Transmission and Multiplexing (TM); The control of jitter and wander in transport networks

DEN/TM-01067

Prenos in multipleksiranje (TM) – Obvladovanje trepetanja in zdrsavanja v prenosnih omrežjih

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Publication Date
28-Feb-2000
Current Stage
12 - Completion
Due Date
04-Feb-2000
Completion Date
29-Feb-2000

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2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Prenos in multipleksiranje (TM) – Obvladovanje trepetanja in zdrsavanja v prenosnih omrežjihTransmission and Multiplexing (TM); The control of jitter and wander in transport networks33.040.20Prenosni sistemTransmission systemsICS:Ta slovenski standard je istoveten z:EN 302 084 Version 1.1.1SIST EN 302 084 V1.1.1:2003en01-december-2003SIST EN 302 084 V1.1.1:2003SLOVENSKI
STANDARD



SIST EN 302 084 V1.1.1:2003



ETSIEN302084V1.1.1(2000-02)EuropeanStandard(Telecommunicationsseries)TransmissionandMultiplexing(TM);ThecontrolofjitterandwanderintransportnetworksSIST EN 302 084 V1.1.1:2003



ETSIETSIEN302084V1.1.1(2000-02)2ReferenceDEN/TM-01067Keywordscontrol,performance,transmission,synchronization,interface,transportETSIPostaladdressF-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 302 084 V1.1.1:2003



ETSIETSIEN302084V1.1.1(2000-02)3ContentsIntellectualPropertyRights.5Foreword.5Introduction.51Scope.62References.63Definitionsandabbreviations.73.1Definitions.73.2Abbreviations.84Networkwanderspecification.94.1Wanderreferencemodel.94.2SpecificationofwanderbyMRTIEparameter.105Networklimitsforoutputjitterandwander.105.1Networklimitsforoutputjitter.105.2Networklimitsforoutputwander.115.2.12048kbit/sinterfaceoutputwanderlimit.125.2.234368kbit/sinterfaceoutputwanderlimit.135.2.3139264kbit/sinterfaceoutputwanderlimit.135.2.4STM-Ninterfaceoutputwanderlimit.146Jitterandwandertoleranceofequipmentinterfaces.146.164kbit/sinputjitterandwandertolerance.156.22048kbit/sinputjitterandwandertolerance.166.38448kbit/sinputjitterandwandertolerance.176.434368kbit/sinputjitterandwandertolerance.186.5139264kbit/sinputjitterandwandertolerance.196.6STM-Ninputjitterandwandertolerance.20AnnexA(informative):WanderlimitconsiderationsforSDHtransportnetworks.24A.1Introduction.24A.1.1WanderreferencemodelforSDH.24A.1.2Sourcesofwander.25A.1.3Wanderaccumulationlimitingeffects.25A.1.4Networkconfigurationandperformance.25A.1.5Correlationofwandersources.26A.1.6Networkconditionsfortheoutputwanderlimits.26A.2Derivationofwanderspecificationlimits.26AnnexB(informative):Measurementmethodologiesforoutputwander.28B.1Synchronizationinterfaces.28B.1.1Synchronoussignals(SDHandPDHbit-rates).28B.2Trafficinterfaces.28B.2.1Synchronoussignals(PDHbit-rates).29B.2.2Asynchronoussignals(PDHbit-rates).29B.2.2.1Asynchronoussignals,sourcereferenceclockavailable.29B.2.2.2Asynchronoussignals,sourcereferenceclockunavailable.30SIST EN 302 084 V1.1.1:2003



ETSIETSIEN302084V1.1.1(2000-02)4AnnexC(informative):Measurementguidelinesforinputjitterandwandertoleranceofequipmentinterfaces.32AnnexD(informative):Relationbetweenparametersforinputjittertoleranceandoutputjitterlimits.34History.36SIST EN 302 084 V1.1.1:2003



