Kohn11, paper OTuI3. S. Bauer, H. Ding, J. Kreissl, M. Biletzke, B. P. Leisching7 and G. Walf, Netz der Zukunft – Sartorius, L. Molle, C. Caspar and R. Freund, BMBF-Förderschwerpunkt Eibone, ntz, 2005, M. Galili14, B. Hüttl, C. Schmidt-Langhorst, R. Compact RZ-DPSK transmitter applying a Heft 6, pp. 15 – 17. Ludwig, F. Futami13, S. Watanabe13 and C. phaseCOMB laser as carved source, Proc. Schubert, All-optical combination of DPSK Optical Fiber Communication Conf. (OFC 2006), S. Ferber, C. Schmidt-Langhorst, R. Ludwig, and OOK to 160 Gbit/s DQPSK data signals, Anaheim (CA, USA), paper OThG6. C. Boerner, C. Schubert and V. Marembert, Proc. Optical Fiber Communication Conf. (OFC M. Kroh and H.G. Weber, 160 Gbit/s OTDM 2007) and National Fiber Optic Engineers Conf. C. Boerner, R. Ludwig, S. Ferber, S. Weisser3, long-haul transmission with long-term (NFOEC 2007), paper OThi5. A. Benz3, L. Raddatz3 and H.G. Weber, Burst stability using RZ-DPSK modulation format switching capability of electro-optical PLL- (invited), IEICE Trans. Commun., vol. E88-B, P. Gelpke, M. Schlosser, E. Patzak and H. Buchta, based clock recovery for 170 Gbit/s, Proc. no. 5, May 2005, pp. 1947 – 1954. TCP performance in OBS networks with 31th Europ. Conf. on Optical Communication load dependent contention, Proc. 8. ITG- (ECOC 2005), Glasgow (UK), vol. 3, p. 385 – 6. S. Ferber, C. Schmidt-Langhorst, R. Ludwig, Fach tagung Photonische Netze, Leipzig (DE), C. Boerner, C. Schubert and V. Marembert, pp. 163 – 170. H. Buchta and E. Patzak, Analysis of the phys- M. Kroh and H.G. Weber, 160 Gbit/s transmis- ical impairment on the maximum size and sion with long-term stability, 6. ITG-Fachta - J.P. Gelpke, M. Schlosser, E. Patzak and H. throughput of SOA based optical burst gung “Photonische Netze”, Leipzig (DE), 2005, Buchta, Assessment of TCP performance switching nodes, Journal of Lightwave Tech- pp. 71 – 78. in OBS networks with load dependent con- nology, 2007. tention, Proc. ICTON 2007, July, vol. 3, pp. S. Ferber, C. Schubert, R. Ludwig, C. Boerner, C. 101 – 104. K. Cvecek4, K. Sponsel4, C. Stephan4, R. Ludwig, Schmidt-Langhorst and H.G. Weber, 640 Gbit/s C. Schubert, G. Onishchukov4, B. Schmauss4 DQPSK single-channel transmission over G. Großkopf, K. Habel, W. Keusgen, D. Rohde and G. Leuchs4, Phase-preserving 2R-regen- 480 km fibre link, Proc. 31th Europ. Conf. and K.-D. Langer, 1.25 Gbit/s indoor radio link eration of an 80-Gb/s RZ-DQPSK signal by on Opt. Comm. (ECOC 2005), Glasgow (UK), extension of a Gigabit Ethernet CWDM using a nonlinear amplifying loop mirror, vol. 3, p. 437 – 8. access network, Proc. IET Int. Conf. on Access ECOC 2007. Technologies 2006, pp. 25– 28. S. Ferber, C. Schubert, R. Ludwig, C. Boerner, C. S. Chennu, K. Habel and K.-D. Langer, Pro - Schmidt-Langhorst and H.G. Weber, 640 Gbit/s tected rings for optical access networks, ITG DQPSK single-channel transmission over Fachbericht 193, Photonische Netze, Leipzig 480 km fibre link, Electronics Letters, vol. 41, (DE), April 2006, pp. 29 – 36. no. 22, Oct. 2005, pp. 1236 – 1237. *The list of footnotes is on page 126.

110 Annual Report | Jahresbericht 2006/2007 COMMUNICATIONS AND EVENTS

J. Grubor, V. Jungnickel and K.-D. Langer, vestigial sideband modulation, Proc. Optical J.J. Lepley19, M.P. Thakur19, I. Tsalamanis19, S.D. Adaptive-modulation technique in wireless Fiber Communication Conf. (OFC 2007) and Walker19, K. Habel, K.-D. Langer, G.-J. Rijcken- infrared indoor communications, ITG National Fiber Optic Engineers Conf. (NFOEC berg18, A. Ng’oma18 and A.M.J. Koonen18, Inter - Fachbericht 193, Photonische Netze, Leipzig 2007), Paper OWE3. operability of simultaneous last mile access (DE), April 2006, pp. 193 – 200. technologies over a passiv optical ring net- S. Kieckbusch24, C. Schmidt-Langhorst, S. Ferber, work: Results of the MUSE demonstration, J. Grubor, V. Jungnickel and K.-D. Langer, C. Schubert, E. Brinkmeyer24 and H.-G. Weber, Proc. Europ. Conf. on Optical Communication Bit-loading for modulation-adaptive Automatic compensation of PMD and chro- (ECOC 2006), vol. 1, pp. 45 – 46. transmission in infrared wireless indoor matic dispersion in a 160 Gb/s transmission communication, Proc. Int. Conf. on Access experiment, Proc. 32nd Europ. Conf. on Optical J.J. Lepley19, I. Tsalamanis19, M.P. Thakur19, K. Technologies (IET 2006), pp. 9– 12. Communications (ECOC 2006), Cannes (FR), Habel, K.-D. Langer and S.D. Walker19, Hybrid vol. 4, paper Th3.5.1., pp. 177 – 178. fibre-VDSL transmission over a CWDM pas - J. Grubor, V. Jungnickel and K.-D. Langer, sive ring access network, Proc. Int. Conf.on Capacity analysis in indoor wirless infrared M. Kroh, S. Ferber, C. Schmidt-Langhorst, Telecommunications (ICT 2006), Madeira (PT). communication using adaptive multiple V. Marembert, C. Schubert, R. Ludwig and subcarrier transmission, Proc. 7th Int. Conf. H. G. Weber, Transmitter enabling ultra- R. Ludwig, Ultrafast transmission technology On Transparent Optical Networks (ICTON 2005), high-speed transmission of phase modu - (invited), Proc. 31th Europ Conf. on Opt. Barcelona (ES), vol. 2, pp. 171 – 174. lated data signals up to 640 (invited), Proc. Comm. (ECOC), 25 – 29 Sep. 2005, Glasgow Optical Fiber Communication Conf. and Na- (UK), vol. 5, pp. 159 – 188. J. Grubor, V. Jungnickel and K.-D. Langer, tional Fiber Optic Engineers Conf. (OFC/ NFOEC Rate-adaptive multiple sub-carrier-based 2006), Anaheim (CA, USA), 5–10 March 2006, R. Ludwig, Ultrafast transmission technology, transmission for broadband infrared wire- paper OWW1. Proc. Int. Symp. on Photonics and Advanced less communication, Proc. National Fiber Optic Networks (ISPAN 2006), 10 Jan. 2006, Tokyo (JP). Communication Conf. (NFOEC 2006), paper M. Kroh, B. Hüttl, S. Ferber and H.G. Weber, NThG2. Low noise 400 fs pulse generation by mono- R. Ludwig, S. Ferber, C. Boerner, C. Schubert, C. lithic semiconductor mode-locked laser and Schmidt-Langhorst, M. Kroh, V. Marembert and J. Grubor, O.C. Gaete Jamett7, J.W. Walewski7, soliton pulse compression, Proc. Electro-Optics H.G. Weber, Technologies enabling ultrahigh S. Randel7 and K.-D. Langer, High-speed wire- Europe (CLEO/Europe 2005), Munich (DE), speed transmission (invited), Proc. Optical Amp- less indoor communication via visible light, p. 125. lifiers and Applications (OAA 2005), Budapest ITG-Fachbericht 198, Breitbandvesorgung in (HU), paper SUB2. Deutschland – Vielfalt für alle?, 2007, pp. K.-D. Langer, D.W. Faulkner25 and R. Neat26 203 – 208. (Eds), Proc. of the 11th Europ. Conf. on R. Ludwig, S. Ferber, C. Boerner, C. Schubert, C. Networks and Optical Communications Schmidt-Langhorst, M. Kroh, V. Marembert and M. Gunkel15, D. Breuer15, H. Reiner16, H. (NOC 2006), published by the Fraunhofer H.G. Weber, 160 Gbit/s transmission systems, Cremer16, R. Freund, Ch. Caspar, F. Raub, D. Institute for Telecommunications, Heinrich- ready for operation? (invited), Proc. 10th Mirto17, and S. Ten17, Dispersion-managed Hertz-Institut. Optoelectronics and Communication Confer ence fiber (DMF): Experimental & economic (OECC), July 2005, Seoul (KR), paper 8B1-1, evaluation, Proc. 31st Europ. Conf. on Optical K.-D. Langer and J. Grubor, Recent develop- pp. 772 – 773. Communication (ECOC 2005), Glasgow (UK), ments in optical wireless communications paper We4.P.007, pp. 515– 516. using infrared and visible light (invited), Proc. R. Ludwig, S. Ferber, C. Schubert, C. Schmidt- 9th Int. Conf. on Transparent Optical Networks Langhorst, B. Huettl and H.G. Weber, Single K. Habel, K.-D. Langer, G.-J. Rijckenberg18, (ICTON 2007), vol. 3, pp. 146 – 151. channel transmission beyond 1 Tbit/s: tech- A. Ng’oma18, T. Koonen18, J. Lepley19 and nology and challenges, Proc. 11th OptoElec- S. Walker19, Broadband access solutions on K.-D. Langer, K. Habel, F. Raub and M. Seimetz, tronics and Communications Conf. (OECC 2006), a common CWDM platform, Proc. 11th CWDM access network and prospects for 3 – 7 July 2006, Kaohsiung (TW), paper 4F2-1. Europ. Conf. on Networks and Optical introduction of full duplex wavelength Communications (NOC 2006), pp. 157 – 164. channels, Proc. 10th Europ. Conf. On Networks R. Ludwig, S. Ferber, C. Schubert, C. Schmidt- & Optical Communications (NOC 2005), London Langhorst, B. Huettl and H.G. Weber, Single B. Hüttl, A. Gual i Coca, R. Elschner20, Ch.-A. (UK), pp. 68 – 75. channel transmission beyond 1 Tbit/s (in - Bunge20, K. Petermann20, C. Schmidt-Langhorst, vited), Proc. Frontiers in Optics 2006, The 90th R. Ludwig and C. Schubert, Optimization of K.-D. Langer, K. Habel, J. Vathke and C. Arellano1, OSA Annual Meeting Laser Science XXII (OSA SBS-suppression for 320 Gbit/s DQPSK all- Recent developments on WDM-PON techno- 2006), 8 – 12 Oct. 2006, Rochester (NY, USA), optical wavelength conversion, ECOC 2007. logy (invited), Proc. 8th Int. Conf. on Transparent paper FTuP5. Optical Networks (ICTON 2006), pp. 12– 13. B. Hüttl, R. Elschner20, H. Suche21 (2), A. Gual i R. Ludwig, S. Ferber, C. Schubert, C. Schmidt- Coca, Ch.-A. Bunge20, C. Schmidt-Langhorst, K.-D. Langer, K. Habel, J. Vathke, C. Paul and C. Langhorst, B. Huettl and H.G. Weber, Ultrafast R. Ludwig, R. Nouroozi21, H.G. Weber, K. Arellano1, Single-fibre passive optical net- transmission technology (invited), in: Optical Petermann20, W. Sohler21 and C. Schubert, work using full duplex wavelength channels, Transmission, Switching and Subsystems IV, All-optical wavelength converter concepts ITG Fachbericht 189, Breitbandver sorgung in Proc. of SPIE vol. 6353, (APOC 2006), paper for high data rate D(Q)PSK transmission, Deutschland – wie schaffen wir den Anschluss?, 6353-81. APOC 2007. Berlin (DE), Oct. 2005, pp. 99 – 104. R. Ludwig, W.S. Lee27, C. Schubert, S. Ferber, C. S.L. Jansen18, R.H. Derksen7, C. Schubert, X. G. Lehmann7, R.H. Derksen7, C. Schubert and Boerner, C. Schmidt-Langhorst and H.G. Weber, Zhou22, M. Birk22, C.-J. Weiske7, M. Bohn18, D. M. Winter20, 100 Gigabit Ethernet Trans- 80 Gbit/s DPSK transmission over 480 km van den Borne18, P.M. Krummrich7, M. Möller8, mission – Physical Layer Issues, Proc. Optical dispersion-managed fiber with balanced F. Horst23, B.J. Offrein23, H. de Waardt18, G.D. Fiber Communication Conf. (OFC 2007) and detection ETDM receiver, Proc. 31th Europ. Khoe18 and A. Kirstädter7, 107-Gb/s Full-ETDM National Fiber Optic Engineers Conf. (NFOEC Conf. on Opt. Comm. (ECOC 2005), Glasgow transmission over field installed fiber using 2007), Paper OthD5. (UK), vol. 3, p. 381 – 2.

Annual Report | Jahresbericht 2006/2007 111 COMMUNICATIONS AND EVENTS

R. Ludwig, C. Schmidt, C. Schubert, S. Ferber, V. V. Marembert, C. Schubert, H.G. Weber, C. Schubert, S. Ferber, M. Kroh, C. Schmidt- Marembert, M. Kroh and H.G. Weber, All op - A.M. Melo20, S. Randel20 and K. Petermann20, Langhorst, R. Ludwig, B. Hüttl, R. Kaiser and tical signal processing technologies and Reduction of pattern effects in an SOA- H.G. Weber, 40 GHz semiconductor mode- their applications (invited), Proc. 9th Int. based 40 Gb/s wavelength converter, Proc. lokked laser pulse source for 160 Gbit/s Symp. on Contemporary Photonics Technology Optical Amplifiers and Applications (OAA 2005), RZ-DPSK data transmission, Proc. 31th Europ. (CPT 2006), January 11–13, 2006, Tokyo (JP), Budapest (HU). Conf. on Opt. Comm. (ECOC 2005), Glasgow vol. 09 G-1 pp. 145 – 148. (UK), vol. 2, p. 167– 8. C. Meuer20, M. Laemmlin20, G. Fiol20, M. R. Ludwig, C. Schmidt-Langhorst, B. Huettl, C. Kuntz20, N.N. Ledentsov28, A.R. Kovsh28, S. C. Schubert, S. Ferber, R. Ludwig, C. Schmidt- Schubert, S. Weisser3 and L. Raddatz3, Trans - Ferber, C. Schubert, A. Steffan29, A. Umbach29 Langhorst and H.G. Weber, High-speed transmission systems beyond 100 Gbit/s: Status and D. Bimberg20, High frequency signal mission based on a 40 Gbaud DQPSK and technologies (invited), IEEE/LEOS Summer amplification using quantum dot semicon- system, 7. ITG Fachtagung Photonische Netze, Topical Meeting on Ultra-High Data-Rate ductor optical amplifiers at 1.3 µm, Proc. Leipzig (DE), ITG Fachbericht 193, p. 45 – 49. (> 80 Gb/s) Transmission, Portland (USA), 32nd Europ. Conf. on Optical Communications 23. – 25.07.07, paper ME3.2. (ECOC 2006), 24 – 28 September 2006, Cannes C. Schubert, R. Ludwig, S. Ferber, C. Schmidt- (FR) vol. 3, pp. 543 – 544, paper We4.6.5. Langhorst, B. Huettl and H.G. Weber, Single R. Ludwig, C. Schubert, S. Weisser3 and L. channel transmission beyond 1 Tbit/s (in - Raddatz3, 5.4 bit/s (64*85.2) Gbit/s DQPSK L. Molle, Ch. Caspar, R. Freund, S. Desbruslais12, vited), Proc. 19th Annual Meeting of the IEEE transmission with 100 GHz channel spacing R. Oberland12, J. Schwartz12, Upgrades of non- Lasers and Electro-Optics Society (LEOS 2006), over 2000 km non-zero dispersion shifted slope matched submarine transmission sys- Montreal (CA), paper ThX1. fiber, Proc. 11th OptoElectronics and Commu - tems using differential phase shift keying, nications Conf. (OECC 2006), 3 – 7 July 2006, Proc. Optical Fiber Communication Conference C. Schubert, C. Schmidt-Langhorst, R. Ludwig, Kaohsiung (TW), postdeadline paper 4F2-1. (OFC 2007), paper OWM2. S. Ferber, B. Huettl and H.G. Weber, Terabit transmission on a single wavelength chan- R. Ludwig, S. Weisser3, L. Raddatz3, A. Benz3, J. Mulet30, M. Kroh and J. Mørk14, Pulsewidth nel (invited), Proc. 11th Europ. Conf. on Net- S. Ferber, C. Boerner and H.G. Weber, Single and noise properties of external-cavity works & Optical Communications (NOC 2006), channel 170 Gbit/s transmission up to mode-locked semiconductor lasers: Simu- Berlin (DE), pp. 105 – 108. 4000 km using dispersion managed fiber lations and experiments, Proc. Electro-Optics spans and all raman amplification, Proc. 10th Europe (CLEO/Europe), 12 – 17 June 2005, E. Schulze, A. Warnke and F. Raub, 40 Gb/s Optoelectronics and Commununication Conf. Munich (DE), p. 7. WDM-transmission with EDFAs in compari- (OECC), July 2005, Seoul (KR). son to Raman amplified transmission with L. Nederlof17, D. Mirto17, S. Ten17, M. Gunkel15, Raman fiber lasers as first-order and R. Ludwig, S. Weisser3, C. Schmidt-Langhorst, D. Breuer15, H. Reiner16, H. Cremer16, R. Freund, second-order pump, Proc. Optical Fiber L. Raddatz3 and C. Schubert, Unrepeatered Ch. Caspar and F. Raub, Cost optimization Communication Conf. (OFC 2005), Anaheim transmission of of 160 Gb/s RZ-DPSK over study using dispersion-managed fiber in a (CA, USA), paper OThF2. 240km dispersion managed fiber, ECOC 2007. German backbone network, Proc. 5th Int. Workshop on Design of Reliable Communi ca - J. Schwartz12, R. Freund, L. Molle, C. Caspar, S. R. Ludwig, S. Weisser3, C. Schmidt-Langhorst, tion Networks (DCRN 2005), Island of Ischia (IT). Webb12 and S. Barnes12, Upgrades of sub - L. Raddatz3 and C. Schubert, 160 Gb/s-DPSK marine systems using higher bitrates and OTDM-transmission over 480 km using M. Schlosser, P. Gelpke and E. Patzak, Auswir - advanced modulation formats, Proc. Asia 160 km repeater spans and advanced kungen von Deflection Routing auf die TCP Optical Fiber Communication & Optoelectronic forward-error-correction, Proc. Optical Fiber Performance in Optical Burst Switching Exposition (AOE 2006), Shanghai (CN), pp. Communication Conf. (OFC 2007) and National Netzen, Proc. 6. ITG-Fachtagung Photonische 126 – 128. Fiber Optic Engineers Conf. (NFOEC 2007), Netze, Leipzig 2005, pp. 131 – 135. Paper OWE4. J. Schwartz12, S. Webb12, S. Barnes12, R. Freund, M. Schlosser, E. Patzak and P. Gelpke, Impact L. Molle und C. Caspar, Higher bitrates and M. Malach20, C.-A. Bunge20, K. Petermann20, of deflection routing on TCP performance advanced modulation formats facilitate L. Molle, R. Freund and H.J. Thiele, Cross- in optical burst switching networks, Proc. overlay upgrades of installed submarine phase modulation suppression method in 7th Int. Conf.on Transparant Optical Networks systems, SubOptic 2007. multispan dispersion-managed WDM (ICTON 2005), Barcelona (ES), pp. 220 – 223. transmission systems, Proc. 7th Int. Conf. on M. Seimetz, Multi-format transmitters for Transparent Optical Networks (ITCON 2005), C. Schmidt-Langhorst, R. Ludwig, M. Galili14, B. coherent optical M-PSK and M-QAM trans- We.C1.2, pp. 68 – 71. Huettl, F. Futami13, S. Watanabe13 and C. mission, Proc. 7th Int. Conf. on Transparent Schubert, 160 Gbit/s all-optical OOK to DPSK Optical Networks (ITCON 2005), Barcelona (ES), M. Malach20, K. Petermann20, L. Molle, R. Freund in-line format conversion, Proc. 32nd Europ. paper Th.B1.5. and H.-J. Thiele, Unterdrückung der XPM in Conf. on Optical Communications (ECOC 10 Gb/s WDM Übertragungssys temen, Work - 2006), 24 – 28 September 2006, Cannes (FX) M. Seimetz, Phase diversity for homodyne shop der ITG Fachgruppe 5.3.1, Dortmund (DE), vol. 6, pp. 37– 38, postdeadline paper Th4.3.5. detection of optical DQPSK signals, IEEE February 2005. Journal of Lightwave Technology, vol. 24, no. 9, C. Schubert, R.H. Derksen7, M. Möller8, R. 2006, pp. 3384 – 391. V. Marembert, C. Schubert, C. Schmidt- Ludwig, C.-J. Weiske7, J. Lutz8, S. Ferber and C. Langhorst, M. Kroh, S. Ferber and H.G. Weber, Schmidt-Langhorst, 107 Gbit/s transmission M. Seimetz, Performance of coherent optical Investigation of fiber based gates for time using an integrated ETDM receiver, Proc. square-16-QAM-systems based on IQ-trans- division demultiplexing up to 640 Gbit/s, 32nd Europ. Conf. on Optical Communications mitters and homodyne receivers with digital Proc. Optical Fiber Communication Conf. and (ECOC 2006), 24 – 28 September 2006, Cannes phase estimation, Proc. Fiber Optic Engineers National Fiber Optic Engineers Conf. (OFC/NFOEC (FR) vol. 2, paper Tu1.5.5., pp. 33– 34. Conf. (NFOEC 2006), Anaheim (CA, USA), 2006), 5 – 10 March 2006, Anaheim (CA, USA), paper NWA4. paper OWI12.

