1、 International Telecommunication Union ITU-T J.361TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU (11/2006) SERIES J: CABLE NETWORKS AND TRANSMISSION OF TELEVISION, SOUND PROGRAMME AND OTHER MULTIMEDIA SIGNALS IPCablecom IPCablecom2 codec and media ITU-T Recommendation J.361 ITU-T Rec. J.361 (11/200
2、6) i ITU-T Recommendation J.361 IPCablecom2 codec and media Summary This new IPCablecom2 Recommendation addresses interfaces for audio, video and text communications between user equipment (UE), media gateways (MG) and other network elements, such as media servers, that process media. Specifically,
3、it identifies the audio and video codecs and other features necessary to provide the highest quality and the most resource-efficient media streams to the customer. Source ITU-T Recommendation J.361 was approved on 29 November 2006 by ITU-T Study Group 9 (2005-2008) under the ITU-T Recommendation A.8
4、 procedure. It includes the modifications introduced by Amendment 1 approved on 29 July 2007. ii ITU-T Rec. J.361 (11/2006) FOREWORD The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications. The ITU Telecommunication Standardization
5、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 telecommunications on a worldwide basis. The World Telecommunication Standardization Assembly (WTSA), which meets e
6、very 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 procedure laid down in WTSA Resolution 1. In some areas of information technology which fall within ITU-Ts purv
7、iew, 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 telecommunication administration and a recognized operating agency. Compliance with this Recommendation is volu
8、ntary. 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 mandatory provisions are met. The words “shall“ or some other obligatory language such as “must“ and the
9、 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 draws attention to the possibility that the practice or implementation of this Recommendation may involve
10、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 development process. As of the date of approval of this Recommen
11、dation, 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 represent the latest information and are therefore strongly urged to consult the TSB patent database at ht
12、tp:/www.itu.int/ITU-T/ipr/. ITU 2008 All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. ITU-T Rec. J.361 (11/2006) iii CONTENTS Page 1 Scope and introduction . 1 1.1 Scope 1 1.2 Introduction 1 2 References. 3 3 Te
13、rms and definitions . 8 4 Abbreviations and acronyms 9 5 Conventions 10 6 Common criteria for media transport over IP. 11 6.1 IP network criteria for codec support . 11 6.2 Overall quality targets 13 6.3 Media security 13 7 Gap analysis between 3GPP, 3GPP2 and IPCablecom codec requirements 13 7.1 Au
14、dio codecs 13 7.2 Video codecs 14 7.3 Quality metrics . 15 8 Codec and media requirements. 15 8.1 RTP requirements. 17 8.2 RTCP requirements 17 8.3 General session description for codecs. 19 8.4 Narrow-band codec specifications . 23 8.5 Wideband codec specification 47 8.6 Super-wideband codec specif
15、ications. 56 8.7 Video codec specification. 65 8.8 Media quality measurement and monitoring 75 Annex A H.263 profiles and levels. 82 Annex B H.264/AVC profiles and levels 84 Appendix I Characteristics of narrow-band codecs 86 Appendix II Characteristics of wideband codecs 91 Bibliography. 94 ITU-T R
16、ec. J.361 (11/2006) 1 ITU-T Recommendation J.361 IPCablecom2 codec and media 1 Scope and introduction 1.1 Scope This Recommendation addresses interfaces for audio, video and text communications between user equipment (UE), media gateways (MG) and other network elements, such as media servers that pr
17、ocess media. Specifically, it identifies the audio and video codecs and other features necessary to provide the highest quality and the most resource-efficient media streams to the customer. 1.2 Introduction 1.2.1 Background IPCablecom2 defines a modular architecture and a set of interoperable inter
18、faces that leverage emerging communications technologies, such as SIP, to support the rapid introduction of new IP-based communications and streaming services onto the cable network. A modular approach allows operators to deploy network capabilities as required by their specific service offerings, w
19、hile maintaining interoperability across a variety of devices from multiple suppliers. Examples of the service capabilities include: Enhanced residential VoIP and IP video communications Capabilities such as wideband audio and video telephony plus click-to-dial type call processing based on presence
