SIST EN 301 706 V7.1.1:2003

• Abstract:

  Adaptive Multi- Rate (AMR) Comfort noise

• Status: Published
• Publication Date: 30-Nov-2003
• ICS: 33.070.50 - Global System for Mobile Communication (GSM)
• Technical Committee: SS EIT - Technical Board for the electrotechnical, information technology and telecommunications fields
• 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
• Ref Project: ETSI EN 301 706 V7.1.1 (1999-12) - Digital cellular telecommunications system (Phase 2+) (GSM); Comfort noise aspects for Adaptive Multi-Rate (AMR) speech traffic channels (GSM 06.92 version 7.1.1 Release 1998)

Overview

SIST EN 301 706 V7.1.1:2003 defines the requirements for comfort noise aspects in adaptive multi-rate (AMR) speech traffic channels within the digital cellular telecommunications system (GSM Phase 2+). Developed by the Slovenski inštitut za standardizacijo (SIST) and identical to the EN 301 706 version from ETSI, this standard addresses how comfort noise is evaluated, encoded, and generated in both Mobile Stations (MS) and Base Station Systems (BSS) when Discontinuous Transmission (DTX) is used. The goal is to ensure seamless audio quality and a natural listening experience during periods of silence in GSM voice calls by synthesizing background noise.

Keywords: GSM, Adaptive Multi-Rate, comfort noise, AMR codec, speech channels, DTX, digital cellular telecommunications.

Key Topics

• Comfort Noise Evaluation: Methods for analyzing and characterizing background acoustic noise at the transmitter (TX) side.
• Parameter Encoding and Decoding: Procedures for encoding comfort noise parameters into Silence Descriptor (SID) frames on the transmit side, and decoding them on the receive (RX) side.
• SID Frames: Special frames that deliver comfort noise parameters to the decoder to enable background noise generation during silent periods.
• Discontinuous Transmission (DTX): Optimization approach to reduce transmission power and bandwidth during silence; this can create unnatural pauses if not handled properly by comfort noise generation.
• AMR Speech Channels: Application of comfort noise techniques specifically for AMR full-rate and half-rate speech traffic channels in GSM networks.
• Noise Generation and Updating: Ongoing adaptation of synthetic noise on the receiver side to reflect changing background conditions as encountered on the transmitter side.

Applications

• Mobile Voice Communications: Ensures GSM telephony maintains a natural user experience by generating comfort noise, maintaining continuity and intelligibility of calls during silences.
• Network Efficiency: Facilitates effective use of DTX, improving spectral efficiency and reducing energy consumption for GSM networks and mobile devices.
• Base Station Operation: Required for BSS that support AMR codecs, enabling them to properly generate and update comfort noise for downlink channels.
• Handset Implementation: Mandatory for devices supporting AMR speech channels, to uphold call quality standards and meet regulatory requirements.

Practical Value

Implementing SIST EN 301 706 V7.1.1:2003 delivers several advantages:

• Enhanced User Experience: Prevents sudden absence of background noise, which can be jarring or make speech less intelligible, especially in high-noise environments like vehicles.
• Consistent Audio Quality: Smooth transitions between speech and silence, avoiding unnatural gaps.
• Interoperability: Supports harmonized operation across compliant GSM equipment from different vendors, facilitating global connectivity.

Related Standards

For comprehensive implementation of comfort noise and AMR functionalities in GSM systems, consider the following related standards:

• GSM 06.73: ANSI-C code for the GSM Adaptive Multi-Rate speech codec.
• GSM 06.90: AMR speech transcoding.
• GSM 06.91: Substitution and muting of lost frames for AMR speech channels.
• GSM 06.93: Discontinuous Transmission (DTX) for AMR speech traffic channels.
• GSM 01.04: General abbreviations and acronyms in GSM.

These documents provide detailed algorithms, implementation guidelines, and interoperability requirements integral to the effective deployment of comfort noise and AMR speech services in GSM networks.

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SIST EN 301 706 V7.1.1:2003 forms a vital part of the GSM standards family, supporting the delivery of high-quality mobile voice communications through effective comfort noise generation in AMR speech channels. For network operators, equipment manufacturers, and developers, adherence ensures compliance and outstanding service quality in digital cellular environments.