112 Annual Report | Jahresbericht 2006/2007 COMMUNICATIONS AND EVENTS

M. Seimetz, L. Molle, D. Gross, B. Auth and S. Weisser3, R. Ludwig, W. Müller3, L. Raddatz3, York, ISSN 1619-8638 (Online), DOI: 10.1007/s R. Freund, Coherent RZ-8PSK transmission at C. Schubert and O. Wohlgemuth3, 85.2 Gbit/s 10297-005-0038-0, Issue: Online Firs, Nov. 2005. 30 Gbit/s over 1200 km employing homo- NRZ-DQPSK DWDM transmission over dyne detection with digital carrier phase 2000 km non-zero dispersion shifted fiber, H.-G. Bach, Ultra-high speed photodetectors estimation, Proc. ECOC 2007. ECOC 2007. for 80 to 160 Gbit/s applications (invited), Proc. 210th Meeting of the Electrochemical M. Seimetz, M. Nölle and E. Patzak, Optical S. Weisser3, L. Raddatz3, R. Ludwig and C. Society’s (ECS 2006), Cancun (MX), on CD-ROM. systems with high-order DPSK and star Schubert, 2000 km DWDM transmission of QAM modulation based on interferometric 85.2 Gbit/s DQPSK data with 100 GHz chan- H.-G. Bach, A. Beling, G.G. Mekonnen, Devel - direct detection, IEEE Journal of Lightwave nel spacing over non-zero dispersion shifted opment roadmap towards 100 GHz photo- Technology, vol. 25, no. 6, 2007, pp. fiber, Proc. 32nd Europ. Conf. on Optical detectors and receivers and beyond (invited), 1515 – 1530. Communications (ECOC 2006), 24 – 28 11th Europ. Conf. on Networks and Optical September 2006, Cannes (FR), vol.1, paper Communications (NOC 2006), Berlin (DE), M. Seimetz and R. Freund, Coherent systems Mo3.2.4, pp. 7– 8. pp. 87– 96. using multi-level modulation formats and electronic distortion equalisation, Proc. J. Wellen31, R. Smets31, W. Hellenthal31, J. H.-G. Bach, H. Buelow9, J.-P. Elbers11, A. Färbert33, Workshop on Optical Transmission an Lepley19, I. Tsalamanis19, S. Walker19, A. H. Griesser11, N. Hanik5, H. Haunstein3, P. M. Equalisation (WOTE 2005), Shanghai (CN), Ng’oma18, G.-J. Rijckenberg18, T. Koonen18, Krummrich7, A. Schinabeck3, M. Schneiders34, paper B1, pp. 19 – 20. K. Habel and K.-D. 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Beling, InP- bility and availability of 2 × 4 90°-hybirds for 40 Gbit/s DPSK demodulation, ECOC 2007. based narrow band photodetector modules coherent optical systems, IEEE Journal of for 40 to 100 GHz linear high power appli- Lightwave Technology, vol. 24, no. 3, 2006, pp. cations (invited), Proc. Annual Meeting of the 1317 – 1322. Photonic Components IEEE Lasers & Electro-Optics Society (LEOS 2006), Montreal, Quebec (CA), CD-ROM, paper J. Vathke, C. Paul, W. Wenisch and K.-D. Langer, D. Alexandropoulos32, A. Kapsalis32, D. Syvridis32, ThY4, pp. 925 – 926. Breitbandige optische Zugangsnetze mit U. Troppenz, M. Hamacher, H. Heidrich, Design CWDM: Stand der Technik und Perspek tiven, considerations for spatial monomode oper - S. Bauer, H. Ding, J. Kreissl, M. Biletzke, B. ITG Fachbericht 193, Photonische Netze, Leipzig ation of InP-based passive vertically coupled Sartorius, L. Molle, C. Caspar, R. Freund, A. (DE), April 2006, pp. 37– 44. microring resonators, Proc. 5th Int. Conf. on Umbach29, A. Steffan29, Compact RZ-DPSK Numerical Simulation of Optoelectronic Devices transmitter applying a phaseCOMB laser as H.G. Weber, S. Ferber, M. Kroh, C. Schmidt- (NUSOD 2005), pp. 119 – 120. carved source, Proc. 31th Conf. Optical Fiber Langhorst, R. Ludwig, V. Marembert, C. Communications (OFC 2006), Anaheim (CA, Boerner, F. Futami13, S. Watanabe13 and C. H.-G. Bach, Electrical properties/semicon- USA), p. 3. Schubert, Single channel 1.28 Tbit/s and ductors, Chap. C.9, sect. 9.4, in: Springer 2.56 Tbit/s DQPSK transmission, Proc. 31th Handbook “Materials Measurement Methods”, A. Beling, InP-based 1.55 µm waveguide- Europ. Conf. on Opt. Comm. (ECOC 2005), Springer-Verlag, H. Czichos, T. Saito, L. Smith integrated photodetectors for high-speed Glasgow (UK), vol. 6, pp. 3 – 4. (Eds), (2006), ISBN-13:978-3-540-20785-6, applications (invited), Proc. SPIE’s Intern. Symp. pp. 453 – 472. on Integrated Optoelectronic Devices 2006, H.-G. Weber, S. Ferber, M. Kroh, C. Schmidt- San Jose, (CA, USA), on CD-ROM, vol. 6123, Langhorst, R. Ludwig, V. Marembert, C. H.-G. Bach, Ultra-broadband photodiodes 61230K to 61230K-12. Boerner, F. Futami13, S. Watanabe13 and C. and balanced detectors towards 100 Gbit/s Schubert, Single channel 1.28 Tbit/s and and beyond, Proc. of SPIE Optics East Symp., A. Beling, PIN photodiode modules for 2.56 Tbit/s DQPSK transmission, Electronics “Active and Passive Optical Components for 80 Gb/s and beyond (invited), Proc. 31th Conf. Letters, vol. 42, no. 3, pp 178 – 179. WDM Communications V”, Boston, vol. 6014, on Optical Fiber Communication (OFC 2006), published online Oct. 24, 2005. Anaheim, (CA, USA), Tech. Digest, paper OFI1. H.-G. Weber, R. Ludwig, S. Ferber, C. Schmidt- Langhorst, M. Kroh, V. Marembert, C. Boerner H.-G. Bach, Ultrafast photodetectors and A. Beling, H.-G. Bach, R. Kunkel, G.G. and C. Schubert, Ultrahigh-speed OTDM- receivers, Chap. 7 in: Springer book series on Mekonnen, D. 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Annual Report | Jahresbericht 2006/2007 113 COMMUNICATIONS AND EVENTS

A. Beling, H.-G. Bach, G.G. Mekonnen, R. Summer School (2006), Berlin-Tucson-Ottawa, tal laser with integrated wavelength moni- Kunkel, D. Schmidt, Miniaturized waveguide- Adaptive Optics and Microoptics, Berlin (DE), tor, Proc. 32nd Europ. Conf. on Optical Com - integrated p-i-n photodetector with Technical Digest, 05a-Tue, on CD-ROM. munication (ECOC 2006), Cannes (FR), paper 120 GHz bandwidth and high responsivity, Tu3.4.2. IEEE Photon. Techn. Lett., vol. 17, no. 10, M. Ferstl, G. Devendra, R. Grunwald46, M. October 2005, pp. 2152 – 2154. Bock46, Lithographically fabricated micro- N. Keil, H. Yao, C. Zawadzki, W. Döldissen, optical array beam shapers for ultra-short W. Schlaak, M. Möhrle, D. Schmidt, Polymer as H. Benisty35, L. Martinelli35, O. Khayam35, M. pulse lasers, (CLEO/QELS 2006), Long Beach integration platform for low-cost devices in Ayre36, M. Kotlyar36, T. F. Krauss36, M. Midrio37, (CA, USA), Technical Digest CD-ROM, paper future optical networks, Proc. 11th Europ. R. Brénot38, G.H. Duan38, F. Van Laere39, D. Van JThC98. Conf. on Networks & Optical Communications Thourhout39, K. Janiak, H. Heidrich, M. Kamp40, (NOC 2006), Berlin (DE), Conf. Dig., 2006. H. Scherer40, R. Houdré41, L.A. Dunbar41, D. D. Franke, P. Harde, J. Böttcher, M. Möhrle, Gallagher42, Photonic-crystal-based optical A. Sigmund and H. Künzel, Improved emission C. Koos47, M. Fujii48, C.G. Poulton4, R. functions for metropolitan area networks: wavelength reproducibility of InP-based all Steingrüber, J. Leuthold47, W. Freude47, FDTD- Polarisation control, linear amplification, MOVPE grown 1.55 µm quantum dot lasers, modelling of dispersive nonlinear ring wavelength selection, Proc. 32nd Europ. Proc. 19h Int. Conf. on Indium Phosphide and resonators: Accuracy studies and experi- Conf. on Optical Communication (ECOC 2006), Related Materials (IPRM 2007), accepted for ments, IEEE Journal of QuantumElectronics, Cannes (F), paper We1.2.2. publication. vol. 42, no. 12, Dec 2006, pp. 1215 – 1223.

H. Benisty35, A. David35, L. Martinelli35, E. N. Grote, M. Möhrle, K. Janiak, J. Kreissl, Laser B. Kuhlow, G. Przyrembel, S. Schlüter, W. Fürst, Viasnoff-Schwoob35, C. Weisbuch35, G.-H. diodes for hybrid optical board technology, R. Steingrüber, C. Weimann, Photonic crystal Duan38, K. Janiak, H. Heidrich, From modal Proc. of the Int. Optronics Symp. (OPTRO 2005), microcavities in SOI for WDM filter appli- control to spontaneous emission and gain Paris (FR). cations, IEEE Journal of Lightwave Technology, in photonic crystal waveguides, Photonics accepted for publication. and Nanostructures – Fundamentals and N. Grote, M. Möhrle, N. Keil, L. Mörl, Laser Applications, vol. 4, Issue 1, 2006, p. 1–1. devices for hybrid optical integration, 4th R. Kunkel, A. Beling, H.-G. Bach, G.G Mekonnen, Joint Symp. on Opto- and Microelectronic D. Schmidt, C. Sydlo49, D. Schönherr49, M. H. Benisty35, L. Martinelli35, E. Viasnoff- Devices and Circuits (SODC ’06), Duisburg (DE), Feiginov49, H.L. Hartnagel49, and P. Meisner49, Schwoob35, M. A. Pinault35, C. Weisbuch35, Conf. Dig., session 5, 2006. Monolithic integration of a waveguide- G. Duan38, H. Heidrich, K. Janiak, Role of 1D integrated p-i-n photodiode and a planar singularities in the operation of some B. Hüttl, R. Kaiser, C. Kindel, S. Fidorra, W. antenna for THz applications, Proc. Optical photonic-crystal based devices (invited), Proc. Rehbein, H. Stolpe, G. Sahin, U. Bandelow2, Terahertz Science and Technology Meeting Photonic West 2006, San Diego, (CA, USA). M. Radziunas2, A. Vlanimirov2, H. Heidrich, (OTST 2007), Orlando (FL, USA), accepted for Experimental investigations on the sup- publication. K. Biermann, H. Künzel, Ch. Villas-Boas presssion of Q-switching in monolithic Tribuzy43, S. Ohser43, H. Schneider43, M. Helm43, 40 GHz mode-locked semiconductor lasers, P. Matthijsse50, G. Kuyt50, F. Gooijer50, F. Achten50, Impact of interface formation on intersub- WIAS-publication, ISSN 0946-8633 and Appl. R. 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Petermann20, CWDM Symp. on Opto- and Microelectronic Devices B. Hüttl, R. Kaiser, W. Rehbein, H. Stolpe, transmitter module based on hybrid inte- and Circuits (SODC ’06), Duisburg (DE), Conf. Ch. Kindel, S. Fidorra, A. Steffan, A. Umbach, gration, IEEE Journal of Selected Topics in Dig., session 3, 2006. H. Heidrich, Low noise monolithic 40 GHz Quantum Electronics, vol. 12, Issue 5, 2006 mode-locked DBR lasers based on GaInAsP/ pp. 983 – 987. W. Döldissen, N. Keil, M. Möhrle, W. Schlaak, H. InP, Proc. 17th Conf. Indium Phosphide and Yao, C. Zawadzki, Berlin Access: an initiative Related Materials (IPRM 2005), Glasgow (UK), T. Mitze20, M. Schnarrenberger20, L. Zimmer- of Berlin SMEs and Fraunhofer-HHI for new paper Tu/Optoelectronics 5, pp. 633 – 636. mann20, J. Bruns, F. Fidorra51, J. Kreissl, K. FTTH technologies Workshop on Optical Janiak, S. Fidorra, H. Heidrich, K. Petermann20, Components for Broadband Communi ca - R. Kaiser, H. 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BH-DFB-lasers for uncooled operation, M. Töpper54, T. Rosin, T. Fritzsch54, R. Jordan54, I. Blau, G. Wunder, Optimal service allocation IEEE Photonic Technology Letters, vol. 18, no. 8, G. Mekonnen, C. Sakkas, R. Kunkel, K. in multi-system scenarios with linear subsys- pp. 962 – 964. Scherpinski54, D. Schmidt54, H. Oppermann54, tem capacity regions, Proc. Int. Symp. on L. Dietrich54, A. Beling, Th. Eckhardt, H.-G. Bach, Wireless Personal Multimedia Communications M. Möhrle, A. Sigmund, A. Suna, L. Mörl, W. H. Reichl54, Thin film substrate technology (WPMC 2006), San Diego, (CA, USA), on CD- Fürst, A. Dounia, W.-D. Molzow, High single- and FC interconnection for very high fre- ROM. mode yield, tapered 1.55 µm DFB lasers for quency applications, Proc. 56th Electronic CWDM applications, Proc. 31th Europ. Conf. Components and Technology Conf. (ECTC H. Boche, E.A. 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Pohl, Approximation and conver- für optische Breitband-Zugangsnetze, gence behavior of spectral factorization J. Slovak, C. Bornholdt, J. Kreissl, S. Bauer, Workshop “Mikrooptik im Fokus der Photonik”, methods, Proc. IEEE Intern. Symp. on Informa - M. Biletzke, M. Schlak, B. Sartorius, Bit rate Karlsruhe (DE), Conf. Dig., 2005. tion Theory (ISIT 2007), Nice (FR), pp. 1131– and wavelength transparent all-optical 1135. clock recovery scheme for NRZ coded PRBS signals, IEEE Photonics Technology Letters, Mobile Broadband Networks and Systems H. Boche, V. Pohl, Approximation and repre- vol 18, no. 20, Oct. 2006. sentation of transfer functions of MIMO I. Bjelakovic, H. Boche, Structure of optimal systems under stability, causality and R. Steingrüber, M. Ferstl, Electronbeam litho- input covariance matrices for MIMO systems smoothness constrains, Proc. 38th South- graphy and micro- and nano-scale optical with covariance feedback under general eastern Symp. on System Theory (SSST 2006) components, Internat. Photonics Cluster correlated fading, Proc. IEEE Int. Symp. on Cookeville (TN, USA), on CD-ROM. Summer School (2006), Berlin-Tucson-Ottawa, Information Theory (ISIT 2006), Seattle (WA, Adaptive Optics and Microoptics, Berlin (DE), USA), pp. 1014 –1045. H. Boche, V. Pohl, Basis selection problems Technical Digest 05b-Tue, on CD-ROM. for different performance measures – I. Bjelakovic, H. Boche, Capacity of input- fundamental limits, Proc. 6th Int. ITG-Conf. C.W. Tee53, K.A. Williams53, 18, R.V. Penty53, memoryless causal ergodic classical-quan- on Source and Channel Coding (SSC 2006), I.H. White53, M. Hamacher, U. Troppenz, H. tum channels, Proc. IEEE Intern. Symp. on Munich (DE), on CD-ROM. Heidrich, Non-critical waveguide alignment Information Theory (ISIT 2007), Nice (FR), for vertically-coupled microring using a pp. 251 – 255. H. Boche, V. Pohl, Behavior of the spectral mode-expanded bus architecture, Proc. factorization for continuous spectral 32nd Europ. Conf. on Optical Communication I. Bjelakovic, H. Boche, Ergodic classical- densities, Signal Processing, vol. 87, no. 5, (ECOC 2006), Cannes (FR), paper We2.6.3. quantum channels: structure and coding pp. 1078 –1088. theorems, IEEE Trans. on Information Theory, C.W. Tee53 , K. A. Williams53, 18, R. V. Penty53, accepted. H. Boche, V. Pohl, BIBO norm in spectral I. H, White53 , U. Troppenz, M. Hamacher, H. factorization and Wiener filtering, Proc. Heidrich, Novel regrowth-free vertical active- I. Bjelakovic, T. Oechtering, C. Schnurr, H. Boche, Canadian Workshop on Information Theory passive integration scheme with improved On the strong converse for the broadcast (CWIT 2005), Montreal (CA), pp. 347– 350. fabrication tolerance, Proc. Conf. on Lasers capacity region of two-phase bidirectional and Electro-Optics, Quantum Electronics & Laser relaying, Proc. IEEE Information Theory Work- H. Boche, V. Pohl, Characterization of holo- Science Conf. (CLEO 2005), vol. 2, pp. shop on Information Theory for Wireless Net - morphic functions in terms of their moduli, 948 – 950. works (ITW 2007), Bergen (NO), on CD-ROM. Complex Variables, vol. 50, no. 13 (2005), pp. 1025 –1029.

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H. Boche, V. Pohl, Characterization of the approximation – fundamental limits (in - H. Boche, M. Schubert, Convergence behavior behavior of outer functions with applica- vited), Special Issue of European Trans. on of matrix-based iterative transceiver, Proc. tions to spectral factorization and system Telecommunications (ETT on Turbo-Coding- 7th IEEE Workshop on Signal Processing design, Proc. American Control Conference 2006), vol. 18, no. 1. Advances in Wireless Communications (SPAWC (ACC 2006), Minneapolis (MN, USA), pp. 2006), Cannes (FR), on CD-ROM. 4320 – 4325. H. Boche, V. Pohl, Spectral factorization in the disk algebra, Complex Variables, vol. 50, H. Boche, M. Schubert, Duality theory for H. Boche, V. Pohl, Continuity of the outer no. 6 (2005), pp. 383 – 387. uplink downlink multiuser beamforming, in: factorization and mapping properties with ‘Smart Antennas – State-of-the-Art’, EURASIP applications, Proc. 44th IEEE Conf. on Decision H. Boche, V. Pohl, Spectral factorization, Book Series on Signal Processing and and Control and Europ. Control Conf. ECC whitening- and estimation filter – stability, Communications, Hindawi Publishing (CDC-ECC 2005), Sevilla (ES), pp. 548 – 553. smoothness properties and FIR approxima- Corporation (2005), pp. 545 – 576. tion behavior, Proc. IEEE Int. Symp. on Infor - H. Boche, V. Pohl, General characterization of mation Theory (ISIT 2005), Adelaide (AU), pp. H. Boche, M. Schubert, Iterative power con- bezout space-time equalizers and precoder, 1701 – 1705. trol and resource allocation for general Proc. Int. Zurich Seminar (IZS 2006), Zurich (CH), interference functions – A superlinearly pp. 30 – 33. H. Boche, V. Pohl, Structural properties of convergent algorithm, Proc. 45th IEEE Conf. the Wiener filter; stability, smoothness on Decision and Control (CDC 2006), San Diego H. Boche, V. Pohl, General structure of the properties, and FIR approximation behavior, (CA, USA), pp. 2974-2979. causal and stable inverses of MIMO systems IEEE Trans. on Information Theory, vol. 25, no. 9 with ISI, Proc. 16th IEEE Int. Symp. on Personal, (2006), pp. 4272 – 4282. H. Boche, M. Schubert, Multiuser interfer - Indoor and Mobile Radio Communications ence balancing for general interference (PIMRC 2005), Berlin (DE), vol. 1, pp. 102 – 106. H. Boche, V. Pohl, The peak-to-average functions – a convergence analysis, Proc. IEEE power reduction problem – Fundamental Internat. Conf. on Commun. (ICC 2007), H. Boche, V. Pohl, Geometrical characteriza- limits and connection with Fourier analysis, Glasgow (UK), on CD-ROM. tion of the optimal causal linear MIMO- Proc. 5th MATHMOD Conf. 2006, Vienna (AT), channel inverse, Proc. Int. Symp. on Wireless on CD-ROM. H. Boche, M. Schubert, Non-symmetric Nash Personal Multimedia Communications (WPMC bargaining solution for resource allocation 2005), Aalborg, (DK), on CD-ROM. H. Boche, V. Pohl, There exists no always in wireless networks and connection to convergent algorithm for the calculation of interference function calculus (invited), Proc. H. Boche, V. Pohl, MIMO-ISI channel equaliza- spectral factorization, Wiener filter, and 15th Int. Europ. Signal Processing Conf. (EUSIP- tion – which prize we have to pay for caus- Hilbert transform, Proc. IEEE Int. Symp. on CO 2007), Poznan (PL). ality (invited), Proc. 14th Int. Europ. Signal Information Theory (ISIT 2006), Seattle (WA, Processing Conf. (EUSIPCO 2006), Florence (IT). USA), pp. 118 – 122. H. Boche, M. Schubert, On the existence of a proportionally fair operating point for wire- H. Boche, V. Pohl, MIMO-ISI channels: inner- H. Boche, V. Pohl, There is no free lunch with less communication systems, Proc. 8th IEEE outer factorization and applications to causal approximations, Proc. IEEE Intern. Workshop on Signal Processing Advances in equalization (invited), International Wireless Conf. on Acoustics, Speech, and Signal Pro - Wireless Communications (SPAWC 2007), Communications & Mobile Computing cessing (ICASSP 2007), Honolulu (HI, USA), Helsinki (FI), on CD-ROM. Conference (IWCMC 2006), Vancouver (CA), vol. 3, pp. 765 – 768. pp. 1393 –1398. H. Boche, M. Schubert, On the structure of H. Boche, M. Schubert, Advanced interfer - the multiuser QoS region, IEEE Trans. on H. Boche, V. Pohl, Necessary and sufficient ence calculus – a general framework for Sig nal Processing, vol. 55, no. 7, pp. 3484 – condition for the continuity of all causal interference coordination (invited) Proc. 8th 3495. projections with applications, Proc. 45th IEEE IEEE Workshop on Signal Processing Advances Conf. on Decision and Control (CDC 2006), San in Wireless Communications (SPAWC 2007), H. Boche, M. Schubert, Resource allocation Diego (CA, USA), pp. 5353 – 5358. Helsinki (FI). for multi-antenna multi-user systems, Proc. IEEE Int. Conf. on Communications (ICC 2005), H. Boche, V. Pohl, On the behavior of causal H. Boche, M. Schubert, A general theory for Seoul (KR), vol. 2, pp. 855 – 859. projections with applications, Signal Proces - SIR balancing, EURASIP J. on Wireless Com - sing, published online July 2007. munications and Networking, article ID 60681, H. Boche, M. Schubert, Resource allocation in vol. 2006 (2006), 18 pages. multi-antenna systems – Achieving max-min H. Boche, V. Pohl, On the behavior of disk fairness by optimizing a sum of inverse SIR, algebra bases with applications, Signal Pro - H. Boche, M. Schubert, An algebra for log- IEEE Trans. on Signal Processing, vol. 54, no. 6 cessing, vol. 86, no. 12 (2006), pp. 3915 – 3922. convex interference functions, Int. Symp. on (2006), pp. 1990 –1997. Information Theory and its Applications (ISITA H. Boche, V. Pohl, On the boundedness 2006), Seoul (KR), pp. 551– 556. H. Boche, M. Schubert, SIR balancing and behavior of the spectral factorization in the Perron root optimization, Proc. Canadian Wiener algebra for FIR data, Proc. 15th Int. H. Boche, M. Schubert, Characterization of Workshop on Information Theory (CWIT 2005), Europ. Signal Processing Conf. (EUSIPCO 2007), the QoS feasibility region of multiuser sys- Montreal (CA), pp. 426 – 429. Poznan (PL), accepted. tems – The complete SIR-balancing theory, Proc. Int. ITG/IEEE Workshop on Smart Antennas H. Boche, M. Schubert, The supportable H. Boche, V. Pohl, Robustness of the (WSA 2005), Duisburg (DE), on CD-ROM. QoS region of a multiuser system with log- inner-outer factorization and of the spectral convex interference functions, Proc. IEEE factorization for FIR data, IEEE Trans. on H. Boche, M. Schubert, Characterization of Intern. Conf. on Acoustics, Speech, and Signal Signal Processing, accepted. the structure of general interference func- Processing (ICASSP 2007), Honolulu (HI, US), tions, Proc. IEEE Intern. Symp. on Information vol. 3, pp. 677– 680. H. Boche, V. Pohl, Signal representation and Theory (ISIT 2007), Nice (FR), pp. 2431– 2435.

