Cable Technician Pocket Guide Subscriber Access Networks
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Digital Subscriber Line (DSL) Technologies
CHAPTER21 Chapter Goals • Identify and discuss different types of digital subscriber line (DSL) technologies. • Discuss the benefits of using xDSL technologies. • Explain how ASDL works. • Explain the basic concepts of signaling and modulation. • Discuss additional DSL technologies (SDSL, HDSL, HDSL-2, G.SHDSL, IDSL, and VDSL). Digital Subscriber Line Introduction Digital Subscriber Line (DSL) technology is a modem technology that uses existing twisted-pair telephone lines to transport high-bandwidth data, such as multimedia and video, to service subscribers. The term xDSL covers a number of similar yet competing forms of DSL technologies, including ADSL, SDSL, HDSL, HDSL-2, G.SHDL, IDSL, and VDSL. xDSL is drawing significant attention from implementers and service providers because it promises to deliver high-bandwidth data rates to dispersed locations with relatively small changes to the existing telco infrastructure. xDSL services are dedicated, point-to-point, public network access over twisted-pair copper wire on the local loop (last mile) between a network service provider’s (NSP) central office and the customer site, or on local loops created either intrabuilding or intracampus. Currently, most DSL deployments are ADSL, mainly delivered to residential customers. This chapter focus mainly on defining ADSL. Asymmetric Digital Subscriber Line Asymmetric Digital Subscriber Line (ADSL) technology is asymmetric. It allows more bandwidth downstream—from an NSP’s central office to the customer site—than upstream from the subscriber to the central office. This asymmetry, combined with always-on access (which eliminates call setup), makes ADSL ideal for Internet/intranet surfing, video-on-demand, and remote LAN access. Users of these applications typically download much more information than they send. -
A Technology Comparison Adopting Ultra-Wideband for Memsen’S File Sharing and Wireless Marketing Platform
A Technology Comparison Adopting Ultra-Wideband for Memsen’s file sharing and wireless marketing platform What is Ultra-Wideband Technology? Memsen Corporation 1 of 8 • Ultra-Wideband is a proposed standard for short-range wireless communications that aims to replace Bluetooth technology in near future. • It is an ideal solution for wireless connectivity in the range of 10 to 20 meters between consumer electronics (CE), mobile devices, and PC peripheral devices which provides very high data-rate while consuming very little battery power. It offers the best solution for bandwidth, cost, power consumption, and physical size requirements for next generation consumer electronic devices. • UWB radios can use frequencies from 3.1 GHz to 10.6 GHz, a band more than 7 GHz wide. Each radio channel can have a bandwidth of more than 500 MHz depending upon its center frequency. Due to such a large signal bandwidth, FCC has put severe broadcast power restrictions. By doing so UWB devices can make use of extremely wide frequency band while emitting very less amount of energy to get detected by other narrower band devices. Hence, a UWB device signal can not interfere with other narrower band device signals and because of this reason a UWB device can co-exist with other wireless devices. • UWB is considered as Wireless USB – replacement of standard USB and fire wire (IEEE 1394) solutions due to its higher data-rate compared to USB and fire wire. • UWB signals can co-exists with other short/large range wireless communications signals due to its own nature of being detected as noise to other signals. -
Frequency and Network Planning Aspects of DVB-T2
