1、 ETSI TR 1Digital cellular telecoA-interfac(3GPP TR 43.9TECHNICAL REPORT 143 903 V13.0.0 (2016communications system (Phaace over IP study (AINTIP) .903 version 13.0.0 Release 13GLOBAL SYSTEMOBILE COMMUN16-01) hase 2+); 13) TEM FOR ICATIONSRETSI ETSI TR 143 903 V13.0.0 (2016-01)13GPP TR 43.903 versio
2、n 13.0.0 Release 13Reference RTR/TSGG-0043903vd00 Keywords GSM 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 Association but non lucratif enregistre la Sous-Prfecture de Grasse (06) N 7803/88 I
3、mportant 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 print versions of the present document shall not be modified without the prior writ
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6、ng 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 photocopying and microfilm except as authorized by written permission of ETSI. The content of the PDF ver
7、sion 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 2016. All rights reserved. DECTTM, PLUGTESTSTM, UMTSTMand the ETSI logo are Trade Marks of ETSI regis
8、tered 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 registered and owned by the GSM Association. ETSI ETSI TR 143 903 V13.0.0 (2016-01)23GPP TR 43.903 vers
9、ion 13.0.0 Release 13Intellectual 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, is publicly available for ETSI members and non-members, and can be found in ETSI SR 000 314: “
10、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 the ETSI Web server (https:/ipr.etsi.org/). Pursuant to the ETSI IPR Policy, no investigation,
11、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 be, or may become, essential to the present document. Foreword This Technical Report (TR) has
12、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 should be interpreted as being references to the corresponding ETSI deliverables. The cross ref
13、erence 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 “shall“, “shall not“, “should“, “should not“, “may“, “need not“, “will“, “will not“, “can“ and “cannot“ are to be interpreted as described in
14、 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 143 903 V13.0.0 (2016-01)33GPP TR 43.903 version 13.0.0 Release 13Contents Intellectual Property Rights
15、 2g3Foreword . 2g3Modal verbs terminology 2g3Foreword . 5g3Introduction 5g31 Scope 6g32 References 6g33 Definitions, symbols and abbreviations 7g33.1 Definitions 7g33.2 Symbols 8g33.3 Abbreviations . 9g34 Requirements 9g35 Overview 10g35.1 Background 10g35.2 Architecture 11g35.2.1 Legacy Architectur
16、e 11g35.2.2 PCM encoded speech (G.711) over IP 12g35.2.3 Compressed speech over IP 13g35.2.4 Example Deployment Scenarios . 15g35.3 Functional Impacts . 19g35.3.1 G.711 and compressed speech over IP 19g35.3.2 Support for Data and Fax Services . 20g35.3.3 Functional Impacts for Migration . 20g36 Stud
17、y Results, User Plane 20g36.1 User Plane Principles 20g36.1.1 Transport network User Plane for A over IP 20g36.1.1.1 PCM coded speech (G.711) over IP 20g36.1.1.2 Compressed speech and data/fax over IP 21g36.1.2 Transport network Control Plane for A over IP 21g36.1.3 Potential impact on the Nb and Nc
18、 interfaces . 21g36.2 Payload Formats . 21g36.2.1 Existing TRAU Frames for Speech 21g36.2.2 RTP profiles for speech 25g36.2.2.1 RTP profiles for G.711 encoded speech on the A over IP interface 25g36.2.2.2 RTP profiles for compressed speech on the A over IP 25g36.2.2.3 RTP profiles for compressed spe
19、ech on Nb interface . 26g36.2.3 RTP profiles for data and fax calls . 26g36.2.3.1 RTP profiles for data and fax calls with rate adaptation in BSS . 26g36.2.3.2 RTP profiles for data and fax calls with rate adaptation in CN . 26g36.3 Transport Layer 27g36.3.1 Link Layer and Physical Layer . 27g36.3.2
20、 UDP and IP . 27g36.3.3 RTP . 27g36.3.4 RTCP 27g36.3.5 IP Multiplexing . 27g36.4 Handover Procedure (User Plane) 28g36.4.1 Alternative 1 . 28g36.4.1.1 General Handover Procedure 28g36.4.1.2 Intra-BSC Handover to a compatible target cell . 28g36.4.1.3 Intra-BSC Handover to an incompatible target cell
21、 28g36.4.1.4 Inter-BSC Handover 28g3ETSI ETSI TR 143 903 V13.0.0 (2016-01)43GPP TR 43.903 version 13.0.0 Release 136.4.2 Alternative 2 . 28g36.5 Time Alignment . 28g36.5.1 Introduction. 28g36.5.2 Time Alignment principles . 29g36.5.3 Time Alignment performances evaluation 30g36.5.4 Proposed implemen
