DWDM 系统的功能以及技术特点

DWDM系统的功能以及技术特点DWDM密布波分复用技能是指选用单模光纤的宽带以及低损耗的特性，以多个波长作为载波，答应各载波信道在光纤内一起传输的光纤通讯技能，并且选用添加波长的方法就能够轻松完成体系扩容。别的，DWDM作为通讯工程最有用、最经济的新技能，能够充沛满意现阶段的网络宽带事务开展需要，一起也为将来全面完成光传输网络奠定了坚实的根底。DWDMofdensewavelengthdivisionmultiplexingskillisthatbroadbandsingle-modefiberandlowlosscharacteristicsselection,withmultiplewavelengthasthecarrier,thecarriertochanneltransmissioninfiberopticalcommunicationskills,andthemethodofaddingwavelengthcaneasilycompletethesystemexpansion.Other,newskillsDWDMascommunicationengineeringisthemostuseful,themosteconomical,canfullysatisfytheneedsofdevelopingbroadbandservices,alsohaslaidasolidfoundationforthefuturetocompleteacomprehensiveopticaltransmissionnetwork.端、光中继扩大器端、光监控信道以及网络办理体系。其间光发射机端是指每一条复用通路的光发送机别离发射出不一样标称波长的光信号，各光通路都承载着不一样的事务信号;光接纳机端是指线路光纤由光前置扩大器扩大今后，经过火波器将光通路信号进行分化，然后将分化后的信号各自输入到相应的复用通路光接纳机中；光中继扩大器端是现代光纤通讯体系中必不可少的要害器材，坐落光传输线路的中心方位，是一种不只能够对光信号进行直接扩大，一起还具有实时、高增益、低损耗、低噪声的全光扩大器。当前遍及运用的光纤扩大器中包含掺铒光纤扩大器、半导体光扩大器和光纤拉曼扩大器等。因为掺铒光纤扩大器兼具长间隔、大容量以及高速率等优越性，使其在光纤通讯中作为前置扩大器、线路扩大器和功率扩大器的运用最为广泛;光监控信道是专门为监控DWDM光传输体系建立的，运用一个独立波长为光监控通道，传送承载着DWDM网元办理以及监控信息的光信号，使网络办理体系能实时的对DWDM体系进行操控；DWDM的网络办理体系是指对光扩大单元、波分复用器、波分变换器以及监控信道的设备在功用、毛病、装备以及安全等方面进行归纳办理，其办理信息来源于光监控通道中的监控信号。BasiclayoutDWDMsystemincludesoptical

transmitter,opticalreceiver,opticalrelayamplifierendend,opticalsupervisorychannelandnetworkmanagementsystem.Theopticaltransmitterispartingopticaltransmittereveryreusepathsemitlightsignalisnotthesamenominalwavelength,theopticalpatharecarryingthetransactionsignalisnotthesame;opticalreceiverterminalreferstolineopticalfiberbyopticalpreamplifiertoexpandinthefuture,throughthefilterwilllightthesignalpathwayofdifferentiation,thenthesignalafterdifferentiationoftheirinputtothemultiplexchannelcorrespondingopticalreceiver;opticalrelayamplifierendisthekeyequipmentessentialtothemodernopticalfibercommunicationsystem,thecenterpositionislocatedinanopticaltransmissionline,isacannotonlydirectexpansionoftheopticalsignal,opticaltogetheralsohasreal-time,highgain,lowloss,lownoiseamplifier.Thecurrentwidelyusedopticalfiberamplifierincludeserbium-dopedfiberamplifier,semiconductoropticalamplifierandRamanfiberamplifier.Becausetheerbium-dopedfiberamplifier

