SIST EN 300 972 V7.0.1:2003
(Main)Digital cellular telecommunications system (Phase 2+) (GSM); Half rate speech; Discontinuous Transmission (DTX) for half rate speech traffic channels (GSM 06.41 version 7.0.1 Release 1998)
- Abstract
Upgrade from Phase 2+ to Release 1998
- Status
- Published
- Publication Date
- 30-Nov-2003
- Current Stage
- 6060 - National Implementation/Publication (Adopted Project)
- Start Date
- 01-Dec-2003
- Due Date
- 01-Dec-2003
- Completion Date
- 01-Dec-2003
- Mandate
- T-172
SIST EN 300 972 V7.0.1:2003 is the Slovenian adoption of ETSI EN 300 972 version 7.0.1 for GSM half rate speech discontinuous transmission (DTX). It specifies how DTX works on half rate speech traffic channels in the transmitter and receiver of GSM Mobile Stations (MS) and Base Station Systems (BSS), so implementers can keep air-interface behavior and speech-decoder output consistent. The DTX functions are mandatory in all GSM MSs; receiver requirements are mandatory in all GSM BSSs, and transmitter requirements apply to BSSs that use downlink DTX.
What does SIST EN 300 972 V7.0.1:2003 specify?
SIST EN 300 972 V7.0.1:2003 specifies the general baseband operation of half rate speech traffic channels during DTX. The document focuses on the behavior of the transmitter side and the receiver side, and it describes the functions using the block diagrams shown in the standard.
Clause 1 sets the scope, clause 2 lists the referenced GSM specifications, clause 3 defines the terms, symbols and abbreviations, clause 4 gives the general principle, clauses 5 and 6 cover TX and RX behavior, and Annex A records the change request history.
| Annex | What it covers |
|---|---|
| Annex A | Change request history |
What are the key requirements of SIST EN 300 972 V7.0.1:2003?
DTX is the GSM mechanism described
Clause 4 states that DTX lets the radio transmitter switch off for much of the time during speech pauses. In practice, this reduces MS power use and lowers overall interference on the air interface. The same clause says DTX shall operate in GSM MS when commanded by the network.
The transmit side uses VAD, SP flags and SID handling
Clause 5 says the TX side continuously passes traffic frames to the Radio SubSystem (RSS), with each frame marked by the SP flag. A Voice Activity Detector (VAD) controls whether a frame is treated as speech or as a SID frame, so the transmitter can stop sending full speech during pauses.
Clause 5.1.1 requires the first frames after reset to be treated as speech, and it describes a hangover period after speech ends. In practice, this avoids cutting off the end of spoken words and gives the system time to prepare comfort-noise information.
Clause 5.1.2 says the RSS schedules transmission of all speech-marked frames, the first SID frame after speech, and other SID frames aligned with the SACCH multiframestructure. If a SID frame is stolen for FACCH signalling, the next frame is sent instead. This matters because the radio path must keep sending enough SID updates to support comfort noise on the receive side.
Short speech bursts are treated specially
Clause 5.1.1 also covers the case where speech stops before a new SID frame is ready. If fewer than 24 frames have elapsed since the last SID frame, the last SID frame is repeated until a new updated SID frame is available. This reduces unnecessary air-interface activity when a short noise spike is mistaken for speech.
The receive side classifies frames using BFI, UFI, SID and TAF
Clause 6 says the RSS passes received traffic frames to the RX DTX handler with Bad Frame Indicator (BFI), Unreliable Frame Indicator (UFI), SID and Time Alignment Flag (TAF). Table 1 classifies the frames as valid SID frame, good speech frame, invalid SID frame or unusable frame. In practice, this classification tells the receiver whether to play speech directly, generate comfort noise, or apply concealment.
RX handling depends on frame type
Clause 6.1.2 says good speech frames go directly to the speech decoder. Lost speech or lost SID frames use the substitution and muting procedure defined in GSM 06.21, while valid SID frames drive comfort noise generation until the next SID frame is expected or speech returns. Invalid SID frames are replaced by the last valid SID frame. This keeps the audio output stable when the radio channel introduces errors.
