1、 ETSI TR 126 980 V15.0.0 (2018-07) 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 15.0.0 Release 15
2、) TECHNICAL REPORT ETSI ETSI TR 126 980 V15.0.0 (2018-07)13GPP TR 26.980 version 15.0.0 Release 15Reference RTR/TSGS-0426980vf00 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
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9、s registered and owned by the GSM Association. ETSI ETSI TR 126 980 V15.0.0 (2018-07)23GPP TR 26.980 version 15.0.0 Release 15Intellectual Property Rights Essential patents IPRs essential or potentially essential to normative deliverables may have been declared to ETSI. The information pertaining to
10、 these essential IPRs, if any, 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. La
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13、ty of ETSI, and conveys no right to use or reproduce any trademark and/or tradename. Mention of those trademarks in the present document does not constitute an endorsement by ETSI of products, services or organizations associated with those trademarks. Foreword This Technical Report (TR) has been pr
14、oduced 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 should be interpreted as being references to the corresponding ETSI deliverables. The cross reference
15、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“, “will“, “will not“, “can“ and “cannot“ are to be interpreted as described in clause 3.2 of the ETSI Draft
16、ing 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 V15.0.0 (2018-07)33GPP TR 26.980 version 15.0.0 Release 15Contents Intellectual Property Rights 2g3Foreword . 2g3Modal verbs
17、 terminology 2g3Foreword . 6g3Introduction 6g31 Scope 7g32 References 7g33 Definitions and abbreviations . 9g33.1 Definitions 9g33.2 Abbreviations . 10g34 Overview 10g35 Media Handling in Current 3GPP Conferencing 10g36 Use cases 12g36.1 Overview 12g36.2 Use case A: Transcoding Free Continuous Prese
18、nce 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 Handling 16g36.4.1 Problem Description . 17g36.4.2 Proposed Solution . 17g36.4.2.1 Single-stream to multi-s
19、tream . 17g36.4.2.2 Multi-stream to single-stream . 17g36.4.2.3 Multi-stream to multi-stream without bandwidth restriction 18g36.4.2.4 Multi-stream to multi-stream with minor bandwidth restrictions 19g36.4.2.5 Multi-stream to multi-stream with severe bandwidth restriction 19g36.4.2.6 Multi-stream UE
20、 to multi-stream UE in point-to-point . 20g36.5 Use Case D: Active Speaker Override . 20g36.5.1 Problem Description . 21g36.5.2 Proposed Solution . 21g36.6 Use Case E: Pausing Unused Streams 23g36.6.1 Problem Description . 24g36.6.2 Proposed Solution . 25g36.7 Use Case F: Conference Rate Adaptation
21、Considerations 26g36.7.1 Problem Description . 26g36.7.2 Proposed Solution . 26g36.8 Use Case G: Multi-stream Audio Steering or Panning . 28g36.9 Use Case H: De-jitter Buffer Handling 29g36.10 Use Case I: Audio Spatialization based on head-tracking 30g36.11 Use Case J: Mixing at the Rendering Device
22、 Media Handling, Distribution via Multi-Unicast . 31g36.11.1 Concurrent Codec Capabilities Exchange . 32g36.11.1.1 Concurrent Decoding 32g36.11.1.2 Concurrent Encoding 32g36.11.1.3 Further Considerations in Concurrency 33g36.11.1.4 Prioritizing and Ignoring of Received Media Streams 34g36.11.1.5 Con
23、clusions . 34g36.12 Use Case K: Mixing at the Rendering Device Media Handling, Distribution via Multicast . 34g36.12.1 Session Establishment. 34g36.12.1.1 In the presence of a Conference Focus 34g36.12.2 Media Handling 35g3ETSI ETSI TR 126 980 V15.0.0 (2018-07)43GPP TR 26.980 version 15.0.0 Release
24、156.12.2.1 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 Establishment. 37g36.13.2 Media Handling 37g36.13.3 Multi-stream Concurrent Encoding/Decoding Capabil
25、ities . 38g36.13.3.1 Querying and Capabilities Exchange SIP OPTIONS . 38g36.13.3.2 Common/Preferred Codec Identification and Usage . 41g36.13.3.2.1 General 41g36.13.3.2.2 Common/Preferred Codec Information Exchange. 41g36.13.3.2.3 Indicating the Common and Preferred Codec Selection Through SDP . 42g
26、36.13.4 MSMTSI MRF Handling with Reduced m-lines 42g36.13.4.1 Introduction . 42g36.13.4.2 RTP Stream Selective Forwarding 43g36.14 Use Case M: Provisioning of Talker ID . 44g36.14.1 Use Case Description 44g36.14.2 Problem Description . 45g36.14.3 Suggested Solution . 45g36.15 Use Case N: Mixing at t
27、he Rendering Device Media Handling, Concurrent Codec Capabilities Exchange 46g36.15.1 Format of the Concurrent Codec Capabilities Information . 46g36.15.1.1 Using Current SDP Parameters . 46g36.15.1.2 Using Compact SDP Parameters . 47g36.15.1.2.1 SDP Line Compression 48g36.15.1.2.2 SDP Line Compress
28、ion for Terminal Performing Trimming of Streams . 50g36.15.1.2.3 Conclusions 50g36.15.2 Protocol for Concurrent Codec Capabilities Exchange (CCCEx). 50g36.15.2.1 Recommended Requirements for the CCCEx . 50g36.15.2.2 Potential Solution for the CCCEx . 50g36.15.3 Examples of Concurrent Codec Capabilit