hastheadvantagesoflongdistance,largecapacityandhighspeed,sothatintheopticalfibercommunicationasapreamplifier,circuitamplifierandpoweramplifierarewidelyused;opticalsupervisorychannelisdedicatedtomonitoringDWDMopticaltransmissionsystem,usingaseparatewavelengthsoflightmonitorchannel,transmissioncarryingDWDMnetworkelementmanagementandmonitoringinformationoftheopticalsignal,sothatthenetworkmanagementsystemcanreal-timecontroloftheDWDMsystem;DWDMnetworkmanagementsystemreferstothelightexpandedunit,wavelengthdivisionmultiplexing,wavelengthconverterandequipmentmonitoringchannelaresummarizedforfunction,fault,equipmentandsecurity,monitoringsignalprocessinginformationfromtheopticalsupervisorychannel.2.DWDM体系根本布局2basiclayoutDWDMsystem在DWDM体系中依据波分体系在网络中所在的方

位，可划分为光终端复用网元、光线路扩大网元以及光分插复用网元三种网元类型。IntheDWDMsystembasedonWDMsysteminthenetworkrange,canbedividedintoopticalterminalmultiplexingnetworkelement,opticallinetoexpandthenetworkelementandopticaladd-dropmultiplexingnetworkofthreekindsofelementtypes.(1)光终端复用网元设置在终端站，分为发送和承受两部分。在发送端将由不一样客户端设备输出的光信号进行光波长变换以及复用，然后合并在一根光纤里进行扩大传输;接纳端则是将合并在一根光纤里传输的一切信号进行别离，然后再别离发送到相应的客户端设备上。(1)opticalterminalmultiplexernetworkelementisarrangedintheterminalstation,dividedintosendingandreceivingparttwo.Inthesendingendbythelightsignalisnotthesameoutputclientequipmentoftheopticalwavelengthconversionandreuse,andthenmergethetransmissioninasingleopticalfiber;thereceivingendwillbecombinedinasingleopticalfibertransmissionwere

allsignal,andthenweresenttothecorrespondingclientdevices.(2)光线路扩大网元设置在中继站上，是由光扩大、色散抵偿、光纤线路接口、体系操控与通讯等功用单元组成，经过对双向传输的光信号进行扩大以及色散抵偿，并扩大无电中继的传输间隔。在接纳端，光纤线路接口单元将光信号分化为事务合路信号和光监控信号。其间事务合路信号经过掺铒光纤扩大单元扩大的一起被色散抵偿单元进行色散抵偿；而光监控信号则被发送到光监控信道处置单元进行各种处置。在接纳端，经过扩大以及色散抵偿的事务合路信号和光监控信道处置的再生光监控信号经过光纤线路接口单元进行合波传输。(2)theopticallinetoexpandthenetworksettings,intherelaystation,iscomposedoflightamplification,dispersioncompensation,fiberinterface,systemcontrolandcommunicationfunctionunit,aftertheopticalsignalforbidirectionaltransmissionexpansionanddispersioncompensation,andexpandthetransmissionintervalwithoutelectricrelay.Inthereceivingend,fiberinterfaceunitwilllightsignalintotransaction

combinedsignalandcontrolsignal.Meanwhileaffairscombinedsignalaftererbium-dopedfiberexpansionunitexpandedbydispersioncompensationunitfordispersioncompensation;opticalmonitorsignalissenttotheopticalsupervisorychannelprocessingunitfordisposal.Inthereceivingend,afterregenerationexpansionanddispersioncompensationaffairsofcompositesignalandopticalsupervisorychanneldisposalopticalmonitoringsignalsthroughfiberinterfaceunitforwavetransmission.（3）光分插复用网元包含光转发、事务会聚、合波分波、分插复用、光扩大以及监控六种事务渠道。在光变换渠道中选用光一电一光的方法将事务信号与线路信号之间的波长进行变换;事务会聚渠道是将多路低速率信号会聚到一个波长进行传输;合分波渠道将来自于以上两种渠道不一样波长的信号耦合到一根光纤上进行传输，然后再将来自光扩大渠道的线路光信号依照波长信道的不一样进行别离，再发送到不一样的光转发渠道和事务会聚渠道;分插复用渠道用来进行光信号固定波长的分插以及复用功用；光扩大渠道坐落合波渠道后、分波渠道前以及线路传输中心方位，运用光扩大技能对经过长间隔传输的光

