DWDM系統的功能以及技術特點DWDM密布波分復用技能是指選用單模光纖的寬帶以及低損耗的特性，以多個波長作為載波，答應各載波信道在光纖內一起傳輸的光纖通訊技能，并且選用添加波長的方法就能夠輕松完成體系擴容。別的，DWDM作為通訊工程最有用、最經濟的新技能，能夠充沛滿意現階段的網絡寬帶事務開展需要，一起也為將來全面完成光傳輸網絡奠定了堅實的根底。DWDMofdensewavelengthdivisionmultiplexingskillisthatbroadbandsingle-modefiberandlowlosscharacteristicsselection,withmultiplewavelengthasthecarrier,thecarriertochanneltransmissioninfiberopticalcommunicationskills,andthemethodofaddingwavelengthcaneasilycompletethesystemexpansion.Other,newskillsDWDMascommunicationengineeringisthemostuseful,themosteconomical,canfullysatisfytheneedsofdevelopingbroadbandservices,alsohaslaidasolidfoundationforthefuturetocompleteacomprehensiveopticaltransmissionnetwork.端、光中繼擴大器端、光監控信道以及網絡辦理體系。其間光發射機端是指每一條復用通路的光發送機別離發射出不一樣標稱波長的光信號，各光通路都承載著不一樣的事務信號;光接納機端是指線路光纖由光前置擴大器擴大今后，經過火波器將光通路信號進行分化，然后將分化后的信號各自輸入到相應的復用通路光接納機中；光中繼擴大器端是現代光纖通訊體系中必不可少的要害器材，坐落光傳輸線路的中心方位，是一種不只能夠對光信號進行直接擴大，一起還具有實時、高增益、低損耗、低噪聲的全光擴大器。當前遍及運用的光纖擴大器中包含摻鉺光纖擴大器、半導體光擴大器和光纖拉曼擴大器等。因為摻鉺光纖擴大器兼具長間隔、大容量以及高速率等優越性，使其在光纖通訊中作為前置擴大器、線路擴大器和功率擴大器的運用最為廣泛;光監控信道是專門為監控DWDM光傳輸體系建立的，運用一個獨立波長為光監控通道，傳送承載著DWDM網元辦理以及監控信息的光信號，使網絡辦理體系能實時的對DWDM體系進行操控；DWDM的網絡辦理體系是指對光擴大單元、波分復用器、波分變換器以及監控信道的設備在功用、毛病、裝備以及安全等方面進行歸納辦理，其辦理信息來源于光監控通道中的監控信號。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體系根本布局2basiclayoutDWDMsystem在DWDM體系中依據波分體系在網絡中所在的方

位，可劃分為光終端復用網元、光線路擴大網元以及光分插復用網元三種網元類型。IntheDWDMsystembasedonWDMsysteminthenetworkrange,canbedividedintoopticalterminalmultiplexingnetworkelement,opticallinetoexpandthenetworkelementandopticaladd-dropmultiplexingnetworkofthreekindsofelementtypes.(1)光終端復用網元設置在終端站，分為發送和承受兩部分。在發送端將由不一樣客戶端設備輸出的光信號進行光波長變換以及復用，然后合并在一根光纖里進行擴大傳輸;接納端則是將合并在一根光纖里傳輸的一切信號進行別離，然后再別離發送到相應的客戶端設備上。(1)opticalterminalmultiplexernetworkelementisarrangedintheterminalstation,dividedintosendingandreceivingparttwo.Inthesendingendbythelightsignalisnotthesameoutputclientequipmentoftheopticalwavelengthconversionandreuse,andthenmergethetransmissioninasingleopticalfiber;thereceivingendwillbecombinedinasingleopticalfibertransmissionwere