The standard depends on related GSM specifications
Clause 2 and the foreword tie this specification to GSM 06.02, GSM 06.20, GSM 06.21, GSM 06.22, GSM 06.42 and GSM 08.61. These documents provide the speech processing functions, transcoding, frame substitution, comfort noise, VAD and in-band control details that DTX uses.
What terms does SIST EN 300 972 V7.0.1:2003 define?
- Accepted SID frame - A traffic frame flagged as SID="1" or SID="2" by the Radio SubSystem.
- Valid SID frame - A good traffic frame flagged SID="2"; it can update comfort-noise parameters at any time.
- Good traffic frame - A frame flagged BFI="0" and UFI="0" by the Radio SubSystem.
- Bad traffic frame - A frame flagged BFI="1" or UFI="1".
- SP flag - A binary flag from the TX DTX handler that marks a frame as speech or SID.
- VAD flag - A binary flag from the VAD algorithm that indicates speech present or absent.
- TAF - Time Alignment Flag, used to mark traffic frames aligned with the SACCH multiframe structure.
- SID frame - A frame carrying the Silence Descriptor codeword and conveying acoustic background noise information.
Who uses SIST EN 300 972 V7.0.1:2003?
GSM modem and handset designers use this standard when implementing transmit-side DTX in GSM Mobile Stations. Base station and BSS engineers use it to implement receive-side DTX behavior, especially where downlink DTX is used.
Speech codec, transcoder and radio-subsystem developers use it to coordinate VAD, SID handling, comfort noise and error concealment. Test, quality and integration teams use it to verify that frame classification, hangover behavior and SID scheduling match the GSM Release 1998 rules.
What changed in SIST EN 300 972 V7.0.1:2003 from the previous edition?
This document is the Release 1998 version 7.0.1 of GSM 06.41. Annex A lists the change request history leading through earlier release versions and records the version update to 7.0.1 for publication.
Which standards are used with SIST EN 300 972 V7.0.1:2003?
Clause 2 names the companion GSM specifications that this document uses:
- GSM 01.04 - Abbreviations and acronyms used across GSM documents.
- GSM 04.08 - Mobile radio interface layer 3 specification, used here for network command of DTX.
- GSM 05.05 - Radio transmission and reception, used for performance requirements on BFI, UFI and SID detection.
- GSM 05.08 - Radio subsystem link control, used for SACCH multiframe scheduling.
- GSM 06.02 - Half rate speech processing functions.
- GSM 06.20 - Half rate speech transcoding.
- GSM 06.21 - Substitution and muting of lost frames.
- GSM 06.22 - Comfort noise aspects and SID codeword details.
- GSM 06.42 - Voice Activity Detector for half rate speech traffic channels.
- GSM 08.61 - In-band control of remote transcoders and rate adaptors for half rate traffic channels.
- GSM 06.06 - ANSI-C code for the GSM half rate speech codec.
What does the SIST EN 300 972 V7.0.1:2003 document contain?
The document contains a scope, references, defined terms, symbols and abbreviations, then separate TX and RX procedure descriptions. Figures 1 and 4 give block diagrams of the transmit and receive DTX functions.
Figures 2 and 3 illustrate hangover behavior and short speech burst handling. Table 1 classifies received traffic frames, and Annex A provides the change request history used to track the document’s development.
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Frequently Asked Questions
SIST EN 300 972 V7.0.1:2003 is a standard published by the Slovenian Institute for Standardization (SIST). Its full title is "Digital cellular telecommunications system (Phase 2+) (GSM); Half rate speech; Discontinuous Transmission (DTX) for half rate speech traffic channels (GSM 06.41 version 7.0.1 Release 1998)". This standard covers: Upgrade from Phase 2+ to Release 1998
Upgrade from Phase 2+ to Release 1998
SIST EN 300 972 V7.0.1:2003 is classified under the following ICS (International Classification for Standards) categories: 33.070.50 - Global System for Mobile Communication (GSM). The ICS classification helps identify the subject area and facilitates finding related standards.