信号进行功率抵偿;监控渠道用是运用指定的监控光通道进行信息传输。(3)opticaladd-dropmultiplexerelementcomprisingopticaltransmission,transactionconvergence,wave-synthesis,add-dropmultiplexing,lightamplificationandmonitoringsixkindsoftransactionchannel.Intheopticaltransformchannelselectionmethodoflight-electric-lightwilltransactionsbetweensignalandsignalwavelengthconversion;transactionconvergingchannelislow-speedratesignalsconvergetoawavelengthtransmission;combinedwavechannelwillcomefromthecouplingsignalfromtheabovetwokindofdifferentwavelengthchannelsinafiberfortransmission,andthencomingfromthelighttoexpandthechannelsoflineopticalsignalaccordingtothewavelengthchannelnotasseparation,thensenttothedifferentopticaltransmissionchannelandtransactionconvergingchannel;add-dropmultiplexerchannelusedforopticalsignalwithfixedwavelengthadd-dropmultiplexingfunctionandexpand

channelslocated;lightwavechannels,dividedwavechannelandtransmissioncenterrange,theuseoflighttoexpandtheabilityoflightsignalpassingthroughlongdistancetransmissionpowercompensation;monitoringchannelisusedformonitoringopticalchannelspecifiedforinformationtransmission.3.DWDM组网描绘Describe3DWDMnetworkDWDM设备经过装备为光终端复用网元、光线路扩大网元和光分插复用网元设备，构成不一样的网络拓扑，满意各层次的组网需要，其组网方法首要能够分为链型以及环形组网两种方法。其间链型组网，能够供给光层线路维护和电层SDH设备的通道或许复用段维护。在进行短间隔传输时，DWDM设备能够供给无线路扩大器的点对点组网，而在长间隔传输时，能够在终端设备之间添加光中继扩大器。环形组网在运用进程中，能够依据实际需要运用光分插复用设备构成环形网，这其间有必要要有一个站点用背靠背光终端复用网元来组成光分插复用网元。别的，在进行DWDM组网描绘时还应该思考到以下几点：

DWDMequipmentaftertheequipmentforopticalelement,opticallineterminalmultiplexerexpandingelementandopticaladd-dropmultiplexingnetworkelementequipment,constituteanetworktopologyisnotthesame,eachlevelneedssatisfiednetwork,thenetworkmethodbasicallycanbedividedintochainandtheannularnettedtwomethods.Thechaintypenetwork,cansupplytheopticallayerlinemaintenanceandlayerSDHdevicechanneloracomplexsegmentmaintenance.Inshortdistancetransmission,supplynolinebroadeningpeer-to-peernetworkingdevicetoDWDMdevice,andinthelongdistancetransmission,canaddlightrelayamplifierbetweentheterminalequipment.Theringnetworkintheuseprocess,accordingtotheactualneedtouseopticaladd-dropmultiplexingequipmentcomposedofringnetwork,itisnecessarytohaveasitewiththebackterminalmultiplexingnetworkelementtobacklightopticaladd-dropmultiplexingnetwork.Theother,intheDWDMnetworkdescriptionshouldalsoconsiderthefollowingpoints:

色散受限间隔。详细是指由发送光源的光谱特性以及光纤色度色散所发作的影响光传输间隔的要素。关于几十到几百公里的体系来说，色度色散的影响能够忽略不计，但跟着光纤通讯体系传输的速率不断进步，以及体系中光扩大器数量的添加，使得整个传输网络中的总色散值随之增大，所以色散约束已经成为制约传输体系中再生中继间隔的重要要素。因而，在进行DWDM网络描绘时有必要注重色散受限间隔，详细是将整个网络划分红若干个再生中继间隔段，使每个再生中继段间隔都小于光源的色散受限间隔，进而能够减小色度色散对整个网络带来的影响。(1)dispersionlimitedinterval.Adetailedfactorreferstoinfluencewhathappensbyspectralcharacteristicsoftransmittinglightsourceandfiberchromaticdispersionoftheopticaltransmissioninterval.Abouttenstohundredsofkilometersofsystem,influenceofchromaticdispersioncanbeneglected,butwiththeopticalfibercommunicationsystemtransmissionrateofprogress,addingdevicenumberoflightamplificationandsystem,sothatthetotaldispersionofthetransmissioninthenetworkvalueincreases,sothedispersion

