1、Union internationale des tlcommunications Place des Nations 1211 GENVE 20 Suisse Switzerland Suiza COVERING NOTE GENERAL SECRETARIAT INTERNATIONAL TELECOMMUNICATION UNION Geneva, 2 September 2002 ITU TELECOMMUNICATION STANDARDIZATION SECTOR Subject: Amendement 1 (02/2002) ITU-T Recommendation J.112-
2、Annex B (03/2001) Data-over-cable service interface specifications: Radio-frequency interface specification Change Annex O “Privacy for J.112 Annex B Implementations“ status from informative to normative INTERNATIONAL TELECOMMUNICATION UNION ITU-T J.112TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU
3、 Annex B(03/2001) SERIES J: CABLE NETWORKS AND TRANSMISSION OF TELEVISION, SOUND PROGRAMME AND OTHER MULTIMEDIA SIGNALS Interactive systems for digital television distribution Transmission systems for interactive cable television services Annex B: Data-over-cable service interface specifications: Ra
4、dio-frequency interface specification ITU-T Recommendation J.112 Annex B ITU-T J-SERIES RECOMMENDATIONS CABLE NETWORKS AND TRANSMISSION OF TELEVISION, SOUND PROGRAMME AND OTHER MULTIMEDIA SIGNALS General Recommendations J.1J.9 General specifications for analogue sound-programme transmission J.10J.19
5、 Performance characteristics of analogue sound-programme circuits J.20J.29 Equipment and lines used for analogue sound-programme circuits J.30J.39 Digital encoders for analogue sound-programme signals J.40J.49 Digital transmission of sound-programme signals J.50J.59 Circuits for analogue television
6、transmission J.60J.69 Analogue television transmission over metallic lines and interconnection with radio-relay links J.70J.79 Digital transmission of television signals J.80J.89 Ancillary digital services for television transmission J.90J.99 Operational requirements and methods for television trans
7、mission J.100J.109 Interactive systems for digital television distribution J.110J.129 Transport of MPEG-2 signals on packetised networks J.130J.139 Measurement of the quality of service J.140J.149 Digital television distribution through local subscriber networks J.150J.159 IPCablecom J.160J.179 Misc
8、ellaneous J.180J.199 Application for Interactive Digital Television J.200J.209 For further details, please refer to the list of ITU-T Recommendations. ITU-T Rec. J.112/Annex B (03/2001) i ITU-T Recommendation J.112 Transmission systems for interactive cable television services ANNEX B Data-over-cabl
9、e service interface specifications: Radio-frequency interface specification Summary This annex defines the radio-frequency interface specifications for high-speed data-over-cable systems. Two options for physical layer technology are included. One option is based on the downstream multi-programme te
10、levision distribution that is deployed in North America using 6 MHz channelling, and supports upstream transmission in the region 5 MHz to 42 MHz. The other one is based on the corresponding European multi-programme television distribution and supports upstream in the region 5 MHz to 65 MHz. Source
11、Annex B to ITU-T Recommendation J.112 was prepared by ITU-T Study Group 9 (2001-2004) and approved under the WTSA Resolution 1 procedure on 9 March 2001. Annex O “Privacy for J.112 Annex B Implementations“, which was informative at J.112 Annex B approval in March 2001, was changed to normative by IT
12、U-T Rec. J.112 Annex B/Amendment 1 (02/2002). ii ITU-T Rec. J.112/Annex B (03/2001) FOREWORD The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications. The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of I
13、TU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics
14、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 procedure laid down in WTSA Resolution 1. In some areas of information technology which fall within ITU-Ts purview, the necessary standards are prepare
15、d on a collaborative basis with ISO and IEC. NOTE In this Recommendation, the expression “Administration“ is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. INTELLECTUAL PROPERTY RIGHTS ITU draws attention to the possibility that the practi
16、ce 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 or others outside of the Recommendation developm
17、ent process. As of the date of approval of this Recommendation, ITU had received notice of intellectual property, protected by patents, which may be required to implement this Recommendation. However, implementors are cautioned that this may not represent the latest information and are therefore str
18、ongly urged to consult the TSB patent database. ITU 2002 All rights reserved. No part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from ITU. ITU-T Rec. J.112/Annex B (03/20