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H. Boche, M. Schubert, E. Jorswieck, A. Sezgin, H. Boche, M. Wiczanowski, The interplay of equal power in allocated subcarriers for A general framework for concave/convex link layer and physical layer under MIMO OFDM uplink, Proc. 40th Asilomar Conference interference coordination problems and enhancement – benefits and challenges on Signals, Systems, and Computers, Pacific network utility optimization, ITG/IEEE (invited), IEEE Wireless Communications Grove (CA, USA), on CD-ROM. Workshop on Smart Antennas (WSA 2007), Magazine, vol. 13, no. 4 (2006), pp. 48 – 55. Vienna (AT), on CD-ROM. T. Haustein, A. Forck, H. Gaebler, V. Jungnickel, H. Boche, M. Wiczanowski, M. Schubert, Inter- S. Schiffermueller, Real-time experiments on H. Boche, M. Schubert, S. Stanczak, A unifying ference topology in wireless networks – channel adaptive transmission in the multi- approach to multiuser receiver design under Supportable QoS region and max-min fair- user up-link at very high data rates using QoS constraints, Proc. 61st IEEE Semiannual ness, Proc. 39th Conf. on Information Sciences MIMO-OFDM (invited), Proc. 14th Int. Europ. Vehicular Techn. Conf. (VTC 2005), Stockholm and Systems (CISS 2005), Baltimore (MD, USA), Signal Processing Conf. (EUSIPCO 2006), (SE), vol. 2, pp. 992 – 996. on CD-ROM. Florence (IT), on CD-ROM.

H. Boche, M. Schubert, S. Stanczak, Propor - H. Boche, M. Wiczanowski, S. Stanczak, Char- T. Haustein, A. Forck, H. Gaebler, V. Jungnickel, tional fair resource allocation for wireless acterization of the fairness gap in resource S. Schiffermueller, Real time signal processing networks, Proc. Internat. ITG/IEEE Workshop on allocation for wireless cellular networks, Int. for multi-antenna systems: algorithms, Smart Antennas (WSA 2007), Vienna (AT), on Symp. on Information Theory and its Appli- optimization and implementation on an CD-ROM. cations (ISITA 2006), Seoul (KR), pp. 540 – 545. experimental test-bed, EURASIP – special issue on Implementation Aspects and Testbeds for H. Boche, M. Schubert, S. Stanczak, M. Wiczan- H. Boche, M. Wiczanowski, S. Stanczak, On MIMO Systems, vol. 2006 (2006), Article ID owski, An axiomatic approach to resource optimal resource allocation in cellular net- 27573, 21 pages. allocation and interference balancing, Proc. works with best-effort traffic, IEEE Trans. on IEEE Int. Conf. on Acoustics, Speech, and Signal Wireless Communications, accepted. T. Haustein, A. Forck, H. Gaebler, S. Schiffer - Processing (ICASSP 2005), Philadelphia (PA, mueller, From theory to practice: MIMO real- USA), vol. 3, pp. 545 – 548. H. Boche, M. Wiczanowski, S. Stanczak, time experiments of adaptive bit-loading Unifying view on min-max fairness, max- with linear and non-linear transmission and H. Boche, S. Stanczak, A note on some pro- min fairness, and utility optimization in detection schemes, Proc. 61st IEEE Semiannual perties of the Perron root of nonnegative cellular networks, EURASIP J. on Wireless Vehicular Techn. Conf. (VTC 2005), Stockholm irreducible matrices, Applicable Algebra in Communications and Networking, accepted. (SE), vol. 2, pp. 1115 –1119. Engineering, Communication and Computing (AAECC), accepted. H. Boche, M. Wiczanowski, S. Stanczak, T. Haustein, V. Jungnickel, E. Schulz, W. Zirwas7, Unifying view on min-max fairness and MIMO-OFDM for wireless high data rate H. Boche, S. Stanczak, Log-convexity of the utility optimization in cellular networks, (invited), 13th Int. Conf. on Telecommunica - minimal total power in CDMA systems with Proc. IEEE Wireless Communications and tions (ICT 2006), Madeira Island (PT), on CD- certain quality-of-service guaranteed, IEEE Networking Conf. (WCNC 2005), New Orleans ROM. Trans. on Inform. Theory, vol. 51, no. 1 (2005), (LA, USA), vol. 3, pp. 1280 –1285. pp. 374 – 381. T. Haustein, S. Schiffermueller, V. Jungnickel, C. Degen56, O. Koch56, W. Keusgen, B. M. Schellmann, T. Michel, G. Wunder, Inter - H. Boche, S. Stanczak, The infeasible SIR Rembold56, Evaluation of MIMO systems polation and noise reduction in MIMO- region is not a convex set, Proc. IEEE Int. with respect to front-end imperfections, OFDM – A complexity driven perspective, Symp. on Information Theory (ISIT 2005), Europ. Trans. on Telecommunications (ETT), Proc. 8th Int. Symp. on Signal Processing and Its Adelaide (AU), pp. 695 – 699. vol. 17, no. 3 (2006), pp. 313 – 323. Applications (ISSPA 2005), Sydney (AU), vol. 1, pp. 143-146. H. Boche, S. Stanczak, The Kullback-Leibler A. Feistel, S. Stanczak, Dynamic resource allo- divergence and nonnegative matrices, IEEE cation in wireless ad-hoc networks based on T. Haustein, M. Wiczanowski, H. Boche, E. Trans. on Information Theory, vol. 52, no. 12 QS-CDMA, Proc. 16th IEEE Int. Symp. on Per - Schulz7, Realtime implementation of cross- (2006), pp. 5539 – 5545. sonal, Indoor and Mobile Radio Communi - layer optimization: multi-antenna high cations (PIMRC 2005), Berlin (DE), on CD-ROM. speed uplink packet access, Proc. IEEE Int. H. Boche, M. Wiczanowski, Optimization- Conf. on Acoustics, Speech, and Signal theoretic analysis of stability-optimal trans- G. Fettweis, E. Zimmermann, V. Jungnickel, E.A. Processing (ICASSP 2005), Philadelphia (PA, mission policy for multiple antenna multiple Jorswieck, Challenges in Future Short Range USA), vol. 3, pp. 533 – 536. access channel, IEEE Trans. on Signal Pro - Wireless Systems, IEEE Vehicular Technology cessing, vol. 55, no. 6, pp. 2688 –2702. Magazine, vol. 1, no. 2 (2006), pp. 24 – 31. O. Henkel, Construction of coherent space time codes from non-coherent ones, Proc. H. Boche, M. Wiczanowski, Scheduling for Y. Gao, M. Schubert, Group-oriented beam- IEEE Int. Conf. on Acoustics, Speech, and Signal multiuser MIMO MAC, in: ‘Smart Antennas – forming for multi-stream multicasting based Processing (ICASSP 2005), Philadelphia (PA, State-of-the-Art’, EURASIP Book Series on Signal on quality-of-service requirements, 1st IEEE USA), vol. 3, pp. 1065 –1068. Processing and Communications, Hindawi Int. Computational Advances in Multi-Sensor Publishing Corporation (2005), pp. 577– 612. Adaptive Processing (CAMSAP 2005), Puerto O. Henkel, Geometrical relations between Vallarta (MX), pp. 193 –196. space time block code designs and com - H. Boche, M. Wiczanowski, Stability-optimal plexity reduction, IEEE Trans. on Inform. transmission policy for multiple antenna Y. Gao, M. Schubert, Power allocation for Theory, vol. 52, no. 12 (2006), pp. 5324– 5335. multiple access channel in the geometric multi-group multicasting with beam forming, view (invited), Signal Processing, Special Proc. Int. ITG/IEEE Workshop on Smart Antennas O. Henkel, Space frequency codes from Section: Advances in Signal Processing-assisted (WSA 2006), Ulm (DE), on CD-ROM. spherical codes, Proc. IEEE Int. Symp. on Cross-layer Designs, vol. 86, no. 8 (2006), pp. Information Theory (ISIT 2005), Adelaide (AU), 1815 –1833. A. Giovanidis, T. Haustein, Y. Hadisusanto, A. pp. 1305 –1309. Sezgin, D. Kim57, Multiuser scheduling using

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O. Henkel, Space time codes from permuta- Conf. on Communications (2006), Istanbul (TR), V. Jungnickel, H. Chen, V. Pohl, A MIMO RAKE tion codes, Proc. IEEE Global Telecommun. vol. 4, pp. 1526 –1531. receiver with enhanced interference cancel- Conf. (GLOBECOM 2006), San Francisco (CA, lation, Proc. 61st IEEE Semiannual Vehicular USA), on CD-ROM. E.A. Jorswieck, H. Boche, M. Weckerle58, Techn. Conf. (VTC 2005), Stockholm (SE), vol. 5, Optimal transmitter and jamming strategies pp. 3137– 3141. O. Henkel, Sphere-packing bounds in the in Gaussian MIMO channels, Proc. 61st IEEE Grassmann and Stiefel manifolds, IEEE Trans. Semiannual Vehicular Techn. Conf. (VTC 2005), V. Jungnickel, A. Forck, T. Haustein, C. Juchems59, on Inform. Theory, vol. 51, no. 10 (2005), pp. Stockholm (SE), vol. 2, 978 – 982. W. Zirwas7, Gigabit mobile communications 3445 – 3456. using real-time MIMO-OFDM signal proces- E.A. Jorswieck, W. B. Chamekh, M. Weckerle58, sing, book chapter in MIMO System Technology O. Henkel, G. Wunder, Space frequency codes Optimal chunk processing for multi-user for Wireless Communications, ed. G. Tsoulos, from sphere packings, Proc. Int. ITG/IEEE MIMO OFDM wireless systems, Proc. 17th Taylor & Francis, CRC Press, March 2006. Workshop on Smart Antennas (WSA 2005), IEEE Int. Symp. on Personal, Indoor and Mobile Duisburg (DE), on CD-ROM. Radio Communications (PIMRC 2006), Helsinki V. Jungnickel, A. Forck, T. Haustein, S. Schiffer - (FI), on CD-ROM. mueller, C. von Helmolt, F. Luhn59, M. Pollock59, S. Jaeckel, V. Jungnickel, Multi-cell outdoor C. Juchems59, M. Lampe60, W. Zirwas7, J. MIMO-measurements, Proc. VDE Kongress E.A. Jorswieck, T. Oechtering, H. Boche, Perfor- Eichinger7, E. Schulz7, 1 Gbit/s MIMO-OFDM (2006), Aachen (DE), on CD-ROM. mance analysis of combining techniques transmission experiments, Proc. 62nd IEEE with correlated diversity, Proc. IEEE Wireless Semiannual Vehicular Techn. Conf. (VTC 2005), L. Jiang, L. Thiele, V. Jungnickel, On the model- Communications and Networking Conference Dallas (TX, USA), vol. 2, pp. 861– 866. ling of polarized MIMO channel, 13th (WCNC 2005), New Orleans (MS, USA), vol. 2, European Wireless (EW 2007), Paris (FR), on CD- pp. 849 – 854. V. Jungnickel, T. Hindelang, T. Haustein, W. ROM. Zirwas7, SC-FDMA waveform design, perfor- E.A. Jorswieck, A. Sezgin, H. Boche, Outage mance, power dynamics and evolution to E. Jorswieck, Transmission strategies for the probability of OSTBC: Optimal transmit MIMO, IEEE Int. Conf. on Portable Information MIMO MAC, in ‘Smart Antennas – State-of- strategy and suboptimality of odd number Devices (Portable 2007), Orlando (CA, USA). the-Art’, EURASIP Book Series on Signal Proces - of transmit antennas, Proc. IEEE Int. Conf. on sing and Communications, Hindawi Publishing Acoustics, Speech, and Signal Processing (ICAS- V. Jungnickel, S. Jaeckel, L. Thiele, U. Krueger, Corporation (2005), pp. 423 – 441. SP 2006), Toulouse (FR), vol. 4, pp. 177–180. A. Brylka, C. von Helmolt, Capacity measurements in a multicell MIMO system, Proc. IEEE E. A. Jorswieck, H. Boche, Delay-limited cap - E.A. Jorswieck, A. Sezgin, Y. Gao, D. Kim57, On Global Telecommun. Conf. (GLOBECOM 2006), acity of fading MIMO channels, Proc. Int. the tradeoff between feedback signaling San Francisco (CA, USA), on CD-ROM. ITG/IEEE Workshop on Smart Antennas (WSA and performance for tile based MIMO- 2005), Duisburg (DE), on CD-ROM. OFDMA systems, Proc. Intern. Symp. On Wire- S. Litsyn61, G. Wunder, Generalized bounds less Personal Multimedia Communications on the crest-factor distribution of OFDM E.A. Jorswieck, H. Boche, Delay-limited cap- (WPMC 2006), San Diego, (CA, USA), on CD- signals with applications to code design, acity of parallel fading channels, Proc. 6th ROM. IEEE Trans. on Inform. Theory, vol. 52, no. 3 IEEE Workshop on Signal Processing Advances (2006), pp. 992 – 1006. in Wireless Communications (SPAWC 2005), P. Jung, Precoding for 2 × 2 doubly-dispersive New York (NY, USA), pp. 495– 499. WSSUS channels, Proc. 6th Int. ITG-Conf. on T. Michel, G. Wunder, A (not so) many user Source and Channel Coding (SSC 2006), sum capacity analysis for the MIMO OFDM E.A. Jorswieck, H. Boche, MIMO transceiver Munich (DE), on CD-ROM. broadcast channel, Proc. Int. ITG/IEEE Work - design via majorization theory, Foundations shop on Smart Antennas (WSA 2005), Duisburg and Trends in Communications and Information P. Jung, Weighted norms of ambiguity func- (DE), on CD-ROM. Theory, vol. 4, June 2007, now Publishers Inc., tions and Wigner distributions, Proc. IEEE Int. Boston-Delft. Symp. on Information Theory (ISIT 2006), T. Michel, G. Wunder, Minimum rates Seattle, (WA, USA), pp. 1519 –1523. scheduling for OFDM broadcast channels, E.A. Jorswieck, H. Boche, Multiple-antenna Proc. IEEE Int. Conf. on Acoustics, Speech, and capacity in the low-power regime: Channel P. Jung, G. Wunder, A group-theoretic ap - Signal Processing (ICASSP 2006), Toulouse (FR), knowledge and correlation, Proc. IEEE Int. proach to the WSSUS pulse design problem, on CD-ROM. Conf. on Acoustics, Speech, and Signal IEEE Int. Symp. on Information Theory (ISIT Processing (ICASSP 2005), Philadelphia (PA, 2005), Adelaide, (AU), pp. 870 – 874. T. Michel, G. Wunder, Optimal and low com- USA), vol. 3, pp. 385 – 388. plexity suboptimal transmission schemes for P. Jung, G. Wunder, On time-variant dis- MIMO-OFDM broadcast channels, Proc. IEEE E.A. Jorswieck, H. Boche, Outage probability tortions in multicarrier transmission with Int. Conf. on Communications (ICC 2005), in multiple antenna systems, Europ. Transac - application to frequency offsets and phase Seoul (KR), vol. 1, pp. 438 – 442. tion on Telecommunications (ETT), vol. 18, no. noise, IEEE Trans. on Communications, vol. 53, 3, pp. 217– 233. no. 9 (2005), pp. 1561–1570. T. Michel, G. Wunder, Solution to the sum power minimization problem under given E.A. Jorswieck, H. Boche, Performance analy- P. Jung, G. Wunder, The WSSUS pulse design rate requirements for the OFDM multiple sis of MIMO systems in spatially correlated problem in multicarrier transmission, IEEE access channel, Proc. 43rd Annual Allerton fading using matrix-monotone functions, Trans. on Communications, in press. Conf. on Communication, Control, and Com- IEICE Trans. Fundamentals, vol. E89-A, no. 5 puting (2005), Monticello (IL, USA), on CD- (2006), pp. 1454 –1472. V. Jungnickel, Mobile Zugangstechniken für ROM. Datenraten bis in den Gbit/s Bereich (in - E.A. Jorswieck, H. Boche, Throughput analysis vited), ITG-Fachkonferenz Breitbandversorgung T. Michel, G. Wunder, Sum rate iterative of cellular downlink with different types of (2007), Berlin (DE). water-filling for Gaussian MIMO broadcast channel state information, Proc. IEEE Int. channels, Proc. Intern. Symp. On Wireless

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Personal Multimedia Communications (WPMC M.A. Piqueras62, G. Grosskopf et al., Optically S. Schiffermüller, V. Jungnickel, Practical chan- 2006), San Diego (CA, USA), on CD-ROM. beamformed beam-switched adaptive nel interpolation for OFDMA, Proc. IEEE antennas for fixed and mobile broad-band Global Telecommun. Conf. (GLOBECOM 2006), T. Michel, G. Wunder, Throughput aware wireless access networks (invited), IEEE Trans. San Francisco (CA, USA), on CD-Rom. power-balancing for the MIMO Gaussian on Microwave Theory and Techniques, vol. 54, MAC, Proc. 8th IEEE Workshop on Signal no. 2 (2006), pp. 887– 899. C. Schnurr, S. Stanczak, On correlated binary Processing Advances in Wireless Communi - data: Bounds, optimal sequences, and their cations (SPAWC 2007), Helsinki (FI), on CD- V. Pohl, H. Boche, N. Vucic, Relation between dependence on stochastic interactions, Proc. ROM. robustness and noise enhancement of 6th Int. ITG-Conf. on Source and Channel causal inverses for MIMO systems, Proc. Int. Coding (SCC 2006), Munich (DE), on CD-ROM. T. Michel, C. Zhou, G. Wunder, A generic ITG/IEEE Workshop on Smart Antennas (WSA OFDM downlink scheduling policy in - 2006), Ulm (DE), on CD-ROM. C. Schnurr, S. Stanczak, On the bit error pro- corporating service induced rate constraints, bability in CDMA channels with correlated 15th IST Mobile & Wireless Communications V. Pohl, V. Jungnickel, C. von Helmolt, The binary data: Bounds and optimal sequences, Summit (2005), Myconos (GR), on CD-ROM. algebraic structure of frequency-selective Proc. 39th Asilomar Conf. on Signals, Systems, MIMO channels, IEEE Trans. on Signal Pro - and Computers (2005), Pacific Grove (CA, USA), T. Oechtering, H. Boche, Bidirectional relaying cessing, vol. 53, no. 7 (2005), pp. 2498 – 2512. pp. 116 – 120. using interference cancellation, ITG/IEEE Workshop on Smart Antennas (WSA 2007), V. Pohl, P.H. Nguyen, V. Jungnickel, C. v. C. Schnurr, S. Stanczak, A. Sezgin, The impact Vienna (AT), on CD-ROM. Helmolt, Continuous flat fading MIMO chan- of different MIMO strategies on the net- nels: Achievable rate and the optimal work-outage performance, ITG/IEEE Work- T. Oechtering, H. Boche, Capacity of Gaussian length of the training and data phase, IEEE shop on Smart Antennas (WSA 2007), Vienna FIR linear relay network, Proc. Int. Conf. on Trans. on Wireless Commun., vol. 4, no. 4 (AT), on CD-ROM. Wireless Networks, Communications, and (2005), pp. 1889 –1900. Mobile Computing (WirelessCom 2005), Maui M. Schubert, H. Boche, A generic approach to (HI, USA), vol. 2, pp. 1307– 1312. M. Schellmann, Improvements for time and QoS-based transceiver optimization, IEEE frequency synchronization in OFDM Trans. on Communications, August 2007. T. Oechtering, H. Boche, Optimal resource systems, 11th Int. OFDM-Workshop (InOWo allocation for a bidirectional regenerative 2006), Hamburg (DE), on CD-ROM. M. Schubert, H. Boche, Iterative multiuser half-duplex relaying, Int. Symp. on Informa - uplink and downlink beamforming under tion Theory and its Applications (ISITA 2006), M. Schellmann, V. Jungnickel, Effects of multi- SINR constraints, IEEE Trans. on Signal Pro - Seoul (KR), pp. 528 – 533. ple users’ CFOs in OFDM-SDMA up-link – an cessing, vol. 53, no. 7 (2005), pp. 2324 – 2334. interference model, Proc. IEEE Int. Conf. on T. Oechtering, H. Boche, Optimal transmit Communications (ICC 2006), Istanbul (TR), on M. Schubert, H. Boche, Properties and opera- strategies in multi-antenna bidirectional CD-ROM. tional characterization of proportionally relaying, Proc. IEEE Intern. Conf. on Acoustics, fair resource allocation (invited), Proc. 8th Speech, and Signal Processing (ICASSP 2007), M. Schellmann, V. Jungnickel, Instantaneous IEEE Workshop on Signal Processing Advances Honolulu (HI, USA), vol. 3, pp. 145 – 148. synchronization for the up-link of multi- in Wireless Communications (SPAWC 2007), user MIMO-OFDM systems, 10th International Helsinki (FI), special session. T. Oechtering, H. Boche, Piggyback a common OFDM-Workshop (2005), Hamburg (DE), on CD- message on bidirectional relaying, Intern. ROM. M. Schubert, H. Boche, QoS-based resource Workshop on Wireless Networks, Communi - allocation and transceiver optimization, cation, Cooperation and Competition (WNC3), M. Schellmann, V. Jungnickel, C. von Helmolt, Foundations and Trends in Communications and Limassol (CY), on CD-ROM. On the value of spatial diversity for the Information Theory, vol. 2, no. 6 (2005), now synchronisation in MIMO-OFDM systems, Publishers Inc., Boston-Delft, pp. 383 – 529. T. Oechtering, H. Boche, Relay selection in Proc. 16th IEEE Int. Symp. on Personal, Indoor bidirectional relay communication, Proc. 8th and Mobile Radio Communications (PIMRC M. Schubert, H. Boche, QoS control for multi- IEEE Workshop on Signal Processing Advances 2005), Berlin (DE), on CD-ROM. user networks – a joint approach to receiver in Wireless Communications (SPAWC 2007), design and resource allocation, Proc. 19th Helsinki (FI), on CD-ROM. M. Schellmann, V. Jungnickel, A. Sezgin, E. Int. Teletraffic Congress (ITC19) 2005, Beijing Costa7, Rate-maximized switching between (CN), pp. 1977–1986. T. Oechtering, H. Boche, Stability region of an spatial transmission modes, Proc. 40th efficient bidirectional regenerative half- Asilomar Conf. on Signals, Systems, and Com - M. Schubert, H. Boche, Robust resource allo- duplex relaying protocol, Proc. IEEE puters (2006), Monterey (CA, USA), on CD- cation, Proc. IEEE Information Theory Workshop Information Theory Workshop (ITW 2006), ROM. (ITW 2006), Chengdu (CN), pp. 556 – 560. Chengdu (CN), pp. 380 – 384. M. Schellmann, A. Sezgin, G. Wunder, H. M. Schubert, H. Boche, S. Stanczak, Joint power T. Oechtering, C. Schnurr, I. Bjelakovic, H. Boche, Halbauer9, R. Muenzner9, Performance of the control and multiuser receiver design – fair- Achievable rate region of a two phase bi- WiMAX ranging process in high mobility ness issues and cross-layer optimization, Proc. directional relay channel, Proc. 41th Con- environments, Proc. Int. Symp. on Wireless 14th IST Mobile and Wireless Commun ications ference on Information Sciences and Systems Personal Multimedia Communications (WPMC Summit 2005, Dresden (DE), on CD-ROM. (CISS 2007), Baltimore (MD, USA), on CD-ROM. 2006), San Diego (CA, USA), on CD-ROM. M. Schubert, H. Boche, S. Stanczak, Strict T. Oechtering, B. Schubert, H. Boche, FIR linear M. Schellmann, S. Stanczak, Multi-user MIMO convexity of the QoS feasible region for relay network with frequency selective channel estimation in the presence of car- log-convex interference functions, Proc. 40th channels, Proc. IEEE Int. Conf. on Communi - rier frequency offsets, Proc. 39th Asilomar Asilomar Conf. on Signals, Systems, and Com - cations (ICC 2006), Istanbul (TR), vol. 9, pp. Conf. on Signals, Systems, and Computers, puters (2006), Pacific Grove (CA, USA), on CD- 4065 – 4070. Pacific Grove (CA, USA), pp. 462 – 466. ROM.