allsignal,andthenweresenttothecorrespondingclientdevices.(2)光線路擴大網元設置在中繼站上，是由光擴大、色散抵償、光纖線路接口、體系操控與通訊等功用單元組成，經過對雙向傳輸的光信號進行擴大以及色散抵償，并擴大無電中繼的傳輸間隔。在接納端，光纖線路接口單元將光信號分化為事務合路信號和光監控信號。其間事務合路信號經過摻鉺光纖擴大單元擴大的一起被色散抵償單元進行色散抵償；而光監控信號則被發送到光監控信道處置單元進行各種處置。在接納端，經過擴大以及色散抵償的事務合路信號和光監控信道處置的再生光監控信號經過光纖線路接口單元進行合波傳輸。(2)theopticallinetoexpandthenetworksettings,intherelaystation,iscomposedoflightamplification,dispersioncompensation,fiberinterface,systemcontrolandcommunicationfunctionunit,aftertheopticalsignalforbidirectionaltransmissionexpansionanddispersioncompensation,andexpandthetransmissionintervalwithoutelectricrelay.Inthereceivingend,fiberinterfaceunitwilllightsignalintotransaction

combinedsignalandcontrolsignal.Meanwhileaffairscombinedsignalaftererbium-dopedfiberexpansionunitexpandedbydispersioncompensationunitfordispersioncompensation;opticalmonitorsignalissenttotheopticalsupervisorychannelprocessingunitfordisposal.Inthereceivingend,afterregenerationexpansionanddispersioncompensationaffairsofcompositesignalandopticalsupervisorychanneldisposalopticalmonitoringsignalsthroughfiberinterfaceunitforwavetransmission.（3）光分插復用網元包含光轉發、事務會聚、合波分波、分插復用、光擴大以及監控六種事務渠道。在光變換渠道中選用光一電一光的方法將事務信號與線路信號之間的波長進行變換;事務會聚渠道是將多路低速率信號會聚到一個波長進行傳輸;合分波渠道將來自于以上兩種渠道不一樣波長的信號耦合到一根光纖上進行傳輸，然后再將來自光擴大渠道的線路光信號依照波長信道的不一樣進行別離，再發送到不一樣的光轉發渠道和事務會聚渠道;分插復用渠道用來進行光信號固定波長的分插以及復用功用；光擴大渠道坐落合波渠道后、分波渠道前以及線路傳輸中心方位，運用光擴大技能對經過長間隔傳輸的光

信號進行功率抵償;監控渠道用是運用指定的監控光通道進行信息傳輸。(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組網描繪Describe3DWDMnetworkDWDM設備經過裝備為光終端復用網元、光線路擴大網元和光分插復用網元設備，構成不一樣的網絡拓撲，滿意各層次的組網需要，其組網方法首要能夠分為鏈型以及環形組網兩種方法。其間鏈型組網，能夠供給光層線路維護和電層SDH設備的通道或許復用段維護。在進行短間隔傳輸時，DWDM設備能夠供給無線路擴大器的點對點組網，而在長間隔傳輸時，能夠在終端設備之間添加光中繼擴大器。環形組網在運用進程中，能夠依據實際需要運用光分插復用設備構成環形網，這其間有必要要有一個站點用背靠背光終端復用網元來組成光分插復用網元。別的，在進行DWDM組網描繪時還應該思考到以下幾點：

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

色散受限間隔。詳細是指由發送光源的光譜特性以及光纖色度色散所發作的影響光傳輸間隔的要素。關于幾十到幾百公里的體系來說，色度色散的影響能夠忽略不計，但跟著光纖通訊體系傳輸的速率不斷進步，以及體系中光擴大器數量的添加，使得整個傳輸網絡中的總色散值隨之增大，所以色散約束已經成為制約傳輸體系中再生中繼間隔的重要要素。因而，在進行DWDM網絡描繪時有必要注重色散受限間隔，詳細是將整個網絡劃分紅若干個再生中繼間隔段，使每個再生中繼段間隔都小于光源的色散受限間隔，進而能夠減小色度色散對整個網絡帶來的影響。(1)dispersionlimitedinterval.Adetailedfactorreferstoinfluencewhathappensbyspectralcharacteristicsoftransmittinglightsourceandfiberchromaticdispersionoftheopticaltransmissioninterval.Abouttenstohundredsofkilometersofsystem,influenceofchromaticdispersioncanbeneglected,butwiththeopticalfibercommunicationsystemtransmissionrateofprogress,addingdevicenumberoflightamplificationandsystem,sothatthetotaldispersionofthetransmissioninthenetworkvalueincreases,sothedispersion