19、01) iii CONTENTS Page Annex B Data-over-cable service interface specifications: Radio-frequency interface specification 1 B.1 Scope 1 B.1.1 General scope 1 B.1.2 Conventions. 2 B.1.3 Background . 2 B.2 References 6 B.3 Definitions and abbreviations. 9 B.3.1 Definitions. 9 B.3.2 Abbreviations 16 B.4
20、Functional assumptions 18 B.4.1 Broadband access network 18 B.4.2 Equipment assumptions. 18 B.4.3 RF channel assumptions 19 B.4.4 Transmission levels . 21 B.4.5 Frequency inversion 21 B.5 Communication protocols 21 B.5.1 Protocol stack 21 B.5.2 The MAC Forwarder. 25 B.5.3 Network Layer. 27 B.5.4 Abo
21、ve the Network Layer . 29 B.5.5 Data Link Layer 29 B.5.6 Physical layer 30 B.6 Physical media-dependent sublayer specification 30 B.6.1 Scope . 30 B.6.2 Upstream . 30 B.6.3 Downstream 50 B.7 Downstream transmission convergence sublayer. 54 B.7.1 Introduction . 54 B.7.2 MPEG packet format. 55 B.7.3 M
22、PEG Header for DOCSIS Data-Over-Cable 55 B.7.4 MPEG Payload for DOCSIS Data-Over-Cable 56 B.7.5 Interaction with the MAC sublayer. 56 B.7.6 Interaction with the Physical layer 57 B.7.7 MPEG Header synchronization and recovery. 57 B.8 Media access control specification. 58 B.8.1 Introduction . 58 B.8
23、.2 MAC Frame formats . 59 iv ITU-T Rec. J.112/Annex B (03/2001) Page B.8.3 MAC Management Messages . 80 B.9 Media Access Control Protocol Operation. 124 B.9.1 Upstream Bandwidth Allocation. 124 B.9.2 Support for multiple channels . 130 B.9.3 Timing and synchronization 130 B.9.4 Upstream transmission
24、 and contention resolution 133 B.9.5 Data link encryption support . 135 B.10 Quality of Service another vendor may omit the same item. Other text is descriptive or explanatory. B.1.3 Background B.1.3.1 Service goals Cable operators are interested in deploying high-speed packet-based communications s
25、ystems on cable television systems that are capable of supporting a wide variety of services. Services under consideration by cable operators include packet telephony service, video conferencing service, T1/frame relay equivalent service, and many others. It has been decided to prepare a series of i
26、nterface specifications that will permit the early definition, design, development and deployment of data-over-cable systems on a uniform, consistent, open, non-proprietary, multi-vendor interoperable basis. The intended service will allow transparent bidirectional transfer of Internet Protocol (IP)
27、 traffic, between the cable system headend and customer locations, over an all-coaxial or hybrid-fiber/coax (HFC) cable network. This is shown in simplified form in Figure B.1-1. T0904770-97Transparent IP traffic through the systemWide AreaNetworkCMTSNetwork SideInterfaceCableModemTerminationSystem(
28、CMTS)CableNetworkCable Modem(CM)CM Customer PremisesEquipment InterfaceCustomerPremisesEquipmentFigure B.1-1/J.112 Transparent IP traffic through the data-over-cable system ITU-T Rec. J.112/Annex B (03/2001) 3 The transmission path over the cable system is realized at the headend by a Cable Modem Te
29、rmination System (CMTS), and at each customer location by a Cable Modem (CM). At the headend (or hub), the interface to the data-over-cable system is called the Cable Modem Termination System Network-Side Interface (CMTS-NSI) and is specified in DOCSIS3. At the customer locations, the interface is c
30、alled the cable-modem-to-customer-premises-equipment interface (CMCI) and is specified in DOCSIS4. The intent is for operators to transparently transfer IP traffic between these interfaces, including but not limited to datagrams, DHCP, ICMP, and IP Group addressing (broadcast and multicast). B.1.3.2
31、 Reference architecture The reference architecture for the data-over-cable services and interfaces is shown in Figure B.1-2. 4 ITU-T Rec. J.112/Annex B (03/2001) 50-860 MHz5-42 MHzT0904780-97PSTNVideo 1Video 2DataDataFiberCoaxWANWANDistribution Hub or HeadendOperations Support SystemCombinerBackbone
32、NetworkTelco ReturnAccessConcen-trator(TRAC)CopperPairs,DS1 or DS3 Data Over Cable SystemOSS Interface (DOCS-OSSI)Cable ModemTermination SystemNetwork Side Interface(CMTS-NSI)Cable ModemTermination SystemGenericHeadendSwitch orBackboneTransportAdapterLocalServerFacilityRemoteServerFacilityData Over
33、CableSecurity System(DOCSS)Cable Modem Termination SystemDownstream RF InterfaceCustomerPremiseEquipmentRemovableSecurityModuleCableModemO/ENodeO/ENodeO/ENodeCable Modem toCPE Interface(CMCI)Cable ModemTelco ReturnInterface (CMTRI)Cable Modem Termination SystemUpstream RF InterfaceModDemodTxRxTelcor
34、eturnSecurity between the CMTS and the cable network, in the downstream direction (traffic toward the customer); between the CMTS and the cable network, in the upstream direction (traffic from the customer). Security requirements Baseline data-over-cable security is defined in DOCSIS8. NOTE This arc
