ETSI EN 300 420 V1.2.1 (2001-07)

Access and Terminals (AT); 2 048 kbit/s digital structured leased lines (D2048S); Terminal equipment interface

REN/AT-020007

Dostop in terminali (AT) - Digitalni zakupljeni vodi za prenosno hitrost 2 048 kbit/s in za strukturirane signale (D2048S) - Vmesnik terminalske opreme

General Information

• Status: Published
• Publication Date: 03-Jul-2001
• Technical Committee: AT Digital - AT Digital
• Current Stage: 12 - Completion
• Due Date: 06-Jul-2001
• Completion Date: 04-Jul-2001
• Mandate: T-147-2
• Ref Project: SIST EN 300 420 V1.2.1:2004 - Access and Terminals (AT); 2 048 kbit/s digital structured leased lines (D2048S); Terminal equipment interface

Standards Content (Sample)

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Dostop in terminali (AT) - Digitalni zakupljeni vodi za prenosno hitrost 2 048 kbit/s in za strukturirane signale (D2048S) - Vmesnik terminalske opremeAccess and Terminals (AT); 2 048 kbit/s digital structured leased lines (D2048S); Terminal equipment interface33.040.50Vodi, zveze in tokokrogiLines, connections and circuitsICS:Ta slovenski standard je istoveten z:EN 300 420 Version 1.2.1SIST EN 300 420 V1.2.1:2004en01-oktober-2004SIST EN 300 420 V1.2.1:2004SLOVENSKI
STANDARD



SIST EN 300 420 V1.2.1:2004



ETSIEN300420V1.2.1(2001-07)EuropeanStandard(Telecommunicationsseries)AccessandTerminals(AT);2048kbit/sdigitalstructuredleasedlines(D2048S);TerminalequipmentinterfaceSIST EN 300 420 V1.2.1:2004



ETSIETSIEN300420V1.2.1(2001-07)2ReferenceREN/AT-020007Keywordsdigital,leasedline,network,ONP,terminalETSI650RoutedesLuciolesF-06921SophiaAntipolisCedex-FRANCETel.:[phone]Fax:[phone]SiretN°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:[e-mail]opartmaybereproducedexceptasauthorizedbywrittenpermission.Thecopyrightandtheforegoingrestrictionextendtoreproductioninallmedia.©EuropeanTelecommunicationsStandardsInstitute2001.Allrightsreserved.SIST EN 300 420 V1.2.1:2004



ETSIETSIEN300420V1.2.1(2001-07)3ContentsIntellectualPropertyRights.5Foreword.5Introduction.61Scope.72References.73Definitionsandabbreviations.83.1Definitions.83.2Abbreviations.84Requirements.94.1Physicalcharacteristics.94.1.1Hardwiredconnection.104.1.2Alternativemeansofconnection.104.2Electricalcharacteristics.104.2.1Outputport.104.2.1.1Signalcoding.104.2.1.2Waveformshape.104.2.1.3Outputtiming.114.2.1.4Impedancetowardsground.124.2.1.5Outputjitter.124.2.1.6Outputreturnloss.124.2.1.7Outputsignalbalance.124.2.1.8Outputstructure.124.2.1.8.1CRC-4.134.2.1.8.2UseoftheE-bits.134.2.1.8.3UseoftheA-bit.134.2.1.8.4UseoftheSabits.144.2.2Inputport.144.2.2.1Signalcoding.144.2.2.2Inputreturnloss.144.2.2.3Inputlosstolerance.144.2.2.4Immunityagainstreflections.154.2.2.5Tolerablelongitudinalvoltages.154.2.2.6Impedancetowardsground.154.2.2.7Inputjittertolerance.154.2.2.8Inputclocktolerance.164.2.2.9Inputframestructure.164.2.2.9.1Framealignment.164.2.2.9.2Multiframealignment.174.3Safety.174.4Overvoltage.174.5ElectroMagneticCompatibility(EMC).17AnnexA(normative):Testmethods.18A.1General.18A.1.1Additionalinformationtosupportthetest.18A.1.2Equipmentconnection.18A.2Testmethods.19A.2.1Signalcodingattheoutputport.19A.2.2Waveformshapeatoutputport.19A.2.3Outputtiming.20A.2.4Returnlossatinputport.21A.2.5Inputlosstoleranceandimmunityagainstreflections.21SIST EN 300 420 V1.2.1:2004



