ETSI TS 148 103-2017 Digital cellular telecommunications system (Phase 2+) (GSM) Base Station System - Media GateWay (BSS-MGW) interface User plane transport mechanism (V14 0 0 3GP.pdf

1、 ETSI TS 148 103 V14.0.0 (2017-04) Digital cellular telecommunications system (Phase 2+) (GSM); Base Station System - Media GateWay (BSS-MGW) interface; User plane transport mechanism (3GPP TS 48.103 version 14.0.0 Release 14) TECHNICAL SPECIFICATION GLOBAL SYSTEM FOR MOBILE COMMUNICATIONSRETSI ETSI

2、 TS 148 103 V14.0.0 (2017-04)13GPP TS 48.103 version 14.0.0 Release 14Reference RTS/TSGR-0648103ve00 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 enre

3、gistre 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 print versions of the present do

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9、n. ETSI ETSI TS 148 103 V14.0.0 (2017-04)23GPP TS 48.103 version 14.0.0 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, is publicly available for ETSI me

10、mbers 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 the ETSI Web server (https:/ipr.et

11、si.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 be, or may become, essential to t

12、he present document. Foreword This Technical Specification (TS) 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 should be interpreted as be

13、ing 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 “shall“, “shall not“, “should“, “should not“, “may“, “need not“, “will“,

14、“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 TS 148 103 V14.0.0 (2017-04)33GPP TS 4

15、8.103 version 14.0.0 Release 14Contents Intellectual Property Rights 2g3Foreword . 2g3Modal verbs terminology 2g3Foreword . 4g31 Scope 5g32 References 5g33 Definitions, symbols and abbreviations . 6g33.1 Definitions 6g33.2 Abbreviations . 6g34 Transport over TDM 7g34.1 General . 7g34.2 Transport dur

16、ing local switching 7g35 Transport over IP 8g35.1 General . 8g35.2 IP 8g35.3 UDP 8g35.4 Transport without RTP multiplexing 8g35.4.1 Introduction. 8g35.4.2 RTP . 8g35.4.2.1 RTP Header . 9g35.4.2.1.1 Version 9g35.4.2.1.2 Padding 9g35.4.2.1.3 Extension . 9g35.4.2.1.4 Contributing Source (CSRC) count .

17、9g35.4.2.1.5 Marker Bit . 9g35.4.2.1.6 Payload Type . 9g35.4.2.1.7 Sequence Number 9g35.4.2.1.8 Timestamp . 9g35.4.2.1.9 Synchronisation Source (SSRC) 9g35.4.2.1.10 CSRC list. 10g35.4.2.2 RTP Payload . 10g35.4.2.3 RTP Packetization Time . 10g35.4.3 RTCP 10g35.5 Transport with RTP multiplexing . 11g3

18、5.5.1 Introduction. 11g35.5.2 RTP . 11g35.5.2.1 Transport format for multiplexing without RTP header compression. 11g35.5.2.2 Transport format for multiplexing with RTP header compression 12g35.5.3 RTCP 13g35.5.3.1 General 13g35.5.3.2 Multiplexing negotiation via RTCP 13g35.5.3.3 RTCP Multiplexing p

19、acket . 14g35.6 Transport of CSData . 16g35.6.1 Introduction. 16g35.6.2 Transport formats for CSData . 17g35.6.2.1 Transport format for CSData without redundancy 17g35.6.2.2 Transport format for CSData with redundancy . 18g35.6.2.3 Start and Stop of RTP streams with redundancy . 19g35.7 Transport du

20、ring local switching 20g3Annex A (informative): Change History 21g3History 22g3ETSI ETSI TS 148 103 V14.0.0 (2017-04)43GPP TS 48.103 version 14.0.0 Release 14Foreword This Technical Specification has been produced by the 3rdGeneration Partnership Project (3GPP). The contents of the present document

21、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: Version x.y.z where: x th

22、e 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 third digit is incremen

23、ted when editorial only changes have been incorporated in the document. ETSI ETSI TS 148 103 V14.0.0 (2017-04)53GPP TS 48.103 version 14.0.0 Release 141 Scope The present document specifies the User Plane data transport protocols used between BSSs and the Core Network (MGWs) across the A interface.