Report ITU-R BT.2254 (09/2012) Frequency and network planning aspects of DVB-T2 BT Series Broadcasting service (television) ii Rep. ITU-R BT.2254 Foreword The role of the Radiocommunication Sector is to ensure the rational, equitable, efficient and economical use of the radio-frequency spectrum by all radiocommunication services, including satellite services, and carry out studies without limit of frequency range on the basis of which Recommendations are adopted. The regulatory and policy functions of the Radiocommunication Sector are performed by World and Regional Radiocommunication Conferences and Radiocommunication Assemblies supported by Study Groups. Policy on Intellectual Property Right (IPR) ITU-R policy on IPR is described in the Common Patent Policy for ITU-T/ITU-R/ISO/IEC referenced in Annex 1 of Resolution ITU-R 1. Forms to be used for the submission of patent statements and licensing declarations by patent holders are available from http://www.itu.int/ITU-R/go/patents/en where the Guidelines for Implementation of the Common Patent Policy for ITU-T/ITU-R/ISO/IEC and the ITU-R patent information database can also be found. Series of ITU-R Reports (Also available online at http://www.itu.int/publ/R-REP/en) Series Title BO Satellite delivery BR Recording for production, archival and play-out; film for television BS Broadcasting service (sound) BT Broadcasting service (television) F Fixed service M Mobile, radiodetermination, amateur and related satellite services P Radiowave propagation RA Radio astronomy RS Remote sensing systems S Fixed-satellite service SA Space applications and meteorology SF Frequency sharing and coordination between fixed-satellite and fixed service systems SM Spectrum management Note: This ITU-R Report was approved in English by the Study Group under the procedure detailed in Resolution ITU-R 1. -
Reservation - Time Division Multiple Access Protocols for Wireless Personal Communications
tv '2s.\--qq T! Reservation - Time Division Multiple Access Protocols for Wireless Personal Communications Theodore V. Buot B.S.Eng (Electro&Comm), M.Eng (Telecomm) Thesis submitted for the degree of Doctor of Philosophy 1n The University of Adelaide Faculty of Engineering Department of Electrical and Electronic Engineering August 1997 Contents Abstract IY Declaration Y Acknowledgments YI List of Publications Yrt List of Abbreviations Ylu Symbols and Notations xi Preface xtv L.Introduction 1 Background, Problems and Trends in Personal Communications and description of this work 2. Literature Review t2 2.1 ALOHA and Random Access Protocols I4 2.1.1 Improvements of the ALOHA Protocol 15 2.1.2 Other RMA Algorithms t6 2.1.3 Random Access Protocols with Channel Sensing 16 2.1.4 Spread Spectrum Multiple Access I7 2.2Fixed Assignment and DAMA Protocols 18 2.3 Protocols for Future Wireless Communications I9 2.3.1 Packet Voice Communications t9 2.3.2Reservation based Protocols for Packet Switching 20 2.3.3 Voice and Data Integration in TDMA Systems 23 3. Teletraffic Source Models for R-TDMA 25 3.1 Arrival Process 26 3.2 Message Length Distribution 29 3.3 Smoothing Effect of Buffered Users 30 3.4 Speech Packet Generation 32 3.4.1 Model for Fast SAD with Hangover 35 3.4.2Bffect of Hangover to the Speech Quality 38 3.5 Video Traffic Models 40 3.5.1 Infinite State Markovian Video Source Model 41 3.5.2 AutoRegressive Video Source Model 43 3.5.3 VBR Source with Channel Load Feedback 43 3.6 Summary 46 4. -
Loudspeaker FM and AM Distortion an 10
Loudspeaker FM and AM Distortion AN 10 Application Note to the KLIPPEL R&D SYSTEM The amplitude modulation of a high frequency tone f1 (voice tone) and a low frequency tone f2 (bass tone) is measured by using the 3D Distortion Measurement module (DIS) of the KLIPPEL R&D SYSTEM. The maximal variation of the envelope of the voice tone f1 is represented by the top and bottom value referred to the averaged envelope. The amplitude modulation distortion (AMD) is the ratio between the rms value of the variation referred to the averaged value and is comparable to the modulation distortion Ld2 and Ld3 of the IEC standard 60268 provided that the loudspeaker generates pure amplitude modulation of second- or third-order. The measurement of amplitude modulation distortion (AMD) allows assessment of the effects of Bl(x) and Le(x) nonlinearity and radiation distortion due to pure amplitude modulation without Doppler effect. CONTENTS: 1 Method of Measurement ............................................................................................................................... 