SIST EN 301 248 V4.1.1:2003
(Main)Digital cellular telecommunications system (Phase 2) (GSM); Discontinuous Transmission (DTX) for Enhanced Full Rate (EFR) speech traffic channels (GSM 06.81 version 4.1.1)
General Information
- Abstract
EN created for GSM Phase2 MS type approval purposes (a revision of GSM Phase 2+ ETS)
- 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
Overview
SIST EN 301 248 V4.1.1:2003, titled Digital cellular telecommunications system (Phase 2) (GSM); Discontinuous Transmission (DTX) for Enhanced Full Rate (EFR) speech traffic channels (GSM 06.81 version 4.1.1), is a European Standard developed for type approval of GSM Phase 2 mobile stations. This standard defines the baseband operation of Enhanced Full Rate (EFR) speech traffic channels during Discontinuous Transmission (DTX) in both the transmitter and receiver sections of GSM Mobile Stations (MS) and Base Station Systems (BSS).
DTX is a mechanism designed for digital cellular telecommunications systems to conserve battery power and reduce interference in the GSM radio network, especially during periods when the user is not actively speaking. EFR speech traffic channels benefit from DTX by optimizing speech codec performance and radio resource usage.
Key Topics
- Discontinuous Transmission (DTX):
- Enables the radio transmitter to switch off during speech pauses, leading to significant power savings and reduced network interference.
- Enhanced Full Rate (EFR) Speech Channels:
- Focuses on improved speech quality using the EFR codec, crucial for GSM mobile communication.
- Transmit and Receive Side Operations:
- Transmit (TX) involves Voice Activity Detection (VAD), background noise evaluation, and signaling of frame status using special flags.
- Receive (RX) focuses on error concealment, comfort noise generation, and processing of various frame types (speech, SID, invalid, unusable).
- Comfort Noise Generation:
- Ensures user experience is maintained by producing representative noise during silence, matching real-world acoustic conditions.
- Frame Classification and Handling:
- Introduces specific flags and procedures to manage speech frames, SID (Silence Descriptor) frames, bad frames, and unusable frames for optimal decoding and user experience.
Applications
This standard has practical value in the following areas:
- Mobile Device Type Approval:
- Compliance with SIST EN 301 248 is mandatory for GSM Phase 2 mobile stations seeking type approval, ensuring interoperability and network efficiency.
- Base Station Implementation:
- Required for all GSM base station systems to correctly handle DTX and EFR speech channels, especially for receiving operations.
- Power Optimization:
- Implementing DTX reduces mobile station battery drain, which extends the life between charges - an essential feature for mobile users.
- Network Interference Minimization:
- Reducing unnecessary transmissions during silence periods lessens air interface congestion and overall interference.
- Speech Quality Assurance:
- EFR and comfort noise mechanisms ensure clarity and natural sound, even in variable network conditions.
- Radio Interface Optimization:
- Mandatory interfaces and flags, especially in systems with remote transcoders, maintain correct operation across different GSM network configurations.
Related Standards
Integration and implementation of SIST EN 301 248 are supported by a range of closely related GSM standards that define components such as speech coding, error correction, and radio subsystem management. Relevant standards include:
- GSM 01.04: Abbreviations and acronyms for digital cellular telecommunications
- GSM 04.08: Mobile radio interface layer 3 specification
- GSM 05.03: Channel coding
- GSM 05.05: Radio transmission and reception
- GSM 05.08: Radio subsystem link control
- GSM 06.51: General description of EFR speech processing
- GSM 06.53: ANSI-C code for EFR speech codec
- GSM 06.54: Test vectors for EFR speech codec
- GSM 06.60: EFR speech transcoding
- GSM 06.61: Substitution and muting of lost frames for EFR
- GSM 06.62: Comfort noise aspects for EFR
- GSM 06.82: Voice Activity Detector (VAD) for EFR
- GSM 08.60: In-band control of remote transcoders and rate adaptors
By following SIST EN 301 248 and its related standards, manufacturers and network operators ensure robust, energy-efficient, and high-quality GSM voice services, aligning with international type approval and operational requirements.
