ITU-T G.989.2(11 2001) (英)Phoneline networking tra

INTERNATIONALTELECOMMUNICATIONUNIONITU-TG.989.2TELECOMMUNICATIONSTANDARDIZATIONSECTOROFITU(11/2001)SERIESG:TRANSMISSIONSYSTEMSANDMEDIA,DIGITALSYSTEMSANDNETWORKSDigitalsectionsanddigitallinesystem–OpticallinesystemsforlocalandaccessnetworksPhonelinenetworkingtransceivers–PayloadformatandlinklayerrequirementsITU-TRecommendationG.989.2ITU-TG-SERIESRECOMMENDATIONSTRANSMISSIONSYSTEMSANDMEDIA,DIGITALSYSTEMSANDNETWORKSINTERNATIONALTELEPHONECONNECTIONSANDCIRCUITSG.100–G.199GENERALCHARACTERISTICSCOMMONTOALLANALOGUECARRIER-TRANSMISSIONSYSTEMSG.200–G.299INDIVIDUALCHARACTERISTICSOFINTERNATIONALCARRIERTELEPHONESYSTEMSONMETALLICLINESG.300–G.399GENERALCHARACTERISTICSOFINTERNATIONALCARRIERTELEPHONESYSTEMSONRADIO-RELAYORSATELLITELINKSANDINTERCONNECTIONWITHMETALLICLINESG.400–G.449COORDINATIONOFRADIOTELEPHONYANDLINETELEPHONYG.450–G.499TESTINGEQUIPMENTSG.500–G.599TRANSMISSIONMEDIACHARACTERISTICSG.600–G.699DIGITALTERMINALEQUIPMENTSG.700–G.799DIGITALNETWORKSG.800–G.899DIGITALSECTIONSANDDIGITALLINESYSTEMG.900–G.999GeneralG.900–G.909ParametersforopticalfibrecablesystemsG.910–G.919Digitalsectionsathierarchicalbitratesbasedonabitrateof2048kbit/sG.920–G.929Digitallinetransmissionsystemsoncableatnon-hierarchicalbitratesG.930–G.939DigitallinesystemsprovidedbyFDMtransmissionbearersG.940–G.949DigitallinesystemsG.950–G.959DigitalsectionanddigitaltransmissionsystemsforcustomeraccesstoISDNG.960–G.969OpticalfibresubmarinecablesystemsG.970–G.979OpticallinesystemsforlocalandaccessnetworksG.980–G.989AccessnetworksG.990–G.999QUALITYOFSERVICEANDPERFORMANCEG.1000–G.1999TRANSMISSIONMEDIACHARACTERISTICSG.6000–G.6999DIGITALTERMINALEQUIPMENTSG.7000–G.7999Forfurtherdetails,pleaserefertothelistofITU-TRecommendations.ITU-TRec.G.989.2(11/2001)iITU-TRecommendationG.989.2Phonelinenetworkingtransceivers–PayloadformatandlinklayerrequirementsSummaryThisRecommendationspecifiesapayloadformatandlinklayerproceduresforPhonelineNetworkingTransceiver(PNT)devices.ItassumestheuseofMediumAccessControl(MAC)andencapsulationproceduresdefinedinITU-TRec.G.989.1.RequirementsinthisRecommendationareintendedtoensureinteroperabilitybetweendevices.Theyarewrittenfromtheperspectiveofaconformingtransmitter,althoughsomeminimumperformancerequirementsareestablishedforreceivers.SourceITU-TRecommendationG.989.2waspreparedbyITU-TStudyGroup15(2001-2004)andapprovedundertheWTSAResolution1procedureon29November2001.iiITU-TRec.G.989.2(11/2001)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.INTELLECTUALPROPERTYRIGHTSITUdrawsattentiontothepossibilitythatthepracticeorimplementationofthisRecommendationmayinvolvetheuseofaclaimedIntellectualPropertyRight.ITUtakesnopositionconcerningtheevidence,validityorapplicabilityofclaimedIntellectualPropertyRights,whetherassertedbyITUmembersorothersoutsideoftheRecommendationdevelopmentprocess.AsofthedateofapprovalofthisRecommendation,ITUhadreceivednoticeofintellectualproperty,protectedbypatents,whichmayberequiredtoimplementthisRecommendation.However,implementorsarecautionedthatthismaynotrepresentthelatestinformationandarethereforestronglyurgedtoconsulttheTSBpatentdatabase.ITU2002Allrightsreserved.Nopartofthispublicationmaybereproduced,byanymeanswhatsoever,withoutthepriorwrittenpermissionofITU.ITU-TRec.G.989.2(11/2001)iiiCONTENTSPage1Scope.............................................................................................................................12References.....................................................................................................................13Definitions....................................................................................................................14Abbreviations................................................................................................................25Physicallayerspecification..........................................................................................35.1Overview........................................................................................................35.2Modulation.....................................................................................................35.2.1Carrierfrequencyandtolerance...........................