1、STD-ETSI GSM 08-20-ENGL 2997 m 3400855 0229807 OT3 m GSM GSM 08.20 August 1997 Version 5.2.0 Source: ETSI SMG Reference: TS/SMG-O30820QRl ICs: 33.020 Key words: Digital cellular telecommunications system, Global System for Mobile communications (GSM) Digital cellular telecommunications system (Phase
2、 2+); Rate adaption on the Base Station System - Mobile-services Switching Centre (BSS - MSC) interface (GSM 08.20 version 5.2.0) ETSI European Telecommunications Standards Institute ETSI Secretariat Postal address: F-O6921 Sophia Antipolis CEDEX - FRANCE Office address: 650 Route des Lucioles - Sop
3、hia Antipolis - Valbonne - FRANCE X.400: c=fr, a=atlas, p=etsi, ssecretariat - Internet: secretariatetsi.fr Tel.: 43 4 92 94 42 O0 - Fax: +33 4 93 65 47 16 Copyright Notification: No part may be reproduced except as authorized by written petmission. The copyright and the foregoing restriction extend
4、 to reproduction in all media. O European Telecommunications Standards Institute 1997. All rights reserved. STD-ETSI GSM 08-20-ENGL 3777 m 3400855 0229830 835 m Page 2 GSM 08.20 version 5.2.0: August 1997 Whilst every care has been taken in the preparation and publication of this document, errors in
5、 content, typographical or otherwise, may occur. If you have comments concerning its accuracy, please write to “ETCI Editing and Committee Support Dept.“ at the address shown on the title page. STDOETSI GSM 08.20-ENGL 1777 m 3400855 02298LL 751 m Page 3 GSM 08.20 version 5.2.0: August 1997 Contents
6、Foreword . 5 1 2 3 4 5 6 7 8 9 10 11 12 13 14 Scope . 7 Normative references . 7 2.1 Abbreviations and definitions 8 General approach 8 The RA0 Function 8 The RA1 Function 8 The RA1“ Function . 9 SplitlCombine and Padding Functions . -9 7.1 7.3 7.4 Data Frame distribution into the channels by the Sp
7、litlCombine function . 9 Initial Substream Synchronisation for Transparent Services . 9 V11 O Frame Synchronisation (TCHE9.6 or TCH/F4.8 channel coding) . 9 7.4.1 Initial V110 Synchronisation . 9 7.4.2 Action on loss of V.110 frame synchronisation for non-transparent services 9 7.4.3 Action on loss
8、of V.11 O frame synchronisation for transparent services . 9 A-TRAU Frame Synchronisation (TCH/F14.4 channel coding) 9 7.5.1 Search for Frame Synchronisation . 9 7.5.3 Action on loss of A-TRAU frame synchronisation . 10 7.6 Network Independent Clocking . 10 7.7 Padding 10 7.2 Substream numbering 9 7
9、.5 The RAl/RAl Function 10 8.1 Radio Interface rate of 12 kbit/s . 10 8.2 Radio Interface rate of 6 kbit/s . 10 8.3 Radio Interface rate of 3.6 kbit/s 10 8.4 Synchronisation . 11 8.5 Idle frames . 11 THE RAl/RAA FUNCTION 11 9.1 Radio Interface rate of 14. 5 kbitk 11 9.2 Synchronisation . 11 9.3 Idle
10、 frames . 11 THE RAA FUNCTION 11 10.1 10.2 Coding of A-TRAU frame . 11 10.2.1 FPS encoding . 12 Framing Pattern Substitution in A-TRAU frame . 12 THE RAA“ FUNCTION . 15 The RA2 Function 15 The Multiplexing Function 15 Support of non-transparent bearer services . 16 14.1 TCH/F9.6 and TCWF4.8 kbi/s ch
11、annel codings . 16 . STDmETSI GSM 08-20-ENGL 1997 = 3400855 0227832 b98 Page 4 GSM 08.20 version 5.2.0: August 1997 14.1.1 Alignment . 17 14.1.2 Support of Discontinuous Transmission (DTX) . 17 14.1.3 Order of Transmission . 17 TCH/F14.4 channel coding 17 14.2.1 Alignment . 18 14.2.2 14.2 Support of
12、 Discontinuous Transmission (DTX) . 18 15 Support of transparent bearer services 18 15.1 TCWF9.6 and TCH/F4.8 channel codings 18 15.1.1 User rate adaptation on the A interface. AIUR less or equal to 38. 4 kbiVs . 18 15.1.2 User rate Adaptation on the A-interface. AIUR greater than 38. 4 kbit/s . 19
13、15.1.3 Relation between AIUR and the number of channels 19 15.1.4 Handling of status bits X. SA. SB . 20 15.1.5 Handling of bits El to E7 . 20 TCH/F14.4 channel coding 20 15.2.1 User rate adaptation on the A interface. AIUR less or equal to 56 kbiVs 20 15.2.2 User Rate Adaptation on the A-interface.