ETSIETSIEN302084V1.1.1(2000-02)5IntellectualPropertyRightsIPRsessentialorpotentiallyessentialtothepresentdocumentmayhavebeendeclaredtoETSI.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)hasbeenproducedbyETSITechnicalCommitteeTransmissionandMultiplexing(TM).NationaltranspositiondatesDateofadoptionofthisEN:21January2000DateoflatestannouncementofthisEN(doa):30April2000DateoflatestpublicationofnewNationalStandardorendorsementofthisEN(dop/e):31October2000DateofwithdrawalofanyconflictingNationalStandard(dow):31October2000IntroductionInatransportnetwork,jitterandwanderaccumulateondatapathsaccordingtothejitterandwandergenerationandtransfercharacteristicsofeachequipmentinterconnected.Theseequipmentsmaybedifferenttypesofmultiplexers/demultiplexers,cross-connectsandlinesystems,forexample.Anexcessiveamountofjitterandwandercanadverselyaffectbothdigitalsignals(e.g.bygenerationofbiterrors,uncontrolledslipsandotherabnormalities)andanaloguesignals(e.g.byunwantedphasemodulationofthetransmittedsignal).Theconsequencesofsuchimpairmentwill,ingeneral,dependontheparticularservicethatisbeingcarriedandtheterminatingoradaptationequipmentinvolved.Itisthereforenecessarytosetlimitsonthemagnitudeofjitterandwanderatnetworkinterfaces,inordertoguaranteeaproperqualityofthetransmittedsignalsandaproperdesignoftheequipment.Thejitterandwandercontrolphilosophyofthepresentdocumentisbasedontheneed:•tospecifyamaximumnetworklimitofjitterandwanderthatshouldnotbeexceededatanyrelevantinterface;•tospecifyaminimumequipmenttolerancetojitterandwanderthatshouldbeprovidedatanyrelevantinterface;•toestablishaconsistentframeworkforthespecificationofindividualdigitalequipmenttypes;and•toprovidesufficientinformationandguidelinesfororganizationstomeasureandstudyjitterandwandercharacteristicsinanynetworkconfiguration.SIST EN 302 084 V1.1.1:2003



ETSIETSIEN302084V1.1.1(2000-02)61ScopeThepresentdocumentspecifiestherelevantparametersandtheirlimitingvaluesthatareabletosatisfactorilycontroltheamountofjitterandwanderpresentatsynchronousdigitalhierarchy(SDH)andplesiochronousdigitalhierarchy(PDH)network-networkinterfaces(NNI).ThepresentdocumentalsoprovidestheminimumjitterandwanderrequirementsatSDHandPDHuser-networkinterfaces(UNI).However,particularterminalsorservicesmayhaveadditionaljitterandwanderrequirementsandinthosecasestherelevantstandardsapply.Thejitterandwanderrequirementsspecifiedinthepresentdocumentareapplicabletotheinterfacesirrespectiveofthetransportmechanism(PDH,SDHorATMnetworks,forexample).Thejitterandwanderrequirementsforaninterfacewillbedifferent,dependingonwhetherthesignalattheinterfaceisusedtotransportdataonly,orsynchronizationaswell.TherequirementsforsynchronizationinterfacesarespecifiedinEN300462-3-1[7]andreferenceismadetothatdocumentwhereappropriate.ThepresentdocumentalsospecifiesthejitterandwanderrequirementsforinterfacesusingthegenericframestructuresatPDHratesasdescribedinETS300337[3].TheelectricalcharacteristicsoftherelevantnetworkinterfacesforSDHandPDHinterfacesaredescribedinspecificationETS300166[1]andthecharacteristicsofSDHopticalinterfacesaredescribedinspecificationETS300232[2].2ReferencesThefollowingdocumentscontainprovisions,which,throughreferenceinthistext,constituteprovisionsofthepresentdocument.•Referencesareeitherspecific(identifiedbydateofpublication,editionnumber,versionnumber,etc.)ornon-specific.•Foraspecificreference,subsequentrevisionsdonotapply.•Foranon-specificreference,subsequentrevisionsdoapply.•Anon-specificreferencetoanETSshallalsobetakentorefertolaterversionspublishedasanENwiththesamenumber.[1]ETS300166:"TransmissionandMultiplexing(TM);Physicalandelectricalcharacteristicsofhierarchicaldigitalinterfacesforequipmentusingthe2048kbit/s-basedPlesiochronousorSynchronousDigitalHierarchies".[2]ETS300232:"TransmissionandMultiplexing(TM);OpticalinterfacesforequipmentsandsystemsrelatingtotheSynchronousDigitalHierarchy[ITU-TRecommendationG.957(1993),modified]".[3]ETS300337:"TransmissionandMultiplexing(TM);Genericframestructuresforthetransportofvarioussignals(includingAsynchronousTransferMode(ATM)cellsandSynchronousDigitalHierarchy(SDH)elements)attheITU-TRecommendationG.702hierarchicalratesof2048kbit/s,34368kbit/sand139264kbit/s".[4]EN300417-1-1:"TransmissionandMultiplexing(TM);Genericrequirementsoftransportfunctionalityofequipment;Part1-1:Genericprocessesandperformance".[5]EN300462-1-1:"TransmissionandMultiplexing(TM);Genericrequirementsforsynchronizationnetworks;Part1-1:Definitionsandterminologyforsynchronizationnetworks".[6]EN300462-2-1:"TransmissionandMultiplexing(TM);Genericrequirementsforsynchronizationnetworks;Part2-1:Synchronizationnetworkarchitecture".SIST EN 302 084 V1.1.1:2003



