OTN學(xué)習(xí)筆記1-5-完整版

OTN學(xué)習(xí)筆記1、Theopticaltransporthierarchy(OTH)supportstheoperationandmanagementaspectsofopticalnetworksofvariousarchitectures,e.g.,point-to-point,ringandmesharchitectures.ThisRecommendationdefinestheinterfacesoftheopticaltransportnetworktobeusedwithinandbetweensubnetworksoftheopticalnetwork,intermsof:–opticaltransporthierarchy(OTH);–functionalityoftheoverheadinsupportofmulti-wavelengthopticalnetworks;–framestructures;–bitrates;–formatsformappingclientsignals.光傳送序列（OTH）支持各種體系結(jié)構(gòu)（即點對點、環(huán)形和網(wǎng)孔形體系結(jié)構(gòu)）光網(wǎng)絡(luò)的運行和管理。依據(jù)光傳送序列（OTH）、多波長光網(wǎng)絡(luò)支持中的開銷功能、幀結(jié)構(gòu)比特率及映射客戶信號的方式，本建議定義了光傳送網(wǎng)絡(luò)的接口，以便將這些接口用于光網(wǎng)絡(luò)的子網(wǎng)內(nèi)部和子網(wǎng)之間。2、opticaltransportmodule(OTM-n.m):TheOTMistheinformationstructurethatistransportedacrossanONNI.Theindexnandmdefinethenumberofsupportedwavelengthsandbitratesattheinterface.TwoOTMstructuresaredefined:TheOTMwithfullfunctionality(OTM-n.m)istheinformationstructureusedtosupportopticaltransmissionsection(OTS)layerconnectionsintheOTN.Thecharacteristicinformationoftheopticaltransmissionsectionlayer(OTS_CI)consistsofinformationpayload(OTS_CI_PLD)andopticaltransmissionsectionoverheadinformationfields(OTS_CI_OH).Theopticaltransmissionsectionoverhead(OTS_OH)informationfieldsarecontainedwithintheOTMoverheadsignal(OOS)informationstructure.TheOTM-n.mconsistsofuptonmultiplexedopticalchannelsandanOTMoverheadsignaltosupportthenon-associatedoverhead.TheOTMwithreducedfunctionality(OTM-nr.m/OTM-0)istheinformationstructureusedtosupportopticalphysicalsection(OPS)layerconnectionsintheOTN.Thecharacteristicinformationoftheopticalphysicalsectionlayer(OPS_CI)consistsofinformationpayload(OPS_CI_PLD).OTM-0consistsofasingleopticalchannelwithoutaspecificcolourassigned.TheOTM-nr.mconsistsofuptonmultiplexedopticalchannels.Non-associatedoverheadisnotsupported光傳送模塊（OTM）：OTM是穿越ONNI傳送的信息結(jié)構(gòu)。n和m定義了接口支持的波長數(shù)量和比特率。定義了兩種OTM：完全功能OTM（OTM-n.m）和簡化功能OTM（OTM-0和OTM-nr.m）。完全功能OTM（OTM-n.m）是用于支持OTN中光傳輸段（OTS）層連接的信息結(jié)構(gòu)。光傳輸段層的特征信息（OTS_CI）由信息凈荷（OTS_CI_PLD）和光傳輸段開銷信息（OTS_CI_OH）組成。光傳輸段開銷（OTS_OH）信息包含在OTM開銷信號（OOS）信息結(jié)構(gòu)中。為了支持非聯(lián)合開銷，完全功能OTM-n.m由最多n個復(fù)用的光信道和一個OTM開銷構(gòu)成。簡化功能OTM（OTM-nr.m/OTM-0）是用于支持OTN中光物理段（OPS）層連接的信息結(jié)構(gòu)。光物理段層的特征信息（OPS_CI）由信息凈荷（OPS_CI_PLD）組成。OTM-0由不具有分配特定顏色的單個光信道構(gòu)成。OTM-nr.m最多由n個復(fù)用光信道組成。不支持非聯(lián)合開銷。3、opticalchannel(OCh[r]):TheOChistheinformationstructureusedtosupporttheOChtrail.TwoOChstructuresaredefined.TheOChclientsignalsdefinedinthisRecommendationaretheOTUksignals.Otherdigitalclientsignals(e.g.,STM-n,GbE)maybesupportedbytheOTM.Opticalchannelwithfullfunctionality(OCh):TheOChisaninformationstructureconsistingoftheinformationpayload(OCh_PLD)withacertainbandwidthandnon-associatedoverhead(OCh_OH)formanagementoftheopticalchannel.Opticalchannelwithreducedfunctionality(OChr):TheOChrisaninformationstructureconsistingoftheinformationpayload(OCh_PLD)withacertainbandwidth.Non-associatedoverheadisnotsupported.