ETSIETSIEN300420V1.2.1(2001-07)4A.2.6Tolerablelongitudinalvoltage,HDB3inputcoding.23A.2.7Impedancetowardsground.24A.2.8Inputandoutputjitter.24A.2.9Framestructure.26A.2.9.1OutputstructureandCRC-4generation.26A.2.9.2TerminalsnotusingtheE-bits.27A.2.9.3TerminalsusingtheE-bitstoindicateerroredSMFs.27A.2.9.4UseoftheA-bit.28A.2.10Inputframestructure.29A.2.10.1Framealignment.29A.2.10.2Multiframealignment.30AnnexB(normative):DefinitionofHDB3code.32B.1General.32B.2Definition.32AnnexC(normative):Definitionofframestructure.33C.1Framestructure.33C.2CRC-4.33C.2.1CRC-4generation.34C.2.2CRC-4monitoring.34AnnexD(normative):RequirementsTable(RT).35AnnexE(informative):Timingsynchronization.37E.1General.37E.1.1Usertiming.37E.1.2Networktiming.37E.2Furtherinformation.38AnnexF(informative):Bibliography.39History.40SIST EN 300 420 V1.2.1:2004



ETSIETSIEN300420V1.2.1(2001-07)5IntellectualPropertyRightsIPRsessentialorpotentiallyessentialtothepresentdocumentmayhavebeendeclaredtoETSI.TheinformationpertainingtotheseessentialIPRs,ifany,ispubliclyavailableforETSImembersandnon-members,andcanbefoundinETSISR000314:"IntellectualPropertyRights(IPRs);Essential,orpotentiallyEssential,IPRsnotifiedtoETSIinrespectofETSIstandards",whichisavailablefromtheETSISecretariat.LatestupdatesareavailableontheETSIWebserver(http://www.etsi.org/ipr).PursuanttotheETSIIPRPolicy,noinvestigation,includingIPRsearches,hasbeencarriedoutbyETSI.NoguaranteecanbegivenastotheexistenceofotherIPRsnotreferencedinETSISR000314(ortheupdatesontheETSIWebserver)whichare,ormaybe,ormaybecome,essentialtothepresentdocument.ForewordThisEuropeanStandard(Telecommunicationsseries)hasbeenproducedbyETSITechnicalCommitteeAccessandTerminals(AT).ThepresentdocumentresultsfromamandatefromtheCommissionoftheEuropeanCommunity(CEC)toprovidestandardsforthesupportoftheDirectiveonOpenNetworkProvision(ONP)ofleasedlines(92/44/EEC).Therearetwootherstandardsdirectlyrelatedtothepresentdocument:-EN300418:"AccessandTerminals(AT);2048kbit/sdigitalunstructuredandstructuredleasedlines(D2048UandD2048S);Networkinterfacepresentation";-EN300419:"AccessandTerminals(AT);2048kbit/sdigitalstructuredleasedlines(D2048S);Connectioncharacteristics".ThepresentdocumentisbasedoninformationfromITU-TRecommendationsandETSIpublicationsandtherelevantdocumentsarequotedwhereappropriate.NationaltranspositiondatesDateofadoptionofthisEN:29June2001DateoflatestannouncementofthisEN(doa):30September2001DateoflatestpublicationofnewNationalStandardorendorsementofthisEN(dop/e):31March2002DateofwithdrawalofanyconflictingNationalStandard(dow):31March2002SIST EN 300 420 V1.2.1:2004



ETSIETSIEN300420V1.2.1(2001-07)6IntroductionTheCouncilDirectiveontheapplicationofONPtoleasedlines(92/44/EEC)concernstheharmonizationofconditionsforopenandefficientaccessto,anduseof,theleasedlinesprovidedoverpublictelecommunicationsnetworks,andtheavailabilitythroughouttheEuropeanUnion(EU)ofaminimumsetofleasedlineswithharmonizedtechnicalcharacteristics.TheconsequenceoftheDirectiveisthattelecommunicationsorganizationswithintheEUshallmakeavailableasetofleasedlinesbetweenpointsinthesecountrieswithspecifiedconnectioncharacteristicsandspecifiedinterfaces.Twocategories(voluntaryandregulatory)ofstandardwereusedfortheinterfacesofterminalequipmentdesignedforconnectiontotheONPleasedlines.TechnicalBasisforRegulations(TBRs)gavetheearlieressentialrequirementsundertheDirective91/263/EEC,laterreplacedby98/13/EC,forattachmenttotheleasedlines,whereasothervoluntarystandards(ETSsorENs)gavethefulltechnicalspecificationsfortheseinterfaces.Thisdocument,whichisbasedonanearlierETS,belongstothesecondcategory.TherequirementsofTBR13areasubsetofthepresentdocument.Thepresentversionofthepresentdocumenthasbeenproducedtointroducesomenecessarychanges.ETS300166andITU-TRecommendationsG.703[1],G.704[2]andG.706wereusedasthebasisfortheterminalinterfaceaspectsofthepresentdocument.SIST EN 300 420 V1.2.1:2004