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M. Schubert, S. Shi, MMSE transmit opti- A. Sezgin, E. Jorswieck, H. Boche, Performance S. Shi, M. Schubert, H. Boche, Transceiver mization with interference pre-compen - optimization of open-loop MIMO systems optimization for multi-user MIMO systems: sation, Proc. 61st IEEE Semiannual Vehicular with orthogonal space-time block codes, min-max relative user-MSE under total Techn. Conf. (VTC 2005), Spring, Stockholm IEEE Signal Processing Letters, vol. 14, no. 1, pp. power constraint, Int. Symp. on Information (SE), vol. 2, pp. 845 – 849. 13 – 16, January 2007. Theory and its Applications (ISITA 2006), Seoul (KR), pp. 348 – 353. M. Schubert, S. Shi, H. Boche, Iterative trans- A. Sezgin, E.A. Jorswieck, H. Boche, E. Costa7, ceiver optimization for linear multiuser Utilizing channel mean information with S. Stanczak, H. Boche, On the convexity of MIMO channels with per-user MMSE requi- MMSE detection for LDC in MIMO systems, feasible QoS regions, IEEE Trans. on Infor - rements (invited paper), Proc. 14th Int. Europ. Proc. IEEE Int. Symp. on Information Theory (ISIT mation Theory, vol. 53, no. 2, pp. 779–783, Signal Processing Conf. (EUSIPCO 2006), 2006), Seattle (WA, USA), pp. 1569 – 1573. February 2007. Florence (IT), on CD-ROM. A. Sezgin, E.A. Jorswieck, E. Costa7, Optimal S. Stanczak, H. Boche, On the existence and M. Schubert, S. Shi, E.A. Jorswieck, H. Boche, transmit strategies for QSTBC in MIMO uniqueness of proportionally fair power Downlink sum-MSE transceiver optimization Ricean channels with linear detection, Proc. allocation, Proc. IEEE Information Theory for linear multi-user MIMO systems, Proc. 16th IEEE Int. Symp. on Personal, Indoor and Workshop (ITW 2006), Chengdu (CN), pp. 39th Asilomar Conf. on Signals, Systems, and Mobile Radio Communications (PIMRC 2005), 561 – 565. Computers 2005, Pacific Grove (CA, USA), Berlin (DE), on CD-ROM. pp. 1424 –1428. S. Stanczak, H. Boche, The infeasible SIR A. Sezgin, P. Jung, M. Schellmann, H. Halbauer9, region is not a convex set, IEEE Trans. on A. Sezgin, On mutual information of stacked R. Muenzner9, On the impact of mobility on Communications, vol. 54, no. 11 (2006), pp. OSTBC, Proc. IEEE Global Telecommun. Conf. the channel estimation in WIMAX OFDMA- 1905 – 1907. (GLOBECOM 2006), San Francisco (CA, USA), uplink, Proc. 17th IEEE Int. Symp. on Personal, on CD-ROM. Indoor and Mobile Radio Communications S. Stanczak, H. Boche, Towards a better (PIMRC 2006), Helsinki (FI), on CD-ROM. understanding of the quality-of-service A. Sezgin, H. Boche, Iterative decoding of tradeoff in multiuser multiple antenna wrapped space-time codes, IEEE Trans. on A. Sezgin, M. Schellmann, V. Jungnickel, E. systems, in: ‘Smart Antennas – State-of-the- Signal Processing, vol. 53, no. 5 (2005), pp. Costa7, Throughput analysis of diversity and Art’, EURASIP Book Series on Signal Processing 1937–1941. multiplexing schemes for MIMO-SIC OFDM and Communications, Hindawi Publishing systems, Proc. 40th Asilomar Conf. on Signals, Corporation (2005), pp. 521 – 543. A. Sezgin, O. Henkel, Capacity, BER and Systems, and Computers (2006), Monterey (CA, coding gain analysis for rate one QSTBC: a USA), on CD-ROM. S. Stanczak, H. Boche, M. Wiczanowski, Strict general approach, Proc. 39th Asilomar Conf. log-convexity of the minimum power on Signals, Systems, and Computers (2005), S. Shi, M. Schubert, Iterative MMSE opti- vector, Proc. IEEE Int. Symp. on Information Pacific Grove (CA, USA), pp. 1273 –1277. mization for multiuser MIMO systems, Proc. Theory (ISIT 2006), Seattle (WA, USA), pp. Int. ITG/IEEE Workshop on Smart Antennas 2471 – 2475. A. Sezgin, O. Henkel, Stacked OSTBC: Error (WSA 2006), Ulm (DE), on CD-ROM. performance and rate analysis, IEEE Trans. on S. Stanczak, H. Boche, M. Wiczanowski, Signal Processing, accepted. S. Shi, M. Schubert, MMSE region, Proc. 16th Towards a better understanding of medium IEEE Int. Symp. on Personal, Indoor and Mobile access control for multiuser beamforming A. Sezgin, E.A. Jorswieck, Capacity achieving Radio Communications (PIMRC 2005), Berlin systems, Proc. IEEE Wireless Communications high rate space-time block codes, IEEE (DE), on CD-ROM. and Networking Conf. (WCNC 2005), New Communications Letters, vol. 9, no. 5 (2005), Orleans (MS, USA), vol. 2, pp. 689 – 694. pp. 435 – 437. S. Shi, M. Schubert, H. Boche, Capacity balancing for multiuser MIMO systems, Proc. IEEE S. Stanczak, M. Wiczanowski, Distributed fair A. Sezgin, E.A. Jorswieck, Impact of the Int. Conf. on Acoustics, Speech, and Signal power control for wireless networks: object - mapping strategy on the performance of Processing (ICASSP 2007), Honolulu (HI, USA), ives and algorithms (invited), Proc. 43rd APP decoded space-time block codes, IEEE vol. 3, 397– 400. Annual Allerton Conf. on Communication, Trans. on Signal Processing, vol. 53, no. 12 Control, and Computing (2005), Monticello (IL, (2005), pp. 4685 – 4690. S. Shi, M. Schubert, H. Boche, Computational USA), on CD-ROM. efficient transceiver optimization for multi- A. Sezgin, E.A. Jorswieck, On the performan- user MIMO systems: power minimization S. Stanczak, M. Wiczanowski, H. Boche, ce of partial feedback based orthogonal with user-MMSE requirements, Proc. 40th Distributed power control for optimizing a block coding, Proc. 62nd IEEE Semiannual Asilomar Conf. on Signals, Systems, and Com - weighted sum of QoS values, Proc. IEEE Vehicular Techn. Conf. (VTC 2005), Dallas (TX, puters 2006, Pacific Grove (CA, USA), on CD- Global Telecommun. Conf. (GLOBECOM 2005), USA), vol. 3, pp. 1504 –1508. ROM. St. Louis (MO, USA), pp. 3539 – 3543.

A. Sezgin, E.A. Jorswieck, Tight upper bound S. Shi, M. Schubert, H. Boche, Downlink S. Stanczak, M. Wiczanowski, H. Boche, on the outage probability of QSTBC, IEEE MMSE transceiver optimization for multi- Distributed utility-based power control: Communications Letters, vol. 10, no. 11 (2006), user MIMO systems: duality and sum-MSE objectives and algorithms, IEEE Trans. on pp. 784 –786. minimization, IEEE Trans. on Signal Processing, Signal Processing, accepted. accepted. A. Sezgin, E.A. Jorswieck, H. Boche, On the S. Stanczak, M. Wiczanowski, H. Boche, Theory average rate of precoded QSTBC in MIMO S. Shi, M. Schubert, H. Boche, Downlink and algorithms for resource allocation pro- channels with non-zero mean, Proc. 7th IEEE MMSE transceiver optimization with layer- blems in wireless networks, Lecture Notes in Workshop on Signal Processing Advances in MSE requirements, 1st Int. Conf. on Computer Science, Springer-Verlag (2006), Wireless Communications (SPAWC 2006), Communications and Networking in China LNCS 4000. Cannes (FR), on CD-ROM. (ChinaCom 2006), Beijing (CN), on CD-ROM.

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S. Stanczak, G. Wunder, H. Boche, Pilot-based its Applications (ISITA 2006), Seoul (KR), pp. Theory Workshop (ITW 2006), Punta del Este multipath channel estimation for uplink 534 – 539. (UY), on CD-ROM. CDMA systems: lower bounds and opitmal pilot sequences, IEEE Trans. on Signal Pro - M. Wiczanowski, H. Boche, S. Stanczak, Power G. Wunder, T. Michel, C. Zhou, A framework cessing, vol. 54, no. 2 (2006), pp. 512 – 519. allocation and resource assignment in the for resource allocation in OFDM broadcast view of blocking and antiblocking poly - systems (invited), Proc. 14th Internat. European L. Thiele, V. Jungnickel, Out-of-cell channel hedra, Proc. IEEE Information Theory Workshop Signal Processing Conf. (EUSIPCO 2006), statistics at 5.2 GHz, Proc. 1st Europ. Conf. on (ITW 2006), Chengdu (CN), pp. 566 – 570. Florence (IT), on CD-ROM. Antennas and Propagation (EuCAP 2006), Nice (FR), on CD-ROM. M. Wiczanowski, H. Boche, S. Stanczak, G. Wunder, C. Zhou, S. Kaminski9, H.E. Bakker9, Unifying characterization of max-min Concept of an OFDM HSDPA air interface L. Thiele, M. Peter, V. Jungnickel, Statistics of fairness in wireless networks by graphs, for UMTS downlink, Proc. 14th IST Mobile & the Ricean K-factor at 5.2 GHz in an urban Proc. IEEE Int. Conf. on Commun. (ICC 2007), Wireless Communication Summit (2005), macro-cell scenario, Proc. 17th IEEE Int. Symp. Glasgow (UK), on CD-ROM. Dresden (DE), on CD-ROM. on Personal, Indoor and Mobile Radio Communi - cations (PIMRC 2006), Helsinki (FI), on CD-ROM. M. Wiczanowski, Y. Chen, S. Stanczak, H. G. Wunder, C. Zhou, T. Michel, Delay and Boche, Optimal energy control in energy- buffer size bounds for OFDM broadcast N. Vucic, H. Boche, Causal channel inversion constrained wireless networks with random systems , Int. Symp. on Information Theory and for MIMO ISI systems: equalization error arrivals under stability constraints, Proc. 6th its Applications (ISITA 2006), Seoul (KR), pp. modelling and robustness, Proc. 5th MATH- IEEE Workshop on Signal Processing Advances 717–722. MOD Conf 2006, Vienna (AT), on CD-ROM. in Wireless Communications (SPAWC 2005), New York (NY, USA), pp. 831– 836. G. Wunder, C. Zhou, T. Michel, Minimum N. Vucic, H. Boche, Equalization for MIMO delay and buffer length bounds for stable ISI systems using channel inversion under M. Wiczanowski, A. Feistel, S. Stanczak, H. OFDM broadcast systems, Int. Symp. on causality, stability and robustness con- Boche, On energy cost of bit and bit/s in Information Theory and its Applications (ISITA straints, Proc. IEEE Intern. Conf. on Acoustics, multiantenna wireless networks under 2006), Seoul (KR), on CD-ROM. Speech, and Signal Processing (ICASSP 2006), hardware constraints, ITG/IEEE Workshop on Toulouse (FR), vol. 4, pp. 141–144. Smart Antennas (WSA 2007), Vienna (AT), on C. Zhou, G. Wunder, H.E. Bakker9, S. Kaminski9, CD-ROM. OFDM-HSDPA: conceptual approach, simula- N. Vucic, M. Schubert, Antenna selection for tion methodology and throughput perfor- BER performance improvement in multi- M. Wiczanowski, S. Stanczak, H. Boche, mance, 10th Int. OFDM-Workshop (2005), antenna systems with MMSE-SIC detection, Autonomous QoS control for wireless mesh Hamburg (DE), on CD-ROM. Proc. 61st IEEE Semiannual Vehicular Techn. and ad-hoc networks – the generalized Conf. (VTC 2005), Spring, Stockholm (SE), vol. Lagrangean approach (invited), Proc. 14th Int. C. Zhou, G. Wunder, T. Michel, Utility maxi- 2, pp. 855 – 858. Europ. Signal Processing Conf. (EUSIPCO 2006), mization for OFDMA systems over discrete Florence (IT), on CD-ROM. sets, Proc. IEEE Int. Conf. on Commun. (ICC S. Wahls, H. Boche, Stable and causal LTI-pre- 2007), Glasgow (UK), on CD-ROM. coders and equalizers for MIMO-ISI channels M. Wiczanowski, S. Stanczak, H. Boche, with optimal robustness properties, ITG/IEEE Distributed optimization and duality in QoS W. Zirwas7, E. Schulz7, J. H. Kim7, V. Jungnickel, Workshop on Smart Antennas (WSA 2007), control for wireless best-effort traffic, Proc. M. Schubert, Distributed organization of Vienna (AT), on CD-ROM. 39th Asilomar Conf. on Signals, Systems, and cooperative antenna systems, 12th Europ. Computers 2005, Pacific Grove (CA, USA), Wireless (2006), Athens (GR), on CD-ROM. D. Wang, E.A. Jorswieck, A. Sezgin, E. Costa7, pp. 30 – 35. Joint Tomlinson-Harashima precoding with W. Zirwas7, J. H. Kim7, V. Jungnickel, M. orthogonal space time block codes for M. Wiczanowski, S. Stanczak, H. Boche, Schubert, T. Weber, A. Ahrens, M. Haardt, multiuser MIMO OFDM systems, Proc. 61st Quadratically converging decentralized Distributed organization of coorperative IEEE Semiannual Vehicular Techn. Conf. (VTC power allocation algorithm for wireless antenna systems, book chapter in Distributed 2005), Spring, Stockholm (SE), vol. 2, pp. ad-hoc networks – the max-min framework, Antenna Systems – Open Architecture for 1017 – 1021. Proc. IEEE Int. Conf. on Acoustics, Speech, and Future Wireless Communications, ed. by H. Hu, Signal Processing (ICASSP 2006), Toulouse (FR), Y. Zhang, J. Luo, Auerbach Publications, CRC M. Wiczanowski, H. Boche, S. Stanczak, vol. 4, pp. 245 – 248. Press, May 2007. Characterization of max-min fair performance in large networks via Szemeredi’s M. Wiczanowski, S. Stanczak, Y. Chen, W. Zirwas7, E. Schulz7, M. Schubert, W. regularity lemma, Proc. IEEE Intern. Symp. Throughput-fairness trade-off in probabil - Mennerich, V. Jungnickel, L. Thiele, Coopera - on Information Theory (ISIT 2007), Nice (FR), istic medium access control for wireless ad tive antenna concepts for interference pp. 146 – 150. hoc networks, Proc. 61st IEEE Semiannual mitigation, 13th European Wireless (EW 2007), Vehicular Techn. Conf. (VTC 2005), Stockholm Paris (FR), on CD-ROM. M. Wiczanowski, H. Boche, S. Stanczak, (SE), vol. 4, pp. 2468 – 2472. Characterization of optimal resource allocation in cellular networks – optimization G. Wunder, T. Michel, Approaching the delay- Electronic Imaging theoretic view and algorithmic solutions, limited OFDM broadcast capacity with Proc. 19th Int. Teletraffic Congress (ITC19) OFDMA, Proc. 7th IEEE Workshop on Signal A. Alatan63, Y. Yemez64, U. Güdükbay65, X. 2005, Beijing (CN), pp. 2199 – 2208. Processing Advances in Wireless Communi ca - Zabulis66, K. Müller, C. Erdem67, C. Weigel68, tions (SPAWC 2006), Cannes (FR), on CD-ROM. and A. Smolic, Scene representation tech - M. Wiczanowski, H. Boche, S. Stanczak, nologies for 3DTV – A survey (invited), IEEE Characterization of optimal resource assign- G. Wunder, T. Michel, Delay-limited OFDM Transactions on Circuits and Systems for Video ments in the framework of blocking system broadcast capacity region and impact of Technology, Special Issue on Multi-view Video theory, Int. Symp. on Information Theory and system parameters, Proc. IEEE Information Coding and 3DTV, scheduled November 2007.

