A Secure Audio Teleconference System D
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Radio Communications in the Digital Age
Radio Communications In the Digital Age Volume 1 HF TECHNOLOGY Edition 2 First Edition: September 1996 Second Edition: October 2005 © Harris Corporation 2005 All rights reserved Library of Congress Catalog Card Number: 96-94476 Harris Corporation, RF Communications Division Radio Communications in the Digital Age Volume One: HF Technology, Edition 2 Printed in USA © 10/05 R.O. 10K B1006A All Harris RF Communications products and systems included herein are registered trademarks of the Harris Corporation. TABLE OF CONTENTS INTRODUCTION...............................................................................1 CHAPTER 1 PRINCIPLES OF RADIO COMMUNICATIONS .....................................6 CHAPTER 2 THE IONOSPHERE AND HF RADIO PROPAGATION..........................16 CHAPTER 3 ELEMENTS IN AN HF RADIO ..........................................................24 CHAPTER 4 NOISE AND INTERFERENCE............................................................36 CHAPTER 5 HF MODEMS .................................................................................40 CHAPTER 6 AUTOMATIC LINK ESTABLISHMENT (ALE) TECHNOLOGY...............48 CHAPTER 7 DIGITAL VOICE ..............................................................................55 CHAPTER 8 DATA SYSTEMS .............................................................................59 CHAPTER 9 SECURING COMMUNICATIONS.....................................................71 CHAPTER 10 FUTURE DIRECTIONS .....................................................................77 APPENDIX A STANDARDS -
A Guide to Radio Communications Standards for Emergency Responders
A GUIDE TO RADIO COMMUNICATIONS STANDARDS FOR EMERGENCY RESPONDERS Prepared Under United Nations Development Programme (UNDP) and the European Commission Humanitarian Office (ECHO) Through the Disaster Preparedness Programme (DIPECHO) Regional Initiative in Disaster Risk Reduction March, 2010 Maputo - Mozambique GUIDE TO RADIO COMMUNICATIONS STANDARDS FOR EMERGENCY RESPONDERS GUIDE TO RADIO COMMUNICATIONS STANDARDS FOR EMERGENCY RESPONDERS Table of Contents Introductory Remarks and Acknowledgments 5 Communication Operations and Procedures 6 1. Communications in Emergencies ...................................6 The Role of the Radio Telephone Operator (RTO)...........................7 Description of Duties ..............................................................................7 Radio Operator Logs................................................................................9 Radio Logs..................................................................................................9 Programming Radios............................................................................10 Care of Equipment and Operator Maintenance...........................10 Solar Panels..............................................................................................10 Types of Radios.......................................................................................11 The HF Digital E-mail.............................................................................12 Improved Communication Technologies......................................12 -
Digital Television Systems
This page intentionally left blank Digital Television Systems Digital television is a multibillion-dollar industry with commercial systems now being deployed worldwide. In this concise yet detailed guide, you will learn about the standards that apply to fixed-line and mobile digital television, as well as the underlying principles involved, such as signal analysis, modulation techniques, and source and channel coding. The digital television standards, including the MPEG family, ATSC, DVB, ISDTV, DTMB, and ISDB, are presented toaid understanding ofnew systems in the market and reveal the variations between different systems used throughout the world. Discussions of source and channel coding then provide the essential knowledge needed for designing reliable new systems.Throughout the book the theory is supported by over 200 figures and tables, whilst an extensive glossary defines practical terminology.Additional background features, including Fourier analysis, probability and stochastic processes, tables of Fourier and Hilbert transforms, and radiofrequency tables, are presented in the book’s useful appendices. This is an ideal reference for practitioners in the field of digital television. It will alsoappeal tograduate students and researchers in electrical engineering and computer science, and can be used as a textbook for graduate courses on digital television systems. Marcelo S. Alencar is Chair Professor in the Department of Electrical Engineering, Federal University of Campina Grande, Brazil. With over 29 years of teaching and research experience, he has published eight technical books and more than 200 scientific papers. He is Founder and President of the Institute for Advanced Studies in Communications (Iecom) and has consulted for several companies and R&D agencies. -
Using Satellite-Based Videoconferencing to Integrate the Satnex Research Community