20、, device capability, and identity. Cross platform feature integration Capabilities such as caller-id and video telephony display on the television, and call treatment from the television. Mobility services and integration with cellular and wireless networks Capabilities such as call hand-off and roa
21、ming between IPCablecom VoIP over wireless LAN and cellular networks. Multimedia applications Capabilities such as QoS-enabled audio and video streaming, and real-time conversational text. The network capabilities required to support this variety of services encompass protocol support, media support
22、, architecture and network element types, security, bandwidth management, and network management. As with previous IPCablecom Recommendations, IPCablecom2 leverages existing open standards wherever possible. IPCablecom2 is based on the IP multimedia subsystem (IMS) as defined by the 3rd generation p
23、artnership Project (3GPP). Figure 1-1 below illustrates the functional components that are included in the IPCablecom2 architecture. Refer to the IPCablecom2 architecture framework Recommendation for more detail b-ITU-T J.360. 2 ITU-T Rec. J.361 (11/2006) J.361(06)_F01LocalnetworkAccessnetworkOperat
24、ionalsupport systemsInterconnectCoreApplicationPacketCablemultimediaEdgePresenceserverS-CSCFCMSPolicyserverSTUN server P-CSCFI-CSCFPSTN GWMGMGCSGApplicationserverMedia proxyTURN ServerOtherAccesspointENUMNMS and EMS CDFTimeDHCPCMTSCablemodemNAT andFirewallPacketCable application managerSLFBGCFUE UE
25、UE UE UEDNSHSSDOCSISPA CPeernetworkinterconnectproxyBorder elementPSTNPacketCableE-MTAsCablemodemCablemodemE-MTACablemodemFigure 1-1 IPCablecom reference architecture Concerning media support, the subject of this Recommendation, the quality of audio, video and text delivered over the IPCablecom2 arc
26、hitecture depends on multiple factors starting with the inherent capabilities and performance of the end devices, the networks performance and quality, and the intelligence of the network resource allocation. To assure interoperability for both “on-net“, including different VoIP network types such a
27、s cable-Wi-Fi networks, and “off-net“ connections, this Recommendation defines codecs and capabilities for supporting narrow-band and wideband audio applications, video and real-time conversational text applications, with emphasis on the stringent requirements of IP-based voice, video and text commu
28、nications. Acceptable two-way voice and video communications and real-time text conversation imposes strict latency and packet-loss criteria on IP implementations and will thus stress system resources, particularly if bandwidth becomes congested or saturated. Entertainment-quality audio and video st
29、reaming applications, while more tolerant of latency, still impose strict packet-loss requirements ITU-T Rec. J.361 (11/2006) 3 and generally require more bandwidth than two-way communications applications. The IPCablecom architecture is designed to support both types of applications simultaneously.
30、 Audio compression and video compression are evolving technologies. New algorithms are being enabled as more sophisticated and higher-performing processors become available at lower cost. Additionally, the system infrastructure and mechanisms for allocating resources will evolve. Due to this dynamis
31、m, the priority in designing IPCablecom architecture is to define a robust system that accommodates evolving technology without creating a legacy burden. 1.2.2 Purpose of this Recommendation The purpose of this Recommendation is to specify profiles for codecs, packetization rules, encodings, and qua
32、lity metrics to assure successful media interworking within an IPCablecom network and between an IPCablecom network and interconnecting networks including the PSTN and cellular networks. The media specified in this Recommendation include narrow-band audio, wideband audio, image, video and real-time
33、text for communications services. The actual codecs and other requirements that are mandatory, recommended, or optional depend on the functional component within the IPCablecom architecture, and the intended capability of the device or application. These requirements are specified in separate applic