22、tation . 31g36.5.5 Summary . 32g37 Study Results, Control Plane 33g37.1 Control Plane Principles . 33g37.1.1 Exchange of Transport Layer Information 33g37.1.2 Need for a Call Identifier for IP-based calls . 34g37.1.3 Exchange of Codec Information . 35g37.1.3.1 Exchange of Codec Information at Call E
23、stablishment 35g37.1.3.2 Exchange of Codec Information at Handover . 37g37.1.4 Location of Transcoder Resource in BSS or CN 38g37.1.5 Exchange of RTP Parameters . 38g37.2 Signalling Messages . 40g37.2.1 BSSMAP 40g37.2.1.1 Assignment Request 40g37.2.1.2 Assignment Complete . 40g37.2.1.3 Handover Requ
24、ired . 41g37.2.1.4 Handover Request . 42g37.2.1.5 Handover Request Acknowledge 43g37.2.1.6 Handover Performed . 43g37.2.1.7 Complete Layer 3 Information 44g37.2.1.8 BSC-SCL and MSC-PCL 44g37.2.1.9 Speech Codec (Chosen) 45g37.2.1.10 Speech Codec (Used) 45g37.2.1.11 Circuit Switched Data Codec (CSD Du
25、mmy Codec) 45g37.2.2 DTAP 46g37.2.3 VGCS/VBS Protocol 46g37.2.4 H.248 Protocol 46g37.3 Procedures 46g37.3.1 Codec Negotiation at Call Setup . 46g37.3.2 Codec Negotiation at Handover 48g37.3.2.1 Intra-BSC Handover to a Compatible Target Cell 49g37.3.2.2 Intra-BSC Handover to an Incompatible Target Ce
26、ll 49g37.3.2.3 Inter-BSC Handover 52g37.3.3 Codec Re-Negotiation after Inter-BSC Handover 54g37.4 Impacts on the A Interface Control Plane 56g37.4.1 New Information Element: BSC-SCL 56g37.4.2 New Information Element: MSC-PCL . 58g37.4.3 New Information Element: Speech Codec (Chosen) 59g37.4.4 New In
27、formation Element: Speech Codec (Used) 59g38 Informative: Network Design Issues 60g38.1 Solution 1 . 60g38.2 Solution 2 . 60g39 Expected impacts to existing specifications . 60g310 Summary and Conclusion 60g3Annex A (informative): Change history . 62g3History 63g3ETSI ETSI TR 143 903 V13.0.0 (2016-0
28、1)53GPP TR 43.903 version 13.0.0 Release 13Foreword This 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 cont
29、ents 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: 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 do
30、cument under change control. y the second digit is incremented 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 The present document captures the res
31、ults of the feasibility study for introducing support for A-interface over IP. ETSI ETSI TR 143 903 V13.0.0 (2016-01)63GPP TR 43.903 version 13.0.0 Release 131 Scope The present document contains the result from the study of introduction of support for A-interface over IP. High level areas that are
32、studied are e.g. potential placement of transcoders in the core network, effective bandwidth utilisation at the A-interface, impact on call related messages, payload formats. The following items shall be covered in the study: square4 In the target solution it is wanted to transfer compressed speech
33、as far as possible end-to-end to achieve efficient transport and speech quality. The possibility to free GERAN from handling all kind of transcoders shall be studied, and the architecture might place Codecs in the core network. square4 Impacts/changes on current A-interface procedures resulting from
34、 placing transcoders in the core network as well as in the BSS shall be studied, e.g. impacts on the assignment and handover procedures. square4 In addition to allow compressed speech over the A-interface the study shall provide further solution for effective bandwidth utilisation at the A interface
35、, which means it shall describe multiplexing of RTP flows and how this will be negotiated between the BSS and CN nodes. square4 The study shall describe a solution for “true end-to-end Codec negotiation“, which considers on a call basis the preference/situation of the radio network. square4 It shall
36、 be studied how call related messages have to be adapted, e.g. transfer of Codec related information, identification of calls/sessions. square4 The study shall describe the wanted payload formats and other relevant user plane parameters like packetization time etc. 2 References The following documen
37、ts 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 non
38、-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 TR 21.905: “Vocabulary for 3GPP Specificati
39、ons“. 2 3GPP TS 23.205: “Bearer-independent circuit-switched core network“. 3 3GPP TS 25.415: “UTRAN Iu Interface User Plane Protocols“. 4 3GPP TS 48.006: “Signaling Transport Mechanism Specification for the Base Station System - Mobile-services Switching Centre (BSS - MSC) Interface“. 5 3GPP TS 23.
