ETSI EN 300 945 V7.0.3 (1999-12)

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Digital cellular telecommunications system (Phase 2+) (GSM); Rate adaption on the Mobile Station - Base Station System (MS - BSS) Interface (GSM 04.21 version 7.0.3 Release 1998)33.070.50Globalni sistem za mobilno telekomunikacijo (GSM)Global System for Mobile Communication (GSM)ICS:Ta slovenski standard je istoveten z:EN 300 945 Version 7.0.3SIST EN 300 945 V7.0.3:2003en01-december-2003SIST EN 300 945 V7.0.3:2003SLOVENSKI
STANDARD



SIST EN 300 945 V7.0.3:2003



ETSIEN300945V7.0.3(1999-12)EuropeanStandard(Telecommunicationsseries)Digitalcellulartelecommunicationssystem(Phase2+);RateadaptionontheMobileStation-BaseStationSystem(MS-BSS)Interface(GSM04.21version7.0.3Release1998)GLOBALSYSTEMFORMOBILECOMMUNICATIONSRSIST EN 300 945 V7.0.3:2003



ETSIETSIEN300945V7.0.3(1999-12)2(GSM04.21version7.0.3Release1998)ReferenceREN/SMG-040421Q7(8r003i20.PDF)KeywordsDigitalcellulartelecommunicationssystem,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,thereferenceshouldbetheprintingonETSIprintersofthePDFversionkeptonaspecificnetworkdrivewithinETSISecretariat.CopyrightNotificationNopartmaybereproducedexceptasauthorizedbywrittenpermission.Thecopyrightandtheforegoingrestrictionextendtoreproductioninallmedia.©EuropeanTelecommunicationsStandardsInstitute1999.Allrightsreserved.SIST EN 300 945 V7.0.3:2003



ETSIETSIEN300945V7.0.3(1999-12)3(GSM04.21version7.0.3Release1998)ContentsIntellectualPropertyRights.5Foreword.51Scope.62References.62.1Abbreviationsanddefinitions.73Generalapproach.73.1Overviewofdataratesandconfigurations.74TheRA0Function.104.1Asynchronous-to-SynchronousConversion(RA0).104.2Breaksignal.104.3Overspeed/Underspeed.104.4ParityBits.104.5FlowControl.115TheRA1Function.115.1Adaptationofsynchronousdataratesupto38,4kbit/s.115.1.1NetworkIndependentClocking.125.1.1.1MultiframeStructure.125.1.1.2Encodingandcompensation.126TheRA1''function.136.1Rateadaptationof48kbit/suserrateswithDTE/DCEstatusto64kbit/s.136.2Rateadaptationof56kbit/suserrateto64kbit/s.137TheRA2Function.148TheRA1/RA1'Function.148.1Singleslotrates.148.1.1Radiointerfacerateof14,5kbit/s.158.1.1.1Multiframestructureovertheradio-interface.158.1.1.2Radio-interfacedatablockforTCH/F14.4channelcoding.178.1.2RadioInterfacerateof12kbit/s.178.1.4RadioInterfacerateof6kbit/s.188.1.5RadioInterfacerateof3,6kbit/s(transparentservicesonly).198.1.6Synchronisation.198.1.7Idleframes.198.2Multislotrates.198.2.1TCH/F14.4multislotoperation.208.2.2AIURsupto38,4kbit/susingTCH/F9.6andTCH/F4.8channelcodings.208.2.3AIURsupto38,4kbit/susingTCH/F14.4channelcoding.208.2.4AIURof48kbit/s;Intermediaterateof64kbit/s;Radiointerfacerateof5x12kbit/s.218.2.5AIURof48kbit/s;Intermediaterateof64kbit/s;Radiointerfacerateof4x14,5kbit/s.218.2.6AIURof56kbit/s;Intermediaterateof64kbit/s;.218.2.7AIURof56kbit/s;Intermediaterateof64kbit/s;Radiointerfacerateof4x14,5kbit/s.228.2.8AIURof64kbit/s;Radiointerfacerateof6x12kbit/s.228.2.9AIURof64kbit/s;Radiointerfacerateof5x14,5kbit/s.229TheRA1'Function.229.1Synchronoususerratesupto9,6kbit/s.239.2Synchronoususerratesfrom9,6kbit/sonward;TCH/F9.6/4.8channelcodings.239.3Synchronoususerratesfrom9,6kbit/sonward;TCH/F14.4channelcoding.2310TheSplit/CombineandPadding-functions.2410.1Dataframedistributionintothesubstreams/channelsbytheSplit/Combinefunction.2410.1.1Dataframedistributionintothesubstreams/channelsbytheSplit/Combinefunction(TCH/F9.6andTCH/F4.8channelcodings).24SIST EN 300 945 V7.0.3:2003