ETSIETSIEN302084V1.1.1(2000-02)7[7]EN300462-3-1:"TransmissionandMultiplexing(TM);Genericrequirementsforsynchronizationnetworks;Part3-1:Thecontrolofjitterandwanderwithinsynchronizationnetworks".[8]EN300462-4-1:"TransmissionandMultiplexing(TM);Genericrequirementsforsynchronizationnetworks;Part4-1:TimingcharacteristicsofslaveclockssuitableforsynchronizationsupplytoSynchronousDigitalHierarchy(SDH)andPlesiochronousDigitalHierarchy(PDH)equipment".[9]EN300462-5-1:"TransmissionandMultiplexing(TM);Genericrequirementsforsynchronizationnetworks;Part5-1:TimingcharacteristicsofslaveclockssuitableforoperationinSynchronousDigitalHierarchy(SDH)equipment".[10]EN300462-6-1:"TransmissionandMultiplexing(TM);Genericrequirementsforsynchronizationnetworks;Part6-1:Timingcharacteristicsofprimaryreferenceclocks".[11]ITU-TRecommendationG.803:"Architectureoftransportnetworksbasedonthesynchronousdigitalhierarchy(SDH)".[12]ITU-TRecommendationO.150:"Generalrequirementsforinstrumentationforperformancemeasurementsondigitaltransmissionequipment".[13]ITU-TRecommendationO.171:"Timingjitterandwandermeasuringequipmentfordigitalsystemswhicharebasedontheplesiochronousdigitalhierarchy(PDH)".[14]ITU-TRecommendationO.172:"Jitterandwandermeasuringequipmentfordigitalsystemswhicharebasedonthesynchronousdigitalhierarchy(SDH)".[15]ITU-TRecommendationG.703:"Physical/electricalcharacteristicsofhierarchicaldigitalinterfaces".3Definitionsandabbreviations3.1DefinitionsForthepurposesofthepresentdocument,thefollowingtermsanddefinitionsapply.AdditionaldefinitionsrelatingtosynchronizationnetworksareprovidedinEN300462-1-1[5],whilstthearchitecturalprinciplesofsynchronizationnetworksaredescribedinEN300462-2-1[6].trafficinterface:theseinterfacesmaybesynchronous(i.e.normallyPRC-traceable)orasynchronous(e.g.meetingthefrequencyoffsetrequirementsofETS300166[1]).NetworkjitterandwanderlimitsarespecifiedinthepresentdocumentandwanderisspecifiedusingtheMRTIE(MaximumRelativeTimeIntervalError)parameter.Inputjitterandwandertoleranceisalsospecifiedinthepresentdocument.Thisinterfacecategorycanbefurthersub-dividedasfollows:•interfaceisnotabletoprovidesynchronization,andisnotrequiredto.Anexampleisaninterfacesupportingonly34368kbit/sor139264kbit/sPDHsignalsaccordingtoETS300166[1];•interfaceisnotabletoprovidesynchronizationatthedefinedperformancelevel,butneverthelessisusedtoprovidetimingtoothernetworkelementssuchasterminalequipment,remoteconcentrators,etc.Examplesinclude2048kbit/s,34368kbit/sand139264kbit/sPDHsignalsandleasedlinestransportedonSDH,whichmaybesubjecttopointerjustifications.ITU-TRecommendationG.803[11]recommendsthattheseinterfacesarenotusedforsynchronization,butinsomenetworkapplicationsthereislittlealternative;•interfaceisabletoprovidesynchronizationatthedefinedperformancelevel,inwhichcaseitisdefinedtobeasynchronizationinterface.AnexampleisSTM-Ninterfaces.Thissub-categorymayalsoincludeinterfacesusingthegenericframestructuresatPDHratesasdescribedinETS300337[3].SIST EN 302 084 V1.1.1:2003