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N. Atzpadin, J. Mulligan69, Stereo analysis, in: C. Fehn, 3D TV broadcasting, in: 3D Video - S. Heymann, A. Smolic, K. Müller, T. Wiegand, 3D Videocommunication, Schreer, Kauff, Sikora communication, Schreer, Kauff, Sikora (Eds), B. Froehlich 78, Real-time video capture for (Eds), Wiley 2005, pp. 115 – 132. Wiley, 2005, pp. 23– 38. illumination reconstruction in augmented reality applications, ACM SIGGRAPH 2005 P. Chojecki, How to increase website us- C. Fehn, N. Atzpadin, M. Müller, O. Schreer, A. Symp. on Interactive 3D Graphics and Games, ability with link annotations, Proc. 20th Int. Smolic, R. Tanger, P. Kauff, An advanced 3DTV Washington DC (WA, USA), April 2005, poster Sym. on Human Factors in Telecommunication concept providing interoperability and and on CD-ROM. (HFT 06), Sofia Antipolis (FR), March 2006. scalability for a Wide Range of Multi-Base- line Geometries, Proc. of 13th Int. Conf. on T. Hinz, H. Schwarz, T. Wiegand, FGS for field R. Civanlar64, J. Ostermann70, H. Ozaktas65, Image Processing (ICIP 2006), Atlanta (GA, USA), pictures and MBAFF frames, Joint Video Team A. Smolic, and J. Watson71, Special issue on October 2006, pp. 2961 – 2964. (JVT), Bangkok (TH), JVT-R062, Jan. 2006, three-dimensional video and television – http://ftp3.itu.org/av-arch/jvt-site. Guest Editorial, Signal Processing: Image C. Fehn, C. Weissig, I. Feldmann, M. Müller, Communication, in press. P. Eisert, P. Kauff, H. Bloß72, Creation of high- T. Hinz, H. Schwarz, T. Wiegand, First concepts resolution video panoramas of sport events, for inter-layer prediction with MBAFF frames, C. Conomis, Conics-based homography Proc. of IEEE Int. Symp. on Multimedia, San Joint Video Team (JVT), Bangkok (TH), JVT-R063, estimation from invariant points ans pole- Diego (CA, USA), Dec. 2006, pp. 291 – 298. Jan. 2006, http://ftp3.itu.org/av-arch/jvt-site. polar relationships, 3rd Int. Symp. on 3D Data Processing, Visualization and Transmission (3D- I. Feldmann, P. Eisert, P. Kauff, Towards T. Hinz, H. Schwarz, T. Wiegand, MBAFF imple- PVT 2006), Chappel Hill (NC, USA), on CD- arbitrary camera movements for image mentation in the JSVM Software, Joint Video ROM. cube trajectory analysis, Proc. Int. Conf. on Team (JVT), Bangkok (TH), JVT-R061, Jan. 2006, Image Processing (ICIP 2005), Genova (IT), Sept. http://ftp3.itu.org/av-arch/jvt-site. C. Conomis, S. Pastoor, R. de la Barré, H. Röder, 2005, vol. III, pp. 812 – 815. A 3D free-viewing mixed reality system with K. Hopf, Novel user interaction technologies video-based tracking, Workshop on Immersive I. Feldmann, M. Heinrichs, P. Kauff, P. Eisert, in 3D display systems, Proc. 7th International Communication and Broadcast Systems (ICOB Handling of homogeneous regions for Meeting on Information Display (IMID 2007), 3D), Berlin, Oct. 2005, on CD-ROM. image cube trajectory analysis, Proc. 6th Int. August 27– 31, 2007, Daegu (KR), in press. Workshop on Image Analysis for Multimedia J. Eberspächer5, W. v. Reden (Eds), Umhegt Interactive Services (WIAMIS 2005), Montreux K. Hopf, P. Chojecki, F. Neumann, D. Przewozny, oder abhängig – Der Mensch in einer digi - (CH), April 2005, on CD-ROM. Novel autostereoscopic single-user displays talen Umgebung, Springer Berlin Heidelberg with user interaction, Proc. of SPIE, Three- 2006, ISBN-10 3-50-28143-6. K. Franke73 K.-R. Müller74, B. Nickolay73, R. Dimensional TV, Video, and Display V, vol. 6392, Schäfer, Pattern recognition LNCS 4174 Boston (MA, USA), October 2006. P. Eisert, Reconstruction of volumetric 3D “28th DAGM Symposium”, Berlin, Sept. 2006, models, in: 3D Videocommunication, Schreer, Springer Verlag, ISBN 3-540-44412-2. P. Kauff, N. Atzpadin, C. Fehn, M. Mueller, O. Kauff, Sikora (Eds), Wiley, 2005, pp. 133– 150. Schreer, A. Smolic, R. Tanger, Depth map cre- A. Fuldseth75, T. Wiegand, Draft new Annex ation and image-based rendering for ad - P. Eisert, Virtual conferencing using 3D B/H.241, ITU-T/SG16/Q.1, Geneva (CH), April vanced 3DTV services providing interopara- model-assisted image-based rendering, Proc. 2006. bility and scalability, Signal Processing: Image 2nd Conf. on Visual Media Production CVMP Com munication. Special Issue on 3DTV, in press. 2005, London (UK), Nov. 2005, pp. 185 – 193. Ch. Hentschel, S. Stober76, A. Nürnberger76, M. Detyniecki77, Automatic image annotation P. Kauff, O. Schreer, Immersive videocon - P. Eisert, P. Kauff, A. Smolic, R. Schäfer, Free using a visual dictionary based on reliable ferencing, in: 3D Videocommunication, Schreer, viewpoint video – Der Nächste Schritt in der image segmentation, Proc. 5th Int. Workshop Kauff, Sikora (Eds), Wiley 2005, pp. 75 – 90. Unterhaltungselektronik, Fernseh- und on Adaptive Multimedia Retrieval (AMR 2007), Kinotechnik, FKTG, no. 5, 2006, pp. 59 – 64. Paris, in press. P. Kauff, A. Smolic, P. Eisert, C. Fehn, K. Müller, R. Schäfer, Data format and coding for free P. Eisert, J. Rurainsky, Geometry-assisted S. Heymann, K. Müller, A. Smolic, B. Froehlich78, viewpoint video, Proc. of Int. Broadcast Conf. image-based rendering for facial analysis and T. Wiegand, SIFT implementation and (IBC 2005), Amsterdam (NL), Sept. 2005, on and synthesis, Signal Processing: Image Com- optimization for general-purpose GPU, 15th CD-ROM. munication, vol. 21, no. 6, 2006, pp. 493 – 505. Int. Conf. in Central Europe on Computer Graphics, Visualization and Computer Vision H. Kirchhoffer79, D. Marpe, and T. Wiegand, P. Eisert, J. Rurainsky, Image-based rendering (WSCG ’07), Plzen (CZ), January 2007. A context modeling scheme for coding of and tracking of faces, Proc. Int. Conf. on texture refinement information, IEEE Int. Image Processing (ICIP 2005), Genova (IT), Sept. S. Heymann, A. Smolic, K. Müller, B. Froehlich78, Conf. on Image Processing (ICIP ’07), San 2005, pp. 1037–1040. Illumination reconstruction from real-time Antonio (TX, USA), Sept. 2007, accepted. video for interactive augmented reality, P. Eisert, J. Rurainsky, Rendering and analysis Int. Workshop on Image Analysis for Multimedia H. Kirchhoffer79, D. Marpe, and T. Wiegand: of faces using multiple images with 3D Interactive Services (WIAMIS’05), Montreux A generic context model for uniform-recon- geometry, Proc. 2nd Workshop on Immersive (CH), April 2005, on CD-ROM. struction based SNR-scalable representations Communication and Broadcast Systems, Berlin of residual texture signals, Europ. Signal (DE), October 2005, on CD-ROM. S. Heymann, A. Smolic, K. Müller, Y. Guo, J. Processing Conf. (EUSIPCO 2007), Poznan (PL), Rurainsky, P. Eisert, T. Wiegand, Representation, Sept. 2007, accepted. P. Eisert, J. Rurainsky, Y. Guo, U. Höfker, coding, and interactive rendering of high- Creation and scene composition for high- resolution panoramic images and video H. Kirchhoffer79, D. Marpe, T. Wiegand, resolution panoramas, Proc. 2nd Panoramic using MPEG-4, 2. Panoramic Photogrammetry Verification of JVT-S084 on RCP, Joint Video Photogrammetry Workshop, Berlin (DE), Febr. Workshop, Berlin (DE), Febr. 2005, on CD-ROM. Team (JVT), Geneva (CH), Doc. JVT-S074, April 2005, on CD-ROM. 2006, http://ftp3.itu.org/av-arch/jvt-site.

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H. Kirchhoffer79, D. Marpe, K. Mamou80, K. arithmetic coding, Proc. 14th Europ. Signal P. Merkle, A. Smolic, K. Müller, T. Wiegand, Müller, T. Wiegand: Proposed Modifications Processing Conf. (EUSIPCO ’06), Florence (IT), Comparative study of MVC prediction struc- to Residual Coding Part of Frame-based Sept. 2006, on CD-ROM. tures, JVT-V132, Marrakech (MA), Jan. 2007. Animated Mesh Compression, ISO/IEC JTC1/SC29/WG11, MPEG07/M14697, Lausanne, D. Marpe, H. Kirchhoffer79, T. Wiegand, CE3: P. Merkle, A. Smolic, K. Müller, and T. Wiegand, Switzerland, July 2007. Improved CABAC for PR slices, Joint Video Multi-view video plus depth representation Team (JVT), Doc. JVT-U082, Hangzhou (CN), and coding, IEEE Int. Conf. Image Processing S. Knorr20, A. Smolic, and T. Sikora20, From 2D- Oct. 2006, http://ftp3.itu.org/av-arch/jvt-site. (ICIP'07), San Antonio (TX, USA), Sept. 2007, to stereo- to multi-view video, 3DTV-CON accepted. 2007, Kos Island (GR), May 2007, accepted. D. Marpe, H. Kirchhoffer79, T. Wiegand, CE3: Verification JVT-U034 PR context model, P. Merkle, K. Müller, A. Smolic, T. Wiegand, A. Kubota81, A. Smolic, M. Magnor82, T. Chen83, Joint Video Team (JVT), Doc. JVT-U083, Statistical evaluation of spatio-temporal and M. Tanimoto84, Multi-view imaging and Hangzhou (CN), Oct. 2006, http://ftp3.itu.org/ prediction for multi-view video coding, 2nd 3DTV, IEEE Signal Processing Magazine, Special av-arch/jvt-site. Workshop on Immersive Communication and Issue on Multi-view Imaging and 3DTV, Broadcast Systems (ICOB ’05), Berlin (DE), Oct. scheduled November 2007. D. Marpe, H. Kirchhoffer79, T. Wiegand, CE5, 2005, on CD-ROM. Color Transform Issues and Related Results, G. Liebl5, T. Schierl, T. Wiegand, T. Stock- Joint Video Team (JVT), Geneva (GH), Doc. JVT- M. Morgos90, K. Ignasiak90, I. Feldmann, P. hammer85, Advanced wireless multiuser S073, April 2006, http://ftp3.itu.org/av-arch/jvt- Eisert, P. Leray91, M. Marcon92, Audiovisual video streaming using the scalable video site. scene rendering and interaction, Proc. coding extension of H.264/MPEG4-AVC, IEEE National Conf. on Radiocommunications and Int. Conf. on Multimedia and Expo (ICME ’06), D. Marpe, H. Kirchhoffer79, M. Winken, T. Broadcasting (KKRRiT 2005), Krakow (PL), June Toronton (CA), July 2006, on CD-ROM. Wiegand, Improved CABAC for PR slices, 2005, pp. 41 – 52. Joint Video Team (JVT), Doc. JVT-T077, Klagen - K. Mamou80, D. Marpe, K. Müller, T. Zaharia80, furt (AT), July 2006, http://ftp3.itu.org/av-arch/ L. Mühlbach, Bürgerdienste – mobil und F. Preteux80, Frame-based animated mesh jvt-site. kundennah, Proc. Fachkonferenz „Wachstums - compression: Integration of the CABAC impulse durch mobile Kommunikation“, arithmetic encoder, ISO/IEC JTC1/SC29/WG11, D. Marpe, G. Marten, H. L. Cycon88, A fast Münchner Kreis, Nov. 2006, pp. 113 – 127. MPEG07/M14493, San Jose (CA, USA), March renormalization technique for H.264/ 2007. MPEG4-AVC arithmetic coding, Proc. 51st L. Mühlbach, Mobile Bürgerdienste in Berlin Internationales Wissenschaftliches Kolloquium (MoBüD), Proc. „Synergien im E-Government“, D. Marpe, Adaptive context-based and tree- (IWK), Ilmenau University of Technology (DE), Workshop FH Brandenburg, Oct. 2006, Alcatel based algorithms for image coding and Sept. 11–15, 2006, on CD-ROM. SEL Stiftung für Kommunikationsforschung, in denoising, Mensch & Buch Verlag, Berlin (DE), press. ISBN 3-89820-835-4, 2005. D. Marpe, G. Marten, T. Wiegand, Fast CABAC renormalization for H.264/MPEG4-AVC, Joint L. Mühlbach, R. Sniehotta, R. Wagnitz93, D. Marpe, CE3: PR slice CABAC, Joint Video Video Team (JVT), Doc. JVT-U084, Hangzhou The office of citizen services in the box – Team (JVT), Doc. JVT-T303, Klagenfurt (AT), July (CN), Oct. 2006, http://ftp3.itu.org/av-arch/jvt- Citizen-friendly and secure mGovernment 2006, http://ftp3.itu.org/av-arch/jvt-site. site. services in Berlin, Proc. of the First Europ. Conf. on Mobile Government. Brighton (UK), D. Marpe, S. Gordon86, T. Wiegand, H.264/ D. Marpe, T. Wiegand, G. J. Sullivan89, The July 2005, on CD-ROM. MPEG4- AVC fidelity range ex tensions, H.264/MPEG4 advanced video coding tools, profiles, performance, and applica- standard and its applications (invited), IEEE K. Müller, P. Merkle, H. Schwarz, T. Hinz, A. tion areas, IEEE Int. Conf. on Image Processing Communications Magazine, vol. 44, no. 8 (Aug. Smolic, T. Wiegand, Multi-view video coding (ICIP ’05), Genova (IT), Sept. 2005, vol. I, pp. 2006), pp. 134 – 144. based on H.264/AVC using hierarchical B- 593 – 596. frames, Proc. PCS 2006, Picture Coding Sym - T. Meiers, MPEG-7 als Basis für eine Suche in posium, Beijing (CN), April 2006, on CD-ROM. D. Marpe, H. Kirchhoffer79, V. George87, P. Kauff, Multimedia Datenbanken, Proc. Electronic T. Wiegand, An adaptive color transform Imaging & the Visual Arts (EVA 2006), Berlin, K. Müller, A. Smolic, M. Droese, P. Voigt, T. approach and its application in 4:4:4 video 8. Nov. 2006, pp. 34 – 37. Wiegand, Reconstruction of a dynamic envir- coding, Proc. 14th Europ. Signal Processing onment with fully calibrated background Conf. (EUSIPCO 2006), Florence (IT), Sept. 4 – 8, P. Merkle, A. Smolic, K. Müller, and T. Wiegand: for traffic scenes, IEEE Transactions on Circuits 2006, on CD-ROM. Efficient compression of multi-view depth and Systems for Video Technology, vol. 15, no. data based on MVC, IEEE 3DTV Conf., Kos 4, April 2005, pp. 538 – 549. D. Marpe, H. Kirchhoffer79, V. George87, P. Kauff, (GR), May 2007. T. Wiegand, Macroblock-adaptive residual K. Müller, A. Smolic, M. Kautzner, P. Eisert, T. color space transforms for 4:4:4 video P. Merkle, K. Müller, A. Smolic, T. Wiegand, Wiegand, Rate-distortion-optimized predict - coding, Proc. IEEE ICIP ’06, Atlanta (GA, USA), Efficient compression of multi-view video ive compression of dynamic 3D mesh pp. 3157– 3160. exploiting inter-view dependencies based sequences (invited), Signal Processing: Image on H.264/MPEG4-AVC, IEEE Int. Conf. on Communication, vol. 21, is. 9, Special Issue on D. Marpe, H. Kirchhoffer79, V. George87, C. Fehn, Multimedia and Expo (ICME ’06), Toronto (CA), Interactive representation of still and dynamic P. Kauff, T. Wiegand, MB-adaptive residual July 2006, on CD-ROM. scenes, Oct. 2006, pp. 812 – 828. colour transform for 4:4:4 coding, Joint Video Team (JVT), Bangkok (TH), Doc. JVT-R071, P. Merkle, A. Smolic, K. Müller, and T. Wiegand, K. Müller, A. Smolic, M. Kautzner, T. Wiegand, Jan. 2006, http://ftp3.itu.org/av-arch/jvt-site. Coding efficiency versus complexity of MVC Rate-distortion optimization in dynamic prediction structures, Proc. Europ. Signal mesh compression, Proc. ICIP 2006, Int. Conf. D. Marpe, H. Kirchhoffer79, G. Marten, Fast Processing Conf. (EUSIPCO 2007), Poznan (PL), on Image Processing, Atlanta (GA, USA), Oct. renormalization for H.264/MPEG4-AVC Sept. 2007. 2006, pp. 533 – 536.

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K. Müller, X. Zabulis66, A. Smolic, T. Wiegand, J. Rurainsky, P. Eisert, Text2Video: Text-driven on Image Processing (ICIP ’05), Genova (IT), Evaluation of 3D reconstruction using multi- facial animation using MPEG-4, Proc. Visual Sept. 2005, on CD-ROM. view backprojection, 2nd Workshop on Im - Computation and Image Processing (VCIP), mersive Communication and Broadcast Sys tems Beijing (CN), China, vol. 5960, July 2005, on T. Schierl, M. Kampmann96, T. Wiegand, H.264/ (ICOB’05), Berlin (DE), Oct. 2005, on CD-ROM. CD-ROM. AVC interleaving for 3G wireless video stream ing, IEEE Int. Conf. on Multimedia and P. Ndjiki-Nya, M. Barrado, and T. Wiegand, R. Schäfer, Review and future directions for Expo (ICME ’05), Amsterdam (NL), July 2005, on Efficient full-reference assessment of image 3D-video (invited Keynote), Proc. of Picture CD-ROM. and video quality, IEEE Int. Conf. on Image Coding Symposium 2006, Beijing (CN), 24. – 26. Processing (ICIP’07), San Antonio (TX, USA), April 2006, on CD-ROM. T. Schierl, H. Schwarz, D. Marpe, T. Wiegand, Sept. 2007, accepted. Wireless broadcasting using the scalable R. Schäfer, J. Färber94, DXB – A System con- extension of H.264/AVC, IEEE Int. Conf. on P. Ndjiki-Nya, T. Hinz, C. Stüber, T. Wiegand, A cept for mobile broadcast services of tomor- Multimedia and Expo (ICME ’05), Amsterdam content-based video coding approach for row, Tagungsband der FKTG-Jahrestagung (NL), July 2005, pp. 884 – 887. rigid and non-rigid textures, IEEE Int. Conf. 2006, Potsdam (DE), May 2006, FKT vol. on Image Processing (ICIP ’06), Atlanta (GA, 6/2006, pp. 323 – 326. T. Schierl, K. Sühring, T. Wiegand, R. Schäfer, USA), Oct. 2006, pp. 3171 – 3174. J. Schwiertz97, G. Zurek-Terhard97, Neue Kon - R. Schäfer, H. Schwarz, D. Marpe, T. Schierl, T. zepte für integrierte DVB-H Playouts mit P. Ndjiki-Nya, G. Simo, T. Wiegand, Evaluation Wiegand, MCTF and scalability extension of hocheffizienter Videocodierung, Tagungs - of color image segmentation algorithms H.264/AVC and its application to video band, 11. ITG-Fachtagung Elektronische Medien based on histogram thresholding, Int. Work - trans mission, storage, and surveillance, Proc. Elektronische Medien: Systeme, Technologien, shop on Very Low Bitrate Video (VLBV ’05), of VCIP 2005, Peking (CN), July 2005, on CD- Anwendungen, Dortmund, 26. – 28.9.2005, on Sardinia (IT), Sept. 2005, pp. 214 – 222. ROM. CD-ROM.

P. Ndjiki-Nya, A. Smolic, T. Hinz, T. Wiegand, A T. Schierl, Signaling media decoding depend - T. Schierl, S. Wenger, Signaling media de - generic and automatic content-based ap - ency in session description protocol (SDP), coding dependency in Session Description proach for improved H.264/MPEG4-AVC Internet Engineering Task Force (IETF), Audio Protocol (SDP), Multiparty Multimedia Session video coding, IEEE Int. Conf. on Image Pro - Video Transport Group (avt), Montreal (CA), Control (mmusic) Working Group, Internet cessing (ICIP ’05), Genova (IT), Sept. 2005, pp. June 2006, see web. Engineering Task Force (IETF), Dec. 2006, see 874 – 877. web. T. Schierl, K. Gänger, C. Hellge, K. Grüneberg, P. Ndjiki-Nya, C. Stüber, T. Wiegand, A new D. Marpe, T. Stockhammer85, T. Wiegand, T. Schierl and T. Wiegand: Mobile video trans- generic texture synthesis approach for Video streaming in mobile ad hoc networks, mission using SVC (invited), IEEE Transactions enhanced H.264/MPEG4-AVC video coding, MobiMedia 2006, Sept. 2006, Alghero, Sardinia on Circuits and Systems for Video Technology, in Int. Workshop on Very Low Bitrate Video (VLBV (IT), on CD-ROM. press. ’05), Sardinia (IT), Sept. 2005, pp. 121 – 128. T. Schierl, K. Gänger, C. Hellge, T. Stock ham - O. Schreer, Stereoanalyse und Bildsynthese, P. Ndjiki-Nya, C. Stüber, and T. Wiegand, mer85, T. Wiegand, Multi source streaming Springer-Verlag, Berlin, Heidelberg, New York, Texture synthesis method for generic video for robust video transmission in mobile Tokyo, 2005, ISBN: 3-540-23439-X. sequences, IEEE Int. Conf. on Image Processing ad-hoc networks, IEEE Int. Conf. on Image (ICIP ’07), San Antonio (TX, USA), Sept. 2007. Processing (ICIP ’06), Atlanta (GA, USA), Oct. O. Schreer, P. Eisert, P. Kauff, R. Tanger, R. 2006, on CD-ROM. Englert98, Towards robust intuitive vision- L. Onural65, T. Sikora20, J. Ostermann70, A. Smolic, based user interfaces, Proc. of Int. Conf. on R. Civanlar64, J. Watson71, An assessment of T. Schierl, K. Gänger, C. Hellge, T. Stockham- Multimedia and Expo (ICME 2006), Toronto 3DTV technologies,Proc. NAB 2006, Las Vegas mer85, T. Wiegand, SVC-based multi-source (CA), July 2006, pp. 69 –72. (NA, USA), April 22 – 27, 2006, on CD-ROM. streaming for robust video transmission in mobile ad-hoc networks, IEEE Wireless O. Schreer, C. Fehn, N. Atzpadin, M. Müller, Ch. Petersohn, Sub-shots – Basic units of Communications Magazine, Oct. 2006, pp. A. Smolic, R. Tanger, P. Kauff, A flexible 3D TV video, Proc. IEEE Int. Conf. on Systems, Signals 96 – 103. system for different multi-baseline geo- and Image Processing, and EURASIP Conference metries, Proc. ICME 2006, Int. Conf. on Multi- Focused on Speech and Image Processing, T. Schierl, K. Gänger, C. Hellge, T. Wiegand, media and Expo, Toronto, Ontario (CA), July Multimedia Communications and Services T. Stockhammer85, SVC-based multi source 2006, pp. 1877– 1880. (CBMI 2007), Maribor (SI), on CD-ROM. streaming for robust video transmission in mobile ad-hoc networks (invited), IEEE O. Schreer, P. Kauff, T. Sikora20, 3D videocom- J. Ridge89, D. Marpe, and G. J. Sullivan89, AHG Wireless Communications Magazine, vol.13, munication, John Wiley & Sons, Chichester Report SVC quantization, CAVLC, CABAC, no.5, Oct. 2006, pp. 96 – 103. (UK), 2005, 0-470-02271-X. Joint Video Team, Marrakech (MA), Doc. JVT- V010, Jan. 2007. T. Schierl, S. Johansen95, C. Hellge, T. Stockham - O. Schreer, R. Tanger, P. Eisert, P. Kauff, B. mer85, and T. Wiegand, Distributed rate- Kaspar99, R. Englert98, Real-time avatar D. Runde, mGovernment – bürgernah und distortion optimization for rateless channel animation steered by live body motion, sicher, Proc. 10. Deutscher IT Sicherheitskon - coded scalable video in mobile ad hoc net- Proc. of 13th Int. Conf. on Image Analysis and gress, Bonn, May 2007, pp. 477– 493. works, IEEE Int. Conf. on Image Processing Processing (ICIAP 2005), Cagliari (IT), Sept. (ICIP ’07), San Antonio (TX, USA), Sept. 2007, 2005, pp.147– 154. J. Rurainsky, P. Eisert, Text2Video: A SMS to accepted. MMS conversion, Proc. 11. Dortmunder B. Schumitsch100, H. Schwarz, T. Wiegand, Fernsehseminar, Elektronische Medien: Systeme, T. Schierl, M. Kampmann96, T. Wiegand, 3GPP Optimization of transform coefficient Technologien, Anwendungen, Dortmund (DE), compliant adaptive wireless video strea- selection and motion vector estimation Sept. 2005, pp. 163-168. ming using H.264/MPEG4-AVC, IEEE Int. Conf. considering interpicture dependencies in