35、hitecture illustrates the North American frequency plans only and is not normative for European applications. Refer to B.1.1 for applicability. B.1.3.3.1 Data-Over-Cable Service Interface documents A list of the documents in the Data-Over-Cable Service Interface Specifications family is provided bel
36、ow. For updates, please refer to URL http:/. Designation Title SP-CMCI Cable Modem to Customer Premises Equipment Interface Specification SP-CMTS-NSI Cable Modem Termination System Network Side Interface Specification SP-CMTRI Cable Modem Telco Return Interface Specification SP-OSSI Operations Suppo
37、rt System Interface Specification SP-RFI Radio Frequency Interface Specification SP-BPI+ Baseline Privacy Plus Interface Specification Key to designations SP Specification TP Test Plan A document of test procedures to validate specification conformance, interoperability or performance TR Technical R
38、eport (provides a context for understanding and applying the specification or initial ideas about possible future features) ITU-T Rec. J.112/Annex B (03/2001) 6 B.1.3.4 Statement of compatibility This clause applies only to the first option as defined in B.1.1. This Annex B specifies an interface, c
39、ommonly referred to as DOCSIS 1.1, which is an extension of the interface specified in DOCSIS9, commonly referred to as DOCSIS 1.0. These extensions are entirely backwards and forwards compatible with the previous version of J.112 Annex B. DOCSIS 1.1 compliant CMs have to interoperate seamlessly wit
40、h DOCSIS 1.0 CMTSs. DOCSIS 1.1 compliant CMTSs MUST seamlessly support DOCSIS 1.0 CMs. Refer to Annex B.G for further interoperability information. B.2 References The following Recommendations and other references contain provisions which, through reference in this text, constitute provisions of thi
41、s Annex B. References are either specific (identified by date of publication, edition number, version number, etc.) or non-specific: For a specific reference, subsequent revisions do not apply. For a non-specific reference, the latest version applies. CableLabs1 CableLabs1 (12 April 1995), Two-Way C
42、able Television System Characterization, Cable Television Laboratories, Inc. CableLabs2 CableLabs2 (November 1994), Digital Transmission Characterization of Cable Television Systems, Cable Television Laboratories, Inc. DIX DIX (1982), Ethernet Protocol Version 2.0, Digital, Intel, Xerox. DOCSIS3 Dat
43、a-Over-Cable Service Interface Specifications, Cable Modem Termination System Network Side Interface Specification, SP-CMTS-NSII01-960702. DOCSIS4 Data-Over-Cable Service Interface Specifications, Cable Modem to Customer Premise Equipment Interface Specification, SP-CMCI-I04-000714. DOCSIS5 Data-Ove
44、r-Cable Service Interface Specifications, Operations Support System Interface Specification, SP-OSSIv1.1-I02-000714. DOCSIS6 Data-Over-Cable Service Interface Specifications, Cable Modem Telephony Return Interface Specification, SP-CMTRI-I01-970804. DOCSIS8 Data-Over-Cable Service Interface Specific
45、ations, Baseline Privacy Plus Interface Specification, SP-BPI+-I05-000714. DOCSIS9 Data-Over-Cable Service Interface Specifications, Radio Frequency Interface Specification, SP-RFI-I06-000630. EIA 542 EIA Standard 542 (1997), Cable Television Channel Identification Plan. EN 50081-1 EN 50081-1, Elect
46、romagnetic compatibility Generic emission standard Part 1: Residential, commercial and light industry. EN 50082-1 EN 50082-1, Electromagnetic compatibility Generic immunity standard; Part 1: Residential, commercial and light industry. EN 50083-2 EN 50083-2, Cabled distribution systems for television
47、 and sound signals Part 2: Electromagnetic compatibility for equipment. EN 50083-7 EN 50083-7, Cabled distribution systems for television and sound signals Part 7: System performance. ITU-T Rec. J.112/Annex B (03/2001) 7 EN 50083-10 EN 50083-10, Cable networks for television signals, sound signals a
48、nd interactive services Part 10: System performance of return paths. EN 60950 EN 60950, Safety of information technology equipment. EN 50083-1 EN 50083-1, Cabled distribution systems for television and sound signals Part 1: Safety requirements. EG 201 212 ETSI EG 201 212, Electrical safety; Classifi
49、cation of interfaces for equipment to be connected to telecommunication networks. (This document is also available from CENELEC as ROBT-002.) EN 300 429 ETSI EN 300 429, Digital Video Broadcasting (DVB); Framing structure, channel coding and modulation for cable systems. FCC15 Code of Federal Regulations, Title 47, Part 15 (October 1998), Radio frequency devices. FCC76 Code of Federal Regulations, Title 47, Part 76 (October 1998), Cable televiso