2 2 Checklist for dominant modulation distortion ............................................................................................... 3 3 Using the 3D distortion measurement (DIS) .................................................................................................. 4 4 Setup parameters for DIS Module .................................................................................................................. 4 5 Example ......................................................................................................................................................... -
25. Antennas II
25. Antennas II Radiation patterns Beyond the Hertzian dipole - superposition Directivity and antenna gain More complicated antennas Impedance matching Reminder: Hertzian dipole The Hertzian dipole is a linear d << antenna which is much shorter than the free-space wavelength: V(t) Far field: jk0 r j t 00Id e ˆ Er,, t j sin 4 r Radiation resistance: 2 d 2 RZ rad 3 0 2 where Z 000 377 is the impedance of free space. R Radiation efficiency: rad (typically is small because d << ) RRrad Ohmic Radiation patterns Antennas do not radiate power equally in all directions. For a linear dipole, no power is radiated along the antenna’s axis ( = 0). 222 2 I 00Idsin 0 ˆ 330 30 Sr, 22 32 cr 0 300 60 We’ve seen this picture before… 270 90 Such polar plots of far-field power vs. angle 240 120 210 150 are known as ‘radiation patterns’. 180 Note that this picture is only a 2D slice of a 3D pattern. E-plane pattern: the 2D slice displaying the plane which contains the electric field vectors. H-plane pattern: the 2D slice displaying the plane which contains the magnetic field vectors. Radiation patterns – Hertzian dipole z y E-plane radiation pattern y x 3D cutaway view H-plane radiation pattern Beyond the Hertzian dipole: longer antennas All of the results we’ve derived so far apply only in the situation where the antenna is short, i.e., d << . That assumption allowed us to say that the current in the antenna was independent of position along the antenna, depending only on time: I(t) = I0 cos(t) no z dependence! For longer antennas, this is no longer true. -
Ethnic Migrant Media Forum 2014 | Curated Proceedings 1 FOREWORD
Ethnic Migrant Media Forum 2014 CURATED PROCEEDINGS “Are we reaching all New Zealanders?” Exploring the Role, Benefits, Challenges & Potential of Ethnic Media in New Zealand Edited by Evangelia Papoutsaki & Elena Kolesova with Laura Stephenson Ethnic Migrant Media Forum 2014. Curated Proceedings is licensed under a Creative Commons Attribution- NonCommercial 4.0 International License. Ethnic Migrant Media Forum, Unitec Institute of Technology Thursday 13 November, 8.45am–5.45pm Unitec Marae, Carrington Road, Mt Albert Auckland, New Zealand The Introduction and Discussion sections were blind peer-reviewed by a minimum of two referees. The content of this publication comprises mostly the proceedings of a publicly held forum. They reflect the participants’ opinions, and their inclusion in this publication does not necessarily constitute endorsement by the editors, ePress or Unitec Institute of Technology. This publication may be cited as: Papoutsaki, E. & Kolesova, E. (Eds.) (2017). Ethnic migrant media forum 2014. Curated proceedings. Auckland, New Zealand. Retrieved from http://unitec. ac.nz/epress/ Cover design by Louise Saunders Curated proceedings design and editing by ePress Editors: Evangelia Papoutsaki and Elena Kolesova with Laura Stephenson Photographers: Munawwar Naqvi and Ching-Ting Fu Contact [email protected] www.unitec.ac.nz/epress Unitec Institute of Technology Private Bag 92025, Victoria Street West Auckland 1142 New Zealand ISBN 978-1-927214-20-6 Marcus Williams, Dean of Research and Enterprise (Unitec) opens the forum -
QUALM; *Quoion Answeringsystems