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Digital cellular telecommunications system (Phase 2+) (GSM); Comfort noise aspects for Adaptive Multi-Rate (AMR) speech traffic channels (GSM 06.92 version 7.1.1 Release 1998)33.070.50Globalni sistem za mobilno telekomunikacijo (GSM)Global System for Mobile Communication (GSM)ICS:Ta slovenski standard je istoveten z:EN 301 706 Version 7.1.1SIST EN 301 706 V7.1.1:2003en01-december-2003SIST EN 301 706 V7.1.1:2003SLOVENSKI
STANDARD
ETSIEN301706V7.1.1(1999-12)EuropeanStandard(Telecommunicationsseries)Digitalcellulartelecommunicationsystem(Phase2+);ComfortnoiseaspectsforAdaptiveMulti-Rate(AMR)speechtrafficchannels(GSM06.92version7.1.1Release1998)GLOBALSYSTEMFORMOBILECOMMUNICATIONSRSIST EN 301 706 V7.1.1:2003

ETSIETSIEN301706V7.1.1(1999-12)2(GSM06.92version7.1.1Release1998)ReferenceDEN/SMG-110692Q7KeywordsDigitalcellulartelecommunicationssystem,GlobalSystemforMobilecommunications(GSM)ETSIPostaladdressF-06921SophiaAntipolisCedex-FRANCEOfficeaddress650RoutedesLucioles-SophiaAntipolisValbonne-FRANCETel.:[phone]Fax:[phone]SiretN°34862356200017-NAF742CAssociationàbutnonlucratifenregistréeàlaSous-PréfecturedeGrasse(06)N°7803/[e-mail]ETSIdeliverablecanbedownloadedfromhttp://www.etsi.orgIfyoufinderrorsinthepresentdocument,sendyourcommentto:[e-mail]Ideliverablemaybemadeavailableinmorethanoneelectronicversionorinprint.Inanycaseofexistingorperceiveddifferenceincontentsbetweensuchversions,thereferenceversionisthePortableDocumentFormat(PDF).Incaseofdispute,thereferenceshallbetheprintingonETSIprintersofthePDFversionkeptonaspecificnetworkdrivewithinETSISecretariat.CopyrightNotificationNopartmaybereproducedexceptasauthorizedbywrittenpermission.Thecopyrightandtheforegoingrestrictionextendtoreproductioninallmedia.©EuropeanTelecommunicationsStandardsInstitute1999.Allrightsreserved.SIST EN 301 706 V7.1.1:2003

ETSIETSIEN301706V7.1.1(1999-12)3(GSM06.92version7.1.1Release1998)ContentIntellectualPropertyRights.4Foreword.41Scope.52References.53Definitions,symbolsandabbreviations.53.1Definitions.53.2Symbols.63.3Abbreviations.64General.75Functionsonthetransmit(TX)side.75.1LSFevaluation.75.2Frameenergycalculation.85.3ModificationofthespeechencodingalgorithmduringSIDframegeneration.85.4SID-frameencoding.96Functionsonthereceive(RX)side.96.1AveraginganddecodingoftheLPandenergyparameters.96.2Comfortnoisegenerationandupdating.107Computationaldetailsandbitallocation.11AnnexA(informative):Documentchangehistory.12History.13SIST EN 301 706 V7.1.1:2003

ETSIETSIEN301706V7.1.1(1999-12)4(GSM06.92version7.1.1Release1998)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)hasbeenproducedbySpecialMobileGroup(SMG).ThepresentdocumentintroducestheAdaptiveMulti-Rate(AMR)speechtrafficchannelswithinthedigitalcellulartelecommunicationssystem.ThecontentsofthepresentdocumentissubjecttocontinuingworkwithinSMGandmaychangefollowingformalSMGapproval.ShouldSMGmodifythecontentsofthepresentdocumentitwillbere-releasedwithanidentifyingchangeofreleasedateandanincreaseinversionnumberasfollows:Version7.x.ywhere:7indicatesRelease1998ofGSMPhase2+xtheseconddigitisincrementedforallchangesofsubstance,i.e.technicalenhancements,corrections,updates,etc.ythethirddigitisincrementedwheneditorialonlychangeshavebeenincorporatedinthespecification.NationaltranspositiondatesDateofadoptionofthisEN:3December1999DateoflatestannouncementofthisEN(doa):31March2000DateoflatestpublicationofnewNationalStandardorendorsementofthisEN(dop/e):30September2000DateofwithdrawalofanyconflictingNationalStandard(dow):30September2000SIST EN 301 706 V7.1.1:2003