ETSIETSIEN300945V7.0.3(1999-12)4(GSM04.21version7.0.3Release1998)10.1.2DatablockdistributionintothesubstreamsbytheSplit/Combinefunction(TCH/F14.4channelcoding).2410.2Substreamnumberingintransparentoperation.2510.2.1SubstreamnumberingforTCH/F14.4channelcoding.2510.3SubstreamSynchronisation.2610.4Networkindependentclocking.2610.4.1NetworkIndependentClockingforTCH/F14.4channelcoding(bothsingle-andmultilinks).2610.4.1.1Negativecompensation.2610.4.1.2Positivecompensation.2610.5PaddingTCH/FframeswhentheAIURisnotamultipleof9,6or4,8kbit/s.2710.5.1PaddingforTCH/F14.4channelcoding.2711SupportofNon-TransparentBearerServices.2711.1Supportofnon-transparentoperationforTCH/F9.6andTCH/F4.8channelcodings.2711.2Supportofnon-transparentoperationforTCH/F14.4channelcoding.2812FiguresonFramestructures.28AnnexA(informative):Stacksofrateadaptation.33A.1Stacksofrateadaptationfor9,6/4,8kbit/ssingleslotoperation.33A.2Stacksofrateadaptationfor14,4kbit/ssingleslotoperation.34A.3Stacksofrateadaptationfor9,6/4,8kbit/smultislotoperation.36A.4Stacksofrateadaptationfor14,4kbit/smultislotoperation.37AnnexB(informative):AnexampleofmappingNetworkIndependentClockinginformationforTCH/F14.4whentheS-interfaceisdeployed:.39AnnexC(informative):Changehistory.40History.41SIST EN 300 945 V7.0.3:2003



ETSIETSIEN300945V7.0.3(1999-12)5(GSM04.21version7.0.3Release1998)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)hasbeenproducedbyTechnicalCommitteeSpecialMobileGroup(SMG).ThepresentdocumentdefinestherateadaptationfunctionstobeusedinMobileStations(MS)foradaptingterminalinterfacedataratestotheMobileStation-BaseStationSystem(MS-BSS)interfacedatarateswithinthedigitalcellulartelecommunicationssystem.ThecontentsofthepresentdocumentissubjecttocontinuingworkwithinSMGandmaychangefollowingformalSMGapproval.ShouldSMGmodifythecontentsofthepresentdocument,itwillbere-releasedbySMGwithanidentifyingchangeofreleasedateandanincreaseinversionnumberasfollows:Version7.x.ywhere:7IndicatesGSMPhase2+Release1998;xtheseconddigitisincrementedfortechnicalenhancements,corrections,updates,etcythethirddigitisincrementedwheneditorialonlychangeshavebeenincorporatedinthespecification;NationaltranspositiondatesDateofadoptionofthisEN:3December1999DateoflatestannouncementofthisEN(doa):31March2000DateoflatestpublicationofnewNationalStandardorendorsementofthisEN(dop/e):30September2000DateofwithdrawalofanyconflictingNationalStandard(dow):30September2000SIST EN 300 945 V7.0.3:2003



