opticalnetworkofsdhgraduatethesiss论文正文大学学位论文.docx
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opticalnetworkofsdhgraduatethesiss论文正文大学学位论文
Abstract
Inrecentyears,withthedevelopmentoftheinformationsociety,theglobalInternetbusinessshowedanexplosivegrowthtrend.TheimplementationofthefiberopticalnetworkofSDHisonthebasisofthetransmissionplatformofZTEMP320,itcanprovideasimulationenvironmentfortheentireoptictransmissionnetwork.
ThispaperstudiesthetechniqueofSDHnetwork,describesthebasicprincipleofSDHmappingmultiplexing,structureofframe,categoriesoftopology,andresearchesthemethodsofprotectionoftheopticnetwork.Accordingtotheinstructionrequirement,anoptictransmissionnetworkwith9nodesissetup,theservicesbetweentwonodesareconfiguredthroughthenetworkwiththecostsorminimumresourcesofthenetwork.ThesystemtimeclockisconfiguredandchoosenodeDasprimaryclock.OfficewireiscompletedandchoosenodeDascontrollerofthenetwork.Multiplexingsectionprotectionandpathprotectionisfinished.Aftercarefuldesign,realizedsimulations,performancetestsshowthatthesynchronousdigitalhierarchynetworkisreasonable,itcanbeusedforpracticalengineering.
Keywords:
SDH;networks;opticaltransmission;STM-N;networking;multiplexing;opticalinterface
TableofContents
Chapter1Introduction1
1.1Background1
1.2CharacteristicsofSDHnetwork1
1.3Researchobjectivesandsignificance2
Chapter2SDHPrinciples4
2.1SDHsignalframestructureandmultiplexingsteps4
2.1.1SDHsignalframestructure4
2.1.2SDHmultiplexingstep6
2.2SDHequipmentlogicfunctionblocks5
2.3Thebasicnetworktopology6
2.4Self-healingnetwork8
Chapter3SDHNetworkArchitectures10
3.1Apoint-to-pointSDHlink10
3.2ASDHRingNetwork11
3.3Multi-RingSDHTopology12
3.4SDHRingProtectionMechanisms13
3.5TheRingProtectionArchitectures13
Chapter4RealizationofOpticTransmissionNetwork18
4.1Networktopology18
4.2Networkingrealization18
4.2.1Setupthenetworknodes19
4.2.2Installationoftheboardsinnodes20
4.3SystemClockconfigurations23
4.4Officewireconfigurations26
4.6Serviceconfiguration27
4.6.1AtoI2mb/s*10serviceconfiguration27
4.6.2Theresultsofservicesofnetwork30
4.7Serviceprotectionconfiguration32
4.7.1ServiceprotectionfromAtoB32
4.7.1Serviceprotectionresults35
4.8Multiplexingsectionprotection35
References39
Acknowledgements40
AppendixI41
Chapter1Introduction
Background
TheSDHisaninternationalstandardthatishighlypopularandusedforitshighspeeddatatransferofthetelecommunicationanddigitalsignals.Thissynchronoussystemhasbeenspeciallydesignedinordertoprovideasimpleandflexiblenetworkinfrastructure.Thissystemhasbroughtaconsiderableamountofchangeinthetelecommunicationnetworksthatwerebasedontheopticalfibersasfarasperformanceandcostwereconcerned.
CharacteristicsofSDHnetwork
SDHhasbeenabletorapidlydevelopandthisisitsowncharacteristicsareinseparable,anditsspecificfeaturesareasfollows:
(1)SDHtransmissionsystemsintheworldtohaveaunifiedframestructure,digitaltransmissionstandardrateandstandardopticalinterfaceisnetworkinterworkingsystem,andthereforehasgoodlateralcompatibility,itisfullycompatiblewiththeexistingPDH,andaccommodatesavarietyofnewtrafficsignals,theformationofaglobalunifiedstandarddigitaltransmissionsystemandimprovethereliabilityofthenetwork;(differentlevelsofthecodearrangement)
(2)SDHaccesssystemflowstructureofthepayloadareaoftheframeisveryregular,andthepayloadissynchronizedwiththenetwork,whichusessoftware,adirecthigh-speedsignalcandropoutofthelow-speedtributarysignalstoachievethecharacteristicsofamultiplexovercomePDHplesiochronousmultiplexedmannerforallthehigh-speedsignalmultiplexinggradualdecompositionandregenerationprocessisgreatlysimplifiedbecausetheDXC,reducingtheback-interfacemultiplexequipment,improvedtheservicedeliverynetworktransparency;
(3)Asaresultofthemoreadvancedadd-dropmultiplexer(ADM),digitalcross-connect(DXC),self-healingcapabilitiesandreassemblybranchnetworkbecomesstronger,withastrongsurvival.BecauseSDHframestructurearrangeda5percentoverheadbitsignal,itisparticularlypowerfulnetworkmanagementfunctions,andcanbeunifiedintoanetworkmanagementsystemforautomationnetworks,intelligent,channelutilizationandreducenetworkcostsandvascularviabilityplayedapositiverole;
(4)DuetoavarietyofSDHnetworktopology,thenetworkthatitconsistsofveryflexible,itcanenhancenetworkmonitoring,operationmanagementandauto-configurationcapabilities,optimizenetworkperformance,butalsotonetworkoperationandflexible,safeandreliable,sothenetworkisverycompleteanddiverse;
(5)SDHtransmissionandswitchingperformancehasfreecombinationoffunctionblockscomposedthroughitsfamilyofdevices,toachieveavarietyofdifferentlevelsandnetworktopologyisveryflexible;
(6)SDHdoesnotbelongtoatransmissionmediumwhichcanbeusedfortwistedpair,coaxialcable,butforthetransmissionofSDH.