1 Using Satellite-based Videoconferencing to Integrate the SatNEx Research Community Sergey Raber, Robert Rumeau, Laurent Franck, Tomaso De Cola, Ulla Birnbacher, Georg Egger, Anton Donner, Ray E. Sheriff, Gorry Fairhurst distributed across Europe. Mobility is an important aspect of Abstract— The SatNEx Project provides a pan-European SatNEx’s work, with academic staff and researchers being multimedia network that may be used to rectify fragmentation in encouraged to move between institutions to allow access to satellite communications research, by bringing together Europe’s specialised research equipment and to facilitate knowledge leading academic institutions and research organisations in a cohesive and durable way. The resultant network provides a transfer and research integration. collective grouping of expertise and state-of-the-art laboratory The philosophy underlying the facilities that would otherwise remain dispersed throughout SatNEx approach revolves around Europe. This paper describes the Platform developed by the the selection of focused actions that SatNEx community for use by the community to provide high- capitalise on the expertise present quality videoconferencing facilities, based on a satellite within the Network and ensure a connectivity. durable and effective integration. Index Terms— SatNEx, video conferencing, satellite The focused actions are performed communication, IP multicast, tele-learning, tele-education. jointly by the partners. A key goal of SatNEx is to achieve effective I. INTRODUCTION communication between partners. This requires establishing a EMOVING Barriers, Integrating Research and Spreading common pan-European Platform to provide equitable access to R Excellence are the primary objectives of SatNEx, the real-time communication services for all partners [2]. Satellite Communications Network of Excellence [1]. -
Broadcast Television (1945, 1952) ………………………
Transformative Choices: A Review of 70 Years of FCC Decisions Sherille Ismail FCC Staff Working Paper 1 Federal Communications Commission Washington, DC 20554 October, 2010 FCC Staff Working Papers are intended to stimulate discussion and critical comment within the FCC, as well as outside the agency, on issues that may affect communications policy. The analyses and conclusions set forth are those of the authors and do not necessarily reflect the view of the FCC, other Commission staff members, or any Commissioner. Given the preliminary character of some titles, it is advisable to check with the authors before quoting or referencing these working papers in other publications. Recent titles are listed at the end of this paper and all titles are available on the FCC website at http://www.fcc.gov/papers/. Abstract This paper presents a historical review of a series of pivotal FCC decisions that helped shape today’s communications landscape. These decisions generally involve the appearance of a new technology, communications device, or service. In many cases, they involve spectrum allocation or usage. Policymakers no doubt will draw their own conclusions, and may even disagree, about the lessons to be learned from studying the past decisions. From an academic perspective, however, a review of these decisions offers an opportunity to examine a commonly-asserted view that U.S. regulatory policies — particularly in aviation, trucking, and telecommunications — underwent a major change in the 1970s, from protecting incumbents to promoting competition. The paper therefore examines whether that general view is reflected in FCC policies. It finds that there have been several successful efforts by the FCC, before and after the 1970s, to promote new entrants, especially in the markets for commercial radio, cable television, telephone equipment, and direct broadcast satellites. -
EVOLUTION and CONVERGENCE in TELECOMMUNICATIONS 2002 2Nd Edition 2005
the united nations 11 abdus salam educational, scientific and cultural international organization ISBN 92-95003-16-0 centre for theoretical international atomic physics energy agency lecture notes EVOLUTION AND CONVERGENCE IN TELECOMMUNICATIONS 2002 2nd Edition 2005 editors S. Radicella D. Grilli ICTP Lecture Notes EVOLUTION AND CONVERGENCE IN TELECOMMUNICATIONS 11 February - 1 March 2002 Editors S. Radicella The Abdus Salam ICTP, Trieste, Italy D. Grilli The Abdus Salam ICTP, Trieste, Italy EVOLUTION AND CONVERGENCE IN TELECOMMUNICATIONS - First edition Copyright © 2002 by The Abdus Salam International Centre for Theoretical Physics The Abdus Salam ICTP has the irrevocable and indefinite authorization to reproduce and dissem• inate these Lecture Notes, in printed and/or computer readable form, from each author. ISBN 92-95003-16-0 Printed in Trieste by The Abdus Salam ICTP Publications & Printing Section iii PREFACE One of the main missions of the Abdus Salam International Centre for Theoretical Physics in Trieste, Italy, founded in 1964 by Abdus Salam, is to foster the growth of advanced studies and research in developing countries. To this aim, the Centre organizes a large number of schools and workshops in a great variety of physical and mathematical disciplines. Since unpublished material presented at the meetings might prove of great interest also to scientists who did not take part in the schools the Centre has decided to make it available through a new publication titled ICTP Lecture Note Series. It is hoped that this formally structured pedagogical material in advanced topics will be helpful to young students and researchers, in particular to those working under less favourable conditions. -