ETSIETSIEN302084V1.1.1(2000-02)8synchronizationinterface:theseinterfacesaresynchronous(i.e.normallyPRC-traceable)andtheirrequirementsarenotspecifiedinthepresentdocument.ThenetworklimitsforsynchronizationinterfacesarespecifiedusingMTIE(MaximumTimeIntervalError)andTDEV(TimeDeviation)parameterswithvaluesgiveninEN300462-3-1[7].TheinputjitterandwandertoleranceofclockequipmentportsisspecifiedinEN300462-4-1[8](forequipmentcontaininganSSUfunction)andEN300462-5-1[9](forequipmentcontaininganSECfunction).3.2AbbreviationsForthepurposesofthepresentdocument,thefollowingabbreviationsapply.AdditionalabbreviationsrelatingtosynchronizationnetworksareprovidedinEN300462-1-1[5].ATMAsynchronousTransferModeCMICodedMarkInversionMRTIEMaximumRelativeTimeIntervalErrorMS-AISMultiplexSectionAlarmIndicationSignalMTIEMaximumTimeIntervalErrorNENetworkElementNNINetwork-NetworkInterfacePDHPlesiochronousDigitalHierarchypk-pkpeak-to-peakPLLPhaseLockedLoopppmpartspermillionPRBSPseudo-RandomBinarySequencePRCPrimaryReferenceClockRTIERelativeTimeIntervalErrorSDHSynchronousDigitalHierarchySECSDHEquipmentClockSSUSynchronizationSupplyUnitSTM-1eSynchronousTransportModule,level1(electricalformatCMI-encodedsignal)STM-NSynchronousTransportModule,levelNTDEVTimeDeviationTIETimeIntervalErrorUIUnitIntervalUIppUnitInterval,peak-to-peakUNIUser-NetworkInterfaceVC-nVirtualContainer,levelnSIST EN 302 084 V1.1.1:2003



ETSIETSIEN302084V1.1.1(2000-02)94Networkwanderspecification4.1WanderreferencemodelWanderisalwaysspecifiedandmeasuredasaRelativeTimeIntervalError(RTIE)betweenthesignalofinterestandsomereferenceclock.However,thereferenceclockagainstwhichtheRTIEisspecifiedormeasureddependsonthetypeofsignalofinterest.Forthepurposesofthepresentdocument,twocasescanbedistinguished.1)AsynchronousPDHconnectionTheappropriatereferenceforspecifyingtheoutputwanderofasynchronousPDHsignalsisthesignalsourceitself.Formeasurementpurposes,sincethatsourceisnotnormallyavailableforuseasthereferenceclock,itcanbesubstitutedbyasuitably-filteredversionoftheoutputsignal.AnnexBhasfurtherinformationregardingthis.Thereferencemodelisillustratedinfigure1.CLKPDHsignalsourceTransportNetworkOutputwanderRTIENOTE:CLKfrequencyoffsetconformstobit-ratespecificationsofITU-TRecommendationG.703[15].Figure1:WanderreferencemodelforasynchronousPDHconnection2)SynchronousPDHconnectionTheappropriatereferenceforspecifyingtheoutputwanderofsynchronousPDHsignals(i.e.most2048kbit/ssignalsaswellassignalsframedaccordingtoETS300337[3])isthenetworkclockreferenceusedatthePDHsignaltermination.Thismeansthatthewanderoftworeferenceclockdistributionnetworksisaddedtotheoutputwandergeneratedbythetransportnetwork.Thereferencemodelisillustratedinfigure2.SSUPDHsignalsourceTransportNetworkOutputwanderSSURTIENOTE1:SSUoutputsconformtoEN300462-3-1[7]networkwanderlimit.NOTE2:BothSSUsaretraceabletoaPRC(butnotnecessarilythesamePRC).Figure2:WanderreferencemodelforsynchronousPDHconnectionSIST EN 302 084 V1.1.1:2003



