ITU-T J 185-2012 Transmission equipment for transferring multi-channel television signals over optical access networks by frequency modulation conversion (Study Group 9)《通过频率调制转换在光.pdf
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1、 International Telecommunication Union ITU-T J.185TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU (06/2012) SERIES J: CABLE NETWORKS AND TRANSMISSION OF TELEVISION, SOUND PROGRAMME AND OTHER MULTIMEDIA SIGNALS Digital transmission of television signals Transmission equipment for transferring multi-c
2、hannel television signals over optical access networks by frequency modulation conversion Recommendation ITU-T J.185 Rec. ITU-T J.185 (06/2012) i Recommendation ITU-T J.185 Transmission equipment for transferring multi-channel television signals over optical access networks by frequency modulation c
3、onversion Summary Recommendation ITU-T J.185 describes a transmission method for transferring multi-channel television signals over optical access networks. ITU-T J.185 transmission equipment is capable of realizing multi-channel AM-VSB, 64-QAM, and 256-QAM video signal transmission through the use
4、of frequency modulation conversion. History Edition Recommendation Approval Study Group 1.0 ITU-T J.185 2002-02-13 9 2.0 ITU-T J.185 2012-06-13 9 ii Rec. ITU-T J.185 (06/2012) FOREWORD The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommun
5、ications, information and communication technologies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunic
6、ations on a worldwide basis. The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics. The approval of ITU-T Recommendations is covered by the procedur
7、e laid down in WTSA Resolution 1. In some areas of information technology which fall within ITU-Ts purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. NOTE In this Recommendation, the expression “Administration“ is used for conciseness to indicate both a telecomm
8、unication administration and a recognized operating agency. Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure, e.g., interoperability or applicability) and compliance with the Recommendation is achieved when all of these
9、 mandatory provisions are met. The words “shall“ or some other obligatory language such as “must“ and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party. INTELLECTUAL PROPERTY RIGHTS ITU d
10、raws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members
11、 or others outside of the Recommendation development process. As of the date of approval of this Recommendation, ITU had not received notice of intellectual property, protected by patents, which may be required to implement this Recommendation. However, implementers are cautioned that this may not r
12、epresent the latest information and are therefore strongly urged to consult the TSB patent database at http:/www.itu.int/ITU-T/ipr/. ITU 2012 All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. Rec. ITU-T J.185 (06
13、/2012) iii Table of Contents Page 1 Scope 1 2 References. 1 3 Definitions 2 3.1 Terms defined elsewhere 2 3.2 Terms defined in this Recommendation . 2 4 Abbreviations and acronyms 2 5 Conventions 3 6 System description 4 7 Performance of analogue and/or digital video transmission system 4 7.1 Specif
14、ied transmission quality for analogue video signal 4 7.2 Specified transmission quality for digital video signal 4 Annex A Multi-channel video broadcast system over optical access network: system A 6 A.1 System description 6 A.2 TX . 8 A.3 V-OLT 11 A.4 V-ONT 12 Annex B Multi-channel video broadcast
15、system with cascaded V-OLTs: system B . 14 B.1 System description 14 B.2 TX . 16 B.3 V-OLT 19 B.4 V-ONT 20 Appendix I FM frequency deviation and minimum received optical power for CATV band of 47 to 864 MHz . 23 Appendix II FM frequency deviation and minimum received optical power for CATV band of 4
16、7 to 2100 MHz . 25 Bibliography. 27 Rec. ITU-T J.185 (06/2012) 1 Recommendation ITU-T J.185 Transmission equipment for transferring multi-channel television signals over optical access networks by frequency modulation conversion 1 Scope This Recommendation describes a method of transmitting multi-ch
17、annel television signals over an optical access network that utilizes frequency modulation (FM) conversion. In this FM transmission system, multi-channel frequency-division multiplexing (FDM) television signals are simultaneously converted into one single wideband FM signal. This FM signal is then t
18、ransmitted through the optical access network by using the intensity modulation technique. The video-optical network terminal (V-ONT) at the customer premises converts the received single FM signal into the original multi-channel FDM video signals, i.e., coaxial cable television (CATV) signals. The
19、interface for this FM transmission system is the same as that of the amplitude modulation sub-carrier multiplexing (AM-SCM) system. Therefore, the FM transmission system can replace the AM-SCM system. The FM transmission system is required to have an FM converter, i.e., frequency modulator and frequ
20、ency demodulator, in addition to the AM-SCM transmission systems equipment. However, it has a better efficiency than the AM-SCM transmission system against the noise deterioration caused by optical transmission/splitter loss and optical reflections. In the SCM technique, the main carrier is the opti
21、cal frequency signal carrier; the sub-carriers transfer the electrically multiplexed FDM video signals in the optical sideband. This system can be added to the ITU-T G.983.1 series B-PON system by using ITU-T G.983.3 wavelength-division multiplexing (WDM) technology, to the ITU-T G.984 series G-PON
22、system and ITU-T G.987 series XG-PON system by using ITU-T G.984.5 WDM technology, and to the IEEE 802.3ah/802.3av EPON systems. This integration would allow the system to offer broadcast services and also data and voice communication services over the same optical access network. By using the bidir
23、ectional data PON system, upstream signals, e.g., control functionality and upstream data indicating the users requirements, can be transmitted as well. 2 References The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisio
24、ns of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations
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