40、002: “Network architecture (Release 8)“. 6 3GPP TS 48.008: “Mobile Switching Centre - Base Station System (MSC-BSS) interface Layer 3 specification“. 7 3GPP TS 48.060: “In-band control for remote transcoders and rate adaptors for full rate traffic channels“. 8 3GPP TS 48.061: “In-band control for re
41、mote transcoders and rate adaptors for half rate traffic channels“. 9 3GPP TS 26.103: “Speech Codec list for GSM and UMTS“. ETSI ETSI TR 143 903 V13.0.0 (2016-01)73GPP TR 43.903 version 13.0.0 Release 1310 3GPP TS 29.802: “(G)MSC-S - (G)MSC-S Nc Interface based on the SIP-I protocol“. 11 3GPP TS 23.
42、153: “Out of band transcoder control; Stage 2“. 12 3GPP TS 23.231: “SIP-I based circuit-switched core network; Stage 2“. 13 3GPP TS 29.414: “Core network Nb data transport and transport signalling“. 14 3GPP TS 25.415: “UTRAN Iu interface user plane protocols“. 15 3GPP TS 29.415: “Core Network Nb Int
43、erface User Plane Protocols“. 16 3GPP TS 28.062: “Inband Tandem Free Operation (TFO) of speech codecs; Service description; Stage 3“. 17 3GPP TS 26.093: “Mandatory speech codec speech processing functions Adaptive Multi-Rate (AMR) speech codec; Source controlled rate operation“. 18 IETF RFC 4040: “R
44、TP Payload Format for a 64 kbit/s Transparent Call“. 19 IETF RFC 3551: “RTP Profile for Audio and Video Conferences with Minimal Control“. 20 IETF RFC 768: “User Datagram Protocol“. 21 IETF RFC 791: “Internet Protocol“. 22 IETF RFC 792: “Internet Control Message Protocol“. 23 IETF RFC 2460: “Interne
45、t Protocol, Version 6 (IPv6) Specification“. 24 IETF RFC 4443: “Internet Control Message Protocol (ICMPv6) for the Internet Protocol Version 6 (IPv6) Specification“. 25 IETF RFC 4867: “RTP Payload Format and File Storage Format for the Adaptive Multi-Rate (AMR) and Adaptive Multi-Rate Wideband (AMR-
46、WB) Audio Codecs“. 3 Definitions, symbols and abbreviations 3.1 Definitions For the purposes of the present document, the terms and definitions given in TR 21.905 1 and the following apply. A term defined in the present document takes precedence over the definition of the same term, if any, in TR 21
47、.905 1. example: text used to clarify abstract rules by applying them literally. For the sake of easy explanation the following short terms are defined: Legacy MSC Server: The Legacy MSC server does not support AoIP. Legacy MGW: The Legacy MGW does not support AoIP. Legacy BSS: The Legacy BSS does n
48、ot support AoIP. New MSC Server: The New MSC Server supports only the AoIP-interface. Legacy BSSes are not supported by a New MSC Server. Upgraded MSC Server: The Upgraded MSC Server supports both, the TDM A-interface and the IP A-interface. Both kinds of interfaces could work simultaneously for dif
49、ferent BSSs. It is claimed by some companies (e.g. Ericsson) that it is necessary to support AoTDM and AoIP also for the same, Upgraded BSS. Also legacy BSS, i.e. without any change, is supported by an Upgraded MSC Server. ETSI ETSI TR 143 903 V13.0.0 (2016-01)83GPP TR 43.903 version 13.0.0 Release 13New MGW: The New MGW supports all UMTS and GSM Codecs as specified in 3GPP TS 26.103 18 and has only an IP interface towards the BSS. The New MGW does not support AoTDM, not TFO and not PCMoIP. Upgraded MGW: The Upgrad