14、 AIUR greater than 56 kbit./s . 20 15.2.3 Relation between AIUR and the number of channels 20 15.2.4 Handling of status bits X and SB 21 15.2 16 Frame Formats 21 Annex A (informative): Frame Pattern Substitution . 23 A.l Special cases 23 A.2 False 2 sequence detection 24 History 25 STD-ETSI GSM 08-2
15、0-ENGL 1997 3400855 0227833 524 Page 5 GSM 08.20 version 5.2.0: August 1997 Foreword This Global System for Mobile communications Technical Specification (GTS) has been produced by the Special Mobile Group (SMG) of the European Telecommunications Standards Institute (ETSI). This GTS defines rate ada
16、ptation functions to be used within the digital cellular telecommunications system. The contents of this GTS are subject to continuing work within SMG and may change following formal SMG approval. Should SMG modify the contents of this GTS it w ill then be republished by ETSI with an identifying cha
17、nge of release date and an increase in version number as follows: Version 5.x.y where: y the third digit is incremented when editorial only changes have been incorporated in the specification; x the second digit is incremented for all other types of changes, .e. technical enhancements, corrections,
18、updates, etc. The specification from which this GTS has been derived was originally based on CEPT documentation, hence the presentation of this GTS may not be entirely in accordance with the ETSVPNE rules. STD-ETSI GSM 08.20-ENGL 1777 3Li00855 02298LLi Lib0 D Page 7 GSM 08.20 version 5.2.0: August 1
19、997 1 scope This Global System for Mobile communications Technical Specification (GTS) defines rate adaptation functions to be used in GSM PLMN Base Station Systems (BSS) transc oders and IWF for adapting radio interface data rates to the 64 kbiis used at the A-interface in accordance with GSM 03.10
20、. The number of Base Station System - Mobile-services Switching Centre (BSS - MSC) traffic channels supporting data rate adaptation may be limited. In this case some channels may not support data rate adaptation. Those that do, must conform to this specification. NOTE: This specification should be c
21、onsidered together with GSM 04.21 to give a complete description of PLMN rate adaptation. 2 Normative references This GTS incorporates by dated and undated reference, provisions from other publications. These normative references are cited at the appropriate places in the text and the publications a
22、re listed hereafter. For dated references, subsequent amendments to or revisions of any of these publications apply to this GTS only when incorporated in it by amendment or revision. For undated references, the latest edition of the publication referred to applies. 31 41 91 GSM O1 .O4 (ETR 350): “Di
23、gital cellular telecommunications system (Phase 2+); Abbreviations and acronyms“. GSM 02.34: “Digital cellular telecommunications system (Phase2+): High Speed Circuit Switched Data (HSCSD) - Stagel“ GSM 03.10: “Digital cellular telecommunications system (Phase 2+); GSM Public Land Mobile Network (PL
24、MN) connection types“. GSM 03.34 (TS 1 O1 038): “Digital cellular telecommunications system (Phase 2+): High Speed Circuit Switched Data (HSCSD) - Stage2. GSM 04.21 (ETS 300 945): “Digital cellular telecommunications system; Rate adaption on the Mobile Station - Base Station System (MS - BSS) interf
25、ace“. GSM 04.22 (ETS 300 946): “Digital cellular telecommunications system (Phase 2+); Radio Link Protocol (RLP) for data and telematic services on the Mobile Station - Base Station System (MS - BSS) interface arid the Base Station System - Mobile-services Switching Centre (BSS - MSC) interface“. GS