24、The main purpose of the present document is the AoIP description, however for the sake of completeness the AoTDM case is described as well. MGW Signalling and Data Transfer Interface Signalling Interface UTRAN GERAN Iu mode MSC server GMSC server Mc MGW Nb Nc Iu Iu Mc GERAN A/Gb mode A A Figure 1.1:

25、 CS core network logical architecture Note that the present document does not preclude any Core Network Session Control Protocol implementation (BICC or SIP-I). 2 References The following documents contain provisions which, through reference in this text, constitute provisions of the present documen

26、t. 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 (including

27、 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 Specifications“. 2 IETF RFC 791: “Internet Protocol (IP)“. 3 IETF RFC 2460: “Internet Protocol, Version 6 (IPv6)“. 4

28、 IETF RFC 768: “User Datagram Protocol. (UDP)“. 5 IETF RFC 3550: “RTP: A Transport Protocol for Real Time Applications“. 6 3GPP TS 29.414: “Core network Nb Interface data transport and transport signalling“. 7 IETF RFC 3551: “RTP Profile for Audio and Video Conference with Minimal Control“. 8 3GPP T

29、R 29.814: “Feasibility Study on Bandwidth Savings at Nb Interface with IP transport“. 9 IETF RFC 4040: “RTP Payload Format for a 64 kbits/s Transparent Call“ 10 IETF RFC 4867: “RTP Payload Format and File Storage Format for the Adaptive Multi-Rate (AMR) and Adaptive Multi-Rate Wideband (AMR-WB) Audi

30、o Codecs“ 11 IETF RFC 2198: “RTP Payload for redundant Audio Data“ ETSI ETSI TS 148 103 V14.0.0 (2017-04)63GPP TS 48.103 version 14.0.0 Release 1412 3GPP TR 43.903 A-Interface over IP Study (AINTIP) 13 3GPP TS 48.001 “Base Station System Mobile-services Switching Centre (BSS - MSC) interface; Genera

31、l aspects“ 14 ITU-T Recommendation G.705: “Characteristics of plesiochronous digital hierarchy (PDH) equipment functional blocks“. 15 ANSI T1.102-1993: “Digital Hierarchy - Electrical Interface“. 16 ITU-T Recommendation G.711: “Pulse Code Modulation (PCM) of voice frequencies“. 17 3GPP TS 48.020: “R

32、ate adaption on the Base Station System - Mobile-services Switching Centre (BSS - MSC) interface“. 18 IETF RFC 5993 (2010) “RTP Payload Format for Global System for Mobile Communications Half Rate (GSM-HR)“. 19 3GPP TS 48.008: “Mobile Switching Centre - Base Station System (MSC-BSS) interface; Layer

33、 3 specification“. 20 3GPP TS 26.102: “Adaptive Multi-Rate (AMR) speech codec; Interface to Iu, Uu and Nb“. 21 3GPP TS 23.284: “Local Call Local Switch; Stage 2“. 3 Definitions, symbols and abbreviations 3.1 Definitions For the purposes of the present document, the terms and definitions given in TR

34、21.905 1 and the following apply. Intra-BSS call: A mobile to mobile voice call involving two mobile stations connected to the same BSS. Local call: An Intra-BSS call that can be locally switched by the BSS. For details on the Local Switch Service see 3GPP TS 23.284 21. Access MGW: The MGW interfaci

35、ng to the Radio Access Network 3.2 Abbreviations For the purposes of the present document, the abbreviations given in TR 21.905 1 and the following apply. An abbreviation defined in the present document takes precedence over the definition of the same abbreviation, if any, in TR 21.905 1. AoIP A (in

36、terface) over IP AoTDM A (interface) over TDM APP APPlication BICC Bearer Independent Call Control BSS Base Station Subsystem CS Circuit-Switched CSData CS Data and fax IETF Internet Engineering Task Force IP Internet Protocol IPv4 Internet Protocol version 4 IPv6 Internet Protocol version 6 ITU-T I