DOCUMENT RESUME'. ED 150 955 IR 005 492 AUTHOR Lehnert, Wendy TITLE The Process'of Question Answering. Research Report No. 88. ..t. SPONS AGENCY Advanced Research Projects Agency (DOD), Washington, D.C. _ PUB DATE May 77 CONTRACT ,N00014-75-C-1111 . ° NOTE, 293p.;- Ph.D. Dissertation, Yale University 'ERRS' PRICE NF -$0.83 1C- $15.39 Plus Post'age. DESCRIPTORS .*Computer Programs; Computers; *'conceptual Schemes; *Information Processing; *Language Classification; *Models; Prpgrai Descriptions IDENTIFIERS *QUALM; *QuOion AnsweringSystems . \ ABSTRACT / The cOmputationAl model of question answering proposed by a.lamputer program,,QUALM, is a theory of conceptual information processing based 'bon models of, human memory organization. It has been developed from the perspective of' natural language processing in conjunction with story understanding systems. The p,ocesses in QUALM are divided into four phases:(1) conceptual categorization; (2) inferential analysis;(3) content specification; and (4) 'retrieval heuristict. QUALM providea concrete criterion for judging the strengths and weaknesses'of store representations.As a theoretical model, QUALM is intended to describ general question answerinlg, where question antiering is viewed as aerbal communicb.tion. device betieen people.(Author/KP) A. 1 *********************************************************************** Reproductions supplied'by EDRS are the best that can be made' * from. the original document. ********f******************************************,******************* 1, This work-was -
GLOSSARY of Telecommunications Terms List of Abbreviations for Telecommunications Terms
GLOSSARY of Telecommunications Terms List of Abbreviations for Telecommunications Terms AAL – ATM Adaptation Layer ADPCM – Adaptive Differential Pulse Code Modulation ADSL – Asymmetric Digital Subscriber Line AIN – Advanced Intelligent Network ALI – Automatic Location Information AMA - Automatic Message Accounting ANI – Automatic Number Identification ANSI –American National Standards Institute API – Applications Programming Interface ATM – Asychronous Transfer Mode BHCA – Busy Hour Call Attempts BHCC – Busy Hour Call Completions B-ISDN – Broadband Integrated Services Digital Network B-ISUP – Broadband ISDN User’s Part BLV – Busy Line Verification BNS – Billed Number Screening BRI – Basic Rate Interface CAC – Carrier Access Code CCS – Centi Call Seconds CCV – Calling Card Validation CDR – Call Detail Record CIC – Circuit Identification Code CLASS – Custom Local Area Signaling CLEC – Competitive Local Exchange Carrier CO – Central Office CPE – Customer Provided/Premise Equipment CPN – Called Party Number CTI – Computer Telephony Intergration DLC – Digital Loop Carrier System DN – Directory Number DSL – Digital Subscriber Line DSLAM – Digital Subscriber Line Access Multiplexer DSP – Digital Signal Processor DTMF – Dual Tone Multi-Frequency ESS – Electronic Switching System ETSI - European Telecommunications Standards Institute GAP – Generic Address Parameter GT – Global Title GTT – Global Title Translations HFC – Hybrid Fiber Coax IAD – Integrated Access Device IAM – Initial Address Message ICP – Integrated Communications Provider ILEC -
Atmospheric Downwelling Longwave Radiation at the Surface During Cloudless and Overcast Conditions. Measurements and Modeling
ATMOSPHERIC DOWNWELLING LONGWAVE RADIATION AT THE SURFACE DURING CLOUDLESS AND OVERCAST CONDITIONS. MEASUREMENTS AND MODELING Antoni VIÚDEZ-MORA ISBN: 978-84-694-5001-7 Dipòsit legal: GI-752-2011 http://hdl.handle.net/10803/31841 ADVERTIMENT. La consulta d’aquesta tesi queda condicionada a l’acceptació de les següents condicions d'ús: La difusió d’aquesta tesi per mitjà del servei TDX ha estat autoritzada pels titulars dels drets de propietat intel·lectual únicament per a usos privats emmarcats en activitats d’investigació i docència. No s’autoritza la seva reproducció amb finalitats de lucre ni la seva difusió i posada a disposició des d’un lloc aliè al servei TDX. No s’autoritza la presentació del seu contingut en una finestra o marc aliè a TDX (framing). Aquesta reserva de drets afecta tant al resum de presentació de la tesi com als seus continguts. En la utilització o cita de parts de la tesi és obligat indicar el nom de la persona autora. ADVERTENCIA. La consulta de esta tesis queda condicionada a la aceptación de las siguientes condiciones de uso: La difusión de esta tesis por medio del servicio TDR ha sido autorizada por los titulares de los derechos de propiedad intelectual únicamente para usos privados enmarcados en actividades de investigación y docencia. No se autoriza su reproducción con finalidades de lucro ni su difusión y puesta a disposición desde un sitio ajeno al servicio TDR. No se autoriza la presentación de su contenido en una ventana o marco ajeno a TDR (framing). Esta reserva de derechos afecta tanto al resumen de presentación de la tesis como a sus contenidos. -