34、ation capability documents. This Recommendation is issued to facilitate component design and qualification testing leading to the manufacturability and interoperability of conforming hardware and software by multiple vendors. 1.2.3 High-level requirements for IPCablecom2 IPCablecom2 media stream tra
35、nsport and encoding design goals include the following: minimize the effects of latency, packet loss and jitter on sensitive media streams (e.g., voice and video) to ensure quality in the target environments (including audio/video telephony, IP video streaming and wireless); define a set of audio an
36、d video codecs and associated media transmission protocols that may be supported; accommodate emerging narrow-band and wideband voice codec technologies; accommodate emerging video codec technologies to provide support for applications such as video telephony, IP video streaming, etc.; accommodate r
37、eal-time text conversation sessions; specify minimum requirements for echo cancellation and voice activity detection; support transparent, error-free dual tone multi frequency (DTMF) transmission; support for fax relay, modem relay, DTMF relay, and teletype (TTY); support calculation and reporting o
38、f voice quality metrics. 2 References The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other referenc
39、es are subject to revision; users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. The reference to
40、a document within this Recommendation does not give it, as a stand-alone document, the status of a Recommendation. 4 ITU-T Rec. J.361 (11/2006) ITU-T F.700 ITU-T Recommendation F.700 (2000), Framework Recommendation for multimedia services. ITU-T F.703 ITU-T Recommendation F.703 (2000), Multimedia c
41、onversational services. ITU-T F.724 ITU-T Recommendation F.724 (2005), Service description and requirements for videotelephony services over IP networks. ITU-T G.107 ITU-T Recommendation G.107 (2005), The E-Model, a computational model for use in transmission planning. ITU-T G.114 ITU-T Recommendati
42、on G.114 (2003), One-way transmission time. ITU-T G.168 ITU-T Recommendation G.168 (2004), Digital network echo cancellers. ITU-T G.711 ITU-T Recommendation G.711 (1988), Pulse code modulation (PCM) of voice frequencies. ITU-T G.711 App.I ITU-T Recommendation G.711 Appendix I (1999), A high quality
43、low-complexity algorithm for packet loss concealment with G.711. ITU-T G.711 App.II ITU-T Recommendation G.711 Appendix II (2000), A comfort noise payload definition for ITU-T G.711 use in packet-based multimedia communication systems. ITU-T G.712 ITU-T Recommendation G.712 (2001), Transmission perf
44、ormance characteristics of pulse code modulation channels. ITU-T G.722 ITU-T Recommendation G.722 (1988), 7 kHz audio-coding within 64 kbit/s. ITU-T G.722.2 ITU-T Recommendation G.722.2 (2003), Wideband coding of speech at around 16 kbit/s using Adaptive Multi-Rate Wideband (AMR-WB). ITU-T H.262 ITU
45、-T Recommendation H.262 (2000) | ISO/IEC 13818-2:2000, Information technology Generic coding of moving pictures and associated information: Video. ITU-T T.38 ITU-T Recommendation T.38 (2005), Procedures for real-time Group 3 facsimile communication over IP networks. ITU-T T.140 ITU-T Recommendation
46、T.140 (1998), Protocol for multimedia application text conversation. ITU-T V.18 ITU-T Recommendation V.18 (2000), Operational and interworking requirements for DCEs operating in the text telephone mode. ITU-T V.152 ITU-T Recommendation V.152 (2005), Procedures for supporting voice-band data over IP
47、networks. ANSI/SCTE 24-21 ANSI/SCTE 24-21 (2006), BV16 Speech Codec Specification for Voice over IP Applications in Cable Telephony. ANSI T1.508 ANSI T1.508 (2003), Loss Plan for Digital Networks. ANSI/TIA-127-A ANSI/TIA 127-A (2004), Enhanced Variable Rate Codec Speech Service Option 3 for Wideband
48、 Spread Spectrum Digital Systems. ATSC A/52B ATSC A/52B, Digital Audio Compression (AC-3, E-AC-3), Standard, Rev. B, 14 June 2005. ITU-T Rec. J.361 (11/2006) 5 ETSI TS 102 005 ETSI TS 102 005 V1.3.1 (2007), Digital Video Broadcasting (DVB); Specification for the use of Video and Audio Coding in DVB
49、services delivered directly over IP protocols. ETSI TS 126 091 ETSI TS 126 091 V6.0.0 (2004), AMR speech codec; Error concealment of lost frames. ETSI TS 126 092 ETSI TS 126 092 V6.0.0 (2004), AMR speech codec; Comfort noise for AMR speech traffic channels. ETSI TS 126 093 ETSI TS 126 093 V6.1.0 (2006), AMR speech codec; Source controlled rate operation. ETSI TS 126 094 ETSI TS 126 094 V6.1.0 (2006), AMR speech codec; Voice activity detector for AMR speech traffic channels. ETSI TS 126 101