ETSIETSIEN300420V1.2.1(2001-07)71ScopeThepresentdocumentspecifiesthephysicalandelectricalcharacteristics(exceptsafety,overvoltageandEMCaspects),thenecessaryfunctionalcharacteristicsandthecorrespondingtestprinciplesforaterminalequipmentinterfaceforconnectiontotheNetworkTerminationPoints(NTPs)ofOpenNetworkProvision(ONP)2048kbit/sdigitalstructuredleasedlinesusing120Ωinterfaceswithaninformationtransferrateof1984kbit/swithoutrestrictiononbinarycontent.ThepresentdocumentistoensurethattheinterfaceoftheterminalequipmentiscompatiblewiththeONP2048kbit/sdigitalstructuredleasedline.AterminalequipmentinterfacethatconformstothepresentdocumentwillalsobecompatiblewithanONP2048kbit/sunstructuredleasedline.Thepresentdocumentisapplicabletoallinterfacesdesignedforconnectiontotheleasedline,howeverinthecasesofapparatusthatcarriesaparticularservice,ofcomplexapparatusandofapparatusinprivatenetworks,otherrequirementsmayapplyinadditiontothepresentdocument.CustomerpremiseswiringandinstallationbetweentheterminalequipmentandtheNTPareoutsidethescopeofthepresentdocument.2ReferencesThefollowingdocumentscontainprovisionswhich,throughreferenceinthistext,constituteprovisionsofthepresentdocument.• Referencesareeitherspecific(identifiedbydateofpublicationand/oreditionnumberorversionnumber)ornon-specific.• Foraspecificreference,subsequentrevisionsdonotapply.• Foranon-specificreference,thelatestversionapplies.[1]ITU-TRecommendationG.703(1998):"Physical/electricalcharacteristicsofhierarchicaldigitalinterfaces".[2]ITU-TRecommendationG.704(1998):"Synchronousframestructuresusedat1544,6312,2048,8448and44736kbit/shierarchicallevels".[3]ITU-TRecommendationO.151(1992):"Errorperformancemeasuringequipmentoperatingattheprimaryrateandabove".[4]ITU-TRecommendationO.171(1997):"Timingjitterandwandermeasuringequipmentfordigitalsystemswhicharebasedontheplesiochronousdigitalhierarchy(PDH)".[5]ETSIEN300418:"AccessandTerminals(AT);2048kbit/sdigitalunstructuredandstructuredleasedlines(D2048UandD2048S);Networkinterfacepresentation".[6]ETSIEN300419:"AccessandTerminals(AT);2048kbit/sdigitalstructuredleasedlines(D2048S);Connectioncharacteristics".SIST EN 300 420 V1.2.1:2004



