DWDM 系統(tǒng)的功能以及技術(shù)特點

DWDM系統(tǒng)的功能以及技術(shù)特點DWDM密布波分復(fù)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(yīng)各載波信道在光纖內(nèi)一起傳輸?shù)墓饫w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(jīng)濟(jì)的新技能，能夠充沛滿意現(xiàn)階段的網(wǎng)絡(luò)寬帶事務(wù)開展需要，一起也為將來全面完成光傳輸網(wǎng)絡(luò)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(jiān)控信道以及網(wǎng)絡(luò)辦理體系。其間光發(fā)射機端是指每一條復(fù)用通路的光發(fā)送機別離發(fā)射出不一樣標(biāo)稱波長的光信號，各光通路都承載著不一樣的事務(wù)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(jīng)過火波器將光通路信號進(jìn)行分化，然后將分化后的信號各自輸入到相應(yīng)的復(fù)用通路光接納機中；光中繼擴大器端是現(xiàn)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?qū)庑盘栠M(jìn)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(dāng)前遍及運用的光纖擴大器中包含摻鉺光纖擴大器、半導(dǎo)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(yōu)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(jiān)控信道是專門為監(jiān)控DWDM光傳輸體系建立的，運用一個獨立波長為光監(jiān)控通道，傳送承載著DWDM網(wǎng)元辦理以及監(jiān)控信息的光信號，使網(wǎng)絡(luò)辦理體系能實時的對DWDM體系進(jìn)行操控；DWDM的網(wǎng)絡(luò)辦理體系是指對光擴大單元、波分復(fù)用器、波分變換器以及監(jiān)控信道的設(shè)備在功用、毛病、裝備以及安全等方面進(jìn)行歸納辦理，其辦理信息來源于光監(jiān)控通道中的監(jiān)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(jù)波分體系在網(wǎng)絡(luò)中所在的方

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

allsignal,andthenweresenttothecorrespondingclientdevices.(2)光線路擴大網(wǎng)元設(shè)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(jīng)過對雙向傳輸?shù)墓庑盘栠M(jìn)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(wù)合路信號和光監(jiān)控信號。其間事務(wù)合路信號經(jīng)過摻鉺光纖擴大單元擴大的一起被色散抵償單元進(jìn)行色散抵償；而光監(jiān)控信號則被發(fā)送到光監(jiān)控信道處置單元進(jìn)行各種處置。在接納端，經(jīng)過擴大以及色散抵償?shù)氖聞?wù)合路信號和光監(jiān)控信道處置的再生光監(jiān)控信號經(jīng)過光纖線路接口單元進(jìn)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(fù)用網(wǎng)元包含光轉(zhuǎn)發(fā)、事務(wù)會聚、合波分波、分插復(fù)用、光擴大以及監(jiān)控六種事務(wù)渠道。在光變換渠道中選用光一電一光的方法將事務(wù)信號與線路信號之間的波長進(jìn)行變換;事務(wù)會聚渠道是將多路低速率信號會聚到一個波長進(jìn)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(jìn)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(jìn)行別離，再發(fā)送到不一樣的光轉(zhuǎn)發(fā)渠道和事務(wù)會聚渠道;分插復(fù)用渠道用來進(jìn)行光信號固定波長的分插以及復(fù)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(jīng)過長間隔傳輸?shù)墓?/p>

信號進(jìn)行功率抵償;監(jiān)控渠道用是運用指定的監(jiān)控光通道進(jìn)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(wǎng)描繪Describe3DWDMnetworkDWDM設(shè)備經(jīng)過裝備為光終端復(fù)用網(wǎng)元、光線路擴大網(wǎng)元和光分插復(fù)用網(wǎng)元設(shè)備，構(gòu)成不一樣的網(wǎng)絡(luò)拓?fù)洌瑵M意各層次的組網(wǎng)需要，其組網(wǎng)方法首要能夠分為鏈型以及環(huán)形組網(wǎng)兩種方法。其間鏈型組網(wǎng)，能夠供給光層線路維護(hù)和電層SDH設(shè)備的通道或許復(fù)用段維護(hù)。在進(jìn)行短間隔傳輸時，DWDM設(shè)備能夠供給無線路擴大器的點對點組網(wǎng)，而在長間隔傳輸時，能夠在終端設(shè)備之間添加光中繼擴大器。環(huán)形組網(wǎng)在運用進(jìn)程中，能夠依據(jù)實際需要運用光分插復(fù)用設(shè)備構(gòu)成環(huán)形網(wǎng)，這其間有必要要有一個站點用背靠背光終端復(fù)用網(wǎng)元來組成光分插復(fù)用網(wǎng)元。別的，在進(jìn)行DWDM組網(wǎng)描繪時還應(yīng)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(xì)是指由發(fā)送光源的光譜特性以及光纖色度色散所發(fā)作的影響光傳輸間隔的要素。關(guān)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?shù)乃俾什粩噙M(jìn)步，以及體系中光擴大器數(shù)量的添加，使得整個傳輸網(wǎng)絡(luò)中的總色散值隨之增大，所以色散約束已經(jīng)成為制約傳輸體系中再生中繼間隔的重要要素。因而，在進(jìn)行DWDM網(wǎng)絡(luò)描繪時有必要注重色散受限間隔，詳細(xì)是將整個網(wǎng)絡(luò)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(jìn)而能夠減小色度色散對整個網(wǎng)絡(luò)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(jìn)行長間隔傳輸?shù)墓庑盘栆笃涔β誓軌虻窒饫w的衰耗，在進(jìn)行功率核算時，通常只對傳輸網(wǎng)絡(luò)中兩個相鄰的設(shè)備進(jìn)行功率預(yù)算，而不對準(zhǔn)整個網(wǎng)絡(luò)進(jìn)行一致的功率預(yù)算。將傳輸網(wǎng)絡(luò)中相鄰的兩個設(shè)備間的間隔衰耗稱作中繼間隔衰耗。當(dāng)整個網(wǎng)絡(luò)經(jīng)過色散受限核算，劃分為若干個再生中繼間隔段后，再經(jīng)過功率受限預(yù)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(nèi)發(fā)作光，即所謂擴大的自發(fā)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(fā)輻射噪聲將隨同光信號重復(fù)進(jìn)行衰減和擴大的進(jìn)程。這樣一來，就使得傳輸過來的自發(fā)輻射噪聲在每個光擴大器中都要進(jìn)行擴大疊加，即總的噪聲功率跟著光擴大器數(shù)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(shù)存在區(qū)別，所以在描繪時有必要以光信噪比的最差狀況進(jìn)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(wǎng)。因為非線性要素是在通訊網(wǎng)絡(luò)傍邊與光強有關(guān)的一些物理現(xiàn)象，所以只要在光強到達(dá)特定的臨界值時才會發(fā)作。當(dāng)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(gòu)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