1、 ETSI TR 126 980 V14.2.0 (2017-04) Universal Mobile Telecommunications System (UMTS); LTE; Multimedia telephony over IP Multimedia Subsystem (IMS); Media handling aspects of multi-stream multiparty conferencing for Multimedia Telephony Service for IMS (MTSI) (3GPP TR 26.980 version 14.2.0 Release 14
2、) TECHNICAL REPORT ETSI ETSI TR 126 980 V14.2.0 (2017-04)13GPP TR 26.980 version 14.2.0 Release 14Reference RTR/TSGS-0426980ve20 Keywords LTE,UMTS ETSI 650 Route des Lucioles F-06921 Sophia Antipolis Cedex - FRANCE Tel.: +33 4 92 94 42 00 Fax: +33 4 93 65 47 16 Siret N 348 623 562 00017 - NAF 742 C
3、Association but non lucratif enregistre la Sous-Prfecture de Grasse (06) N 7803/88 Important notice The present document can be downloaded from: http:/www.etsi.org/standards-search The present document may be made available in electronic versions and/or in print. The content of any electronic and/or
4、 print versions of the present document shall not be modified without the prior written authorization of ETSI. In case of any existing or perceived difference in contents between such versions and/or in print, the only prevailing document is the print of the Portable Document Format (PDF) version ke
5、pt on a specific network drive within ETSI Secretariat. Users of the present document should be aware that the document may be subject to revision or change of status. Information on the current status of this and other ETSI documents is available at https:/portal.etsi.org/TB/ETSIDeliverableStatus.a
6、spx If you find errors in the present document, please send your comment to one of the following services: https:/portal.etsi.org/People/CommiteeSupportStaff.aspx Copyright Notification No part may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopyin
7、g and microfilm except as authorized by written permission of ETSI. The content of the PDF version shall not be modified without the written authorization of ETSI. The copyright and the foregoing restriction extend to reproduction in all media. European Telecommunications Standards Institute 2017. A
8、ll rights reserved. DECTTM, PLUGTESTSTM, UMTSTMand the ETSI logo are Trade Marks of ETSI registered for the benefit of its Members. 3GPPTM and LTE are Trade Marks of ETSI registered for the benefit of its Members and of the 3GPP Organizational Partners. GSM and the GSM logo are Trade Marks registere
9、d and owned by the GSM Association. ETSI ETSI TR 126 980 V14.2.0 (2017-04)23GPP TR 26.980 version 14.2.0 Release 14Intellectual Property Rights IPRs essential or potentially essential to the present document may have been declared to ETSI. The information pertaining to these essential IPRs, if any,
10、is publicly available for ETSI members and non-members, and can be found in ETSI SR 000 314: “Intellectual Property Rights (IPRs); Essential, or potentially Essential, IPRs notified to ETSI in respect of ETSI standards“, which is available from the ETSI Secretariat. Latest updates are available on t
11、he ETSI Web server (https:/ipr.etsi.org/). Pursuant to the ETSI IPR Policy, no investigation, including IPR searches, has been carried out by ETSI. No guarantee can be given as to the existence of other IPRs not referenced in ETSI SR 000 314 (or the updates on the ETSI Web server) which are, or may
12、be, or may become, essential to the present document. Foreword This Technical Report (TR) has been produced by ETSI 3rd Generation Partnership Project (3GPP). The present document may refer to technical specifications or reports using their 3GPP identities, UMTS identities or GSM identities. These s
13、hould be interpreted as being references to the corresponding ETSI deliverables. The cross reference between GSM, UMTS, 3GPP and ETSI identities can be found under http:/webapp.etsi.org/key/queryform.asp. Modal verbs terminology In the present document “should“, “should not“, “may“, “need not“, “wil