SIST EN 300 972 V7.0.1:2003 is associated with the following European legislation: Standardization Mandates: T-172. When a standard is cited in the Official Journal of the European Union, products manufactured in conformity with it benefit from a presumption of conformity with the essential requirements of the corresponding EU directive or regulation.
SIST EN 300 972 V7.0.1:2003 is available in PDF format for immediate download after purchase. The document can be added to your cart and obtained through the secure checkout process. Digital delivery ensures instant access to the complete standard document.
Standards Content (Sample)
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Digital cellular telecommunications system (Phase 2+) (GSM); Half rate speech; Discontinuous Transmission (DTX) for half rate speech traffic channels (GSM 06.41 version 7.0.1 Release 1998)33.070.50Globalni sistem za mobilno telekomunikacijo (GSM)Global System for Mobile Communication (GSM)ICS:Ta slovenski standard je istoveten z:EN 300 972 Version 7.0.1SIST EN 300 972 V7.0.1:2003en01-december-2003SIST EN 300 972 V7.0.1:2003SLOVENSKI
STANDARD
ETSIEN300972V7.0.1(2000-01)EuropeanStandard(Telecommunicationsseries)Digitalcellulartelecommunicationssystem(Phase2+);Halfratespeech;DiscontinuousTransmission(DTX)forhalfratespeechtrafficchannels(GSM06.41version7.0.1Release1998)GLOBALSYSTEMFORMOBILECOMMUNICATIONSRSIST EN 300 972 V7.0.1:2003
ETSIETSIEN300972V7.0.1(2000-01)2(GSM06.41version7.0.1Release1998)ReferenceREN/SMG-110641Q7KeywordsDigitalcellulartelecommunicationssystem,GlobalSystemforMobilecommunications(GSM)ETSIPostaladdressF-06921SophiaAntipolisCedex-FRANCEOfficeaddress650RoutedesLucioles-SophiaAntipolisValbonne-FRANCETel.:+33492944200Fax:+33493654716SiretN°34862356200017-NAF742CAssociationàbutnonlucratifenregistréeàlaSous-PréfecturedeGrasse(06)N°7803/88Internetsecretariat@etsi.frIndividualcopiesofthisETSIdeliverablecanbedownloadedfromhttp://www.etsi.orgIfyoufinderrorsinthepresentdocument,sendyourcommentto:editor@etsi.frImportantnoticeThisETSIdeliverablemaybemadeavailableinmorethanoneelectronicversionorinprint.Inanycaseofexistingorperceiveddifferenceincontentsbetweensuchversions,thereferenceversionisthePortableDocumentFormat(PDF).Incaseofdispute,thereferenceshallbetheprintingonETSIprintersofthePDFversionkeptonaspecificnetworkdrivewithinETSISecretariat.CopyrightNotificationNopartmaybereproducedexceptasauthorizedbywrittenpermission.Thecopyrightandtheforegoingrestrictionextendtoreproductioninallmedia.©EuropeanTelecommunicationsStandardsInstitute2000.Allrightsreserved.SIST EN 300 972 V7.0.1:2003
ETSIETSIEN300972V7.0.1(2000-01)3(GSM06.41version7.0.1Release1998)ContentsIntellectualPropertyRights.4Foreword.41Scope.62References.63Definitions,symbolsandabbreviations.73.1Definitions.73.2Symbols.83.3Abbreviations.84General.84.1GeneralOrganisation.85Transmit(TX)side.95.1GeneralOperation.95.1.1FunctionsoftheTXDTXhandler.95.1.2FunctionsoftheTXradiosubsystem.106Receive(RX)side.126.1Generaloperation.126.1.1FunctionsoftheRXradiosubsystem.126.1.2FunctionsoftheRXDTXhandler.13AnnexA(informative):ChangeRequestHistory.14History.15SIST EN 300 972 V7.0.1:2003