ETSIETSIEN300420V1.2.1(2001-07)83Definitionsandabbreviations3.1DefinitionsForthepurposesofthepresentdocument,thefollowingtermsanddefinitionsapply:erroredSub-MultiFrame:Sub-MultiFrame(SMF)wherethecalculatedCyclicRedundancyCheck-4bit(CRC-4)doesnotcorrespondwiththeCRC-4containedwithinthenextSMF(seeclauseC.2.2)frame:sequenceof256bitsofwhichthefirst8bitsdefinetheframestructure(seeannexC)leasedlines:telecommunicationsfacilitiesprovidedbyapublictelecommunicationsnetworkthatprovidedefinedtransmissioncharacteristicsbetweenNTPsandthatdonotincludeswitchingfunctionsthattheusercancontrol,(e.g.on-demandswitching)multiframe:sequenceoftwoSMFscontainingthemultiframealignmentword(seeannexC)NetworkTerminationPoint(NTP):physicalconnectionsandtheirtechnicalaccessspecificationswhichformpartofthepublictelecommunicationsnetworkandarenecessaryforaccesstoandefficientcommunicationthroughthatpublicnetworkPRBS(215-1):PseudoRandomBitSequence(PRBS)(asdefinedinclause2.1ofITU-TRecommendationO.151[3])Sabits:bits4to8(bitsSa4toSa8)inframesnotcontainingtheframealignmentsignal(seeannexC)Sub-Multiframe(SMF):sequenceof8frames,eachof256bits,overwhichtheCRC-4iscalculated(seeannexC)terminalequipment:equipmentintendedtobeconnectedtothepublictelecommunicationsnetwork,i.e.:-tobeconnecteddirectlytotheterminationofapublictelecommunicationnetwork;or-tointerworkwithapublictelecommunicationsnetworkbeingconnecteddirectlyorindirectlytotheterminationofapublictelecommunicationsnetwork,inordertosend,process,orreceiveinformation.3.2AbbreviationsForthepurposesofthepresentdocument,thefollowingabbreviationsapply:AISAlarmIndicationSignalAMIAlternateMarkInversionCRC-4CyclicRedundancyCheck-4bitD2048S2048kbit/sdigitalstructuredleasedlinedcdirectcurrentEMCElectroMagneticCompatibilityHDB3HighDensityBipolarcodeoforder3(seeannexB)ISDNIntegratedServicesDigitalNetworkNTPNetworkTerminationPointONPOpenNetworkProvisionppmpartspermillionPRBSPseudoRandomBitSequenceRAIRemoteAlarmIndicationrmsrootmeansquareRTRequirementsTableRXRXisasignalinput(ateithertheterminalequipmentinterfaceorthetestequipment,seefigure1)SDHSynchronousDigitalHierarchySMFSub-MultiFrameTXTXisasignaloutput(ateithertheterminalequipmentinterfaceorthetestequipment,seefigure1)UIUnitIntervalSIST EN 300 420 V1.2.1:2004



ETSIETSIEN300420V1.2.1(2001-07)94RequirementsTheterminalequipmentinterfaceisforusewith2048kbit/sstructuredleasedlinesthatprovidebi-directional,point-to-pointdigitalconnectionswithaninformationtransferrateof1984kbit/swithoutrestrictiononbinarycontent.Anystructuringofthedatawithinthetransparent1984kbit/spartoftheframeistheresponsibilityoftheuser.4.1PhysicalcharacteristicsCurrentlynostandardizedconnectorisreadilyavailable.Consequently,theonlymethodofconnectionthatcanbespecifiedinthepresentdocumentistheuseofsolidconductorsof0,4mmto0,6mm.Thepresentdocumentrequirestheterminalequipmenttobecapableofpresentingeitherapointfortheattachmentofunterminatedsolidconductors,orsolidconductorsthemselves(seeclause4.1.1).Itisarequirementthatsuchaconnectionmethodbeavailabletobeprovidedforusewiththeterminalequipmentifnecessary.Inordertoallowconnectiontobemadeusingothermethods(e.g.connectors),theterminalequipmentispermittedtobesuppliedwithaconnectionmethodsuitableforusewiththosemethods(seeclause4.1.2).NOTE1:Thefollowingareexamplesofarrangementsthatcomplywiththerequirements.Thelistbelowshouldnotberegardedasanexhaustivelistofallpermittedarrangements:a)acord,permanentlyconnectedtotheterminalequipmentatoneendandunterminatedattheotherend,withwiresthataresolidconductorswithdiametersintherange0,4mmto0,6mm;b)acord,connectedviaaplugandsockettotheterminalequipmentatoneendandunterminatedattheotherend,withwiresthataresolidconductorswithdiametersintherange0,4mmto0,6mm;c)aninsulationdisplacementconnector,designedtoacceptwireswithsolidconductorswithdiametersintherange0,4mmto0,6mm,butwithnocord;d)ascrewconnector,designedtoacceptwireswithsolidconductorswithdiametersintherange0,4mmto0,6mm,butwithnocord;e)thearrangementinb)plusoneormoreadditionalalternativecordswiththesameplugorsocketarrangementattheterminalendandanyplugorsocketattheotherend;f)thearrangementinc)ord)plusoneormorecordssuitableforconnectiontotheterminalequipmentatoneendandanyplugorsocketattheotherend.Thetransmitpairistheoutputfromtheterminalequipmentinterface.Thereceivepairistheinputtotheterminalequipmentinterface,asshowninfigure1.Wheretheterms"output"and"input"areusedwithoutqualificationinthepresentdocument,theyrefertotheterminalequipmentinterface.NetworkInterfaceTXRXRXTXTerminalEquipmentOutputInputOutputInputFigure1NOTE2:TheuseofashieldedcordorcablemaybenecessarytomeetradiationandimmunityrequirementsdefinedinElectroMagneticCompatibility(EMC)standards.SIST EN 300 420 V1.2.1:2004