14、l“, “will not“, “can“ and “cannot“ are to be interpreted as described in clause 3.2 of the ETSI Drafting Rules (Verbal forms for the expression of provisions). “must“ and “must not“ are NOT allowed in ETSI deliverables except when used in direct citation. ETSI ETSI TR 126 980 V14.2.0 (2017-04)33GPP
15、TR 26.980 version 14.2.0 Release 14Contents Intellectual Property Rights 2g3Foreword . 2g3Modal verbs terminology 2g3Foreword . 6g3Introduction 6g31 Scope 7g32 References 7g33 Definitions and abbreviations . 9g33.1 Definitions 9g33.2 Abbreviations . 10g34 Overview 10g35 Media Handling in Current 3GP
16、P Conferencing 10g36 Use cases 12g36.1 Overview 12g36.2 Use case A: Transcoding Free Continuous Presence 12g36.2.1 Problem Description . 13g36.2.2 Proposed Solution . 13g36.3 Use case B: Screen Sharing 14g36.3.1 Problem Description . 14g36.3.2 Proposed Solution . 15g36.4 Use Case C: Bandwidth Handli
17、ng 17g36.4.1 Problem Description . 17g36.4.2 Proposed Solution . 17g36.4.2.1 Single-stream to multi-stream . 18g36.4.2.2 Multi-stream to single-stream . 18g36.4.2.3 Multi-stream to multi-stream without bandwidth restriction 18g36.4.2.4 Multi-stream to multi-stream with minor bandwidth restrictions 1
18、9g36.4.2.5 Multi-stream to multi-stream with severe bandwidth restriction 20g36.4.2.6 Multi-stream UE to multi-stream UE in point-to-point . 20g36.5 Use Case D: Active Speaker Override . 21g36.5.1 Problem Description . 21g36.5.2 Proposed Solution . 22g36.6 Use Case E: Pausing Unused Streams 23g36.6.
19、1 Problem Description . 24g36.6.2 Proposed Solution . 25g36.7 Use Case F: Conference Rate Adaptation Considerations 26g36.7.1 Problem Description . 26g36.7.2 Proposed Solution . 26g36.8 Use Case G: Multi-stream Audio Steering or Panning . 29g36.9 Use Case H: De-jitter Buffer Handling 30g36.10 Use Ca
20、se I: Audio Spatialization based on head-tracking 31g36.11 Use Case J: Mixing at the Rendering Device Media Handling, Distribution via Multi-Unicast . 32g36.11.1 Concurrent Codec Capabilities Exchange . 32g36.11.1.1 Concurrent Decoding 32g36.11.1.2 Concurrent Encoding 33g36.11.1.3 Further Considerat
21、ions in Concurrency 34g36.11.1.4 Prioritizing and Ignoring of Received Media Streams 34g36.11.1.5 Conclusions . 34g36.12 Use Case K: Mixing at the Rendering Device Media Handling, Distribution via Multicast . 35g36.12.1 Session Establishment. 35g36.12.1.1 In the presence of a Conference Focus 35g36.
22、12.2 Media Handling 35g3ETSI ETSI TR 126 980 V14.2.0 (2017-04)43GPP TR 26.980 version 14.2.0 Release 146.12.2.1 In the absence of a Conference Focus for media handling 35g36.13 Use Case L: Mixing at the Rendering Device Media Handling, Distribution via Single Source Multi-Unicast 36g36.13.1 Session
23、Establishment. 38g36.13.2 Media Handling 38g36.13.3 Multi-stream Concurrent Encoding/Decoding Capabilities . 38g36.13.3.1 Querying and Capabilities Exchange SIP OPTIONS . 39g36.13.3.2 Common/Preferred Codec Identification and Usage . 42g36.13.3.2.1 General 42g36.13.3.2.2 Common/Preferred Codec Infor
24、mation Exchange. 42g36.13.3.2.3 Indicating the Common and Preferred Codec Selection Through SDP . 43g36.13.4 MSMTSI MRF Handling with Reduced m-lines 43g36.13.4.1 Introduction . 43g36.13.4.2 RTP Stream Selective Forwarding 43g36.14 Use Case M: Provisioning of Talker ID . 45g36.14.1 Use Case Descript
25、ion 45g36.14.2 Problem Description . 45g36.14.3 Suggested Solution . 46g36.15 Use Case N: Mixing at the Rendering Device Media Handling, Concurrent Codec Capabilities Exchange 47g36.15.1 Format of the Concurrent Codec Capabilities Information . 47g36.15.1.1 Using Current SDP Parameters . 47g36.15.1.