constraintshavebecomeanimportantfactorrestrictingtheregenerationintervaltransmissionsystem.Therefore,intheDWDMnetworkasitisnecessarytopayattentiontodetailislimitedindispersioninterval,dividesthewholenetworkredapluralityofregenerativeintervals,dispersionlimitedintervalsothateachregeneratorsectionintervalislessthanthelightsource,whichcanreducetheinfluenceofchromaticdispersiononthewholenetwork.功率受限。進行長間隔傳輸的光信號要求其功率能夠抵消光纖的衰耗，在進行功率核算時，通常只對傳輸網絡中兩個相鄰的設備進行功率預算，而不對準整個網絡進行一致的功率預算。將傳輸網絡中相鄰的兩個設備間的間隔衰耗稱作中繼間隔衰耗。當整個網絡經過色散受限核算，劃分為若干個再生中繼間隔段后，再經過功率受限預算斷定每個再生中繼段中的中繼間隔段。(2)thepowerlimitation.Forlongdistancetransmissionopticalsignalpowerlossoffsetrequirementsoffibercan,inthepowercalculation,usuallyonlyontheequipmentoftwoadjacent

transmissionnetworkforpowerbudget,andnotonthenetworkforpowerbudgetconsistent.Theintervalattenuationtwodevicesinthetransmissionnetworkbetweenadjacentcalledrelaydistanceattenuation.Whenthewholenetworkislimitedindispersioncalculation,isdividedintoapluralityofregenerativeintervals,thenafterthelimitedpowerbudgetpositsthateachregeneratorsectionoftrunkcompartment.（3）光信噪比。因為光擴大器是在一個較寬的波段內發作光，即所謂擴大的自發輻射。在具有多個摻鉺光纖擴大器的傳輸體系中，光擴大器的自發輻射噪聲將隨同光信號重復進行衰減和擴大的進程。這樣一來，就使得傳輸過來的自發輻射噪聲在每個光擴大器中都要進行擴大疊加，即總的噪聲功率跟著光擴大器數量的添加而不斷擴大，然后影響著光信噪比。在實際操作中，因為摻鉺光纖擴大器增益不均衡可能會致使每條信道輸出功率以及噪聲系數存在區別，所以在描繪時有必要以光信噪比的最差狀況進行思考，并且留有滿足的富余量。(3)theopticalsignal-to-noiseratio.Becausetheopticalamplifieristheonsetoflightinawideband,

theso-calledexpansionofthespontaneousradiation.Inhavingapluralityoferbium-dopedfibertransmissionsystemexpansiondevice,lightamplificationofspontaneousemissionnoisedevicewithlightsignalattenuationandtheprocessrepeatedexpansion.Inthisway,thespontaneousemissionnoisetransmittedineachopticalamplifiershaveexpandedsuperposition,namelythetotalnoisepowerandfollowthelightexpandedaddingdevicenumberandgrowing,andthenaffectstheopticalsignal-to-noiseratio.Inactualoperation,becausetheerbium-dopedfiberamplifiergainimbalancemaycauseeachchanneloutputpowerandnoisefigurearedifferent,soitisnecessarytodescribetheworstsituationtotheopticalsignal-to-noiseratioofthinking,andleavethesurplusamountofsatisfaction.除以上三種首要要素外，還有一些非線性要素影響著DWDM體系組網。因為非線性要素是在通訊網絡傍邊與光強有關的一些物理現象，所以只要在光強到達特定的臨界值時才會發作。當一個信道的光強和相位將遭到與之相鄰信道的影響時就會構成非線性串話，光纖非線性對體系

功用的影響取決于光纖傳輸中的光功率密度以及傳輸間隔。Inadditiontotheabovethreekindsofprimaryfactors,there