ETSIETSIEN300945V7.0.3(1999-12)6(GSM04.21version7.0.3Release1998)1ScopeThepresentdocumentdefinestherateadaptationfunctionstobeusedinGSMPLMNMobileStations(MS)sforadaptingterminalinterfacedataratestotheMobileStation-BaseStationSystem(MS-BSS)interfacedataratesinaccordancewithGSM03.10[3].Theprovisionofthesefunctionswilldependontheservicesaparticularstationisdesignedtosupport.NOTE:ThepresentdocumentshouldbeconsideredtogetherwithGSM08.20[9](RateAdaptationontheBSS-MSCInterface)togiveacompletedescriptionofPLMNrateadaptation.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]GSM02.34:"Digitalcellulartelecommunicationssystem(Phase2+);HighSpeedCircuitSwitchedData(HSCSD)-Stage1".[3]GSM03.10:"Digitalcellulartelecommunicationsystem(Phase2+);GSMPublicLandMobileNetwork(PLMN)connectiontypes".[4]GSM03.34:"Digitalcellulartelecommunicationssystem(Phase2+);HighSpeedCircuitSwitchedData(HSCSD)-Stage2ServiceDescription".[5]GSM05.03:"Digitalcellulartelecommunicationssystem(Phase2+);Channelcoding".[6]GSM07.01:"Digitalcellulartelecommunicationsystem(Phase2+);GeneralonTerminalAdaptationFunctions(TAF)forMobileStations(MS)".[7]GSM07.02:"Digitalcellulartelecommunicationssystem(Phase2+);TerminalAdaptationFunctions(TAF)forservicesusingasynchronousbearercapabilities".[8]GSM07.03:"Digitalcellulartelecommunicationssystem(Phase2+);TerminalAdaptationFunctions(TAF)forservicesusingsynchronousbearercapabilities".[9]GSM08.20:"Digitalcellulartelecommunicationsystem(Phase2+);RateadaptionontheBaseStationSystem-Mobile-servicesSwitchingCentre(BSS-MSC)interface".[10]CCITTRecommendationV.110:"Supportofdataterminalequipments(DTEs)withV-Seriesinterfacesbyanintegratedservicesdigitalnetwork".[11]CCITTRecommendationX.30:"SupportofX.21,X.21bisandX.20bisbasedterminalequipments(DTEs)byintegratedservicesdigitalnetwork(ISDN)".SIST EN 300 945 V7.0.3:2003



ETSIETSIEN300945V7.0.3(1999-12)7(GSM04.21version7.0.3Release1998)2.1AbbreviationsanddefinitionsAbbreviationsusedinthepresentdocumentarelistedinGSM01.04.Overalldatastream:Thedatastreaminthosepartsofthenetworkwherethedataflowisnotsplitintomultiplechannels.Substream:Streamofdatawithexplicitorimplicitnumberingbetweensplitterandcombinerfunctions.Channel:Aphysicalfullratechannelontheradiointerface(TCH/F)independentofthecontentsMultislotintermediaterate:Intermediateratepersubstreaminthosepartsofthenetworkwheretheoveralldatastreamissplitintosubstreams.Intermediaterate:Intermediaterateintheoveralldatastream.Substreamrate:Theuserrateincludingpadding,ifapplicable,ononeindividualsubstream.3GeneralapproachGSM03.10definesthePLMNconnectiontypesnecessarytosupporttheGSMPLMNdataandtelematicservices.WithintheMSthereareseveraldifferentdatarateadaptationfunctions-andaSplit/Combine-functionincaseofamultislotdataconfiguration-whicharecombinedasshowninGSM03.10aspartoftheconnectiontype.TherateadaptationfunctionsareRA0,RA1,RA2,RA1',RA1''andRA1/RA1'.TheRA0,RA1andRA2areequivalenttothosefunctionsdescribedinCCITTrecommendationV.110[11].TheRA1'functionissimilartoRA1buthasareducedbitrateoutputcompatiblewiththecodingschemeproposedfordataservicesontheradiointerface.TheRA1''functionisusedforconvertingbetweensynchronoususerratesof48and56kbit/sandtherate64kbit/s.TheequivalentfunctioninCCITTrecommendationV.110doesnothaveaname.TheRA1/RA1'isarelayfunction,usedasindicatedinGSM03.10.Inmultislotdata-configurationstheoveralldatastreamissplitintoparallelsubstreamsbetweentheSplit/Combine-functions.3.1OverviewofdataratesandconfigurationsInTable1,anoverviewofthesupportedtransparentair-interfaceuserratesisgiven.Foreachrate,alsointermediateratesperchannelbetweenBTSandMSC,overallradiointerfacerates,andchannelconfigurationsaregiven.Forsingleslotconnectionstheintermediateratesareperchannelcarryingtheoveralldatastream,whereasformultislotconnections,theintermediateratesarepersubstream.InTable2,intermediaterateswithintheMS,overallradiointerfacerates,andchannelconfigurationsaregivenfortheair-interfaceuserrates.Theintermediateratesareperoveralldatastream.Forsingleslotratesupto4,8kbit/s,theusedintermediaterateis8kbit/s,andforthe9,6kbit/ssingleslotrate16kbit/s.ForTCH/F9.6andTCH/F4.8channelcodings,themultislotintermediateratesare16and8kbit/sperTCH/F,respectively.ForTCH/F14.4channelcoding,themultislotintermediaterateis16kbit/sperTCH/F.BetweentheTEandtheSplit/Combine-functionattheMS,wheretheoveralldatastreamisnotsplit,intermediateratesof8,16,32and64kbit/sareapplicableSIST EN 300 945 V7.0.3:2003