26、M 05.03 (ETS 300 909): “Digital cellular telecommunications system (Phase 2+); Channel coding“. GSM 07.01 (ETS 300 91 3): “Digital cellular telecommunications system (Phase 2+); General on Terminal Adaptation Functions (TAF) for Mobile Stations (MS) I. GSM 08.08: “Digital cellular telecommunications
27、 system (Phase 2+); Mobile Switching Centre - Base Station System (MSC - BSS) interface; Layer 3 specification“. GSM 09.07 (ETS 300 976): “Digital cellular telecommunications system (Phase 2+); General requirements on interworking between the Public Land Mobile Network (PLMN) and the Integrated Serv
28、ices Digital Network (ISDN) or Public Switched Telephone Network (PSTN)“. CCIT Recommendation V.11 O: “Support of data terminal equipments (DTEs) with V-Series interfaces by an integrated services digital network“. Previous page is blank STD-ETSI GSM 08.20-ENGL L777 3400855 0227815 3T7 Page 8 GSM 08
29、.20 version 5.2.0: August 1997 CCIlT Recommendation 1.460:-Multiplexing, rate adaption and support of existing interfaces. 2.1 Abbreviations and definitions Abbreviations: In addition to those below, abbreviations used in this specification are listed in GSM 01.04. FPS Frame Pattern Substitution FS
30、I Frame Start Identifier ZSP Zero Sequence Position Definitions : Substream: Stream of data with explicit or implicit numbering between splitter and combine functions. Channel: A physical full rate channel on the radio interface (TCH/F) independent of the contents. A interface circuit: The 8 bits th
31、at constitute one 64 kbps circuit on the A interface. A interface subcircuit: One specific bit position or one specific pair of bit positions within the A interface circuit. 3 General approach GSM 03.10 (clause 6) defines the PLMN connection types necessary to support the GSM PLMN data and telematic
32、 services. Within the BSS , transcoder and IWF, there are several data rate adaptation functions which are combined as shown in GSM 03.10 as part of a connection type. These functions are RAO, RAl,RAl/RAl , RA1“ , RAA“, RAl/RAA, RAA and RA2. The RA2 function is equivalent to that described in CCIlT
33、Recommendation V.11 O. In addition, splittinghombining, padding and inband numbering functions as defined in GSM 04.21 and multiplexing as defined herein are used in cases where more than one channel is allowed. The RAl/RAl and RAlYRAA are relay functions used as indicated in GSM 03.10. The BSS uses
34、 the information contained in the ASSIGNMENT REQUEST mess age on the A-interface (see GSM 08.08) to set the “E bits“ and to map the “D bits“ as shown below, as well as to choose the correct channel coding. 4 The RA0 Function The RA0 function is specified in GSM 04.21 5 The RA1 Function For connectio
35、ns where only one channel is allowed used on the radio interface, the specification in GSM 04.21 for adaptation of synchronous data rates up to and including 9,6 kbitls to intermediate rates 8 or 16 kbiVs applies. For connection where more than one channel are used on the radio interface, rate adapt
36、ation is applied on the corresponding substreams as specified in GSM 04.21 for AIUR of 4,8 kbitls or 9,6 kbitls. STDSETSI GSM 08-20-ENGL 1997 = 3400855 02278Lb 233 D Page 9 GSM 08.20 version 5.2.0: August 1997 6 The RAY Function The RAI” function is specified in GSM 04.21. The RA1” function is only
37、applicable in BSS for AIUR higher than 38.4 kbis. 7 SpliCombine and Padding Functions The SpliCombine-function in the IWF is used in cases when up to and including 4substreams are used. The SpliCombine-function in the BSS is used only when more than four substreams are used. 7.1 Data Frame distribut
38、ion into the channels by the SpliCombine function Described in GSM 04.21 7.2 Substream numbering Described in GSM 04.21 7.3 Initial Substream Synchronisation for Transparent Services Described in GSM 04.21 7.4 V11 O Frame Synchronisation (TCHF9.6 or TCH/F4.8 channel coding) 7.4.1 Initial V110 Synchr