37、nternational Telecommunications Union-Telecommunication sector MGW Media GateWay PCM Pulse-Coded Modulation RFC Request For Comment RTP Real-Time Transport Protocol RTCP Real-Time Transport Control Protocol ETSI ETSI TS 148 103 V14.0.0 (2017-04)73GPP TS 48.103 version 14.0.0 Release 14SIP-I Session

38、Initiation Protocol with encapsulated ISUP SSRC Synchronisation Source SVC Switched Virtual Circuit TDM Time-Division MultiplexingUDP User Datagram Protocol UP User Plane 4 Transport over TDM 4.1 General The present chapter describes the transport on the A Interface UP over E1/T1 interface; for more

39、 information see 3GPP TS 48.001 13. Figure 4.1 shows the protocol stack for the transport network user plane on the A interface. Payload (PCM encoded speech or CSData) E1 or T1 Figure 4.1: TDM Protocol stack for the A interface user plane Layer 1 shall utilise digital transmission: - at a rate of 2

40、048 kbit/s with a frame structure of 32 x 64kbit/s time slots, as specified in ITU-T Recommendation G.705 14 clause 3 for E1 interface; or - at a rate of 1 544 kbit/s with a frame structure of 24 x 64 kbit/s time slots, as specified in T1.102 specification for T1 interface 15. The payload is either

41、PCM encoded speech (see ITU-T Recommendation G.711 16) or CSData (see 3GPP TS 48.020 17). 4.2 Transport during local switching When a local switch path is established in the BSS for a local call, the user plane between the BSS and the Access MGWs for both the call legs in uplink and downlink shall n

42、ot be released. ETSI ETSI TS 148 103 V14.0.0 (2017-04)83GPP TS 48.103 version 14.0.0 Release 145 Transport over IP 5.1 General The present chapter describes the transport of the A-Interface User Plane Payload by RTP/UDP/IP. Figure 5.1 shows the protocol stack. Payload (PCM-coded speech, or compresse

43、d speech or CSData) RTP UDP IPv4 or IPv6 Figure 5.1: IP Protocol stack for the A-Interface user plane The specific carrying way at physical/link layer of the IP protocol is not limited by the present document; if Ethernet is adopted, link layer will be MAC protocol while if IPoE1 or POS is adopted,

44、link layer will be PPP protocol. Nevertheless at least Ethernet should be supported. 5.2 IP IPv4 (RFC 791 2) shall be supported IPv6 (RFC 2460 3) may be supported as an option. One BSS/MGW pair may be connected via several IP interfaces. 5.3 UDP The UDP Protocol (see RFC 768 4) shall be applied. Two

45、 consecutive port numbers shall be used at each BSS/MGW for the RTP connection and for the optional RTCP connection that corresponds to a single A interface UP connection. Two such consecutive port numbers are termed “port number block“ in what follows. The first port number shall be even and shall

46、be assigned to the RTP protocol. For a given BSS/MGW, the same port shall be used to send and to receive RTP PDUs. The next port number shall be assigned to the RTCP protocol. This port shall be reserved even if the optional RTCP protocol is not used. If multiplexing is applied with or without heade

47、r compression, the source UDP port number shall indicate the local termination used to combine the multiplexed packet and the destination UDP port number shall indicate the remote port number where PDUs are demultiplexed. The negotiation of whether multiplexing is applied and of the destination UDP

48、port is described in sub-clause 5.5.3.2. If multiplexing was negotiated for an A interface UP user plane connection, the BSS/MGW may apply multiplexing by sending all packets of the user plane connection (multiplexed with other user plane connections packets) towards the negotiated destination UDP p

49、ort. 5.4 Transport without RTP multiplexing 5.4.1 Introduction User Plane transport without RTP multiplexing is default and shall be supported. It shall be applied after call setup, until a User Plane transport with RTP-multiplexing is negotiated via RTCP, see clause 5.5. RTCP, see RFC 3550 5 may be applied in AoIP, it is optional. A BSS or MSC may ignore incoming RTCP packets on AoIP. 5.4.2 RTP The RTP protocol (see RFC 3550 5) shall be applied. ETSI ETSI TS 148 103 V14.0.0 (2017-04)93GPP TS 48.1