ETSIETSIEN300945V7.0.3(1999-12)8(GSM04.21version7.0.3Release1998)Table1:AIUR/MultislotintermediateratesAirinterfaceuserrateDTE/DCEstatusesRA0RA1'/RA1RA1'/RAA'RA1'MultislotintermediaterateFrametypeRadiointerfaceratePadding≤600bit/sXX8kbit/s80bitframes3,6kbit/s1200bit/sXX8kbit/s80bitframes3,6kbit/s2,4kbit/sXX8kbit/s80bitframes3,6kbit/s4,8kbit/sXX8kbit/s80bitframes6kbit/s9,6kbit/sXX16kbit/sor2×8kbit/s80bitframes12kbit/sor2×6kbit/s14,4kbit/sXX2×16kbit/sor3×8kbit/s80bitframes2×12kbit/sor3×6kbit/sP(note1)16kbit/sNote7Note814,5kbit/s19,2kbit/sXX2×16kbit/sor4×8kbit/s80bitframes2×12kbit/sor4×6kbit/s28,8kbit/sXX3×16kbit/s80bitframes3×12kbit/s2x16kbit/sNote7Note82×14,5kbit/s38,4kbit/sXX4×16kbit/s80bitframes4×12kbit/sP(note6)3x16kbit/sNote7Note83×14,5kbit/s48kbit/sXNote2Note25×12kbit/sP(note6)4x16kbit/sNote7Note84×14,5kbit/s56kbit/sNote2Note25×12kbit/s(note3)P(note6)4x16kbit/sNote7Note84×14,5kbit/s64kbit/sNote2Note26×12kbit/s(note3)P(note1)5×14,5kbit/s(note6)P=PaddingusedSIST EN 300 945 V7.0.3:2003