39、onisation When in the IWF, the Split/Combine function is responsible for controlling the initial V. 110 frame synchronisation procedure as described in GSM 09.07. Initial V.11 O frame synchronisation. 7.4.2 Action on loss of V.11 O frame synchronisation for non-transparent services If the IWF detect
40、s a loss of V.110 frame synchronisation on one or more substreams on the MSCIWF- BSS interface, the IWF initiates a re-synchronisation on the substreams in question as specified in GSM 09.07 Action on loss of frame synchronisation for non-transparent services. 7.4.3 Action on loss of V.110 frame syn
41、chronisation for transparent services If the IWF detects a loss of V.110 frame synchronisation on one or more substreams on the MSC/IWF- BSS interface, the IWF initiates a re-synchronisation on the substreams in question as specified in GSM 09.07 Action on loss of frame synchronisation for transpare
42、nt services. 7.5 A-TRAU Frame Synchronisation (TCHFl4.4 channel coding) 7.5.1 Search for Frame Synchronisation When in the IWF, the SpliCombine function is responsible for controlling the initial A-TRAU frame synchronisation procedure. The frame synchronisation is obtained by means of the first two
43、octets in each frame, with all bits coded binary “O” and the first bit in octet no 2 coded binary “1”. The following 17 bit alignment pattern is used to achieve frame synchronisation : 00000000 00000000 1xxxxxxx xxxxxxxx xxxxxxxx xxxxxxxx xxxxxxxx xxxxxxxx xxxxxxxx xxxxxxxx xxxxxxxx xxxxxxxx xxxxxxx
44、x xxxxxxxx XXXXxxxX xxxxxxxx xxxxxxxx xxxxxxxx xxxxxxxx xxxxxxxx xxxxxxxx xxxxxxxx xxxxxxxx xxxxxxxx xxxxxxxx xxxxxxxx xxxxxxxx xxxxxxxx xxxxxxxx xxxxxxxx xxxxxxxx xxxxxxxx xxxxxxxx xxxxxxxx xxxxxxxx xxxxxxxx xxxxxxxx xxxxxxxx xxxxxxxx xxxxxxxx STD-ETSI GSM 08.20-ENGL 1997 = 3400855 0229817 17T Page
45、 10 GSM 08.20 version 5.2.0: August 1997 Once the A-TRAU frame synchronisation is achieved, the IWF starts sending A-TRAU frames to the BSS with the “data rate” set as an acknowledgement indication. 7.5.3 Action on loss of A-TRAU frame synchronisation The IWF shall detect a loss of A-TRAU frame sync
46、hronisation when an A-TRAU frame has been received with at least one error in the synchronisation pattern If the loss of A-TRAU frame synchronisation is detected by the IWF, it sets the control bit UFE (Uplink Frame Error) in the next downlink A-TRAU frame to indicate the framing error to the BSS. T
47、he IWF stops the indication of Uplink Frame Error as soon as it has recovered the A-TRAU frame synchronisation. 7.6 Network Independent Clocking NIC is specified in GSM 04.21 7.7 Padding Padding is specified in GSM 04.21 a The RAl/RAl Function For AlURs less or equal to 38,4 kbit/s, the RAl/RAl func
48、tion in the BSS is applied on each of the n substreams and there are no significant differences between the single slot case and the multislot case. For AlURs less or equal to 38,4 kbits RAl/RAl is as specified in GSM 04.21 for the single slot case. The table below gives a relation between the AIUR,
49、 channel coding and number of substreams. As an example from table 1: The wanted AIUR is 28,8 kbit/s, the number of substreams needed to support this rate is 3. Each individual substream is rate adapted as in the single slot case. For AIURs of 48 kbits, 56 kbit/s and 64 kbis, RAl/RAl” is as specified in GSM 04.21 for these rates. Table 1 : Relationship between AIUR, channel coding and number of channels 8.1 Radio Interface rate of 12 kbis Described in GSM 04.21. 8.2 Radio Interface rate of 6 kbit/s Described in GSM 04.21. 8.3 Radio Interface rate