ETSIETSIEN301706V7.1.1(1999-12)5(GSM06.92version7.1.1Release1998)1ScopeThepresentdocumentgivesthedetailedrequirementsforthecorrectoperationofthebackgroundacousticnoiseevaluation,noiseparameterencoding/decodingandcomfortnoisegenerationinMobileStations(MSs)andBaseStationSystems(BSSs)duringDiscontinuousTransmission(DTX)onadaptivemulti-ratefullrateandhalfratespeechtrafficchannels.TherequirementsdescribedinthepresentdocumentaremandatoryforimplementationinallGSMMSscapableofsupportingtheadaptivemulti-ratefullrateandhalftatespeechtrafficchannels.ThereceiverrequirementsaremandatoryforimplementationinallGSMBSSscapableofsupportingtheadaptivemulti-ratefullrateandhalfratespeechtrafficchannels,thetransmitterrequirementsonlyforthosewheredownlinkDTXwillbeused.IncaseofdiscrepancybetweentherequirementsdescribedinthepresentdocumentandthefixedpointcomputationaldescriptionoftheserequirementscontainedinGSM06.73[2],thedescriptioninGSM06.73[2]willprevail.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]GSM06.73:"Digitalcellulartelecommunicationssystem(Phase2+);ANSI-CcodefortheGSMAdaptiveMulti-Ratespeechcodec".[3]GSM06.90:"Digitalcellulartelecommunicationssystem(Phase2+);AdaptiveMulti-Ratespeechtranscoding".[4]GSM06.91:"Digitalcellulartelecommunicationssystem(Phase2+);SubstitutionandmutingoflostframeforAdaptiveMulti-Ratespeechtrafficchannels".[5]GSM06.93:"Digitalcellulartelecommunicationssystem(Phase2+);Discontinuoustransmission(DTX)forAdaptiveMulti-Ratespeechtrafficchannels".3Definitions,symbolsandabbreviations3.1DefinitionsForthepurposeofthepresentdocument,thefollowingtermsanddefinitionsapply.Frame:timeintervalof20mscorrespondingtothetimesegmentationoftheadaptivemulti-ratespeechtranscoder,alsousedasashorttermfortrafficframe.SIST EN 301 706 V7.1.1:2003

ETSIETSIEN301706V7.1.1(1999-12)6(GSM06.92version7.1.1Release1998)SIDframes:specialSID(SilenceDescriptor)frames.Itmayconveyinformationontheacousticbackgroundnoiseorinformthedecoderthatitshouldstartgeneratingbackgroundnoise.Speechframe:trafficframethatcannotbeclassifiedasaSIDframe.VADflag:voiceActivityDetectionflag.TX_TYPE:oneofSPEECH,SID_FIRST,SID_UPD,NO_DATA(definedinGSM06.93).RX_TYPE:classificationofthereceivedtrafficframe(definedinGSM06.93).OtherdefinitionsoftermsusedinthepresentdocumentcanbefoundinGSM06.90[3]andGSM06.93[5].TheoveralloperationofDTXisdescribedinGSM06.93[5].3.2SymbolsForthepurposeofthepresentdocument,thefollowingsymbolsapply.Boldfacesymbolsareusedforvectorvariables.[]fTfff=1210.UnquantizedLSFvector[].fTfff=1210QuantizedLSFvectorf()mUnquantizedLSFvectorofframemf()mQuantizedLSFvectorofframemfmeanAveragedLSFparametervectorenlogLogarithmicframeenergyenmeanlogAveragedlogarithmicframeenergyfrefReferencevectorforLSFquantizationeComputedLSFparameterpredictionresidualeQuantizedLSFparameterpredictionresidualxnnab()=()()()()=++++−+xaxaxbxb113.3AbbreviationsForthepurposeofthepresentdocument,thefollowingabbreviationsapply.AMRAdaptiveMulti-RateBSSBaseStationSubsystemDTXDiscontinuousTransmissionMSMobileStationSIDSIlenceDescriptorLPLinearPredictionLSPLineSpectralPairLSFLineSpectralFrequencyRXReceiveTXTransmitVADVoiceActivityDetectorForabbreviationsnotgiveninthissubclause,seeGSM01.04[1].SIST EN 301 706 V7.1.1:2003

ETSIETSIEN301706V7.1.1(1999-12
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