ETSIETSIEN300945V7.0.3(1999-12)9(GSM04.21version7.0.3Release1998)Table2:AIUR/IntermediateratesAirinterfaceuserrateDTE/DCEstatusesRA0RA1RA1'IntermediaterateFrametypeRadiointerfaceratePadding≤600bit/sXX8kbit/s80bitframes3,6kbit/s1200bit/sXX8kbit/s80bitframes3,6kbit/s2,4kbit/sXX8kbit/s80bitframes3,6kbit/s4,8kbit/sXX8kbit/s80bitframes6kbit/s9,6kbit/sXX16kbit/s80bitframes12kbit/sor2×6kbit/s14,4kbit/sXX32kbit/s80bitframes2×12kbit/sor3×6kbit/s1x14,5kbit/sP(note1)19,2kbit/sXX32kbit/s80bitframes2×12kbit/sor4×6kbit/s28,8kbit/sXX64kbit/s80bitframes3×12kbit/s2×14,5kbit/s38,4kbit/sXX64kbit/s80bitframes4×12kbit/s3×14,5kbit/sP(note6)48kbit/sXNote4Note45×12kbit/s4×14,5kbit/sP(note6)56kbit/sNote4Note45×12kbit/s(note3)4×14,5kbit/sP(note6)64kbit/sNote5Note56×12kbit/s(note3)5×14,5kbit/sP(note1)(note6)P=PaddingusedNOTE1:Forinformationonthepaddingprocedure,pleaserefertoclause10ofthepresentdocument.NOTE2:Nomultislotintermediaterate;substreamscombinedattheBSS.NOTE3:AIUR11,2kbit/sperchannelNOTE4:ForthisrateGSM-specificrateadaptationfunctionRA1''ratherthanRA1isapplied.NOTE5:ForthisrateRA1-andRA2-adaptationsarenotapplied.NOTE6:PaddingusedasspecifiedforTCH/F14.4channelcodingsNOTE7:Atthenetworkside,RA1'/RA1notapplied;insteadaTCH/F14,4-specificadaptationRA1'/RAA'used(GSM08.20)NOTE8:A320-bitframeformatdescribedinGSM08.60.SIST EN 300 945 V7.0.3:2003



ETSIETSIEN300945V7.0.3(1999-12)10(GSM04.21version7.0.3Release1998)4TheRA0Function4.1Asynchronous-to-SynchronousConversion(RA0)TheRA0Functionisonlyusedwithasynchronousinterfaces.Incomingasynchronousdataispaddedbytheadditionofstopelementstofitthesameornearesthighersynchronousratedefinedby2tothepowern(wheren≤6)times600bit/s,14,4kbit/sor28,8kbit/s.Thusboth75bit/sand300bit/suserdatasignallingratesshallbeadaptedtoasynchronous600bit/sstream.TheresultantsynchronousstreamisfedtoRA1orRA1'.TheRA0usedinGSMisnotidenticaltothatdescribedinITU-TRecommendationV.110whichconverts14,4and28,8kbit/suserratesto19,2and38,4kbit/s,respectively.AsynchronoususerrateSynchronoususerrate≤0.6kbit/s0.6kbit/s1,2kbit/s1,2kbit/s2,4kbit/s2,4kbit/s4,8kbit/s4,8kbit/s9,6kbit/s9,6kbit/s14,4kbit/s14,4kbit/s19,2kbit/s19,2kbit/s28,8kbit/s28,8kbit/s38,4kbit/s38,4kbit/s4.2BreaksignalTheRA0shalldetectandtransmitthebreaksignalinthefollowingfashion:Iftheconverterdetects2Mto2M+3bits,allofstartpolarity,whereMisthenumberofbitspercharacterintheselectedformatincludingstartandstopsbits,theconvertershalltransmit2M+3bitsofstartpolarity.Iftheconverterdetectsmorethan2M+3bitsallofstartpolarity,theconvertershalltransmitallthesebitsasstartpolarity.The2M+3ormorebitsofstartpolarityreceivedfromthetransmittingsidesshallbeoutputtothereceivingterminal.Theterminalmusttransmitoncircuit103atleast2Mbitsstoppolarityafterthestartpolaritybreaksignalbeforesendingfurtherdatacharacter.Theconvertershallthenregaincharactersynchronismfromthefollowingstoptostarttransition.4.3Overspeed/UnderspeedARA0shallinsertadditionalstopelementswhenitsassociatedterminalistransmittingwithalowerthannominalcharacterrate.Iftheterminalistransmittingcharacterswithanoverspeedofupto1%,theasynchronous-to-synchronousconvertermaydeletestopelementsasoftenasisnecessarytoamaximumofoneforeveryeightcharactersat1%overspeed.Theconverteronthereceivingsideshalldetectthedeletedstopelementsandreinserttheminthereceiveddatastream(circuit104).Therealizationofoverspeedhandling,asdescribedabove,attheinterfacetotheassociatedterminalisimplementationdependent.Possibleimplementationsaree.g.thereductionofthelengthofthestopelementsaccordingtoV.110[9]orincreaseddataratesbetweentheTAandterminal.4.4ParityBitsPossibleparitybitsincludedintheuserdataareconsideredasdatabitsbytheRA0function(andRA1function).SIST EN 300 945 V7.0.3:2003