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Frequently Asked Questions
SIST EN 301 248 V4.1.1:2003 is a standard published by the Slovenian Institute for Standardization (SIST). Its full title is "Digital cellular telecommunications system (Phase 2) (GSM); Discontinuous Transmission (DTX) for Enhanced Full Rate (EFR) speech traffic channels (GSM 06.81 version 4.1.1)". This standard covers: EN created for GSM Phase2 MS type approval purposes (a revision of GSM Phase 2+ ETS)
EN created for GSM Phase2 MS type approval purposes (a revision of GSM Phase 2+ ETS)
SIST EN 301 248 V4.1.1:2003 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 301 248 V4.1.1:2003 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 301 248 V4.1.1:2003 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); Discontinuous Transmission (DTX) for Enhanced Full Rate (EFR) speech traffic channels (GSM 06.81 version 4.1.1)33.070.50Globalni sistem za mobilno telekomunikacijo (GSM)Global System for Mobile Communication (GSM)ICS:Ta slovenski standard je istoveten z:EN 301 248 Version 4.1.1SIST EN 301 248 V4.1.1:2003en01-december-2003SIST EN 301 248 V4.1.1:2003SLOVENSKI
STANDARD
ETSIEN301248V4.1.1(2000-04)EuropeanStandard(Telecommunicationsseries)Digitalcellulartelecommunicationssystem(Phase2);DiscontinuousTransmission(DTX)forEnhancedFullRate(EFR)speechtrafficchannels(GSM06.81version4.1.1)GLOBALSYSTEMFORMOBILECOMMUNICATIONSRSIST EN 301 248 V4.1.1:2003
ETSIETSIEN301248V4.1.1(2000-04)2(GSM06.81version4.1.1)ReferenceREN/SMG-110681PR1KeywordsDigitalcellulartelecommunicationssystem,GlobalSystemforMobilecommunications(GSM)ETSI650RoutedesLuciolesF-06921SophiaAntipolisCedex-FRANCETel.:+33492944200Fax:+33493654716SiretN°34862356200017-NAF742CAssociationàbutnonlucratifenregistréeàlaSous-PréfecturedeGrasse(06)N°7803/88ImportantnoticeIndividualcopiesofthepresentdocumentcanbedownloadedfrom:http://www.etsi.orgThepresentdocumentmaybemadeavailableinmorethanoneelectronicversionorinprint.Inanycaseofexistingorperceiveddifferenceincontentsbetweensuchversions,thereferenceversionisthePortableDocumentFormat(PDF).Incaseofdispute,thereferenceshallbetheprintingonETSIprintersofthePDFversionkeptonaspecificnetworkdrivewithinETSISecretariat.Usersofthepresentdocumentshouldbeawarethatthedocumentmaybesubjecttorevisionorchangeofstatus.InformationonthecurrentstatusofthisandotherETSIdocumentsisavailableathttp://www.etsi.org/tb/status/Ifyoufinderrorsinthepresentdocument,sendyourcommentto:editor@etsi.frCopyrightNotificationNopartmaybereproducedexceptasauthorizedbywrittenpermission.Thecopyrightandtheforegoingrestrictionextendtoreproductioninallmedia.©EuropeanTelecommunicationsStandardsInstitute2000.Allrightsreserved.SIST EN 301 248 V4.1.1:2003
ETSIETSIEN301248V4.1.1(2000-04)3(GSM06.81version4.1.1)ContentsIntellectualPropertyRights.4Foreword.41Scope.52References.53Definitions,symbolsandabbreviations.63.1Definitions.63.2Symbols.73.3Abbreviations.74General.74.1Generalorganization.75Transmit(TX)side.85.1Generaloperation.85.1.1FunctionsoftheTXDTXhandler.85.1.2FunctionsoftheTXRadioSubsystem.106Receive(RX)side.116.1Generaloperation.116.1.1FunctionsoftheRXradiosubsystem.116.1.2FunctionsoftheRXDTXhandler.12AnnexA(informative):ChangeRequestHistory.13History.14SIST EN 301 248 V4.1.1:2003
ETSIETSIEN301248V4.1.1(2000-04)4(GSM06.81version4.1.1)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).ThepresentdocumentdescribesthegeneralbasebandoperationofEnhancedFullRatespeechtrafficchannelsinthetransmitterandinthereceiverofGSMMobileStationsandBaseStationSystemsduringDiscontinuousTransmission(DTX)withinthedigitalcellulartelecommunicationssystem.ThepresentdocumentcorrespondstoGSMtechnicalspecification,GSM06.81,version4.1.0.NationaltranspositiondatesDateofadoptionofthisEN:31March2000DateoflatestannouncementofthisEN(doa):30June2000DateoflatestpublicationofnewNationalStandardorendorsementofthisEN(dop/e):31December2000DateofwithdrawalofanyconflictingNationalStandard(dow):31December2000SIST EN 301 248 V4.1.1:2003