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hybrid video coding, IVCP 2005, San Jose (invited), IEEE Transactions on Circuits and A. Smolic, T. Sikora20, Coding and stand - (CA, USA), Jan. 2005, on CD-ROM. Systems for Video Technology, in press. ardization, in: O. Schreer, P. Kauff, and T. Sikora, (Eds), 3D Videocommunication, John H. Schwarz, T. Hinz, D. Marpe, T. Wiegand, H. Schwarz, D. Marpe, T. Wiegand, The scalable Wiley and Sons, Chichester (UK), 2005, pp. Constrained inter-layer prediction for sin- H.264/MPEG4-AVC extension – Technology 193 – 216. gle-loop decoding in spatial scalability, IEEE and applications (invited), Europ. Symp. on Int. Conf. on Image Processing (ICIP ’05), Mobile Media Delivery (EuMob 2006), Alghero, A. Smolic, R. Sondershaus102, N. Stefanosk70, L. Genova (IT), Sept. 2005, vol. 2, pp. 870 – 873. Sardinia (IT), Sept. 20, 2006, on CD-ROM. Vasa103, K. Mueller, J. Ostermann70, and T. Wiegand, A survey on coding of static and H. Schwarz, D. Marpe, T. Wiegand, Analysis of H. Schwarz, D. Marpe, T. Wiegand, J. Reichel101, dynamic 3D meshes, in press in “Three- hierarchical B pictures and MCTF, Proc. IEEE M. Wien56, Skip mode for SVC slice data Dimensional Television: Capture, Transmission, Int. Conf. on Multimedia & Expo (ICME 2006), syntax, Joint Video Team (JVT), Geneva (CH), and Display.”, Editors: Haldun M. Ozaktas and Toronto (CA), July 9-12, 2006, pp. 1929 – 1932. Doc. JVT-S068, April 2006, http://ftp3.itu.org/av- Levent Onural, Springer, Heidelberg, 2007, book arch/jvt-site. chapter. H. Schwarz, D. Marpe, T. Wiegand, Basic concepts for supporting spatial and SNR H. Schwarz and T. Wiegand, Implementation B. Stabernack, R. Großmann7, Design und scalability in the scalable H.264/MPEG4-AVC and performance of FGS, MGS, and CGS, Implementierung eines mobilen Endgerätes extension, Int. Conf. on Systems, Signals and Joint Video Team, Marrakech (MA), Doc. JVT- für DVB-H Empfang, Proc. Dortmunder Fern- Image Processing (IWSSIP 2005), Chalkida (GR), V126, Jan. 2007. sehse minar, ITG/FKTG Fachtagung, Dortmund Sept. 2005, on CD-ROM. (DE), Oct. 2005, pp. 71–78. H. Schwarz and T. Wiegand, R-D optimized H. Schwarz, D. Marpe, T. Wiegand, Closed- multi-layer encoder control for SVC, IEEE Int. B. Stabernack, H. Hübert, K.-I. Wels, A com - loop coding with quality layers, Joint Video Conf. on Image Processing (ICIP ’07), San pan ion chip for H.264/AVC video processing, Team (JVT), Nice (FR), Doc. JVT-Q030, Oct. Antonio (TX, USA), Sept. 2007. Proc. GSPx 2006, Santa Clara (CA, USA), Oct. 2005, http://ftp3.itu.org/av-arch/jvt-site. 2006, on CD-ROM. H. Schwarz and T. Wiegand, Verification of H. Schwarz, D. Marpe, T. Wiegand, Combined H.241/RCDO implementations in the JSVM B. Stabernack, H. Hübert, K.-I. Wels, Terminal scability support for the scalable extension software, Joint Video Team, Marrakech (MA), architectures for DVB-H, Proc. GSPx-TV to of H.264/AVC, IEEE Int. Conf. on Multimedia Doc. JVT-V125, Jan. 2007. Mobile 2006, Amsterdam (NL), March 2006, on and Expo (ICME ’05), Amsterdam (NL), July CD-ROM. 2005, see web. A. Smolic, P. Kauff, Interactive 3D video representation and coding technologies, B. Stabernack, H. Hübert, K.-I. Wels, A H.264 H. Schwarz, D. Marpe, T. Wiegand, Compari - Proc. of the IEEE, Special Issue on Advances in video coprocessor for mobile DVB-H ter- son of MCTF and closed-loop hierarchical B Video Coding and Delivery, vol. 93, no. 1, Jan. minals, IEEE Int. Conf. on Consumer Electronics pictures, Joint Video Team (JVT), Poznan (PL), 2005, pp. 98 – 110. ICCE 2006, Las Vegas (NV, USA), Jan. 2006, Doc. JVT-P059, July 2005, http://ftp3.itu.org/av- pp. 88 – 90. arch/jvt-site. A. Smolic, P. Merkle, K. Müller, C. Fehn, P. Kauff, and T. Wiegand: Compression of multi-view B. Stabernack, H. Richter104, Media processor H. Schwarz, D. Marpe, T. Wiegand, Further video and associated data, book chapter in: architectures for mobile DVB-H terminals, results on constrained inter-layer prediction, “Three-Dimensional Television: Capture, Trans - Proc. GSPx 2005, Santa Clara (CA, USA), Oct. Joint Video Team (JVT), Busan (KR), Doc. JVT- mission, and Display.” Editors: Haldun M. 2005, on CD-ROM. O074, April 2005, http://ftp3.itu.org/av-arch/jvt- Ozaktas and Levent Onural, Springer, Heidel - site. berg, 2007, in press. B. Stabernack, H. Richter104, Realtime optimization techniques for processor based H.264 H. Schwarz, D. Marpe, T. Wiegand, Hierarch - A. Smolic, K. Müller, M. Kautzner, P. Merkle, T. intra frame compression, Proc. GSPx 2005, ical B pictures, Joint Video Team (JVT), Poznan Wiegand, Predictive compression of dynamic Santa Clara (CA, USA), Oct. 2005, on CD-ROM. (PL), Doc. JVT-P014, July 2005, http://ftp3.itu.org/ 3D meshes, IEEE Int. Conf. on Image Processing av-arch/jvt-site. (ICIP ’05), Genova (IT), Sept. 2005, on CD-ROM. T. Stockhammer85, T. Gasiba85, W. A. Samad105, W. Xu105, H. Jenkac5, T. Schierl, A weighted H. Schwarz, D. Marpe, T. Wiegand, Improvment A. Smolic, K. Müller, P. Merkle, N. Atzpadin, C. layered broadcasting scheme for scalable of the progressive refinement coding for Fehn, M. Müller, O. Schreer, R. Tanger, P. Kauff, video transmission with multiple site recep- 8 × 8 luma blocks, Joint Video Team (JVT), T. Wiegand, Z. Megyesi, Multi-view video plus tion, Mobimedia 2006, Alghero, Sardinia (IT), Busan (KR), Doc. JVT-O073, April 2005, depth (MVD) format for advanced 3D video Sept. 2006, on CD-ROM. http://ftp3.itu.org/av-arch/jvt-site. systems, JVT-V100, San Jose (CA, USA), March 2007. T. Stockhammer85, T. Gasiba85, W. A. Samad105, H. Schwarz, D. Marpe, T. Wiegand, Independ - T. Schierl, H. Jenkac5, T. Wiegand, and W. Xu105, ent parsing of spatial and CGS layers, Joint A. Smolic, K. Müller, P. Merkle, C. Fehn, P. Kauff, Nested harmonic broadcasting for scalable Video Team (JVT), Geneva (CH), Doc. JVT-S069, P. Eisert, T. Wiegand, 3D video and free view- video over mobile datacast channels, Wiley April 2006, http://ftp3.itu.org/av-arch/jvt-site. point video – technologies, applications and Journal – Wireless Communications and Mobile MPEG standards, Proc. ICME 2006, Int. Conf. Computing, Special Issue on Video Communi - H. Schwarz, D. Marpe, T. Wiegand, Overview on Multimedia and Expo, Toronto, Ontario (CA), cations for 4G Wireless Systems, vol. 7, is. 2, of the scalable H.264/MPEG4-AVC extension July 2006, pp. 621 – 624. pp. 235 – 256, February 2007. (invited), Proc. IEEE Int. Conf. on Image Pro - cessing (ICIP 2006), Atlanta (GA, USA), Oct. A. Smolic, K. Müller, P. Merkle, M. Kautzner, G. Sullivan89, T. Wiegand, Video compression – 8 –11, 2006, pp. 161–164. T. Wiegand, 3D video objects for interactive from concepts to the H.264/AVC standard applications (invited), Europ. Signal Processing (invited), Proc. of the IEEE, Special Issue on H. Schwarz, D. Marpe, and T. Wiegand: Over - Conf. (EUSIPCO ’05), Antalya (TR), Sept. 2005, Advances in Video Coding and Delivery, vol. 93, view of the scalable video coding standard on CD-ROM. no. 1, Jan. 2005, pp. 18 – 31.

Annual Report | Jahresbericht 2006/2007 125 COMMUNICATIONS AND EVENTS

R. Tanger, N. Atzpadin, M. Müller, C. Fehn, (SVC): Technologie und Anwendungen, FOOTNOTES P. Kauff, C. Herpel106, Depth acquisition for 22. Jahrestagung der FKTG, Mai 2006, Potsdam post-production using trinocular camera (DE), on DVD. 1 Universitat Politècnica de Catalunya, systems and trifocal constraint, Proc, of Int. Barcelona, ES Broadcast Conference (IBC 2006), Amsterdam Wiegand and G. J. Sullivan89, The H.264/AVC 2 WIAS Berlin, DE (NL), Sept. 2006, pp. 329 – 336. video coding standard {Standards in a nut - 3 Lucent Technologies, Nürnberg, DE shell}, IEEE Signal Processing Magazine, vol. 24, 4 University of Erlangen, DE R. Tanger, P. Kauff, O. Schreer, D. Pavy91, S.L. Dit no. 2, March 2007. 5 Technical University München, DE Picard91, G. Saugis91, Team collaboration 6 Nokia Siemens Networks, München, DE mixing immersive video conferencing with T. Wiegand, E. Steinbach5, B. Girod100, Affine 7 Siemens AG Munich, DE shared virtual 3D objects, Proc. of Tyrrhenian multi-picture motion-compensated predic- 8 MICRAM Microelectronics, Bochum, DE Int. Workshop on Digital Communications tion, IEEE Transactions on Circuits and Systems 9 Alcatel SEL AG, Stuttgart, DE Distributed Cooperative Laboratories – Issues in for Video Technology, vol. 15, no. 2, Febr. 2005, 10 T-Systems, Berlin, DE Networking, Instrumentation and Measure- pp. 197– 209. 11 Marconi, Backnang, DE ments, Sorento (IT), July 2005, pp. 3 –10. 12 Azea Networks Ltd, London, UK M. Winken, D. Marpe, H. Schwarz, and T. 13 Fujitsu Laboratories Ldt., Wakamiya, JP S.-H. Voß, M. Talmi, FPGA based high-speed Wiegand, Bit-depth scalable video coding, 14 Technical University of Denmark, system solutions for innovative maskless IEEE Int. Conf. on Image Processing (ICIP ’07), Kopenhagen, DK lithography systems, Proc. of SPIE vol. 6283: San Antonio (TX, USA), Sept. 2007, accepted. 15 T-Systems Nova, Berlin, DE Photomask and Next-Generation Lithography 16 Deutsche Telekom T-Com, Berlin, DE Mask Technology XIII 2006, Yokohama (JP), M. Winken, H. Schwarz, D. Marpe, T. Wiegand, 17 Corning Incorporated, New York, USA p. 62832K-1. Adaptive refinement of motion information 18 Technical University of Eindhoven, NL for fine-granular scalable video coding, 19 University of Essex, UK S.-H. Voß, M. Talmi, Lossless high-speed data Proc. of Europ. Symp. on Mobile Media Delivery 20 Technical University Berlin, DE compression for optical interconnects as (EuMob 2006), Alghero, Sardinia (IT), Sept. 20, 21 University of Paderborn, DE used in maskless lithography systems, Micro - 2006, see web. 22 AT&T, Holmdel, NJ, USA electronic Engineering Journal, vol. 83, Issue 4- 23 IBM, Rüschlikon, CH 9, Micro- and Nano-Engineering MNE 2005, M. Winken, H. Schwarz, D. Marpe, T. Wiegand, 24 Technical University Hamburg-Harburg, DE pp. 972 – 975. Adaptive motion refinement for FGS slices, 25 BT, Ipswich, UK Joint Video Team (JVT), Nice (FR), Doc. JVT-Q031, 26 Brand-Rex Limited, Glenrothes, UK S.-H. Voß, M. Talmi, J. Saniter, Design and October 2005, http://ftp3.itu.org/av-arch/jvt-site. 27 SHF Communication Technologies AG, implementation of an FPGA based high- Berlin, DE speed data buffer for optical interconnects, M. Winken, H. Schwarz, D. Marpe, T. Wiegand, 28 NL Nanosemiconductor GmbH, Dortmund, Proc. 25th IEEE Int. Conf. on Microelectronics Adaptive motion refinement for FGS slices, DE 2006, Belgrad (RS), pp. 634 – 637. Joint Video Team (JVT), CE7, Bangkok (TH), Doc. 29 u²t Photonics AG, Berlin, DE JVT-R022, Jan. 2006, http://ftp3.itu.org/av- 30 Instituto Mediterraneo de Estudios Avan - S.-H. Voß, M. Talmi, J. Saniter, J. Eindorf, A. arch/jvt-site. zados, CSIB-UIB, Palma de Mallorca, ES Reisig, J. Heinitz107, High-speed data storage 31 Lucent Technologies, Hilversum, NL and processing for projection mask-less M. Winken, H. Schwarz, D. Marpe, and T. 32 University of Athens, GR lithography systems, Microelectronic Engin - Wiegand, Joint optimization of transform 33 Core Optics, Nürnberg, DE eering Journal, vol. 83, Issue 4 – 9, Micro- and coefficients in hierarchical B frame coding 34 T-Systems International, Darmstadt, DE Nano-Engineering MNE 2005, pp. 976 – 979. Using H.264/AVC, IEEE Int. Conf. on Image 35 Université Paris-Sud, Institut d’Optique, Processing (ICIP ’07), San Antonio (TX, USA), CNRS, Palaiseau, FR Ch. Weissig, I. Feldmann, J. Schüssler, U. Höfker, September 2007, accepted. 36 University of St Andrews, UK P. Eisert, P. Kauff, A modular high-resolution 37 University of Udine, IT multi-projection system, Proc. of 2nd Work- M. Winken, H. Schwarz, D. Marpe, and T. 38 Alcatel Thales III-V Lab, Palaiseau, FR shop on Immersive Communication and Broad- Wiegand, SVC bit depth scalability, Joint 39 Ghent University, BE cast Systems (ICOB 2005), Berlin (DE), Oct. Video Team, Marrakech (MA), Doc. JVT-V078, 40 University of Wurzburg, DE 2005, on CD-ROM. Jan. 2007. 41 École Polytechnique de Lausanne (EPFL), CH 42 Photon Design, Oxford, UK S. Wenger108, Y.-K. Wang108, T. Schierl, RTP A. Vetro109, Y. Su110, H. Kimata111, and A. 43 Institut f. Ionenstrahlphysik und Materialfor- payload format for SVC video, Internet Smolic, AHG Report: JMVM & JD text schung, Forschungszentrum Dresden, DE Engineering Task Force (IETF), Audio Video editing, Joint Video Team of ISO/IEC MPEG & 44 EV Group E. Thallner GmbH, Schaerding, AT Transport Group (avt), Dec. 2006, see web. ITU-T VCEG, Marrakech (MA), Doc. JVT-V016, 45 Max Planck Institute of Microstructure Jan. 2007. Physics, Halle, DE T. Wiegand, H. Schwarz, and D. Marpe, Over - 46 Max-Born-Institut, Berlin, DE view of the scalable video coding extension X. Zabulis66, G. Kordelas66, K. Mueller, A. 47 University of Karlsruhe, DE of H.264/AVC, Proc. of 12. Dortmunder Fern- Smolic, Increasing the accuracy of the space- 48 University of Toyama, JP seh seminar, ITG/FKTG-Fachtagung, Dortmund sweeping approach to stereo reconstruction 49 Technical University Darmstadt, DE (DE), March 20 – 21, 2007. using spherical backprojection surfaces, 50 Draka Comteq Optical Fibre, Eindhoven, NL Proc. ICIP 2006, Int. Conf. on Image Processing, 51 Merge Optics Berlin, DE T. Wiegand, Scalable video model 3.0, Joint Atlanta (GA, USA), Oct. 2006, pp. 2965 – 2968. 52 VTT Technical Research Centre of Finland, Video Team (JVT), Hong Kong (CN), Doc. JVT- Espoo, FI N015, January 2005, http://ftp3.itu.org/av- Th. Zahariadis112, K. Grüneberg, TK Chiew113, 53 Centre for Photonic Systems, University of arch/jvt-site. Efficient home video surveillance platform, Cambridge, UK Proc. 13th Int. Conf. on Systems, Signals and 54 Fraunhofer IZM, Berlin-Teltow, DE T. Wiegand, H. Schwarz, D. Marpe, T. Schierl, Image Processing (IWSSIP ’06), Budapest (HU), 55 Zen Photonics Co., KR K. Grüneberg, Skalierbare Videocodierung Sept. 2006, pp.143 – 146. 56 RWTH Aachen, DE

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57 Samsung Electronics Co., KR PATENT APPLICATIONS AWARDS 58 Ubidyne GmbH, Ulm, DE 59 IAF GmbH, Braunschweig, DE In the period under review more than 50 inven- E. A. Jorswieck, H. Boche, Best paper award 60 Siemens AG, CN tions were registered, some of these became from the IEEE Signal Processing Society for 61 Tel-Aviv University, IL already given patents. the paper “Optimal transmission strategies and 62 Universidad Politécnica de Valencia, ES impact of correlation in multi-antenna systems 63 Middle East Technical University, TR Im Berichtszeitraum wurden mehr als 50 Er- with different types of channel state informa- 64 Koc University, TR findungen, Gebrauchsmuster und Patente tion”, IEEE Trans. on Signal Processing, vol. 52, 65 Bilkent University, Ankara, TR angemeldet, von denen etliche bereits erteilt no.12, pp. 3440-3453, December 2004. 66 ITI-CERTH, Thessaloniki, GR wurden. 67 Momentum, TR N. Kerksieck, State-of-the-Art-Award für 68 University of Ilmenau, DE zeitgemäße innovative Mediengestaltung, 69 Philipps Eindhoven, NL 13. ITVA Festival October 2005. 70 University of Hannover, DE 71 University of Aberdeen, UK H. Boche, Vodafone Innovation Award 2006 72 Fraunhofer IIS, Erlangen, DE for the development of new mathematical tech- 73 Fraunhofer IPK, Berlin, DE niques for the optimization of existing and next 74 Fraunhofer FIRST, Berlin, DE generation wireless communication systems, 75 Tandberg, Oslo, NO Dresden, June 2006. 76 Otto-von-Guericke-Universität Magdeburg, DE K. Hopf, German Stars – the 50 most ground- 77 Laboratoire d’Informatique de Paris 6 breaking innovations “made in Germany”, (LIP6), Paris, FR everyone should know (Free2C 3D Display), 78 Bauhaus University Weimar, DE July 2006. 79 VisMedia Digital Solutions, Berlin, DE 80 Institut National des Télécommunications, R. de la Barré, S. Pastoor, D. Przewozny, Joseph Evry, FR von Fraunhofer Prize 2006 for outstanding 81 Tokyo Institute of Technology, JP scientific achievements in interactive 2D/3D 82 University of Braunschweig, DE Display Technology, Bremen, October 2006. 83 Carnegy Mellon University, USA 84 University of Nagoya, JP A. Sezgin, ITG Förderpreis, Berlin, 85 Nomor Research GmbH, Bergen, DE November 2006. 86 Broadcom Cooperation, Andover, MA, USA J. Güther, T. Hinz, S. Rauthenberg, R. Schäfer, 87 Ingenieurbüro Valeri George, Berlin, DE T. Schierl, T. Selinger, K. Sühring, T. Wiegand, 88 FHTW Berlin, DE Nomination for Innovationspreis Berlin 89 Microsoft Cooperation, Redmond, WA, Brandenburg 2006, for the development of USA a “DVB-H playout with statistical multiplex”, 90 Warsaw University of Technology, PL December 2006. 91 France Télékom, Paris, FR 92 Politecnico di Milano, IT K.-D. Langer, Best paper award 2006 of the 93 Senatsverwaltung für Inneres, Berlin, DE ITG (Information Technology Society) in the 94 Vodafone, München, DE Association for Electrical, Electronic & Infor ma - 95 Norwegian University of Science, NO tion Technologies (VDE) for the paper “Closed- 96 Ericsson GmbH, Herzogenrath, DE form solutions for key performance measures of 97 Rhode & Schwarz, Berlin, DE packet multiplexers with finite capacity queue”, 98 Deutsche Telekom Laboratories at published in AEÜ International Journal of Ben-Gurion University of the Negev, IL Electronics and Communications, vol. 59 (2005), 99 T-Systems, Darmstadt, DE no. 1, pp. 37 – 47, December 2006. 100 Stanford University, CA, USA 101 GE Security, Ecublens, CH S. Pastoor, Nomination for the 2007 Euro- 102 University of Tuebingen, DE pean ICT Prize (Information and Communica- 103 University of Plzen, CZ tion Technologies), February 2007. 104 University of Rostock, DE 105 BenQ Mobile, München, DE T. Oechtering, H. Boche, Best student paper 106 Deutsche Thomson-Brandt GmbH, award from the SPAWC 2007 program com- Hannover, DE mittee (8th IEEE Workshop on Signal Process. 107 Leica Microsystems Lithography GmbH, Advances in Wireless Comm.) for the paper Jena, DE “Relay selection in bidirectional relay communi- 108 Nokia Research, Helsinki, FI cation”, June 2007. 109 Mitsubishi Electric Research Labs, USA 110 Thomson, USA M. Schubert, H. Boche, Johann Philipp Reis- 111 NTT, Tokyo, JP Preis 2007 for their work about “Interference 112 Algosystems S.A., Kallithea, GR Function Calculus”, Juy 2007. 113 Institute for Infocomm Research, SG

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POSTDOCTORAL THESES DOCTORATE THESES DIPLOMA THESES / MASTER THESES required for qualification as a university lecturer A. Beling, Periodic travelling wave photo - B. Auth, Entwicklung eines pilotträgerbasier- detectors with serial and parallel optical ten optischen Übertragungssystems mit O. Schreer, Stereoanalyse und Bildsynthese, feed based on InP, TU Berlin, Fakultät IV – Überlagerungsempfang und digitalen Springer-Verlag, Berlin, Heidelberg, New York, Elektrotechnik und Informatik, Dr. H.-G. Bach, Phasenmodulationsformaten zur Steigerung Tokyo, 2005, ISBN: 3-540-23439-X. Prof. Dr. K. Petermann. der spektralen Effizienz, Diploma Theses, TFH Berlin. Supervisor at HHI: R. Freund. S. Stanczak, Theoretical framework and H. Buchta, Analysis of physical constraints algorithmic solutions for resource allocation in an optical burst switching network, H. Beyer, Untersuchung des Innenraum-Infra - problems in wireless communication net- TU Berlin, Fakultät IV – Elektrotechnik und rot-Übertragungskanals durch Anwen dung works, TU Berlin, Fakultät IV – Elektrotechnik Informatik, Prof. Dr. K. Petermann, des Ray-Tracing, Diploma Theses, FHTW Berlin, und Informatik. Prof. Dr. P. Meissner. Kommunikationstechnik / Telekommunikations- technik. Supervisors at HHI: J. Grubor, K.-D. G. Wunder, OFDM downlink air interface C. Fehn, Depth-image-based rendering Langer. for UMTS long term evolution fundamental (DIBR), compression, and transmission for capacity and practical design, TU Berlin, a flexible approach on 3DTV, TU Berlin, G. Brustenga, Implementation and analysis Fakultät IV – Elektrotechnik und Informatik. Fakultät IV – Elektrotechnik und Informatik, of a system for interactive mobile-aug- Prof. Dr. T. Sikora, Prof. Dr. M. Alexa. Published mented-reality applications, Diploma Theses, at Mensch & Buch Verlag, Berlin, Germany, TU Berlin, Fakultät IV – Elektrotechnik und 2006. Informatik. Supervisor at HHI: A. Smolic.