ETSIETSIEN300945V7.0.3(1999-12)11(GSM04.21version7.0.3Release1998)4.5FlowControlWhereapplicable,thisfunctionisasspecifiedintherelevantterminaladaptationfunctionSpecification(seeGSM07series).5TheRA1FunctionThisfunctionisusedtoadaptbetweenthesynchronoususerrates,ortheoutputoftheRA0functionandtheintermediaterateof8,16,32or64kbit/s.5.1Adaptationofsynchronousdataratesupto38,4kbit/sSynchronoususerrateIntermediaterate≤2,4kbit/s8kbit/s4,8kbit/s8kbit/s9,6kbit/s16kbit/s14,4kbit/s32kbit/s19,2kbit/s32kbit/s28,8kbit/s64kbit/s38,4kbit/s64kbit/sACCITTV.11080bitsframeisconstructedusingtheuserdatabitsreceived(fromtheRA0intheasynchronouscase),thevaluesoftheSbitsarededucedfromtheRinterface.Adaptationof600bit/sto8Kbit/sisperformedby8timesconsecutiveduplicationofeachuserdatabit.(Figure9)Adaptationof1200bit/sto8Kbit/sisperformedby4timesconsecutiveduplicationofeachuserdatabit.(Figure8)Adaptationof2400bit/sto8kbit/sisperformedby2timesconsecutiveduplicationofeachuserdatabit.(Figure7)Adaptationof4800bit/sto8Kbit/sisperformedbytransmittingthebitstreamwithnoduplication.(Figure3)Adaptationof9600bit/sto16Kbit/sisperformedbytransmittingthebitstreamwithnoduplication(theemittingperiodishalvedwithrespecttothe4800bit/scase).(Figure3)Adaptationof14400bit/sto32Kbit/sisperformedasfor3600bit/sto8kbit/s(theemittingperiodisdividedbyfourwithrespecttothe3600bit/scase).(Adaptationof3600bit/sto8kbit/sisperformedbytransmittingthebitstreamwithnoduplication.)(Figure12)Adaptationof19200bit/sto32Kbit/sisperformedasfor4800bit/sto8kbit/s(theemittingperiodisdividedbyfourwithrespecttothe4800bit/scase).(Figure3)Adaptationof28800bit/sto64Kbit/sisperformedasfor3600bit/sto8kbit/s(theemittingperiodisdividedbyeightwithrespecttothe3600bit/scase).(Figure12)Adaptationof38400bit/sto64Kbit/sisperformedasfor4800bit/s8kbit/s(theemittingperiodisdividedbyeightwithrespecttothe4800bit/scase).(Figure3)TheCCITTV.11080bitframesshowninFigures3and12areused.TheDbitsareusedtoconveytheuserdataandtheSandXbitsareusedtoconveychannelcontrolinformationaccordingtoGSM07.01.SIST EN 300 945 V7.0.3:2003