Webex Meeting Center User Guide
WebEx Meeting Center User Guide For Hosts, Presenters, and Participants WBS29.11 Copyright © 2015 Cisco and/or its affiliates. All rights reserved. WEBEX, CISCO, Cisco WebEx, the CISCO logo, and the Cisco WebEx logo are trademarks or registered trademarks of Cisco and/or its affiliated entities in the United States and other countries. Third-party trademarks are the property of their respective owners. U.S. Government End User Purchasers. The Documentation and related Services qualify as "commercial items," as that term is defined at Federal Acquisition Regulation ("FAR") (48 C.F.R.) 2.101. Consistent with FAR 12.212 and DoD FAR Supp. 227.7202-1 through 227.7202-4, and notwithstanding any other FAR or other contractual clause to the contrary in any agreement into which the Agreement may be incorporated, Customer may provide to Government end user or, if the Agreement is direct, Government end user will acquire, the Services and Documentation with only those rights set forth in the Agreement. Use of either the Services or Documentation or both constitutes agreement by the Government that the Services and Documentation are commercial items and constitutes acceptance of the rights and restrictions herein. Last updated: 01062015 www.webex.com Table of Contents Host a Meeting ............................................................................................................... 1 Quick reference tasks: host a meeting ...................................................................... 1 Grant or remove privileges ....................................................................................... -
Taxation & Regulatory Treatment of Web Conferencing Services
Taxation & Regulatory Treatment of Web Conferencing Services: What a Tangled Web We Weave Taxation & Regulatory Treatment of Web Conferencing Services: Outline of Presentation Part 1: FCC Regulatory Treatment of Web Conferencing Part 2: State and Local Tax Treatment of Web Conferencing Part 3: Where does that leave us now? 2 Background of FCC Treatment of Conferencing Services Timeline of FCC Decisions: • Pulver (2004) – Non-PSTN conferencing • InterCall (2008) – Stand-alone audio-bridging/ conferencing • MeetingOne (2011) – IP-Based audio conferencing (Appeal to FCC pending) • Webex (2013) – Online Collaboration (Appeal to FCC pending) 3 Pulver Free World Dialup (2004) Non-PSTN conferencing classified as an Information Service: • Free World Dialup (FWD) allowed internal, Non-PSTN communications between members via voice, video or text • Membership based, requires broadband connection and softphone • Unique 5 or 6 digit FWD number assigned to each member • Conference bridging capabilities • FCC found the service to be an information service (2004) 4 InterCall Services Description Background: InterCall provides stand-alone audio conferencing services that includes certain features: • validation functions, • collect billing and participant information, • enable participants to record, delete playback, mute and unmute, and access operator assistance • FCC described InterCall as marketing audio, video and web conferencing; however, record is not clear InterCall’s service included anything beyond audio 5 InterCall Order (2008) Stand-alone audio-bridging -
Communications System Utilizing Passive Satellites
The Space Congress® Proceedings 1966 (3rd) The Challenge of Space Mar 7th, 8:00 AM Communications System Utilizing Passive Satellites Robert T. Hart Collins Radio Company Follow this and additional works at: https://commons.erau.edu/space-congress-proceedings Scholarly Commons Citation Hart, Robert T., "Communications System Utilizing Passive Satellites" (1966). The Space Congress® Proceedings. 5. https://commons.erau.edu/space-congress-proceedings/proceedings-1966-3rd/session-1/5 This Event is brought to you for free and open access by the Conferences at Scholarly Commons. It has been accepted for inclusion in The Space Congress® Proceedings by an authorized administrator of Scholarly Commons. For more information, please contact [email protected]. COMMUNICATIONS SYSTEMS UTILIZING PASSIVE SATELLITES Robert T. Hart Collins Radio Company Dallas, Texas Summary Dallas, Texas. The geographical locations of the sta tions permitted mutual visibility on many passes The era of communications systems utilizing with the passive satellites was inaugurated by the launch of satellite at an orbital height of approximately 700 miles. Operational Echo I in 1960. This was followed by Echo II in 1964. frequencies in the S-band region These preliminary experiments have proven system were chosen for maximum radio reflectivity of the sat feasibility and indicated deficiencies of the satellite ellite consistent with available equipment in the ground station materials and configurations. Echo III will be launched complex. in the spring of 1966 to test the latest available A set of disappointing circumstances caused the materials. Echo II satellite to be less than a perfect radio reflec This paper outlines the history of the passive tor, primarily due to ejection of the balloon from the satellite communications experiments to date and canister. -