29、ies (CCC) Usage 50g36.15.4 Compact CCC SDP Parameter for Session Initiation . 55g36.15.4.1 Introduction . 55g36.15.4.2 Compression Gains . 56g36.15.4.3 Offer-Answer Rules 59g36.15.4.4 Conclusions . 60g36.16 Use Case O: Media Distribution Without Conference Focus Session Establishment Aspects 60g36.1
30、6.1 Session Establishment Without a Conference Focus in Multi-unicast Topology . 60g36.17 Use Case P: Codec Migration. 61g36.17.1 General 61g36.17.2 Problem Description . 61g36.17.3 Proposed Solution . 61g36.17.3.1 General 61g36.17.3.2 Codec Fall-back 61g36.17.3.3 Transcoding . 62g36.17.3.4 Codec Si
31、mulcast 62g36.17.3.5 Recommended Requirements for Codec Simulcast 64g37 Conclusion 64g3Annex A: SDP examples for Multi-stream Multiparty Conference Media Handling . 65g3A.1 General . 65g3A.2 MSMTSI video offer/answer examples 65g3A.2.1 MSMTSI offer/answer towards an MTSI client . 65g3A.2.2 MSMTSI an
32、swer from an MSMTSI MRF . 67g3A.2.3 MSMTSI answer from an MSMTSI client in terminal. 70g3A.2.4 MSMTSI Offer and Answer Using Codec Simulcast . 71g3A.3 MSMTSI audio offer/answer examples 73g3A.3.1 MSMTSI offer with multi-stream audio support 73g3A.3.2 MSMTSI answer with multi-stream audio support 74g
33、3A.3.3 MSMTSI CCCEx SDP offer/answer example . 75g3ETSI ETSI TR 126 980 V15.0.0 (2018-07)53GPP TR 26.980 version 15.0.0 Release 15Annex B: QoS for Multi-stream Multiparty Conference Media Handling 79g3B.1 General . 79g3B.2 QoS for MSMTSI video offer/answer examples 79g3Annex C: Technical Background
34、81g3C.1 General . 81g3C.2 Simulcast Stream Identification . 81g3C.2.1 General . 81g3C.2.2 Codec Identification in SDP . 81g3C.2.3 Sampling Identification in SDP 81g3C.2.4 Bandwidth Identification in SDP 82g3C.2.5 Simulcast Usage for WebRTC . 82g3C.2.5.1 General 82g3C.2.5.2 RTP Payload Type Uniquenes
35、s 82g3C.2.5.3 RTP Payload Type Depletion . 82g3C.2.6 Conclusion 82g3Annex D: Change history 84g3History 85g3ETSI ETSI TR 126 980 V15.0.0 (2018-07)63GPP TR 26.980 version 15.0.0 Release 15Foreword This Technical Report has been produced by the 3rdGeneration Partnership Project (3GPP). The contents of
36、 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 the TSG with an identifying change of release date and an increase in version number as follows: Ver
37、sion 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 incremented for all changes of substance, i.e. technical enhancements, corrections, updates, etc. z the t
38、hird 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 26.114 1. MTSI media handling is referred to by GSMA in GSMA PRD IR.92 21 also known as VoLTE and GSMA PR
39、D 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 Media-Handling for MTSI. The work objective is to specify an increment to MTSI client media-handling spe
40、cification 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 proprietary communication services in quality with excellent efficiency and device reach. The present d
41、ocument 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 descriptions and potential solutions. The conclusion gives recommendations as to what needs to be normati
42、vely specified to achieve the MMCMH work item objectives. ETSI ETSI TR 126 980 V15.0.0 (2018-07)73GPP TR 26.980 version 15.0.0 Release 151 Scope The Technical Report provides a study on the media handling aspects of Multi-stream Multiparty Conferencing for MTSI. The study focuses on enabling - suppo
43、rt 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, - compatibility with MTSI TS 26.114 and GSMA IR.94 (Video over LTE) 22 and GSMA IR.92 (VoLTE) 21, and - appli
44、cability 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 contain provisions which, through reference in this text, constitute provisions of the present docum
45、ent. - 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. In the case of a reference to a 3GPP document (i
46、ncluding 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 (IMS); Multimedia Telephony, Media handling and interaction“. 2 Void. 3 3GPP TS 24.147: “Conferencing Us
47、ing 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:“IP Multimedia Session Handling; IP Multimedia Call Model; Stage 2“. 7 3GPP TS 24.228: “Signalling F
48、lows 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 Convergent Multimedia Conferencing“. 10 3GPP TR 29.847: “SIP Conferencing Models, Flows and Protocols“
49、. 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-mmusic-sdp-simulcast/ (WORK IN PROGRESS). 13 IETF RFC 4796: “The Session Description Protocol (SDP) Content Attribute“, February 2007, https:/datatracker.ietf.org/doc/rfc4796/. 14 GSM Association PRD IR.39: “IMS Profile for High Definition Video Conferencing (HDVC) v5.