constraintshavebecomeanimportantfactorrestrictingtheregenerationintervaltransmissionsystem.Therefore,intheDWDMnetworkasitisnecessarytopayattentiontodetailislimitedindispersioninterval,dividesthewholenetworkredapluralityofregenerativeintervals,dispersionlimitedintervalsothateachregeneratorsectionintervalislessthanthelightsource,whichcanreducetheinfluenceofchromaticdispersiononthewholenetwork.功率受限。进行长间隔传输的光信号要求其功率能够抵消光纤的衰耗，在进行功率核算时，通常只对传输网络中两个相邻的设备进行功率预算，而不对准整个网络进行一致的功率预算。将传输网络中相邻的两个设备间的间隔衰耗称作中继间隔衰耗。当整个网络经过色散受限核算，划分为若干个再生中继间隔段后，再经过功率受限预算断定每个再生中继段中的中继间隔段。(2)thepowerlimitation.Forlongdistancetransmissionopticalsignalpowerlossoffsetrequirementsoffibercan,inthepowercalculation,usuallyonlyontheequipmentoftwoadjacent

transmissionnetworkforpowerbudget,andnotonthenetworkforpowerbudgetconsistent.Theintervalattenuationtwodevicesinthetransmissionnetworkbetweenadjacentcalledrelaydistanceattenuation.Whenthewholenetworkislimitedindispersioncalculation,isdividedintoapluralityofregenerativeintervals,thenafterthelimitedpowerbudgetpositsthateachregeneratorsectionoftrunkcompartment.（3）光信噪比。因为光扩大器是在一个较宽的波段内发作光，即所谓扩大的自发辐射。在具有多个掺铒光纤扩大器的传输体系中，光扩大器的自发辐射噪声将随同光信号重复进行衰减和扩大的进程。这样一来，就使得传输过来的自发辐射噪声在每个光扩大器中都要进行扩大叠加，即总的噪声功率跟着光扩大器数量的添加而不断扩大，然后影响着光信噪比。在实际操作中，因为掺铒光纤扩大器增益不均衡可能会致使每条信道输出功率以及噪声系数存在区别，所以在描绘时有必要以光信噪比的最差状况进行思考，并且留有满足的富余量。(3)theopticalsignal-to-noiseratio.Becausetheopticalamplifieristheonsetoflightinawideband,

theso-calledexpansionofthespontaneousradiation.Inhavingapluralityoferbium-dopedfibertransmissionsystemexpansiondevice,lightamplificationofspontaneousemissionnoisedevicewithlightsignalattenuationandtheprocessrepeatedexpansion.Inthisway,thespontaneousemissionnoisetransmittedineachopticalamplifiershaveexpandedsuperposition,namelythetotalnoisepowerandfollowthelightexpandedaddingdevicenumberandgrowing,andthenaffectstheopticalsignal-to-noiseratio.Inactualoperation,becausetheerbium-dopedfiberamplifiergainimbalancemaycauseeachchanneloutputpowerandnoisefigurearedifferent,soitisnecessarytodescribetheworstsituationtotheopticalsignal-to-noiseratioofthinking,andleavethesurplusamountofsatisfaction.除以上三种首要要素外，还有一些非线性要素影响着DWDM体系组网。因为非线性要素是在通讯网络傍边与光强有关的一些物理现象，所以只要在光强到达特定的临界值时才会发作。当一个信道的光强和相位将遭到与之相邻信道的影响时就会构成非线性串话，光纤非线性对体系

功用的影响取决于光纤传输中的光功率密度以及传输间隔。Inadditiontotheabovethreekindsofprimaryfactors,there