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InternationalTelecommunicationUnionITU-TJ.161TELECOMMUNICATIONSTANDARDIZATIONSECTOROFITU(06/2007)SERIESJ:CABLENETWORKSANDTRANSMISSIONOFTELEVISION,SOUNDPROGRAMMEANDOTHERMULTIMEDIASIGNALSIPCablecomAudioandvideocodecrequirementsandusagefortheprovisionofbidirectionalaudioservicesovercabletelevisionnetworksusingcablemodemsITU-TRecommendationJ.161ITU-TRec.J.161(06/2007)iITU-TRecommendationJ.161AudioandvideocodecrequirementsandusagefortheprovisionofbidirectionalaudioservicesovercabletelevisionnetworksusingcablemodemsSummaryITU-TRecommendationJ.161specifiesthemediaaspectsoftheinterfacesbetweenIPCablecomclientdevicesforaudioandvideocommunication.Specifically,itidentifiestheaudioandvideocodecsnecessarytoprovidethehighestqualityandthemostresource-efficientservicedeliverytothecustomer.ThisRecommendationalsospecifiestheperformancerequiredinclientdevicestosupportfutureIPCablecomcodecs.Additionally,thisRecommendationdescribesasuggestedmethodologyforoptimalnetworksupportforcodecs.SourceITU-TRecommendationJ.161wasapprovedon20June2007byITU-TStudyGroup9(2005-2008)undertheITU-TRecommendationA.8procedure.iiITU-TRec.J.161(06/2007)FOREWORDTheInternationalTelecommunicationUnion(ITU)istheUnitedNationsspecializedagencyinthefieldoftelecommunications.TheITUTelecommunicationStandardizationSector(ITU-T)isapermanentorganofITU.ITU-Tisresponsibleforstudyingtechnical,operatingandtariffquestionsandissuingRecommendationsonthemwithaviewtostandardizingtelecommunicationsonaworldwidebasis.TheWorldTelecommunicationStandardizationAssembly(WTSA),whichmeetseveryfouryears,establishesthetopicsforstudybytheITU-Tstudygroupswhich,inturn,produceRecommendationsonthesetopics.TheapprovalofITU-TRecommendationsiscoveredbytheprocedurelaiddowninWTSAResolution1.InsomeareasofinformationtechnologywhichfallwithinITU-T'spurview,thenecessarystandardsarepreparedonacollaborativebasiswithISOandIEC.NOTEInthisRecommendation,theexpressionAdministrationisusedforconcisenesstoindicatebothatelecommunicationadministrationandarecognizedoperatingagency.CompliancewiththisRecommendationisvoluntary.However,theRecommendationmaycontaincertainmandatoryprovisions(toensuree.g.interoperabilityorapplicability)andcompliancewiththeRecommendationisachievedwhenallofthesemandatoryprovisionsaremet.Thewordsshallorsomeotherobligatorylanguagesuchasmustandthenegativeequivalentsareusedtoexpressrequirements.TheuseofsuchwordsdoesnotsuggestthatcompliancewiththeRecommendationisrequiredofanyparty.INTELLECTUALPROPERTYRIGHTSITUdrawsattentiontothepossibilitythatthepracticeorimplementationofthisRecommendationmayinvolvetheuseofaclaimedIntellectualPropertyRight.ITUtakesnopositionconcerningtheevidence,validityorapplicabilityofclaimedIntellectualPropertyRights,whetherassertedbyITUmembersorothersoutsideoftheRecommendationdevelopmentprocess.AsofthedateofapprovalofthisRecommendation,ITUhadreceivednoticeofintellectualproperty,protectedbypatents,whichmayberequiredtoimplementthisRecommendation.However,implementersarecautionedthatthismaynotrepresentthelatestinformationandarethereforestronglyurgedtoconsulttheTSBpatentdatabaseat©ITU2008Allrightsreserved.Nopartofthispublicationmaybereproduced,byanymeanswhatsoever,withoutthepriorwrittenpermissionofITU.ITU-TRec.J.161(06/2007)iiiCONTENTSPage1Scope............................................................................................................................11.1Introductionandoverview..............................................................................11.2PurposeofthisRecommendation...................................................................11.3Phasingofrequirements.................................................................................12References.....................................................................................................................22.1Normativereferences......................................................................................22.2Informativereferences....................................................................................33Termsanddefinitions...................................................................................................44Abbreviations,acronymsandconventions...................................................................54.1Abbreviationsandacronyms..........................................................................54.2Conventions....................................................................................................65Background...................................................................................................................65.1IPCablecomvoicecommunicationsqualityrequirements.............................75.2Networkpreparationforcodecsupport..........................................................76Devicerequirementsforaudiocodecsupport..............................................................96.1Dynamicupdatecapability.............................................................................106.