Youneedtousehighdatarateopticalfiber.Thisfeatureindicates,SDHtrunkchannelssuitableforboth,butalsoforregionalchannels.Forexample,China'snationalandprovincialtrunkcablenetworkisusingSDH,anditisalsoeasytomixcompatiblewithfiber-opticcablenetwork(HFC).
(7)SDHisstrictlysynchronizedtoensurethattheentirenetworkisstableandreliable,lesserror,andeasyadjustmentandmultiplexing.
Researchobjectivesandsignificance
Overtheyears,intelligentopticaltransmissiontechnologyhasbeenofconcernfortheindustry,ithopestobuildintelligentopticaltransmissionnetworktosolvetheproblemseveralaspectsoftheexistingtransmissionnetworkexist:
first,thetraditionalfast-growingonlinenetworkisdifficulttoadaptthedataservicewithunpredictability,dynamicallocationofnetworkbandwidth.Second,thetraditionalopticaltransmissionnetworkmainlyrelyonmanualconfigurationofnetworkconnections,time-consuminganddifficulttoadapttothemodernnetworkexpansionneedsnewbusiness.Third,inordertoimprovethereliabilityofbearerservices,thetraditionalopticaltransportnetworksneedtosetasidealargeamountofsparecapacity,reducingtheefficiencyofthetransportnetworkbandwidthusage.
Inaddition,thetraditionalwaytoprotectbusinessnetworksisrelativelysimple,thelackofadvancedprotection,restorationandroutingfunctions.SynchronousDigitalHierarchy(SDH)iswidelyusedworldwidemetrobackbonenetwork,telecommunicationnetworkandWAN.
SDHtransmissionsystemisacombinationofhigh-speedlarge-capacityopticaltransmissiontechnologyandintelligentnetworktechnology.Itprovidesconvenientandeffectivedatamultiplexinganddemultiplexingfunctions,andcanreliablytransmitdata.
Chapter2SDHPrinciples
2.1SDHsignalframestructureandmultiplexingsteps
2.1.1SDHsignalframestructure
TheSTM-N(SynchronousTransportModulelevel-1)isthefiberopticnetworktransmissionstandard.Ithasabitrateof155.52Mbit/s.Higherlevelsgoupbyafactorof4atatime:
theothercurrentlysupportedlevelsareSTM-4,STM-16,STM-64andSTM-256.Beyondthiswehavewavelength-divisionmultiplexing(WDM)commonlyusedinsubmarinecabling.
Framestructure
TheSTM-1frameisthebasictransmissionformatforSDH(SynchronousDigitalHierarchy).ASTM-1framehasabyte-orientedstructurewith9rowsand270columnsofbytes,foratotalof2,430bytes(9rows*270columns=2430bytes).Eachbytecorrespondstoa64kbit/schannel.
TOH:
TransportOverhead(RSOH+AU4P+MSOH)
MSOH:
MultiplexSectionOverhead
RSOH:
RegenerationSectionOverhead
AU4P:
AU-4Pointers
VC4:
VirtualContainer-4payload(POH+VC-4Data)
POH:
PathOverhead
Framecharacteristics
TheSTM-1baseframeisstructuredwiththefollowingcharacteristics:
Length:
270column×9row=2430bytes
Byte:
1-byte=64kbit/sspeechchannel
Duration(Framerepetitiontime):
125μsi.e.8000frame/s
Rate(Framecapacity):
2430×8×8000=155.520Mbit/s
Payload=2349bytes×8bits×8000frames/sec=150.336Mbit/s
Fig.2.1StructureofSDHframe
SDHframestructureusedtocarryablockofinformation,eachframeiscomposedoflongitudinalandtransverserows9columns270×Nbytes,eachbytecontaining8bit,theframestructureisdividedintoasectionoverhead(SectionOverhead,SOH)area,STM-Npayloadareaandsnap-pointer(AUPTR)threeregionaldistrict.
TheabovemethodcanbeobtainedwhenNisanarbitraryvaluewhentherate14,16,64,256.AscanbeseenfromFigure1,theentireframestructureisdividedintothreeregions:
thesectionoverhead(SOH)totheinformationpayloadareaandsnappointer.Sectionoverhead(SOH)istheSDHframestructureinordertoensurethenormaltransmissionofinformationandadditionalbytesfornetworkoperation,managementandmaintenanceofuse,itslocationintheSTM-Nframestructureisthefirst1~9×Ncolumnsthefirst.
ThefiguredescribesbasicSDHframeconsistingof9rowsand90columns.SDHframeiscomposedof810octets(bytes).Transmissioniscarriedoutrowwisefromlefttorightandfromtoptobottom.Bitsaretransmittedserially.
TheSTS-1frameofSDHiscomposedofsectionoverhead,transportoverhead,payloadoverheadanddatapart.TheframestartswithfixedA1/A2bitpatternof0xf628usedforbit/octetsynchronization.SDHisreferredasoctetsynchronous.ThefirstthreecolumnsofSDHframeisreferredastransportoverhead.Thenext87columnsof