ETSIETSIEN301248V4.1.1(2000-04)5(GSM06.81version4.1.1)1ScopeThepresentdocumentgivesadescriptionofthegeneralbasebandoperationofEnhancedFullRatespeechtrafficchannelsinthetransmitterandinthereceiverofGSMMobileStations(MS)sandBaseStationSystems(BSS)sduringDiscontinuousTransmission(DTX).Forclarity,thedescriptionisstructuredaccordingtotheblockdiagramsinfigures1and4.Exceptinthecasedescribednext,thisstructureofdistributingthevariousfunctionsbetweensystementitiesisnotmandatoryforimplementation,aslongastheoperationontheairinterfaceandonthespeechdecoderoutputremainsthesame.InthecaseofBSSswherethespeechtranscoderislocatedremotelyintheBaseStationController(BSC),theimplementationoftheinterfacesbetweentheDTXhandlersandtheRadioSubSystem(RSS)asdescribedinthepresentdocumenttogetherwithalltheirflagsismandatory,beingpartoftheA-bisinterfaceasdescribedinGSM08.60(ETS300737)[13].TheDTXfunctionsdescribedinthepresentdocumentaremandatoryforimplementationintheGSMMSs.ThereceiverrequirementsaremandatoryforimplementationinallGSMBSSs,thetransmitterrequirementsonlyforthosewheredownlinkDTXwillbeused.2ReferencesThefollowingdocumentscontainprovisionswhich,throughreferenceinthistext,constituteprovisionsofthepresentdocument.• Referencesareeitherspecific(identifiedbydateofpublication,editionnumber,versionnumber,etc.)ornon-specific.• Foraspecificreference,subsequentrevisionsdonotapply.• Foranon-specificreference,thelatestversionapplies.• Anon-specificreferencetoanETSshallalsobetakentorefertolaterversionspublishedasanENwiththesamenumber.[1]GSM01.04(ETR100):"Digitalcellulartelecommunicationssystem(Phase2);Abbreviationsandacronyms".[2]GSM04.08(ETS300557):"Digitalcellulartelecommunicationssystem(Phase2);Mobileradiointerfacelayer3specification".[3]GSM05.03(ETS300575):"Digitalcellulartelecommunicationssystem(Phase2);Channelcoding".[4]GSM05.05(ETS300577):"Digitalcellulartelecommunicationssystem(Phase2);Radiotransmissionandreception".[5]GSM05.08(ETS300578):"Digitalcellulartelecommunicationssystem(Phase2);Radiosubsystemlinkcontrol".[6]GSM06.51(EN301243):"Digitalcellulartelecommunicationssystem;EnhancedFullRate(EFR)speechprocessingfunctions;Generaldescription".[7]GSM06.53(EN301244):"Digitalcellulartelecommunicationssystem;ANSI-CcodefortheGSMEnhancedFullRate(EFR)speechcodec".[8]GSM06.54(EN301250):"Digitalcellulartelecommunicationssystem(Phase2);TestvectorsfortheGSMEnhancedFullRate(EFR)speechcodec".[9]GSM06.60(EN301245):"Digitalcellulartelecommunicationssystem;EnhancedFullRate(EFR)speechtranscoding".SIST EN 301 248 V4.1.1:2003
ETSIETSIEN301248V4.1.1(2000-04)6(GSM06.81version4.1.1)[10]GSM06.61(EN301246):"Digitalcellulartelecommunicationssystem;SubstitutionandmutingoflostframeforEnhancedFullRate(EFR)speechtrafficchannels".[11]GSM06.62(EN301247):"Digitalcellulartelecommunicationssystem;ComfortnoiseaspectsforEnhancedFullRate(EFR)speechtrafficchannels".[12]GSM06.82(EN301249):"Digitalcellulartelecommunicationssystem;VoiceActivityDetector(VAD)forEnhancedFullRate(EFR)speechtrafficchannels".[13]GSM08.60(ETS300737):"Digitalcellulartelecommunicationssystem(Phase2+);InbandcontrolofremotetranscodersandrateadaptorsforEnhancedFullRate(EFR)andfullratetrafficchannels".3Definitions,symbolsandabbreviations3.1DefinitionsForthepurposesofthepresentdocument,thefollowingtermsanddefinitionsapply:acceptedSIDframe:AtrafficframewhichisflaggedwithSID="1"orSID="2"bytheRadioSubsystem.badtrafficframe:AtrafficframeflaggedBFIflag="1"(BadFrameIndication)bytheRadioSubsystem.frame:Timeintervalof20msec.correspondingtothetimesegmentationoftheEnhancedFullRatespeechtranscoder(GSM06.60(EN301245)[9]),alsousedasashorttermforatrafficframe.goodspeechframe:AgoodtrafficframewhichisnotanacceptedSIDframe.goodtrafficframe:AtrafficframeflaggedBFIflag="0"bytheRadioSubsystem.hangoverperiod:Aperiodof7framesaddedattheendofaspeechburstinwhichVADflag="0"andSPflag="1".invalidSIDframe:AnacceptedSIDframewhichwasnotclassifiedasvalidSIDframe.Thisframeisnotvalidforupdatingcomfortnoiseparameters,buttheframeconveysinformationthatcomfortnoisegenerationsshouldbestartedorcontinued.lostSIDframe:AnunusableframereceivedwhentheRXDTXhandlerisgeneratingcomfort
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