ETSIETSIEN300945V7.0.3(1999-12)12(GSM04.21version7.0.3Release1998)TheEbitsareusedtoconveythefollowinginformation:i)UserDataRate-E1,E2,E3(forsingleslotoperationseeFigure4,andformultislotoperationFigure4andsubclause10.7)ii)NetworkIndependentClocking-E4,E5,E6iii)MultiframeSynchronisation-E7Theorderoftransmissionofthe80bitframeisfromlefttorightandtoptobottom.5.1.1NetworkIndependentClockingSynchronousdatasignalsreceivedbytheMTfromtheDTEattheMSorbyIWFfromthemodemonthePSTNmaynotbesynchronizedtothePLMN.ThefollowingmethodshallbeusedtoenabletransferofthosedatasignalsandthecorrespondingbittiminginformationviatheV.110frames.SuchasituationwouldexistwherethesignalsreceivedfromthemodemattheIWFrequireitsownclockorwherethesignalsreceivedfromtheDTEattheMSemploysitsownnetworkindependentclock.Inanycase,thefrequencytoleranceoftheclocksinvolvedis100ppm.5.1.1.1MultiframeStructureThetransmittingendoftheGSMPLMNconnectionshallestablishamultiframestructureutilizingbitE7consistingoffourframesbysettingE7ineveryfourthframetobinary0.ThisstructureisidenticaltotheuseofE7inV.110(andX.30)exceptthatsuchamultiframestructurewillexistforalluserdatarates.ThisframesynchronizationwillbeachievedandmaintainedduringtheentirecallsothatcorrectionsforthenetworkindependentclockingbythereceivingendoftheGSMPLMNconnectioncanbeeasilyrecognizedandappliedbasedonthecodewords(inc1,c2,c3,c4andc5)positionedinbitsE4,E5andE6oftwoconsecutiveV.110framesasillustratedinfigure1.Thus,themultiframestructureallowsforone5-bitcodewordstobetransmittedeverytwoV.110framesforthepurposesofnetworkindependentclocking.Thetwocode-wordsmaybedifferentfromeachotherwithinthemultiframeshowninfigure1.FrameE4E5E6E7MF0ac1c210MF1ac3c4c51MF0bc1c211MF1bc3c4c51Figure1:NICMultiframeStructureOnceMultiframesynchronizationisachieved,eachcodewordisindependentlyevaluatedtodeterminethecompensationneeded,ifany.Thecompensationisappliedasexplainedinsection3.1.2inV.110framesMF1aandMF1b.5.1.1.2EncodingandcompensationTheV.110transmitterwillusethefollowing5-bitcodewords,asshowninfigure2,toindicatethefourpossiblestatesofcompensationrequiredfornetworkindependentclocking.c1c2c3c4c5Nocompensation11111Negativecompensation10010Positivecompensationofazero01001Positivecompensationofone00100Figure2:NICCodeWordsWhennegativecompensationisindicated,onelessuserdatabitthannormalistransportedintheaffectedframe(MF1aorMF1b).AnegativecompensationshallcausethereceivertodeletetheuserdatabitoccupiedbybitpositionD25,sincethetransmittersetsthistobinary1anddoesnotutilizethispositionforuserdata.Atthoseuserdatarateswheretheuserdatabitisrepeated,allcopiesofD25shallbediscarded.Incaseof80-bitframeswith36databits,bitD19isdiscardedinstead.SIST EN 300 945 V7.0.3:2003



ETSIETSIEN300945V7.0.3(1999-12)13(GSM04.21version7.0.3Release1998)Whenapositivecompensationisindicated,oneadditionaluserdatabitistransferredbymeansofthecodeword.Atthereceiver,apositivecompensationwillcauseauserdatabitofbinaryvalue0or1,asindicatedbythecodeword,tobeinsertedbetweentheuserdatabitscarriedinbitpositionsD24andD25(inMF1aorMF1b)oftheV.110frameillustratedinfigure3.Incaseof80-bitframeswith36databits,theinsertionisdonetobetweenbitsD18andD19.Whennocompensationisnecessary,orwhenNICisapplied,thevaluesofE4,E5,E6,E7,onthe4multiframeschemeis:FrameE4E5E6E7MF0a1110MF1a1111MF0b1111MF1b1111WhenNICisnotapplicable,theMSandtheIWFshalldisregardthereceivedvalueofbitsE4,E5,E6andE7inthedatatransmissionphase.NOTE:NICisnotapplicableinthefollowingcases:-transparentasynchronousbearerservices;-thefacsimileteleservicesinthetransparentmode;-everytransparentbearerserviceswheninterworkingwithanUDIInformationTransferCapability.6TheRA1''functionTheRA1''functionisusedforconvertingbetweensynchronoususerratesof48and56kbit/sandthe'intermediate'rateof64kbit/s.(RA1''isaGSM-specifictermwhichisusedfortheone-stepadaptationof48and56kbit/sratesinto64kbit/sasspecifiedinITU-TV.110.ForthepurposesofGSMspecificationstheterm'intermediaterate'isusedfortheresulting64kbit/sratealthoughthisisnotdoneinV
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