ETSIETSIEN300972V7.0.1(2000-01)4(GSM06.41version7.0.1Release1998)IntellectualPropertyRightsIPRsessentialorpotentiallyessentialtothepresentdocumentmayhavebeendeclaredtoETSI.TheinformationpertainingtotheseessentialIPRs,ifany,ispubliclyavailableforETSImembersandnon-members,andcanbefoundinSR000314:"IntellectualPropertyRights(IPRs);Essential,orpotentiallyEssential,IPRsnotifiedtoETSIinrespectofETSIstandards",whichisavailablefromtheETSISecretariat.LatestupdatesareavailableontheETSIWebserver(http://www.etsi.org/ipr).PursuanttotheETSIIPRPolicy,noinvestigation,includingIPRsearches,hasbeencarriedoutbyETSI.NoguaranteecanbegivenastotheexistenceofotherIPRsnotreferencedinSR000314(ortheupdatesontheETSIWebserver)whichare,ormaybe,ormaybecome,essentialtothepresentdocument.ForewordThisEuropeanStandard(Telecommunicationsseries)hasbeenproducedbytheSpecialMobileGroup(SMG).The present document is a GSM technical specification version 7 and is part of the 1998 release of the GSM TechnicalSpecifications.Thepresentdocumentispartofaseriescoveringthehalfratespeechtrafficchannelsasdescribedbelow:GSM06.02"Digitalcellulartelecommunicationssystem(Phase2+);Halfratespeech;Halfratespeechprocessingfunctions".GSM06.06"Digitalcellulartelecommunicationssystem(Phase2+);Halfratespeech;ANSI-CcodefortheGSMhalfratespeechcodec".GSM06.07"Digitalcellulartelecommunicationssystem(Phase2+);Halfratespeech;TestsequencesfortheGSMhalfratespeechcodec".GSM06.20"Digitalcellulartelecommunicationssystem(Phase2+);Halfratespeech;Halfratespeechtranscoding".GSM06.21"Digitalcellulartelecommunicationssystem(Phase2+);Halfratespeech;Substitutionandmutingoflostframesforhalfratespeechtrafficchannels".GSM06.22"Digitalcellulartelecommunicationssystem(Phase2+);Halfratespeech;Comfortnoiseaspectsforhalfratespeechtrafficchannels".GSM06.41"Digitalcellulartelecommunicationssystem(Phase2+);Halfratespeech;DiscontinuousTransmission(DTX)forhalfratespeechtrafficchannels".GSM06.42"Digitalcellulartelecommunicationssystem(Phase2+);Halfratespeech;VoiceActivityDetector(VAD)forhalfratespeechtrafficchannels".ThecontentsofthepresentdocumentissubjecttocontinuingworkwithinSMGandmaychangefollowingformalSMGapproval.ShouldSMGmodifythecontentsofthepresentdocumentitwillbere-releasedwithanidentifyingchangeofreleasedateandanincreaseinversionnumberasfollows:Version7.x.ywhere:7indicatesRelease1998ofGSMPhase2+.xtheseconddigitisincrementedforallchangesofsubstance,i.e.technicalenhancements,corrections,updates,etc.ythethirddigitisincrementedwheneditorialonlychangeshavebeenincorporatedinthespecification.SIST EN 300 972 V7.0.1:2003
ETSIETSIEN300972V7.0.1(2000-01)5(GSM06.41version7.0.1Release1998)NationaltranspositiondatesDateofadoptionofthisEN:31December1999DateoflatestannouncementofthisEN(doa):31March2000DateoflatestpublicationofnewNationalStandardorendorsementofthisEN(dop/e):30September2000DateofwithdrawalofanyconflictingNationalStandard(dow):30September2000SIST EN 300 972 V7.0.1:2003