26、2 Using Compact SDP Parameters . 48g36.15.1.2.1 SDP Line Compression 49g36.15.1.2.2 SDP Line Compression for Terminal Performing Trimming of Streams . 51g36.15.1.2.3 Conclusions 51g36.15.2 Protocol for Concurrent Codec Capabilities Exchange (CCCEx). 51g36.15.2.1 Recommended Requirements for the CCCE
27、x . 51g36.15.2.2 Potential Solution for the CCCEx . 51g36.15.3 Examples of Concurrent Codec Capabilities (CCC) Usage 51g36.15.4 Compact CCC SDP Parameter for Session Initiation . 57g36.15.4.1 Introduction . 57g36.15.4.2 Compression Gains . 57g36.15.4.3 Offer-Answer Rules 60g36.15.4.4 Conclusions . 6
28、1g36.16 Use Case O: Media Distribution Without Conference Focus Session Establishment Aspects 61g36.16.1 Session Establishment Without a Conference Focus in Multi-unicast Topology . 61g36.17 Use Case P: Codec Migration. 62g36.17.1 General 62g36.17.2 Problem Description . 62g36.17.3 Proposed Solution
29、 . 62g36.17.3.1 General 62g36.17.3.2 Codec Fall-back 63g36.17.3.3 Transcoding . 63g36.17.3.4 Codec Simulcast 63g36.17.3.5 Recommended Requirements for Codec Simulcast 65g37 Conclusion 65g3Annex A: SDP examples for Multi-stream Multiparty Conference Media Handling . 66g3A.1 General . 66g3A.2 MSMTSI v
30、ideo offer/answer examples 66g3A.2.1 MSMTSI offer/answer towards an MTSI client . 66g3A.2.2 MSMTSI answer from an MSMTSI MRF . 68g3A.2.3 MSMTSI answer from an MSMTSI client in terminal. 71g3A.2.4 MSMTSI Offer and Answer Using Codec Simulcast . 72g3A.3 MSMTSI audio offer/answer examples 74g3A.3.1 MSM
31、TSI offer with multi-stream audio support 74g3A.3.2 MSMTSI answer with multi-stream audio support 76g3A.3.3 MSMTSI CCCEx SDP offer/answer example . 77g3ETSI ETSI TR 126 980 V14.2.0 (2017-04)53GPP TR 26.980 version 14.2.0 Release 14Annex B: QoS for Multi-stream Multiparty Conference Media Handling 81
32、g3B.1 General . 81g3B.2 QoS for MSMTSI video offer/answer examples 81g3Annex C: Technical Background 83g3C.1 General . 83g3C.2 Simulcast Stream Identification . 83g3C.2.1 General . 83g3C.2.2 Codec Identification in SDP . 83g3C.2.3 Sampling Identification in SDP 83g3C.2.4 Bandwidth Identification in
33、SDP 84g3C.2.5 Simulcast Usage for WebRTC . 84g3C.2.5.1 General 84g3C.2.5.2 RTP Payload Type Uniqueness 84g3C.2.5.3 RTP Payload Type Depletion . 84g3C.2.6 Conclusion 85g3Annex D: Change history 86g3History 87g3ETSI ETSI TR 126 980 V14.2.0 (2017-04)63GPP TR 26.980 version 14.2.0 Release 14Foreword Thi
34、s Technical Report has been produced by the 3rdGeneration Partnership Project (3GPP). The contents of the present document are subject to continuing work within the TSG and may change following formal TSG approval. Should the TSG modify the contents of the present document, it will be re-released by
35、 the TSG with an identifying change of release date and an increase in version number as follows: Version x.y.z where: x the first digit: 1 presented to TSG for information; 2 presented to TSG for approval; 3 or greater indicates TSG approved document under change control. y the second digit is incr
36、emented for all changes of substance, i.e. technical enhancements, corrections, updates, etc. z the third digit is incremented when editorial only changes have been incorporated in the document. Introduction Media handling of Multimedia Telephony Service over IMS, MTSI, are based on 3GPP SA4 TS 26.1
37、14 1. MTSI media handling is referred to by GSMA in GSMA PRD IR.92 21 also known as VoLTE and GSMA PRD IR.94 22 also known as video over LTE. MTSI clients can connect to conferencing IMS communication services. 3GPP conducted a study as part of a work item on Multi-stream Multiparty Conferencing Med