S. Ferber, Fiber-optic data transmission using S. Chennu, QoS-aware Traffic Protection for differential phase modulation and optical Access Rings, Diploma Theses, TU Hamburg- time division multiplexing at 160 Gbit/s and Haarburg, Institute of Communication Net- above, TU Berlin, Fakultät IV – Elektrotechnik works. Supervisor at HHI: K.-D. Langer. und Informatik, Prof. Dr. K. Petermann (TUB), Prof. Dr. B. Schmauß (University Erlangen- P. Chojecki, Survey on Steps – Erhöht SoS, Nuremberg), Prof. Dr. H.-G. Weber. eine Komponente zur Orientierung über Leistungsmerkmale von Websiteoptionen, T. Haustein, Real time signal processing for deren Gebrauchstauglichkeit?, Diploma multi-antenna systems and experimental Theses, Universität Bielefeld, Fakultät für Psy - verification on a reconfigurable hardware cholo gie und Sportwissenschaft. Supervisor at test-bed, TU Berlin, Fakultät IV – Elektrotechnik HHI: J. Faber. und Informatik, Prof. Dr. Dr. H. Boche (TUB), Prof. Dr. J. Huber (University Erlangen-Nurem - J. Danisevskis, Development of algorithms berg). for the detection of permanent changes in video streams, Diploma Theses, TU Berlin, P. Jung, Weyl-Heisenberg representations Fakultät V (Verkehrs- und Maschinensysteme), in communication theory, TU Berlin, Institut für Psychologie und Arbeitswissenschaft. Fakultät IV – Elektrotechnik und Informatik, Supervisor at HHI: S. Pastoor. Prof. Dr. Dr. H. Boche (TUB), Prof. Dr. T. Strohmer (University of California Davis). K. Gänger, Scalable video streaming in mobile ad-hoc Networks using SVC, Diploma M. Kroh, Semiconductor mode-locked laser Theses, TU Berlin, Fakultät IV – Elektrotechnik for high-speed OTDM transmission, und Informatik. Supervisor at HHI: T. Schierl. TU Berlin, Fakultät IV – Elektrotechnik und Infor - matik, Prof. Dr. K. Petermann, Prof. Dr. H.-G. A. Hachmeister, FPGA-basierte elektronische Weber. Entzerrung (Vorverzerrung) von Degrada- tionseffekten bei der faseroptischen Über- V. Marembert, Investigations on ultrafast tragung, Diploma Theses, TFH Berlin, fiber-based optical gates, TU Berlin, Supervisor at HHI: R. Freund. Fakultät IV – Elektrotechnik und Informatik, Prof. Dr. K. Petermann, Prof. Dr. H.-G. Weber. Y. Hadisusanto, OFDM resource allocation using multiuser constant power water- K. Müller, Reconstruction and coding of filling, Master Theses, TU Berlin, Fakultät IV – free viewpoint video, TU Berlin, Fakultät IV – Elektrotechnik und Informatik, Supervisor at Elektrotechnik und Informatik, Prof. Dr. T. HHI: V. Jungnickel. Sikora, Prof. Dr. O. Hellwich. C. Han, Charakterisierung von HEMT-Tran - A. Sezgin, Space-time codes for MIMO sistoren für einen Wanderwellen verstärker systems: Quasi-orthogonal design and (TWA) auf InP-OEIC-Wafern unter Verwen - concatenation, TU Berlin, Fakultät IV – dung von DC-Messtechniken, Diploma Elektrotechnik und Informatik, Prof. Dr. Dr. Theses, TFH Berlin. Supervisor at HHI: R. Kunkel. H. Boche (TUB), Prof. Dr. A. Paulraj (Stanford University).

128 Annual Report | Jahresbericht 2006/2007 COMMUNICATIONS AND EVENTS

C. Hellge, Robuster Transport von skalier- B. Schubert, Analyse des Sphare-Dekodier - M. Winken, Untersuchungen zur feingranu- baren SVC Videodaten über drathlose verfahren in linear-kooperierenden draht- laren Skalierbarkeit auf Basis einer skalier- Broadcast-Kanäle, Diploma Theses, losen Relais-Netzwerken, Diploma Theses, baren Erweiterung von H.264/MPEG4-AVC, TU Ilmenau. Supervisor at HHI: T. Schierl. TU Berlin, Fakultät IV – Elektrotechnik und Diploma Theses, TU Berlin, Fakultät IV – Informatik, Supervisor at HHI: T. Oechtering. Elektrotechnik und Informatik, Institut für M. Hintze, Punktstrahler-Leuchtdioden für Telekommunikationssysteme. Supervisor at HHI: Sensorikanwendungen, Diploma Theses, M. Schubert, Pulskompression von amplitu- D. Marpe. FHTW Berlin. Supervisor at HHI: W. Passenberg. den- und phasenmodulierten Datensig - nalen, Diploma Theses, TU Berlin, Fakultät II – R. Wyrembelski, Analyse der M. Karkri, LabView-gesteuerter Tri-Band- Mathematik und Naturwissenschaften. Diversitätsordnung aufwandseffizienter WDM-Sender zur Steigerung der Kapazität Supervisor at HHI: H.-G. Weber. Dekodierverfahren in linear kooperierenden von breitbandigen optischen Übertragungs- drahtlosen Relais Netzwerken, Master systemen, Diploma Theses, TFH Berlin. M. Schulze, Entwicklung einer Methodik zur Theses, TU Berlin, Fakultät IV – Elektrotechnik Supervisor at HHI: R. Freund. Analyse der Stärken und Schwächen eines und Informatik, Supervisor at HHI: T. Instituts der angewandten Forschung, Oechtering. T. Kayser, Hybride Bewegungsschätzverfah - Diploma Theses, Hochschule Magdeburg- ren, TU Dresden, Fakultät Elektrotechnik und Stendal (FH), Fachbereich Maschinenbau / Tech - Y. Zhang, Non-cooperative interference Informationstechnik. Supervisor at HHI: C. Huck. nische Betriebswirtschaft. Supervisor at HHI: management for OFDM BC in multi-cell W. Döldissen. enviroment, Master Theses, TU Berlin, Fakultät J. Lemmnitz, Erstellung eines webbasierten IV – Elektrotechnik und Informatik, Supervisor at Systems zur Generierung von 3-D-Kopfmo - W. Schwebs, Bildbasiertes Rendering von HHI: G. Wunder. dellen aus Fotos, Diploma Theses, FHTW Panoramen für die Navigation in virtuellen Berlin, Medieninformatik. Supervisor at HHI: Szenen, Diploma Theses, Universität Koblenz P. Eisert. Landau, Computervisualistik. Supervisor at HHI: P. Eisert. J. Luo, Kalibration eines experimentellen Breitband-Mobilfunksystems zur Übertra- R. Stenzel, Property-Rights im Multiprojekt- gung mit sehr hohen Datenraten, Master management-Kontext, Diploma Theses, Theses, TU Berlin, Fakultät IV – Elektrotechnik TU-Berlin, Fakultät VIII (Wirtschaft und Manage - und Informatik, Supervisor at HHI: A. Kortke. ment), Institut für Betriebswirtschaftslehre. Supervisor at HHI: H. Mrowka. G. Marten, Untersuchung von binär arithme- tischen Codierern zur Bildcodierung, S. Thiebes, Synthese von Gesichtsbewegun- Diploma Theses, FHTW Berlin, Fachbereich gen durch Analyse von Sprache, Diploma Ingenieurwissenschaften I. Supervisor at HHI: Theses, HU Berlin, Informatik. Supervisor at HHI: D. Marpe. P. Eisert.

P. Merkle, Entwicklung eines Verfahrens zur D. Tomecki, Optimierung von Sende- und Kodierung von Multi-View Video auf Basis Empfangsstrategien für die Mehrantennen- von H.264/AVC, Diploma Theses, TU Berlin, kommunikation zwischen Basisstationen in Fakultät IV – Elektrotechnik und Informatik. WiMax-Netzen, Master Theses, TU Berlin, Supervisor at HHI: A. Smolic. Fakultät IV – Elektrotechnik und Informatik, Supervisor at HHI: S. Stanczak. T. Neumann, Experimentelle Untersuchung zur Gebrauchstauglichkeit eines Programms C. Überrück, Entwicklung und Charakte ri sie - zur simultanen Bearbeitung von Online - rung eines optischen 20 Gbit/s Über tragungs- dokumenten an verteilten Arbeitsplätzen, systems unter Verwendung Differentieller Diploma Theses, TU Berlin, Fakultät V (Verkehrs- Quadratur-Phasenumtastung (DQPSK), und Maschinensysteme), Institut für Psychologie Diploma Theses, TFH Berlin. Supervisor at HHI: und Arbeitswissenschaft. Supervisor at HHI: R. Freund. J. Faber. S. Wahls, Minimum norm solution to the C. Patzelt, 2D-Simulation wellenleiterinte- operator corona problem and its applica- grierter pin-Photodioden mit der ATLAS / tion to MIMO-ISI channel equalization, BLAZE Simulationssoftware von SILVAC, Master Theses, TU Berlin, Fakultät II – Mathe - Diploma Theses, TFH Berlin. Supervisor at HHI: matik und Naturwissenschaften, Supervisor at H.-G. Bach. HHI: H. Boche.

D. Persdorf, Entwurf und Implementierung M. Wendig, Erstellung eines Messplatzes zur eines Vektorprozessors in VHDL für einen Bestimmung der chromatischen Dispersion HDTV Videoformatkonverter auf FPGA- von Einmodenfasern, Diploma Theses, TFH Basis, Diploma Theses, TU Berlin, Fakultät IV – Berlin. Supervisor at HHI: R. Freund. Elektrotechnik und Informatik, Institut für Technische Informatik und Mikroelektronik. Supervisor a HHI: T. Weber.

Annual Report | Jahresbericht 2006/2007 129 COMMUNICATIONS AND EVENTS

GRADUATE THESES ORAL PRESENTATIONS A. Smolic, 3D Video and Free Viewpoint Video – Technologies, Applications and W. B. Chamekh, Singeluser und Multiuser D. Runde, Das Projekt „Mobile Bürgerdienste MPEG Standards, Colloquium, University of MIMO OFDM Chunk Verarbeitung, TU Berlin, (MoBüd)”: bürgernah und sicher, Tuebingen, June 2006. Fakultät IV – Elektrotechnik und Informatik, 5. Berlin-Brandenburgischer Unternehmens- und Institut für Telekommunikationssysteme. Sicherheitstag, Berlin, 23.2.2006. A. Smolic, 3D Video and Free Viewpoint Supervisor at HHI: M. Schellmann. Video – Technologies, Applications and H. Hübert, B. Stabernack, Using Configurable MPEG Standards, 3DPVT’06, 3rd International A. Grede, Design, Aufbau und Charakte - CPU Cores for Demanding Mobile Symposium on 3D Data Processing, Visualization risierung eines Leistungsverstärkers zur Multimedia Applications (Invited Talk), and Transmission, UNC Chapel Hill (NC, USA), Synchronisation von optischen Laserpuls - Proc. ConfigCon 2006, Taipei, Feb. 2006. June 2006. quellen, TU Berlin, Fakultät IV – Elektrotechnik und Informatik. Supervisor at HHI: C. Schmidt- R. Schäfer, Can we consider 1080p/50, 60?, A. Smolic, 3D Video and Free Viewpoint Langhorst. DVB World 2006, Dublin, 1. – 3.3.2006. Video – Technologies, Applications and MPEG Standards, Workshop on Content W. Mennerich, SNR and SINR-improvement at O. Schreer, Adaptation of multi-view geo - Generation and Coding for 3D-Television, cell edge by collaborative basestaion trans- metries for capturing and 3D reproduction Eindhoven (NL), June 2006. mission, TU Berlin, Fakultät IV – Elektrotechnik in advanced 3D-TV services, LIMA 3D work- und Informatik, Institut für Telekommunikations- shop (Low cost 3D imaging and modelling R. Schäfer, DXB - A Harmonized System systeme. Supervisor at HHI: M. Schubert. automatic system), University of Verona (IT), Concept for mobile TV Services over DVB-H, 17.3.2006. DMB, and MBMS, Euroforum, München, D. Tomecki, Kalibrierung von optoelektroni- 13. – 14.7.2006. schen Pulsmessungen an schnellen Photo de - T. Wiegand, Scalable Video Coding-SVC tektoren bis 110 GHz, TU-Berlin, Fakultät IV – (Tutorial), Workshop GSPx TV to Mobile, A. Gual i Coca, B.Hüttl, R. Ludwig, C.Schmidt- Elektrotechnik und Informatik. Supervisors at Amsterdam (NL), 29.3.2006. Langhorst and C. Schubert, 320 Gbit/s all HHI: A. Beling and H.-G. Bach. optical wavelength conversion using R. Steingrüber, Elektronenstrahllithographie – Periodically Poled Lithium Niobate, A. Wirawan, Modellierung der Bewegung in Methode und Anwendungen (invited), Workshop “Nonlinear Dynamics in Modelocked Ad Hoc Netzen, TU Berlin, Fakultät IV – Elek - Vorlesung Mikrotechnik II an der FH Lasers and Optical Fibers” by the Weierstrass tro technik und Informatik, Institut für Telekom- Wilhelmshaven, 10.4.2006. Institute for Applied Analysis and Stochastics munikationssysteme. Supervisor at HHI: and the Humboldt University of Berlin, Institute S. Stanczak. H. Boche, Trends and Challenges for Algo - of Physics, 13. – 14.7.2006. rithms in Mobile Communications (invited Y. Zhang, Eine Simulationsumgebung für talk), COM Tech Days – Infineon Technologies B. Hüttl, A. Gual i Coca, M. Galili, C. Schubert, Einzelzelle OFDM HSDPA, TU Berlin, Fakultät AG, Ottobrunn (DE), April 2006. C. Schmidt-Langhorst, R. Ludwig, H.G. Weber, IV – Elektrotechnik und Informatik, Institut für R. Elschner and Ch.-A. Bunge, All Optical Telekommunikationssysteme. Supervisor at HHI: R. Schäfer, Mobile TV – DVB-H and Co., Wavelength Conversion by Four Wave G. Wunder. T-Mobile Seminar, Bonn, 11.5.2006 Mixing in Highly Nonlinear Fibers for 160 Gbit/s Phase Modulated Signals, H. Boche, S. Stanczak, Dynamic resource allo- Workshop “Nonlinear Dynamics in Modelocked cation for wireless networks: A significant Lasers and Optical Fibers” by the Weierstrass challenge for signal processing (tutorial), Institute for Applied Analysis and Stochastics Proc. IEEE Int. Conf. on Acoustics, Speech, and and the Humboldt University of Berlin, Institute Signal Processing (ICASSP 2006), Toulouse (FR), of Physics, 13. – 14.7.2006. 15.5.2006. C. Schmidt-Langhorst,M. Kroh, S. Ferber, V. R. Schäfer, Die digitale Welt in der Zukunft – Marembert, C. Schubert, R. Ludwig, B. Hüttl Wohin geht die Reise?, VDE Europakonferenz, and H.G. Weber, Generation and Trans- Brüssel (BE), 31.5.2006. mission of Terabit/s Optical Data Signals, Workshop “Nonlinear Dynamics in Modelocked H. Boche, Innovation in der drahtlosen Lasers and Optical Fibers” by the Weierstrass Kommunikation – Ein Blick in die Zukunft Institute for Applied Analysis and Stochastics (invited talk), 12. Internationale Handelsblatt and the Humboldt University of Berlin, Institute Jahrestagung Telekommarkt Europa, Der of Physics, 13. – 14.7.2006. Branchentreff, Strategien, Technologien und Trends, Deutschland – Euroforum, Bonn (DE), E. Patzak, Hybrid solutions for advanced May 2006. burst/packet switching networks, Proc. 11th European Conference on Networks and Optical R. Schäfer, Systeme und Technologien für Communications (NOC 2006), Berlin, July 2006. Broadcasting to Mobiles, Statusseminar Mobiles Internet, Erlangen, 21.6.2006. R. Schäfer, HDTV – What are the Technology Challenges? Coding Technologies for HDTV A. Feistel, S. Stanczak, Impact of Radio (Invited Talk), HD Theme Day, IBC 2006, Resource Management Mechanisms on Amsterdam, 8.9.2006. Network Performance, Alcatel-Lucent, Stuttgart (DE), June 2006.

130 Annual Report | Jahresbericht 2006/2007 COMMUNICATIONS AND EVENTS

L. Mühlbach, D. Runde, Mobile Bürgerdien ste. C. Fehn, Eine 5000-Spalten-Videoprojektion R.H. Derksen, C. Schubert, S. Jansen, X. Zhou Training Course for Executive Public Admin - für Sport-Events (invited Talk), Regionaltagung and M. Birk, Field trial on 107 Gbit/s trans- istrators from Kasakhstan: Managing for der Fernseh- und Kinotechnischen Gesellschaft mission with pure electrical time-division Quality and the Challenge of E-Govern- (FKTG), Berlin, Germany, November 2006. multiplex over 160 km, 8. ITG-Fachtagung ment, University of Potsdam, Berlin, 15.9.2006. Photonische Netze, Leipzig, 7. – 8.5.2007. G. Wunder, T. Michel, The MIMO OFDM chan- T. Wiegand, Recent Advances in Mobile nel: Fundamental Capacity and Transmission C. Schubert, R. Ludwig, C. Schmidt-Langhorst, Video (Keynote Speech), European Symposium Schemes, 17th Wireless World Research Forum S. Weisser and L. Raddatz, 160 Gbit/s RZ-DPSK on Mobile Media Delivery, Alghero (IT), Meeting, Heidelberg (DE), November 2006. OTDM Übertragung über 480 km mit 160 km 20.9.2006. Repeaterabstand, 8. ITG-Fachtagung Photo- K. Hopf, Man-Machine-Interaction, Workshop nische Netze, Leipzig, 7. – 8.5.2007. R. Schäfer, Mobile TV – Technologien und on Optical Metrology: New Ways into the Implementierungen des HHI, DMB-Work - Future, Worpswede, 8.12.2006. R. Freund, Upgrade von optischen Unter- shop, MDR, Leipzig, 21.9.2006. wasser-Übertragungssystemen mit höheren R. Freund, K. Habel and K.-D. Langer, Glas - Datenraten und neuen Modulations verfah - R. de la Barré, 3D-Displays mit räumlicher fasernetze für Backbone und Access- ren, Kolloquium TU Kiel, 11.6.2007. Interaktion, Deutscher Multimedia Kongress Bereich, Gemeinschaftssseminar Fiber Optic 1, “Interaktives Design”, Stuttgart, 27.9.2006. Dr. M. Siebert GmbH, Berlin, 2006. C. Schmidt-Langhorst, Terabit-Übertragung auf einem einzelnen Wellenlängenkanal, R. Schäfer, DMB vs. DVB-H → Digital Ex - R. Freund, K. Habel and K.-D. Langer, Kolloquium Optische Nachrichtentechnik, TU tended Broadcasting (DXB), BMBF-Vorhaben BerlinAccess: Versuchsnetz und Technolo - Wien, 14.6.2007. präsentieren vor BNetzA und BMWi, Mainz, gien für den optischen Teilnehmer-Breit - 27.9.2006. bandanschluss, Gemeinschaftssseminar Kupfer oder Glas, Dr. M. Siebert GmbH, Berlin, 2006. R. Schäfer, DXB – ein harmonisierter Ansatz für Mobile TV, Zukunft Telekommunikation – T. Wiegand: Free Viewpoint Video (Invited Technologietrends und TK-Regulierung“, Talk), Leibniz University of Hanover, 9.1.2007. Wiesbaden, 28.9.2006. C. Fehn, D. Zier, W. Ruppel, P. List, and R. Schäfer, Get TV on the Mobile – no matter M. Christmann, A File-Based Workflow for what the standard is (?), Mobile TV Confer- Transcoding Theatrical Content to a Variety ence at Danish Technological Institute, of Entertainment Video Formats (Invited Copenhagen (DK), 4. – 5. October 2006. Talk), Hollywood Post Alliance Retreat, Rancho Mirage (CA, USA), January 2007. H. Hübert, B. Stabernack, Using Configurable CPU Cores for Demanding Mobile Multi - A. Smolic, 3D Video and Free Viewpoint media Applications (invited Talk), Proc. Video – Technologies, Applications and ConfigCon 2006, Santa Clara (CA, USA), MPEG Standards, Winter School of Computer October 2006. Graphics (WSCG’07), University of Plzen (CZ), January 2007. L. Molle, Upgrades of Submarine Systems using Higher Bitrates and Advanced T. Wiegand: Recent Advances in Video Modulation Formats, AOE 2006, Shanghai Processing and Communication (Invited Talk), (CN), October 2006. Vienna University of Technology, Vienna (AU), 2.2.2007. S. Stanczak, MIMO in Sensornetzen: Sind Mehrantennensysteme energieeffizient?, T. Wiegand: Overview of the Scalable Video Siemens AG, München (DE), October 2006. Coding Extension of H.264/AVC (Plenary Talk), Dortmunder Fernsehseminar, 21.3.2007. T. Wiegand and J.-R. Ohm, Scalable Video Coding – Standardization and Beyond G. Walf, Inhouse Networks – the Last Meter (Tutorial), IEEE International Conference on to a Broadband World – Potentials of new Image Processing (ICIP'06), Atlanta (GA, USA), Technologies, BITKOM Forum, Berlin, October 2006. 27.3.2007.