ETSIETSIEN300972V7.0.1(2000-01)6(GSM06.41version7.0.1Release1998)1ScopeThepresentdocumentgivesadescriptionofthegeneralbasebandoperationofhalfratespeechtrafficchannelsinthetransmitterandinthereceiverofGSMMobileStations(MS)sandBaseStationSystems(BSS)sduringDiscontinuousTransmission(DTX).Forclarity,thedescriptionisstructuredaccordingtotheblockdiagramsinfigures1and4.Exceptinthecasedescribedbelow,thisstructureofdistributingthevariousfunctionsbetweensystementitiesisnotmandatoryforimplementation,aslongastheoperationontheairinterfaceandonthespeechdecoderoutputremainsthesame.InthecaseofBSSswherethespeechtranscoderislocatedremotelyintheBaseStationController(BSC),theimplementationoftheinterfacesbetweentheDTXHandlersandtheRadioSubSystem(RSS)asdescribedinthepresentdocumenttogetherwithalltheirflagsismandatory,beingapartoftheA-bisinterfaceasdescribedinGSM08.61[10].TheDTXfunctionsdescribedinthepresentdocumentaremandatoryforimplementationinallGSMMSs.ThereceiverrequirementsaremandatoryforimplementationinallGSMBSSs,thetransmitterrequirementsonlyforthosewheredownlinkDTXwillbeused.2ReferencesThefollowingdocumentscontainprovisionswhich,throughreferenceinthistext,constituteprovisionsofthepresentdocument.•Referencesareeitherspecific(identifiedbydateofpublication,editionnumber,versionnumber,etc.)ornon-specific.•Foraspecificreference,subsequentrevisionsdonotapply.•Foranon-specificreference,thelatestversionapplies.•Anon-specificreferencetoanETSshallalsobetakentorefertolaterversionspublishedasanENwiththesamenumber.•ForthisRelease1998document,referencestoGSMdocumentsareforRelease1998versions(version7.x.y).[1]GSM01.04:"Digitalcellulartelecommunicationsystem(Phase2+);Abbreviationsandacronyms".[2]GSM04.08:"Digitalcellulartelecommunicationsystem(Phase2+);Mobileradiointerfacelayer3specification".[3]GSM05.05:"Digitalcellulartelecommunicationssystem(Phase2+);Radiotransmissionandreception".[4]GSM05.08:"Digitalcellulartelecommunicationsystem(Phase2+);Radiosubsystemlinkcontrol".[5]GSM06.02:"Digitalcellulartelecommunicationssystem(Phase2+);HalfratespeechPart1:Halfratespeechprocessingfunctions".[6]GSM06.20:"Digitalcellulartelecommunicationssystem(Phase2+);Halfratespeech;Halfratespeechtranscoding".[7]GSM06.21:"Digitalcellulartelecommunicationssystem(Phase2+);Halfratespeech;Substitutionandmutingoflostframesforhalfratespeechtrafficchannels".[8]GSM06.22:"Digitalcellulartelecommunicationssystem(Phase2+);Halfratespeech;Comfortnoiseaspectsforhalfratespeechtrafficchannels".[9]GSM06.42:"Digitalcellulartelecommunicationssystem(Phase2+);Halfratespeech;VoiceActivityDetector(VAD)forhalfratespeechtrafficchannels".SIST EN 300 972 V7.0.1:2003
ETSIETSIEN300972V7.0.1(2000-01)7(GSM06.41version7.0.1Release1998)[10]GSM08.61:"Digitalcellulartelecommunicationssystem(Phase2+);Inbandcontrolofremotetranscodersandrateadaptorsforhalfratetrafficchannels".[11]GSM06.06:"Digitalcellulartelecommunicationssystem(Phase2+);HalfratespeechPart7:ANSI-CcodefortheGSMhalfratespeechcodec".3Definitions,symbolsandabbreviations3.1DefinitionsForthepurposesofthepresentdocument,thefollowingtermsanddefinitionsapply.acceptedSIDframe:AtrafficframewhichisflaggedwithSID="1"orSID="2"bytheRadioSubsystem.badtrafficframe:AtrafficframeflaggedBFI="1"(BadFrameIndication)orwithUFI="1"(UnreliableFrameIndication)bytheRadioSubsystem.frame:Timeintervalof20mscorrespondingtothetimesegmentationofthehalfratespeechtranscoderdefinedinGSM06.20(ETS300969)[6]),alsousedasashortt
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