ETSIETSIEN302084V1.1.1(2000-02)10Althoughforcases1and2,differentwandersourcescontributetothetotaloutputwander,theresultingmeasuredRTIEwillnotbeverydifferent.Thisisduetoalackofcorrelatingeffectsandbecausestatistically-speakingthetransportnetworkwanderisthedominantsourcecomparedwiththesynchronizationnetworkwander.Consequentlythesamenetworklimitshavebeensetforbothcasesinthefollowingoutputwanderspecifications.ThewanderspecificationsofthepresentdocumentareconsistentwiththederivationoflimitsoutlinedforthecaseofSDHnetworktransportinannexA.4.2SpecificationofwanderbyMRTIEparameterThereareseveralparametersinuseforspecifyingwanderinstandardspecifications,suchasMTIEandTDEV.Forthepurposesofthepresentdocument,MRTIE(MaximumRelativeTimeIntervalError)hasbeenselectedbecauseitismostsuitabletoallowderivationofconsequentequipmentperformancespecifications.Forasynchronouspayloads(refertofigure1)theMRTIEspecifiesthewanderaccumulatedbythenetworkrelativetotheinputsignalphase.Thisisreasonablebecauseitprovidesinformationfordesigningthefilterrequiredforanyfilteringofthetransportedsignalclockinordertoachievetherequiredphasestabilityofthepayload.Forsynchronouspayloads(refertofigure2)theMRTIEspecifiesthewanderofthepayloadoutputrelativetotheclockphaseofaninputbuffer(e.g.locatedinanexchange).Thisisreasonablebecauseitprovidesinformationfordesigningthebuffersize.MeasurementmethodologiesusedtomeasuretheMRTIEparameteraredescribedinannexB.5Networklimitsforoutputjitterandwander5.1NetworklimitsforoutputjitterThelimitsgivenintable1representthemaximumpermissiblelevelsofjitteratinterfaceswithinadigitalnetwork.Jitterasmeasuredovera60secondintervalshallnotexceedthelimitsgivenintable1,whenusingthespecifiedmeasurementbandwidths.Thelimitsshallbemetforalloperatingconditionsandregardlessoftheamountofequipmentprecedingtheinterface.Ingeneral,thesenetworklimitsarecompatiblewiththeminimumtolerancetojitterthatallequipment-inputportsarerequiredtoprovide.Thereisacloserelationshipbetweennetworklimitsandinputtolerancesuchthatintermsofspecification,thefrequencybandwidthusedformeasurementandthefrequencybreakpointsusedfortolerance,aredefinedusingthesamefrequencies.Inotherwords,thejittermeasurementfiltercut-offfrequenciesusedintable1havethesamevaluesasthejittertolerancemaskcornerfrequenciesusedinclause6.AnnexDprovidesfurtherinformationaboutthisrelationship.ThefunctionaldescriptionformeasuringoutputjitteratadigitalinterfacecanbefoundinITU-TRecommendationO.172[14].Thehigh-passmeasurementfiltersoftable1haveasingle-ordercharacteristicandaroll-offof20dB/decade.Thelow-passmeasurementfiltershaveamaximally-flat,Butterworthcharacteristicandaroll-offof60dB/decade.FurtherspecificationsforthefrequencyresponseofthejittermeasurementfunctionsuchasmeasurementfilteraccuracyandadditionalallowedfilterpolesaregiveninITU-TRecommendationO.172[14].InstrumentationinaccordancewithITU-TRecommendationsO.172[14]andO.171[13]isappropriateformeasurementofjitterinSDHandPDHsystems,respectively.ITU-TRecommendationO.172[14]includestestsetspecificationsforthemeasurementofSDHtributariesoperatingatPDHbit-rates,wherethetestsetrequirementsaremorestringentthanthoserelatingonlytoPDHsystems.Therefore,instrumentationinaccordancewithITU-TRecommendationO.172[14]shallbeusedatPDHinterfacesinSDHsystems.SIST EN 302 084 V1.1.1:2003