38、ia-Handling for MTSI. The work objective is to specify an increment to MTSI client media-handling specification TS 26.114 to enable a mass-market multiparty communication service with excellent multiparty user experience and media quality. Such Operator communication service evolution would match pr
39、oprietary communication services in quality with excellent efficiency and device reach. The present document captures the study inputs, discussions and findings of the Multi-stream Multiparty Conference Media Handling (MMCMH) work item. It describes a set of use cases with corresponding problem desc
40、riptions and potential solutions. The conclusion gives recommendations as to what needs to be normatively specified to achieve the MMCMH work item objectives. ETSI ETSI TR 126 980 V14.2.0 (2017-04)73GPP TR 26.980 version 14.2.0 Release 141 Scope The Technical Report provides a study on the media han
41、dling aspects of Multi-stream Multiparty Conferencing for MTSI. The study focuses on enabling - support to receive multi-stream audio/video at the terminals in a multiparty conferencing, - support for at least two video contents, e.g. one main and one presentation, - talker ID provisioning, - compat
42、ibility with MTSI TS 26.114 and GSMA IR.94 (Video over LTE) 22 and GSMA IR.92 (VoLTE) 21, and - applicability to both mobile and fixed access terminals High-level use cases along with current limitations and recommendations are documented in the present document. 2 References The following documents
43、 contain provisions which, through reference in this text, constitute provisions of the present document. - 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
44、 non-specific reference, the latest version applies. In the case of a reference to a 3GPP document (including a GSM document), a non-specific reference implicitly refers to the latest version of that document in the same Release as the present document. 1 3GPP TS 26.114: “IP Multimedia Subsystem (IM
45、S); Multimedia Telephony, Media handling and interaction“. 2 Void. 3 3GPP TS 24.147: “Conferencing Using IP Multimedia Core Network; Stage 3“. 4 3GPP TS 24.605: “CONF Using IP Multimedia Core Network“. 5 3GPP TS 22.228: “Service Requirements for IP Multimedia Core Network; Stage 1“. 6 3GPP TS 23.218
46、:“IP Multimedia Session Handling; IP Multimedia Call Model; Stage 2“. 7 3GPP TS 24.228: “Signalling Flows for IP Multimedia Call Control Based on SIP and SDP; Stage 3“. 8 3GPP TS 24.229: “IP Multimedia Call Control Protocol Based on SIP and SDP; Stage 3“. 9 3GPP TR 22.948: “IP Multimedia Subsystem C
47、onvergent Multimedia Conferencing“. 10 3GPP TR 29.847: “SIP Conferencing Models, Flows and Protocols“. 11 GSM Association: “WebRTC Codecs DRAFT v1.3“, September 2014, http:/ 12 IETF Internet Draft: “Using Simulcast in SDP and RTP Sessions“, June 2016, https:/datatracker.ietf.org/doc/draft-ietf-mmusi
48、c-sdp-simulcast/ (WORK IN PROGRESS). 13 IETF RFC 4796: “The Session Description Protocol (SDP) Content Attribute“, February 2007, https:/datatracker.ietf.org/doc/rfc4796/. ETSI ETSI TR 126 980 V14.2.0 (2017-04)83GPP TR 26.980 version 14.2.0 Release 1414 GSM Association PRD IR.39: “IMS Profile for Hi
49、gh Definition Video Conferencing (HDVC) v5.0“, July 2014, http:/ 15 IETF RFC 4582: “The Binary Floor Control Protocol (BFCP)“, November 2006, https:/datatracker.ietf.org/doc/rfc4582/. NOTE A new version of this RFC is in the process of being published. See 17. 16 IETF RFC 4583: “Session Description Protocol (SDP) Format for Binary Floor Control Protocol (BFCP) Streams“, November 2006, https:/d
