外文翻译--章超_机械仪表_工程科技_专业资料

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1、InternationalJournalofInnovativeTechnologyandExploringEngineering(IJITEE)ISSN:2278-3075,Volume-1,Issue-6,November2012SDHandItsFutureTrendsN.Jyothirmai,R.ManasaValli,A.RamaKrishnaAbstract–SDHpossessaninternationalstandardnetworkingprinciple.Itissynchronousbynatu

2、resonameofthehierarchyistakenfrommultiplexingmethod.TheevolutionofthissystemimprovingtheeconomyofoperabilityandreliabilityofadigitalnetworkSDHevolutionmeetstherequirementofthecustomerwithrespecttothedifferentbandwidthrequirementsanddifferentservices.SDHstandard

3、definesthetransmissionratedevelopedto155.52mbps.Inmultiplexingprocesspayloadsarelayeredintolowerorderandhigherordervirtualcontainer,eachincludingarangeofoverheadfunctionsformanagementanderrormonitoring.framehasarepeativestructureandconsistsofnineequallengthsegm

4、ent.EachsegmentinSTM-1possesstheinformationstructure.TheflexibilityofSDHcanbeusedtobestadvantagebyintroducinganetworktopology.Keywords-CCITT:ComiteConsultifInternationaldeTelegraphiqueetTelephoniqueSTM:SynchronousTransportModuleADM:AddDropMultiplexerPOH:PathOve

5、rHeadSOH:SectionOverHeadI.INTRODUCTIONInFebruary1988anagreementwasreachedatCCITTforaSynchronousDigitalHierarchyrepresentingasingleworldwidestandard.Fortransportingthedigitalsignal.ForsmoothtransformationfromexistingPDHithastoaccommodatethreedifferentstandardsSY

6、NCHRONOUS-OnemasterclockandallelementsynchronisewithitDIGITAL-Informationinbinary,HIERARCHY-setofbitsratesinahierarchicalorder.SDHdefinesasetofhierarchicalstructures,standardsforthetransportofsuitablyadaptedpayloadoverphysicaltransmissionnetworkAsSDHisintroduce

7、dmorewidely,themanagementcapabilityofnetworkgraduallyincreasesbecauseofthecomprehensivemonitoringandhighcapabilitymanagementthroughoutthenetwork.ThecontrolofbandwidthonatimescaleofsecondsforothermultiplexingtechniquesthathaveswitchingcapabilitiessoSDHastheirtra

8、nsportmechanism.ThefirstattempttoformulatestandardsforopticaltransmissionstartedinU.S.AasSONET(SynchronousOpticalNetwork)Theaimofthisstandardswastosimplifyinterconnectionbet