ETSIETSIEN300420V1.2.1(2001-07)104.1.1HardwiredconnectionRequirement:theterminalequipmentshallprovide:a)asetofconnectioncontacts(e.g.aninsulationdisplacementconnectororascrewterminalblock)towhichsolidwireconductorswithdiametersintherange0,4mmto0,6mmmaybeconnected;orb)awiringarrangementconnectedbyanymeanstotheterminalequipment,withunterminatedsolidwireconductorswithdiametersintherange0,4mmto0,6mmattheenddistantfromtheterminalequipment.Test:thereisnotest.Allsubsequenttestsarecarriedoutviathespecifiedconnectionmethod.4.1.2AlternativemeansofconnectionAnyalternativemeansofconnectionmaybeprovidedinadditiontotheconnectionarrangementsunderclause4.1.1.4.2Electricalcharacteristics4.2.1Outputport4.2.1.1SignalcodingRequirement:thesignaltransmittedattheoutputportshallcomplywiththeHighDensityBipolarcodeoforder3(HDB3)encodingrules(seeannexB).Test:thetestshallbeconductedaccordingtoclauseA.2.1.4.2.1.2WaveformshapeRequirement:thepulseattheoutputportshallcomplywiththerequirementsgivenintable1andfigure2,basedonITU-TRecommendationG.703[1].Table1:WaveformshapeatoutputportPulseshape(nominallyrectangular)Allmarksofavalidsignalshallconformtothemask(seefigure2)irrespectiveofthepolarity.ThevalueVcorrespondstothenominalpeakvoltageofamark.Testloadimpedance120Ωnon-reactiveNominalpeakvoltageVofamark3VPeakvoltageofaspace0±0,3VNominalpulsewidth244nsRatiooftheamplitudesofpositiveandnegativepulsesatthecentreofthepulseinterval0,95to1,05Ratioofthewidthsofpositiveandnegativepulsesatthenominalhalfamplitude0,95to1,05SIST EN 300 420 V1.2.1:2004



ETSIETSIEN300420V1.2.1(2001-07)11269ns194ns(244-50)V=100%50%0%10%10%10%10%20%244ns219ns(244-25)488ns(244+244)Nominalpulse20%20%10%10%(244+25)Figure2:Pulsemaskfor2048kbit/spulseTest:thetestshallbeconductedaccordingtoclauseA.2.2.4.2.1.3OutputtimingThisrequirementissuchthattheterminalequipmentiscapableofoperatingwhenconnectedtoleasedlinescapableofcarryingusertimingwithintherange2048kbit/s±50partspermillion(ppm)andwhenconnectedtoleasedlinesthatprovidetimingthatissynchronoustothenetworktiming.ForfurtherinformationseeannexE.Requirement:theterminalequipmentshallhave:a)aninternalclockwhichshallprovideabitrateattheoutputportwithinthelimitsof2048kbit/s±50ppm;andb)thecapabilitytoprovideaclockloopsuchthatthesignaltimingattheoutputportisderivedfromthetimingattheinputport.Theterminalequipmentmayalsohave:c)anexternalreferencesignalinputfromwhichtheoutputtimingmaybederived.Test:forcasea)thetestshallbeconductedaccordingtoclauseA.2.3.Thecapabilitytoprovideaclockloop,caseb),andthederivationofaclocksignalfromanexternalreferencesignalinput,casec),arecoveredbythetestofclauseA.2.8.SIST EN 300 420 V1.2.1:2004



