1、 ETSI TS 146 041 V14.0.0 (2017-04) Digital cellular telecommunications system (Phase 2+) (GSM); Half rate speech; Discontinuous Transmission (DTX) for half rate speech traffic channels (3GPP TS 46.041 version 14.0.0 Release 14) TECHNICAL SPECIFICATION GLOBAL SYSTEM FOR MOBILE COMMUNICATIONSRETSI ETS
2、I TS 146 041 V14.0.0 (2017-04)13GPP TS 46.041 version 14.0.0 Release 14Reference RTS/TSGS-0446041ve00 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 enr
3、egistre 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 d
4、ocument 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 kept on a specific network drive w
5、ithin 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.aspx If you find errors in the pr
6、esent 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 photocopying and microfilm except as author
7、ized 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. All rights reserved. DECTTM, PLUG
8、TESTSTM, 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 registered and owned by the GSM Associati
9、on. ETSI ETSI TS 146 041 V14.0.0 (2017-04)23GPP TS 46.041 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 m
10、embers 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.e
11、tsi.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
12、the 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 b
13、eing 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 146 041 V14.0.0 (2017-04)33GPP TS
15、46.041 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 Symbols 6g33.3 Abbreviations . 7g34 General . 7g34.1 General Organisation 7g
16、35 Transmit (TX) side . 8g35.1 General Operation 8g35.1.1 Functions of the TX DTX handler 8g35.1.2 Functions of the TX radio subsystem . 9g36 Receive (RX) side 11g36.1 General operation . 11g36.1.1 Functions of the RX radio subsystem . 11g36.1.2 Functions of the RX DTX handler 12g3Annex A (informati
17、ve): Change history . 13g3History 14g3ETSI ETSI TS 146 041 V14.0.0 (2017-04)43GPP TS 46.041 version 14.0.0 Release 14Foreword This Technical Specification has been produced by the 3rdGeneration Partnership Project (3GPP). The present document is a GSM technical specification version 7 and is part of
18、 the 1998 release of the GSM Technical Specifications. The present document is part of a series covering the half rate speech traffic channels as described below: GSM 06.02 “Digital cellular telecommunications system (Phase 2+); Half rate speech; Half rate speech processing functions“. GSM 06.06 “Di
19、gital cellular telecommunications system (Phase 2+); Half rate speech; ANSI-C code for the GSM half rate speech codec“. GSM 06.07 “Digital cellular telecommunications system (Phase 2+); Half rate speech; Test sequences for the GSM half rate speech codec“. GSM 06.20 “Digital cellular telecommunicatio
20、ns system (Phase 2+); Half rate speech; Half rate speech transcoding“. GSM 06.21 “Digital cellular telecommunications system (Phase 2+); Half rate speech; Substitution and muting of lost frames for half rate speech traffic channels“. GSM 06.22 “Digital cellular telecommunications system (Phase 2+);
21、Half rate speech; Comfort noise aspects for half rate speech traffic channels“. GSM 06.41 “Digital cellular telecommunications system (Phase 2+); Half rate speech; Discontinuous Transmission (DTX) for half rate speech traffic channels“. GSM 06.42 “Digital cellular telecommunications system (Phase 2+
22、); Half rate speech; Voice Activity Detector (VAD) for half rate speech traffic channels“. 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-releas
23、ed 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 document under change control. y the second digit is
24、 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. ETSI ETSI TS 146 041 V14.0.0 (2017-04)53GPP TS 46.041 version 14.0.0 Release 141 Scope The present d
25、ocument gives a description of the general baseband operation of half rate speech traffic channels in the transmitter and in the receiver of GSM Mobile Stations (MS)s and Base Station Systems (BSS)s during Discontinuous Transmission (DTX). For clarity, the description is structured according to the
26、block diagrams in figures 1 and 4. Except in the case described below, this structure of distributing the various functions between system entities is not mandatory for implementation, as long as the operation on the air interface and on the speech decoder output remains the same. In the case of BSS
27、s where the speech transcoder is located remotely in the Base Station Controller (BSC), the implementation of the interfaces between the DTX Handlers and the Radio Sub System (RSS) as described in the present document together with all their flags is mandatory, being a part of the A-bis interface as
28、 described in GSM 08.61 10. The DTX functions described in the present document are mandatory for implementation in all GSM MSs. The receiver requirements are mandatory for implementation in all GSM BSSs, the transmitter requirements only for those where downlink DTX will be used. 2 References The f
29、ollowing documents 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
30、apply. For a 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 GSM 01.04: “Digital cellular tel
31、ecommunication system (Phase 2+); Abbreviations and acronyms“. 2 GSM 04.08: “Digital cellular telecommunication system (Phase 2+); Mobile radio interface layer 3 specification“. 3 GSM 05.05: “Digital cellular telecommunications system (Phase 2+); Radio transmission and reception“. 4 GSM 05.08: “Digi