ETSIETSIEN302084V1.1.1(2000-02)11Table1:MaximumpermissiblejitteratinterfacesInterfaceMeasurementbandwidth,-3dBfrequencies(Hz)Peak-to-peakamplitude(UIpp)64kbit/s20to20k0,25(note1)3kto20k0,052048kbit/s20to100k1,518kto100k(note2)0,28448kbit/s20to400k1,53kto400k(note2)0,234368kbit/s100to800k1,510kto800k0,15139264kbit/s200to3,5M1,510kto3,5M0,075STM-1e500to1,3M1,5(note3)65kto1,3M0,075STM-1500to1,3M1,565kto1,3M0,15STM-41kto5M1,5250kto5M0,15STM-165kto20M1,51Mto20M0,15STM-6420kto80M1,54Mto80M(note4)NOTE1:Fortheco-directionalinterfaceonly.NOTE2:For2048kbit/sand8448kbit/sinterfaceswithinthenetworkofanoperator,thehigh-passcut-offfrequencymaybespecifiedtobe700Hz(insteadof18kHz)and80kHz(insteadof3kHz)respectively.However,atinterfacesbetweendifferentoperatornetworks,thevaluesinthetableapply,unlessinvolvedpartiesagreeotherwise.NOTE3:ElectricalformatCMI-encoded,accordingtoETS300166[1].NOTE4:Avalueof0,15UIpphasbeenproposed.Theeffectofdispersionandnon-linearitiesontheeyeopeningandonthechoiceofthisvalueisforfurtherstudy.NOTE5:UIUnitInterval:64kbit/s1UI=15,6µs2048kbit/s1UI=488ns8448kbit/s1UI=118ns34368kbit/s1UI=29,1ns139264kbit/s1UI=7,18nsSTM-11UI=6,43nsSTM-41UI=1,61nsSTM-161UI=0,402nsSTM-641UI=0,100ns5.2NetworklimitsforoutputwanderTheMRTIEspecificationsgiveninthisclauseareintendedforapplicationtobothsynchronous(i.e.normallyPRC-traceable)andasynchronous(e.g.liabletoafrequencyoffset)PDHinterfacesofETS300166[1],refertofigure1andfigure2,respectively,forthereferencenetworkconfigurations.Itisrequiredthat,withinasynchronizednetwork,digitalequipmentprovidedatnodesshallaccommodatepermittedphasedeviationsontheincomingsignal,i.e.undernormalsynchronizedconditions,impairmentswillnotoccur.However,itshouldberecognizedthat,asaresultofsomeperformancedegradations,failureconditions,maintenanceactionsandotherevents,theRTIEbetweentheincomingsignalandtheinternaltimingsignaloftheterminatingequipmentmayexceedthejitterandwandertoleranceoftheequipmentwhichmayresultinanabnormaleventsuchasacontrolledsliporbit-errorburst.SIST EN 302 084 V1.1.1:2003



ETSIETSIEN302084V1.1.1(2000-02)12Inaddition,atanodewhichconnectstoanindependently-synchronizednetwork(orwhereplesiochronousoperationisusedinnationalnetworks),theRTIEbetweentheincomingsignalandtheinternaltimingsignaloftheterminatingequipmentmayeventuallyexceedthejitterandwandertoleranceoftheequipmentinwhichcaseanabnormaleventsuchasacontrolledslipmayoccur.Themaximumpermissiblelong-termmeancontrolledsliprateresultingfromthismechanismisderivedfromtheclockperformancedefinedinEN300462-6-1[10],i.e.nomorethanoneslipin70days.Thewandermeasurementrequirements(e.g.samplingtimeandmeasurementinterval)forMTIE,MRTIEandTDEVparameters,the10HzwandermeasurementfiltercharacteristicandthefunctionaldescriptionformeasuringoutputwanderaredescribedinITU-TRecommendationO.172[14].InstrumentationinaccordancewithITU-TRecommendationO.172[14]isappropriateformeasurementofwanderparametersatbothSDHandPDHinterfaces.MeasurementmethodologiesusedtomeasuretheMRTIEparameteraredescribedinannexB.5.2.12048kbit/sinterfaceoutputwanderlimitThemaximumlevelofwanderthatmayexistata2048kbit/snetworkinterface,expressedinMRTIE,shallnotexceedthelimitgivenintable2.Theresultantoverallspecificationisillustratedinfigure3.Table2:2048kbit/sinterfaceoutputwanderlimitObservationIntervalττττ(sec)MRTIErequirement0,05<τ≤0,246τµs0,2<τ≤329µs32<τ≤640,28τµs64<τ≤1000(note)18µsNOTE:Fortheasynchronousconfiguration(refertofigure1),themaximumobservationintervaltobeconsideredis80seconds.0,010,11101001000ObservationIntervalτ
(sec)0,1110100MRTIE(µ
sec)Figure3:2048kbit/sinterfaceoutputwanderlimitSIST EN 302 084 V1.1.1:2003