ETSIETSIEN300420V1.2.1(2001-07)124.2.1.4ImpedancetowardsgroundRequirement:wheretheterminalequipmenthasaground,theimpedancetowardsgroundoftheoutputportshallbegreaterthan1000Ωforfrequenciesintherange10Hzto1MHzwhenmeasuredwithasinusoidaltestvoltageof2Vrootmeansquare(rms).Forthepurposeofthisrequirement,groundshallbetheterminalequipmentcommonreferencepointortestreferencepoint.NOTE:Thisrequirementisincludedtoallowtransformerlessimplementations.Test:thetestshallbeconductedaccordingtoclauseA.2.7.4.2.1.5OutputjitterRequirement:thepeak-to-peakoutputjittershallnotexceedthelimitsoftable2whenmeasuredwithabandpassfilterwithlinearcut-offwiththedefinedcut-offfrequencies.Atfrequenciesbelowthelower3dBpoint,theattenuationofthehighpassfiltershallrisewithavalueequalto20dBperdecade.Atfrequenciesabovetheupper3dBpoint,theattenuationofthelowpassfiltrationshallrisewithavaluegreaterthan,orequalto,60dBperdecade.Forthepurposeoftesting,anysignalinputfromwhichtheoutputtimingisderivedshallbeprovidedwiththemaximumtolerableinputjitter,andwiththemaximumtolerableinputfrequencydeviation,asspecifiedbythemanufacturer.Wheretheoutputtimingoftheterminalequipmentistakenfromtheleasedline,theinputtotheterminalequipmentshallbeprovidedwithcomponentsofsinusoidaljitteratpointsonthecurveoffigure3andtable4.NOTE:Aseparaterequirementforoutputjitteratfrequenciesbelow40Hzisnotrequiredbecausethemeasurementfilterwithafirstorderlowercut-offwillallowthejittertohaveaspectrumwhoseamplituderisesat20dB/decadeasthefrequencyreducesbelow40Hz.Wheretimingistakenfromtheleasedline,thetestusesinputjitterfrequenciesfrom20Hzupwards.Table2:MaximumoutputjitterMeasurementfilterbandwidthOutputjitterLowercut-off(highpass)Uppercut-off(lowpass)UnitInterval(UI)peak-to-peak(maximum)40Hz100kHz0,11UITest:thetestshallbeconductedaccordingtoclauseA.2.8.4.2.1.6OutputreturnlossTherearenorequirementsforoutputreturnlossunderthepresentdocument.NOTE:Arequirementforoutputreturnlossmaybeaddedtothepresentdocumentwhenappropriatespecificationsbecomeavailable.4.2.1.7OutputsignalbalanceTherearenorequirementsforoutputsignalbalanceunderthepresentdocument.NOTE:TheeffectsoftheoutputsignalimbalancearecoveredundertheEMCDirective(89/336/EEC).4.2.1.8OutputstructureRequirement:thebitstreamtransmittedattheoutputoftheterminalequipmentshallbestructuredasdefinedinclauseC.1.Test:thetestshallbeconductedaccordingtoclauseA.2.9.1.SIST EN 300 420 V1.2.1:2004



ETSIETSIEN300420V1.2.1(2001-07)134.2.1.8.1CRC-4Requirement:theCRC-4bitstransmittedattheoutputoftheterminalequipmentshallbeasdefinedintablesC.1andC.2andclauseC.2.1ofannexCandshallcorrespondtothedatatransmittedattheoutputoftheterminalequipment.Test:thetestshallbeconductedaccordingtoclauseA.2.9.1.4.2.1.8.2UseoftheE-bitsTheterminalequipmentshallcomplyeitherwithclause4.2.1.8.2.1orclause4.2.1.8.2.2.4.2.1.8.2.1TerminalsnotusingtheE-bitsThisclauseisapplicabletothoseterminalequipmentswhichdonotusetheE-bitstoindicateerroredSMFs.Requirement:bothE-bitstransmittedattheoutputoftheterminalequipmentshallbesettobinaryONEinallinstances.Test:thetestshallbeconductedaccordingtoclauseA.2.9.2.4.2.1.8.2.2TerminalsusingtheE-bitstoindicateerroredSMFsThisclauseisapplicabletothoseterminalequipmentswhichusetheE-bitstoindicateerroredSMFs.Requirement:theE-bitstransmittedattheoutputoftheterminalequipmentshallindicateerroredSMFsintheinputbitstream.OneE-bitinamultiframeshallbesettobinaryZEROforeacherroredSMFreceivedintheinputbitstream.TheE-bitscorrespondingtonon-erroredSMFsshallbesettobinaryONE.AnydelaybetweenthedetectionofanerroredSMFandthesettingoftheE-bitthatindicatestheerroredSMFshallbelessthan1second.Test:thetestshallbeconductedaccordingtoclauseA.2.9.3.4.2.1.8.3UseoftheA-bitTheterminalequipmentshallcomplyeitherwithclause4.2.1.8.3.1orclause4.2.1.8.3.2.4.2.1.8.3.1TerminalsnotusingtheA-bitRequirement:theA-bittransmittedattheo
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