32、tal cellular telecommunication system (Phase 2+); Radio subsystem link control“. 5 GSM 06.02: “Digital cellular telecommunications system (Phase 2+); Half rate speech Part 1: Half rate speech processing functions“. 6 GSM 06.20: “Digital cellular telecommunications system (Phase 2+); Half rate speech
33、; Half rate speech transcoding“. 7 GSM 06.21: “Digital cellular telecommunications system (Phase 2+); Half rate speech; Substitution and muting of lost frames for half rate speech traffic channels“. 8 GSM 06.22: “Digital cellular telecommunications system (Phase 2+); Half rate speech; Comfort noise
34、aspects for half rate speech traffic channels“. 9 GSM 06.42: “Digital cellular telecommunications system (Phase 2+); Half rate speech; Voice Activity Detector (VAD) for half rate speech traffic channels“. 10 GSM 08.61: “Digital cellular telecommunications system (Phase 2+); Inband control of remote
35、transcoders and rate adaptors for half rate traffic channels“. ETSI ETSI TS 146 041 V14.0.0 (2017-04)63GPP TS 46.041 version 14.0.0 Release 1411 GSM 06.06: “Digital cellular telecommunications system (Phase 2+); Half rate speech Part 7: ANSI-C code for the GSM half rate speech codec“. 3 Definitions,
36、 symbols and abbreviations 3.1 Definitions For the purposes of the present document, the following terms and definitions apply: accepted SID frame: traffic frame which is flagged with SID= “1“ or SID= “2“ by the Radio Subsystem. bad traffic frame: traffic frame flagged BFI= “1“ (Bad Frame Indication
37、) or with UFI= “1“ (Unreliable Frame Indication) by the Radio Subsystem. frame: time interval of 20 ms corresponding to the time segmentation of the half rate speech transcoder defined in GSM 06.20 (ETS 300 969) 6), also used as a short term for a traffic frame. good speech frame: good traffic frame
38、 which is not an accepted SID frame. good traffic frame: traffic frame flagged BFI= “0“ and UFI= “0“ by the Radio Subsystem. GS averaging period: period in which the quantized energy tweak parameters GS are averaged: it corresponds to the hangover period. hangover period: period of 7 frames added at
39、 the end of a speech burst in which VAD flag = “0“ and SP flag= “1“. invalid SID frame: accepted SID frame which was not classified as valid SID frame. This frame is not valid for updating comfort noise parameters, but the frame conveys information that comfort noise generations should be started or
40、 continued. lost SID frame: unusable frame received when the RX DTX Handler is generating comfort noise and a SID frame is expected (Time Alignment Flag TAF= “1“). lost speech frame: unusable frame received when the RX DTX Handler is passing on traffic frames directly to the speech decoder. SID code
41、 word: fixed bit pattern defined in GSM 06.22 8, for labelling a traffic frame as a SID frame. SID field: bit positions defined in GSM 06.22 8, of the SID codeword within a SID frame. SID frame: frame characterised by the SID (Silence Descriptor) code word. It conveys information on the acoustic bac
42、kground noise. SP flag: boolean flag, generated by the TX DTX handler, indicating the presence of a speech frame (“1“) or the presence of a SID frame (“0“). speech frame: traffic frame that cannot be classified as a SID frame. traffic frame: block of 112 information bits transmitted on the half rate
43、 speech traffic channel. unusable frame: bad traffic frame that is not an accepted SID frame. VAD flag: boolean flag, generated by the VAD algorithm defined in GSM 06.42 9, indicating the presence (“1“) or the absence (“0“) of a speech frame. valid SID frame: good traffic frame flagged with SID= “2“
44、 by the Radio Subsystem. This frame is valid for updating comfort noise parameters at any time. 3.2 Symbols For the purposes of the present document, the following symbols apply: ETSI ETSI TS 146 041 V14.0.0 (2017-04)73GPP TS 46.041 version 14.0.0 Release 14GS Energy tweak parameter NelapsedNumber o
45、f elapsed frames since the last updated SID frame 3.3 Abbreviations For the purposes of the present document, the following abbreviations apply: BFI Bad Frame Indicator BSC Base Station Controller BSS Base Station System DTX Discontinuous Transmission FACCH Fast Associated Control CHannel FEC Forwar
46、d Error Correction GSM Global System for Mobile communications MS Mobile StationRSS Radio Sub System RX Receive SACCH Slow Associated Control CHannel SID SIlence Descriptor TAF Time Alignment Flag TX TransmitUFI Unreliable Frame Indicator VAD Voice Activity Detector For abbreviations not given in th
47、is clause, see GSM 01.04 1. 4 General DTX is a mechanism which allows the radio transmitter to be switched off most of the time during speech pauses for the following two purposes: - to save power in the MS; - to reduce the overall interference level over the air interface. DTX shall be in operation
48、 in GSM MS if commanded so by the network, see GSM 04.08 2. 4.1 General Organisation The overall DTX mechanism described in the present document requires the following functions: - a Voice Activity Detector (VAD) on the transmit (TX) side; - evaluation of the background acoustic noise on the TX side
49、, in order to TX characteristic parameters to the receive (RX) side; - generation on the RX side of a similar noise, called comfort noise, during periods where the radio transmission is switched off. The VAD is defined in GSM 06.42 9, the comfort noise functions in GSM 06.22 8. Both are based partly on the speech transcoder and its internal variables, defined in GSM 06.20 6. In addition to these functions, if the parameters arriving at the (RX) side are detected to be corrupted by errors, the speech or comfort noise shall be gen