The Origination and Evolution of Radio Traffic Analysis: the World War I Era
UNCLASSI Fl ED The Origination and Evolution of Radio Traffic Analysis: The World War I Era (b )(3)-P. L. 86-36 Not unlike the telegraph and ita influence on the American Civil War, the invention of radio had a profound affect on World War I military operations and in all conflicts since 1901. Signals intelligence, a new form. of intelligence produced from. the intercept of radio traffic, developed on a parallel course with radio during the early years of the twentieth century. Although signals intelligence was identified as a method to produce useful and critical information during war, it did not mature as a significant tool until after the ,.War to End All Wars." Radio traffic analysis, a branch of signals intelligence, was not even recognized as a separate technique until long after the First World War ended. Nevertheless, traffic analysis, or TIA, existed as a function in that era and made significant contributions to military operations and to the development ofsignals intelligence. For the American signals intelligence service, radio traffic analysis originated as a technique in the codebreaking section and with the clerks in the goniometric or Direction Finding (DF) service of the American Expeditionary Force. The early cryptanalysts developed TIA techniques to identify the originator and receiver of radio messages and to determine the more important encoded or enciphered messages to attack. TIA also evolved in the DF service with the clerks who discovered ways to produce intelligence from analysis of the externals of messages and from the location ofthe radio transmitters. The increasingly more complex communications systems which defied cryptanalytic attack provided the impetus for these developments. -
Introduction to Communication Systems
Introduction to Communication Systems James Flynn Sharlene Katz Communications System Diagram Information Source and Output Transmitter Channel Receiver Input Transducer Transducer 2 Flynn/Katz - SDR July 1, 2010 Communications System Diagram Information Output Transmitter Channel Receiver Source and Input Transducer Transducer Information Source: Audio, image, text, data Input Transducer: Converts source to electric signal . Microphone . Camera . Keyboard 3 Flynn/Katz - SDR July 1, 2010 Communications System Diagram Information Output Source and Input Transmitter Channel Receiver Transducer Transducer Output Transducer: Converts electric signal to useable form . Speaker . Monitor 4 Flynn/Katz - SDR July 1, 2010 Communications System Diagram Information Output Source and Input Transmitter Channel Receiver Transducer Transducer Transmitter: . Converts electrical signal into form suitable for channel . Modulator . Amplifier 5 Flynn/Katz - SDR July 1, 2010 Communications System Diagram Information Output Source and Input Transmitter Channel Receiver Transducer Transducer Channel: Medium used to transfer signal from transmitter to receiver. Point to point or Broadcast . Wire lines . Fiber optic cable . Atmosphere . Often adds noise / weakens & distorts signal 6 Flynn/Katz - SDR July 1, 2010 Communications Channels Wireline Twisted Pair Cable Increasing bandwidth Waveguide Fiber Optics Wireless (radio): Transmission of electromagnetic waves from antenna to antenna KHz to ultraviolet Propagation characteristics vary with frequency 7 -
(NIPP) Communications Sector-Specific Plan for 2015
Communications Sector-Specific Plan An Annex to the NIPP 2013 2015 Table of Contents Letter from the Council Chairs ................................................................................................................................. iii Executive Summary ................................................................................................................................................... iv 1. Introduction ............................................................................................................................................................ 1 2. Sector Overview ..................................................................................................................................................... 3 2.1 Sector Risks ............................................................................................................................................7 2.2 Critical Infrastructure Partners .............................................................................................................. 10 3. Vision, Goals, and Priorities ................................................................................................................................. 13 4. Achieving Sector Goals ........................................................................................................................................ 16 4.1 Risk Management ................................................................................................................................. 16 4.2