ETSIETSIEN302084V1.1.1(2000-02)135.2.234368kbit/sinterfaceoutputwanderlimitThemaximumlevelofwanderthatmayexistata34368kbit/snetworkinterface,expressedinMRTIE,shallnotexceedthelimitgivenintable3.Theresultantoverallspecificationisillustratedinfigure4.34368kbit/ssignalscanbeframedinaccordancewithETS300337[3];inthecasewhentheseareusedasasynchronizationinterface,theoutputwanderlimitisforfurtherstudy.Table3:34368kbit/sinterfaceoutputwanderlimitObservationIntervalττττ(sec)MRTIErequirement0,05<τ≤0,07314τµs0,073<τ≤2,51µs2,5<τ≤100,4τµs10<τ≤804µs0,010,1110100ObservationIntervalτ (sec)0,1110MRTIE(µ sec)Figure4:34368kbit/sinterfaceoutputwanderlimit5.2.3139264kbit/sinterfaceoutputwanderlimitThemaximumlevelofwanderthatmayexistata139264kbit/snetworkinterface,expressedinMRTIE,shallnotexceedthelimitgivenintable4.Theresultantoverallspecificationisillustratedinfigure5.139264kbit/ssignalscanbeframedinaccordancewithETS300337[3];inthecasewhentheseareusedasasynchronizationinterface,theoutputwanderlimitisforfurtherstudy.Table4:139264kbit/sinterfaceoutputwanderlimitObservationIntervalττττ(sec)MRTIErequirement0,05<τ≤0,156,8τµs0,15<τ≤2,51µs2,5<τ≤100,4τµs10<τ≤804µsSIST EN 302 084 V1.1.1:2003



ETSIETSIEN302084V1.1.1(2000-02)140,010,1110100ObservationIntervalτ (sec)0,1110MRTIE(µ sec)Figure5:139264kbit/sinterfaceoutputwanderlimit5.2.4STM-NinterfaceoutputwanderlimitSTM-Ninterfacesaredefinedassynchronizationinterfaces,andthenetworklimitsforwanderatsynchronizationinterfacesarespecifiedinEN300462-3-1[7].6JitterandwandertoleranceofequipmentinterfacesInordertoensurethat,ingeneral,anyequipmentcanbeconnectedtoanyappropriateinterfacewithinanetwork,itisnecessarytoarrangethattheinputportsofallequipmentarecapableofaccommodatinglevelsofjitterandwanderuptoatleasttheminimumlimitsdefinedinthefollowingclauses.ThejitterandwandertoleranceofanSDHorPDHinterfaceindicatestheminimumlevelofphasenoisethattheinputportshallaccommodatewhilst:•notcausinganyalarms;•notcausinganyslips;and•notcausinganybiterrors;exceptforopticalSTM-NinterfacesatjitterfrequenciesabovefP,(refertotable12,table13andtable14)whereanequivalent1dBopticalpowerpenaltyshallnotbeexceeded.Alldigitalinputportsofequipmentshallbeabletotolerateadigitalsignalthathas:•electricalcharacteristicsinaccordancewiththerequirementsofETS300166[1]ortheopticalcharacteristicsofETS300232[2];•aconstantfrequencyoffset(relativetothenominalvalue)intherangedefinedintable5;•arateofchangeinfrequencyuptoatleast0,5ppm/minuteforallSTM-Ninterfaces;and•asinusoidalphasedeviationhavinganamplitude-frequencyrelationshipdefinedinthefollowingclauseswhichindicatestheappropriatelimitsforthedifferentinterfaces.Inprinciple,theserequirementsshallbemetregardlessoftheinformationcontentofthedigitalsignal.However,fortestpurposes,thecontentofthesignalwithjitterandwandermodulationshouldbeastructuredtestsequenceasdefinedinthefollowingclauses.SIST EN 302 084 V1.1.1:2003



ETSIETSIEN302084V1.1.1(2000-02)15Whenspecifyingorassessinginterfacetolerance,twoequipmentoperatingconditionscanbedistinguished:•non-synchronizedoperation,wherethereceivingequipmentisnotbeingtimedfromasourcethatissynchronouswiththeinterfaceunderconsideration.Inthiscase,itistheequipmentcapabilitytoaccommodatephasevariationontheincomingsignal(intermsofclockrecoverycircuitryandsynchronizer/desynchronizerbuffers)thatisofinterest;•synchronizedoperation,wh
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