R. Schäfer, TV Revaluation, Puzzle-Spiel mit L. Mühlbach, M-Government service realiza- Boxen und Bildschirmen, Bitkom-Akademie, tion for citizens in Berlin, at: E-government Frankfurt/M, 14.11.2006. and M-government Modern Technologies of Public Management, Moscow (RU), 6.4.2007. G. Walf, Inhouse Networks – the Last Meter to a Broadband World, ITG Tagung “Zukunft T. Wiegand: Scalable Video Coding (Invited der Netze”, Bremen, 17.11.2006. Talk), Stanford University, Stanford (CA, USA), 18.4.2007. D. Marpe, Neueste Verfahren der Videoco- dierung und deren Standardisierung, T. Wiegand: Video Communication (Invited Trainingsseminar am Europäischen Patentamt, Talk), Cisco Systems, San Jose (CA, USA), Berlin, 30.11.2006. 27.4.2007.

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LECTURES A. Sezgin, Space-Time Kodierung für WORKSHOPS ORGANISED Mehrantennenübertragungssysteme, TU Berlin H.-G. Bach, Grundlagen der optoelektronischen Multiradio Multimedia Communications (MMC) Halbleiterbauelemente, TU Berlin A. Smolic, Entwicklungstendenzen der Workshop 2005, HHI Berlin, January 2005 Multimediakommunikation, TU Berlin H.-G. Bach, Meßverfahren für Halbleiterbau - Simulationsbasiertes Lernen (SimuLearn), HHI elemente, TU Berlin B. Stabernack, Architekturen und Entwurf Berlin, April 2005 applikationsspezifischer Prozessoren, TU Berlin H. Boche, Digitale Mobilkommunikation I+II, Meta camera – 5th Consortium meeting, TU Berlin S. Stanczak, Mehrnutzerdetektion für drahtlose HHI Berlin, June 2005 Kommunikationssysteme, TU Berlin H. Boche, Mehrnutzerinformationstheorie, AmI Reiseassistenz – Intelligente Produkte und TU Berlin S. Stanczak, Ressourcenallokation in Umgebungen, HHI Berlin, September 2005 Mobilfunknetzen: Theorie und Algorithmen, H. Boche, Communication and Control, TU Berlin 2nd Workshop on Immersive Communications TU Berlin and Broadcast Systems (ICOB 2005), HHI Berlin, G. Wunder, Stochastische Prozesse in nach - October 2005 P. Eisert, Visualisierung, Codierung und richtentechnischen Systemen, TU Berlin Über tragung virtueller 3D Welten, TU Berlin ITG Fachkonferenz Breitbandversorgung in G. Wunder, Schätz- und Entscheidungstheorie Deutschland – wie schaffen wir den Anschluss? C. Fehn, Bildverarbeitung und Musterer - für nachrichtentechnische Systeme, TU Berlin Berlin, October 2005 kennung, TFH Berlin G. Wunder, E. Jorswieck, Informationstheorie I, MUSE Workshop on Optical Access Networks, R. Freund, Optische Nachrichtentechnik, TU Berlin Berlin, October 2005 TFH Berlin 3DTV TC5 Meeting, HHI Berlin, March 2006 O. Henkel, Raum-Zeit-Kodierung für die Mobilkommunikation, TU Berlin 11th European Conference on Networks and Optical Communications (NOC 2006) and O. Henkel, Codes und Gitter für die International Workshop on Optical Cabling and Nachrichtenübertragung, TU Berlin Infrastructure (OC&I 2006), Berlin, July 2006

E. Jorswieck, Angewandte Informationstheorie, MUSE Summerschool on Broadband Access TU Berlin Technologies, Berlin, July 2006

V. Jungnickel, MIMO Übertragungssysteme, DAGM 2006, 28th Annual Symposium of the TU Berlin German Association for Pattern Recognition Berlin, Germany, September 2006 V. Jungnickel, Adaptive Übertragungsverfahren, TU Berlin Multiradio Multimedia Communications (MMC) Workshop 2006, HHI Berlin, October 2006 V. Jungnickel, Echtzeitverfahren, TU Berlin Joint Chinese-German workshop on wavelength R. Ludwig, Advanced Fiber- Optic Wavelength conversion for optical burst switched networks, Division Multiplexing System, Hochschule HHI Berlin, October 2006 Bremen ITG Fachkonferenz Breitbandversorgung in D. Marpe, Medientechnik 2, FHTW Berlin Deutschland – Vielfalt für alle? Berlin, March 2007 K. Müller, Nachrichtenübertragung I, TU Berlin

O. Schreer, Stereobildverarbeitung in der Videokommunikation, TU Berlin

O. Schreer, 3D Bildsynthese in der Videokommunikation, TU Berlin

O. Schreer, Stereo Analysis and View Synthesis in 3D Video Communication, University of Verona (IT)

M. Schubert, Array-Signalverarbeitung für die Mobilkommunikation, TU Berlin

A. Sezgin, Kanalkodierung für die Nachrichtenübertragung, TU Berlin

132 Annual Report | Jahresbericht 2006/2007 COMMUNICATIONS AND EVENTS

CONTRIBUTIONS TO EXHIBITIONS IBC 2005 Amsterdam, September: IFA 2006, Berlin, September: Multichannel media encoder with statistical Free2C Kiosk 2005 multiplex for DVB-H 3D World Explorer Smooth Motion Cinema 3 GSM World Congress 2005, Cannes (FR), 3D Media Center February: Science Tunnel 2005, Tokyo (JP), International Broadcasting Convention 1 Gbit/s MIMO-OFDM link September – November: (IBC 2006), Amsterdam (NL), September: Free2C Kiosk OFC 2005, Anaheim/USA, March: Video formats conversion and multi-projection 160 Gbit/s Optical Clock Recovery Hardware/software IPs for DVB-H terminals 2006 Video over IP for handhelds (MBMS, eDAB CeBIT 2005, Hanover, March: and DVB-H) embedded world 2006, Nuremberg (DE), 3D Kiosk-System February: Scalable audio/video over heterogeneous networks (EU IST M-PIPE demonstrator) Free2C Desktop Display Software/Hardware IPs for Embedded Fast Video Retrieval Using MPEG7 Descriptors Multimedia Applications Hardware and Software components for H.264/AVC and DVB-H, Mixed Reality Display Hardware and software solutions for video and Multiprojection 4K Streaming of Virtual Environments audio coding (DVB-H/DMB implementations) H.264/MPEG4-AVC – Efficient Video Laser und Optik 2006, Berlin, March: ECOC 2006, Cannes (FR), September: Compression for Mobiles, TV and Home Cinema Micro- & Nano- optische Komponenten in Silica 160 Gbit/s Optical Clock Recovery DVB-H Live Streaming Server und Silicon 1 Gbit/s MIMO-OFDM system with link Insite 2006, Johannesburg (ZA), September: adaptation OFC 2006, Anaheim/USA, March: Mobile citizen case 160 Gbit/s Optical Clock Recovery Hannover Messe International 2005, April: Fachtagung im Bessy “media meets Free2C Kiosk CeBIT 2006, Hanover, March: technology”, Berlin, October 2006: Free2C Kiosk Multiprojection 4K CeBIT Asia 2005, Shanghai (CN), May: Explore the World (Mixed-Reality Display with 1 Gbit/s MIMO-OFDM system overview Multiradio Multimedia Communications User Tracking) 2006, “Broadcast meets Mobile”, Berlin, Highlights der Physik, Berlin, June: 3D Kiosk mit Gestik-Interface October: Free2C Kiosk 3D Face Processing Video over IP for handhelds (MBMS, eDAB 3D Visualization and DVB-H) LASER 2005, München, June: Multi-Projection ConfigCon2006, Santa Clara (CA, USA), World of Photonics: Diffractive optical Video over IP for MBMS, eDAB and DVB-H October: components distribution to handhelds Configurable Processor Core for Mobile Multi IFA 2005, Berlin, September: Science Tunnel 2006, Singapore (SG) Media processing 2D/3D Display with Natural Interaction March – June, Shanghai (CN) Aug– Oct: IST Event 2006, Helsinki (FI), November: Free2C Display with Gesture Interpretation Free2C Kiosk 3D Media Center Free2C Kiosk European Conference on Computer Vision Video Retrieval (ECCV) 2006, Graz (AU), May: Euro Mold 2006, Frankfurt/Main (DE), H.264 DVB-H live streaming November – December: GestAvatar- Real-Time Animation of Avatars H.264 HDTV quality comparison 3D Media Center H.264 Scalable Video Coding (SVC) Cinevision 2006 Final Presentation, Berlin, June: ITU Telecom World 2006, Hong Kong (CN), H.264 DVB-H implementations December: Immersive 5k Football Panoramas AV streaming for DVB-H 3G LTE Mobile Multimedia Network (with han- High-Resolution Multi-Projection System Motion compensated SDTV/HDTV real-time dover to HSPA) converter New Media and beyond 2006, CinemaxX- Streaming of virtual reality environments – Berlin, June: 2007 interactive panorama Multi-Projection with a resolution of Science Tunnel 2007, Dresden (DE), Facial animation 5000 1400 pixels (5k projection) × December 2006 – February 2007: 132° Multiprojection 5K NOC 2006, Berlin, July: Free2C Kiosk ECOC 2005, Glasgow/Scotland, September: Joint MUSE-MUPBED demonstration 3 GSM World Congress 2007, Barcelona (ES), 160 Gbit/s Optical Clock Recovery February: Medienwoche Berlin-Brandenburg 2006, August: 3G LTE Mobile Multimedia Network (with link adaptation) Multi-programme H.264 streaming with dynamic bit rate allocation through statistical multiplex

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CeBIT 2007, Hanover, March: COMMITTEE ACTIVITIES JVT (ITU-T VCEG and ISO/IEC MPEG), iPoint Explorer H.264/MPEG4-AVC reference software: soft- Standardisation Committees ware coordinator 3D Media Center DIN: Member 3GPP TSG-SA4: Member Free2C_digital DVB Technical Module-File Format (TM-FF): PocketPC Photobrowser Member Research Program Committees Virtual Mirror IETF, Audio-Video-Transport (avt): Member IST (Inform. Society Technologies): Evaluator Mobile TV and Content Encryption IETF, Multiparty Multimedia Session Control 100-Gbit/s-Transmission Life Demo (mmusic): Member Conference and Workshop Program High-Speed InP Components ISMA: Member Committees ISO MPEG, Ad-hoc Group on 3DAV: Chair Asia Optical Fiber Communication & Opto - OFC 2007, Anaheim/USA, March: electronic Exposition & Conference AOE 2006: ISO/IEC 144496-10:2005/Amd.3 | H.264 Annex 160 Gbit/s Optical Clock Recovery Member of General Chair G of MPEG and ITU-T: Editor of SVC specifica- tion Asia-Pacific Optical Communications APOC Hannover Messe International 2007, April: 2006, Gwangju (KR), Subcommittee “Passive ISO/IEC 23002-3 Representation of Auxiliary iPoint Explorer Components and Fiber-Based Devices”: Member Video and Supplemental Information: Editor Asia-Pacific Optical Communications ISO/IEC MPEG Video Sub-Group: Co-Chair Empolis Executive Forum 2007, Berlin, May: APOC2007, Wuhan (CN), Subcommittee Free2C Kiosk ITU-T (VCEG: Video Coding Experts Group): “Passive Com ponents and Fiber-Based Devices”: Associate Rapporteur of Question 6 Member iPoint Explorer JVT (ITU-T SG 16, VCEG/ ISO/MPEG) Ad-hoc Broad Band Europe, Geneva (CH), (2006), TV on Mobile Phone or PDA Group on JD and JMVM text editing: Chair Technical Program Committee: Member Tag der Offenen Tür der Bundesregierung, JVT (ITU-T SG 16, VCEG/ ISO/MPEG) Joint Draft ECOC member of management committee Multiview Video Coding: Editor BMWi Berlin, August: ECOC Technical Program Committee: Member JVT (ITU-T SG 16, VCEG/ ISO/MPEG) Joint 3D Media Center ELBUM: European Lithography Beamwriter User Multiview Video Model: Editor Multi-Projection with a resolution of Meeting: Chairman JVT (ITU-T SG 16, VCEG/ ISO/MPEG) SVC: Editor 5000 × 1400 pixels (5k projection) European Conference and Exhibition on Optical JVT (ITU-T SG 16, VCEG/ ISO/MPEG), Ad-hoc- Communication (ECOC) 2007: Member of IFA 2007, Berlin, September: Group Bit-Depth Scalability: Co-Chair General Chair iPoint Explorer JVT (ITU-T SG 16, VCEG/ ISO/MPEG), Ad-hoc- European Signal Processing Conference Free2C_digital Group Bitstream Extractor: Co-Chair (EUSIPCO): Technical Program Committee PocketPC Photobrowser JVT (ITU-T SG 16, VCEG/ ISO/MPEG), Ad-hoc- European Wireless Conference (2006): Program Group High Level Syntax and Error Resilience: Committee Multi-User 3D Television Display (MUTED) Co-Chair FiberComm fare, Munich: Chairman of the Virtual Mirror JVT (ITU-T SG 16, VCEG/ ISO/MPEG), Ad-hoc- supervisory board Scalable Video Streaming Group JM Text and Reference Software: Human Factors in Telecommunications: Co-Chair Permanent Steering Committee JVT (ITU-T SG 16, VCEG/ ISO/MPEG), Ad-hoc- IEEE Intern. Conference on Acoustic, Speech, Group JSVM and JD Text Editing: Co-Chair and Signal Processing (ICASSP): Program JVT (ITU-T SG 16, VCEG/ ISO/MPEG), Ad-hoc- Committee Group JSVM software and new functionality IEEE Intern. Conference on Image Processing: integration: Co-Chair Technical Program Committee Member JVT (ITU-T SG 16, VCEG/ ISO/MPEG), Ad-hoc- IEEE Intern. Conference on Multimedia & Expo Group JVT Project Management and Errata 2007: Technical Program Committee Member Reporting: Co-Chair IEEE Intern. Symp. on Information Theory (ISIT JVT (ITU-T SG 16, VCEG/ ISO/MPEG), Ad-hoc- 2007): Program Committee Group SVC Complexity Reduction: Co-Chair IEEE Intern. Symp. on Multimedia 2007 JVT (ITU-T SG 16, VCEG/ ISO/MPEG), Ad-hoc- (ISM2007): Program Vice Co-chair Group SVC Quantization, CAVLC and CABAC: Co-Chair IEEE Intern. Workshop on Personal. Indoor and Mobile Radio Communications 2006/2007 JVT (ITU-T SG 16, VCEG/ ISO/MPEG), Advanced (PIMRC): Program Committee 4:4:4 and Intra profiles (H.264 | ISO/IEC 144496-10): Editor IEEE Vehicular Technology Conf. (VTC-Fall- 2007): Track chair for propagation and JVT (ITU-T SG 16, VCEG/ ISO/MPEG), SVC refer- Modeling ence software: Software Coordinator IEEE Wireless Communications and Networking JVT (ITU-T SG 16, VCEG/ ISO/MPEG: Ad-hoc- Conference (WCNC 2006): Program Committee Group Test conditions for coding efficiency work and JSVM coding efficiency test conditions: Co- IMMERSCOM, Immersive Telecomminication Chair Conference2007: Technical Program Committee Member JVT (ITU-T VCEG and ISO/IEC MPEG) Joint Video Team (JVT): Co-Chair Intern Symposium InP and Related Materials (IPRM) ’07: Program Committee member

134 Annual Report | Jahresbericht 2006/2007 COMMUNICATIONS AND EVENTS

Intern. ITG-Conference on Source and Channel Springer Verlag Berlin, Heidelberg, Series EXCHANGE PROGRAM Coding (SCC 2006): Program Committee “Foundations in Signal Processing, Intern. Picture Coding Symposium: Steering and Communications and Networking”: Series Scientists Visiting HHI Program Committee Member Editor C. Arellano Pinilla, Universidad Politecnica de Intern. Symposium on Modeling and Catalunia, Barcelona (ES), financed by Ministerio Optimization in Mobile, Ad hoc, and Wireless Other Committees de Educación y Ciencia, for one year and one Networks (WiOpt 2006): Program Committee Arbeitskreis Integrierte Optik (AkIO): Member month Intern. Symposium on Turbo Codes and Related BITKOM Arbeitskreis Forschungsförderung: P. Bardella, Politecnico Torino (IT), financed by Topics (ISTC): Program Committee 2006 Member Junior Research Exchange, for one month Intern. Zürich Seminar: Program Committee BITKOM Arbeitskreis Netzinfrastruktur: Member IST Mobile and Wireless Communication Competence Center for the Application of H. Chen, Southeastern University Nanjing, Summit: Program Committee Nanostructures in Optoelectronics (NanOp): Nanjing (CN) financed by DAAD, for two years and six months ITG Workshop on Smart Antennas: Program Member of Executive Board Committee DKE Working Group FTTH: Member S. Cho, Electronics and Telecommunications Münchner Kreis, Congress “Growth through FKTG, Urtel-Preis-Komitee: Curatorship Research Institute (ETRI), Daejeon (KR), financed Mobile Communications” 2006: Member of FKTG-Vorstand: Guest member by ETRI, for one month Program Committee FTTH Council Europe: Member Münchner Kreis, Congress “Next Generation M.-S. Choi, for two years and six months IEEE Signal Processing for Communication: Internet” 2007: Member of Program Committee Member of Technical Committee Münchner Kreis, Congress “Searching and S. Dressler, Humboldt University Berlin, financed Industrieverband für optische, medizinische und Finding in the Internet” 2006: Member of by HUB, for two years and three months mechatronische Technologien e.V. (SPECTARIS): Program Committee Member Z. Du, Sino-German Joint Software Institute, Münchner Kreis, Supranational Association for ITG FG 5.2.5 Access- und Inhouse-Netze: Beijing (CN), financed by JSI, for three months Communications Research: Research Committee Member OFC ’06 and OFC 07 Technical Program ITG Technical Committee 5.1: Member W. Fang, Sino-German Joint Software Institute, Committee: Member Beijing (CN), financed by JSI, for three months ITG, FA 3.2 Digitale Bildcodierung: Chairman Packet Video Workshop: Program Committee ITG, FA 5.3 Optische Nachrichtentechnik: Queen’s Biennal Symposium on Communication A. Feistel, Technical University Berlin, financed Member (QBSC 2006): Program Committee by TUB, for two years and six months ITG, FG 5.3.1 Modellierung photonischer SPIE Conf. on three-dimensional TV, Video and Komponenten und Systeme: Committee M Galili, Technical University of Denmark, Display 2006: Program Committee Member Lyngby (DK), financed by COM-DTU, for four SPIE Photonics West, Integrated Optic Devices, months ITG, FG 5.3.2 Photonische Aufbau- und Conf. And Exhibition, San Jose (USA), January Verbindungstechnik: Chairman 2006, January 2007: Program Committee R. Halir, Universidad Màlaga (ES), for one week ITG, FG 5.3.3 Photonische Netze: Member WAPITI / PICMOS Workshop: “III/V photonic components 3 dimensional integration”, ITG, FG 5.4.1 Optische Polymerfasern: Member F. Hopfer, Technical University Berlin, financed Dec. 2006, Halle (DE): Chairman and Head of ITG-Vorstand: Guest member by TUB, for two years and six months Program Committee Kompetenznetz Optische Technologien Berlin L. Jiang, Technical University Berlin, financed by 3DTV-Conference 2007, Greece, Program Brandenburg (OpTecBB), Berlin: Member of TUB, for one year Committee: Member, Technical chair Chair 5th Intern. Workshop on Design of Reliable OPTEC BB, Berlin: Member S. Johansen, Norwegian University of Science Communication Networks (DCRN 2005), Island and Technology, Trondheim (NO), financed by of Ischia (IT), Technical Program Committee: NTNU, for six months Member A. Kortke, Technical University Berlin, financed Editorial Boards by TUB, for one year and six months Elsevier, Signal Processing: Associate Editor H. Kwon, Electronics and Telecommunications Elsevier, Signal Processing: Image Communi - Research Institute (ETRI), Daejeon (KR), financed cation: Guest Editor by ETRI, for one month IEEE JSTQE “Special issue on high-speed integrated photonic circuits”, Jan. 2007: Guest- E. Kurutepe, Koç Universitesi, Istanbul (TR), Editor financed by FhI-HHI, for one month IEEE Signal Processing Magazine: Guest Editor X. Li, Monash University, Melbourne (AU), IEEE Trans. on Circuits and Systems for Video financed by Monash University, for one month Technology: Guest Editor IEEE Trans. on Information Theory (Comm.): W. Mennerich, Siemens AG, München, financed Associate Editor by Siemens AG, for two months Springer Verlag Berlin, Heidelberg, Series “Optical Sciences”: Co-Editor

Annual Report | Jahresbericht 2006/2007 135 COMMUNICATIONS AND EVENTS

C. Möller, NL Nanosemiconductor GmbH, Dortmund (DE), financed by NL Nanosemi - conductor GmbH, for eight months

M. Müller, Technical University Berlin, financed by TUB, for six months

A. Mutig, Technical University Berlin, financed by TUB, for two years and six months

T. Oechtering, Technical University Berlin, financed by TUB, for two years and six months

V Pohl, Technical University Berlin, financed by TUB, for two years and six months

S. Salti (Student), University of Bologna (IT), for six months

S. Schelhase, Merge Optics, Berlin, financed by Merge Optics, for nine months

C. Schnurr, Technical University Berlin, financed by TUB, for one year

B. T. Schowengerdt, University of Washington, Seattle (WA, USA), financed by Alexander von Humboldt research scholarship, for seven months

S. Shi, Technical University Berlin, financed by TUB, for six months

D. Wang, Technical University Berlin, financed by TUB, for two months

M. Wiczanowski, Technical University Berlin, financed by TUB, for two years and six months

HHI Scientists Visiting Foreign Institutes E. Jorswieck, Kungl Tekniska Högskolan (KTH), Stockholm (SE), for one year and four months

M. Schellmann, Technical University Berlin, for one year and ten months

A. Sezgin, Stanford University, Stanford (CA, USA), for nine months

136 Annual Report | Jahresbericht 2006/2007 HHI Report 2006/2007

Editorial coordination: Regina Kiesewetter Wolf von Reden

Layout and typesetting: Zühlke Scholz & Partner Agentur für Kommunikation GmbH, Berlin

Printing: Druckerei Conrad, Berlin

Reproduction is allowed only after permission from HHI and with a complete citation

Fraunhofer-Institut für Nachrichtentechnik Heinrich-Hertz-Institut Einsteinufer 37, 10587 Berlin, Germany

ISSN 1435-1587 Fraunhofer Institute for Telecommunications Heinrich-Hertz-Institut

Einsteinufer 37 10587 Berlin Germany

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