Compatibility and Sharing Analysis Between Dvb–T and Ob (Outside Broadcast) Audio Links in Bands Iv and V
ERC REPORT 90 European Radiocommunications Committee (ERC) within the European Conference of Postal and Telecommunications Administrations (CEPT) COMPATIBILITY AND SHARING ANALYSIS BETWEEN DVB–T AND OB (OUTSIDE BROADCAST) AUDIO LINKS IN BANDS IV AND V Edinburgh, October 2000 ERC REPORT 90 Copyright 2000 the European Conference of Postal and Telecommunications Administrations (CEPT) ERC REPORT 90 Executive Summary This study assesses the compatibility between OB links and DVB–T in bands IV and V and determines the necessary separation distances between OB links and DVB–T as a function of frequency. The study takes account of three spectrum masks: the spectrum mask for sensitive cases according to the Chester Agreement, 19971 and the two spectrum masks recommended by SE PT 212. The results are only valid for the DVB–T and OB links system parameters given in this study. In order to establish if in a given set of circumstances: - the DVB-T service and - OB link usage at a given location are compatible, the relevant separation distances derived in Sections 2 and 3, must be examined. If both separation distances are respected, then usage is compatible. The main results of the study are as follows: • In most cases, Co-channel operation (frequency difference from 0 to 4 MHz between the centre frequencies) of DVB–T and OB links within a DVB–T coverage area will cause unacceptable interference to OB links and vice-versa. • For an operation of OB links in the 1st adjacent channel of DVB–T (frequency difference from 4 to 12 MHz between the centre frequencies), the necessary separation distances obtained in this study are quite large. -
Frequency Plans for Broadcasting Services by Juan Castro Broadcasting Services Division OVERVIEW
Frequency plans for broadcasting services By Juan Castro Broadcasting Services Division OVERVIEW . ITU Regions . Regional Plans . Regional Plans concerning TV broadcasting . Regional Plans concerning sound broadcasting . Article 4: Modifications to the Plans . Useful links ITU REGIONS REGIONAL PLANS - Definition . Regional agreements for: o specific frequency bands o specific region/area o specific services . Adopted by Regional Conferences (technical criteria + frequency plans) . Types of Plans: o Assignment Plans (stations) o Allotment Plans (geographical areas) TYPES OF REGIONAL PLANS . Assignment Plan: frequencies are assigned to stations Station 1 Frequencies f1, f2, f3… Station 3 Station 2 . Allotment Plan: frequencies are assigned to geographical areas Area 1 Frequencies f1, f2, f3… Area 3 Area 2 TV BROADCASTING REGIONAL PLANS . Regional Plans (in force) that concern television broadcasting: o Stockholm 1961 modified in 2006 (ST61) o Geneva 1989 modified in 2006 (GE89) o Geneva 2006 (GE06) TV REGIONAL PLANS: ST61 . ST61: Stockholm 1961 modified in 2006 In 2006 the bands 174-230 MHz and 470-862 MHz were transferred to GE06 Plan . Assignment Plan . Region: European Broadcasting Area (EBA) . Bands: o Band I: 47-68 MHz o Band II: 87.5-100 MHz o Band III: 162-170 MHz . Services: o Broadcasting (sound and television) TV REGIONAL PLANS: GE89 . GE89: Geneva 1989 modified in 2006 In 2006 the bands 174-230 MHz and 470-862 MHz were transferred to GE06 Plan . Assignment Plan . Region: African Broadcasting Area(ABA) . Bands: o Band I: 47-68 MHz o Band III: 230-238 and 246-254 MHz . Services: o Broadcasting (television only) TV REGIONAL PLANS: GE06 . GE06 (Digital Plan): There were 2 plans (analogue and digital).