光信道（OCh）：OCh是用于支持OCh蹤跡的信號結(jié)構(gòu)。定義了兩種結(jié)構(gòu)的OCh。本建議中定義的OCh客戶信號為OTUk信號?？梢酝ㄟ^OTM支持其他數(shù)字客戶信號（即STM-n和GbE）。完全功能光信道（OCh）：為了管理光信道，OCh是一種由具有特定帶寬和非聯(lián)合開銷（OCh_OH）的、信息凈荷（OCh_PLD）組成的信息結(jié)構(gòu)。簡化功能光信道（OChr）：OChr是一種由具有特定帶寬的、信息凈荷組成的信息結(jié)構(gòu)。不支持非聯(lián)合開銷。4、opticalchanneltransportunit(OTUk[V]):TheOTUkistheinformationstructureusedfortransportofanODUkoveroneormoreopticalchannelconnections.ItconsistsoftheopticalchanneldataunitandOTUkrelatedoverhead(FECandoverheadformanagementofanopticalchannelconnection).Itischaracterizedbyitsframestructure,bitrate,andbandwidth.TwoversionsoftheOTUkaredefined:CompletelystandardizedOTUk(OTUk):ThecompletelystandardizedOTUkisusedonOTMIrDIsandmaybeusedonOTMIaDIs.FunctionallystandardizedOTUk(OTUkV):ThepartlystandardizedOTUkisusedonOTMIaDIs.光信道傳送單元（OTUk）：OTUk是為了在一個或多個光信道連接上進行光信道數(shù)據(jù)單元（ODUk）傳送的信息結(jié)構(gòu)。它由ODUk和OTUk相關(guān)開銷（用于光信道連接的FEC和開銷）組成。它由其幀結(jié)構(gòu)、比特率及帶寬規(guī)范。定義了兩種版本的OTUk。完全標(biāo)準(zhǔn)化OTUk（OTUk）：完全標(biāo)準(zhǔn)化OTUk可以用于OTMIrDIs和OTMIaDIs。功能標(biāo)準(zhǔn)化OTUk（OTUkV）：部分標(biāo)準(zhǔn)化OTUk用于OTMIaDIs。5、opticalchannelpayloadunit(OPUk):TheOPUkistheinformationstructureusedtoadaptclientinformationfortransportoveranopticalchannel.ItcomprisesclientinformationtogetherwithanyoverheadneededtoperformrateadaptationbetweentheclientsignalrateandtheOPUkpayloadrateandotherOPUkoverheadsupportingtheclientsignaltransport.Thisoverheadisadaptationspecific.光信道凈荷單元（OPUk）：OPUk是為了用于在一個光信道中傳送適配客戶信息的信息結(jié)構(gòu)。它由客戶信息與需要在客戶信號比特率與OPUk比特率之間完成速率適配的任何開銷和支持客戶信號傳送的其他OPUk開銷一起組成。該開銷是適配特定的。6、opticalmultiplexunit(OMU-n,n≥1):TheOMU-nistheinformationstructureusedtosupportopticalmultiplexsection(OMS)layerconnectionsintheOTN.Thecharacteristicinformationoftheopticalmultiplexsectionlayer(OMS_CI)consistsofinformationpayload(OMS_CI_PLD)andopticalmultiplexsectionoverheadinformationfields(OMS_CI_OH).TheOMS_CI_PLDconsistsoftheOCG-npayload.TheOMS_CI_OHconsistsoftheOCG-noverheadandOMSspecificoverheadandistransportedwithintheOOSinformationstructure.TheorderoftheOMUisdefinedbytheorderoftheOCGthatitsupports光復(fù)用單元（OMU-n,n≥1）：OMU-n是用于在OTN中支持光復(fù)用段（OMS）層連接的信息結(jié)構(gòu)。光復(fù)用段層的特定信息（OMS_CI）由信息凈荷（OMS_CI_PLD）和光復(fù)用段開銷信息（OMS_CI_OH）組成。OMS_CI_PLD由OCG-n凈荷組成。OMS_CI_OH由OCG-n開銷和OMS特定開銷組成，并且在一個OOS信息結(jié)構(gòu)中傳送。OMU的階數(shù)支持的OCG階數(shù)決定。7、opticaltransportnetworknodeinterface(ONNI):Theinterfaceatanopticaltransportnetworknodewhichisusedtointerconnectwithanotheropticaltransportnetworknode.光傳送網(wǎng)絡(luò)節(jié)點接口（ONNI）：用于與其他光傳送網(wǎng)絡(luò)節(jié)點連接的、在光傳送網(wǎng)絡(luò)節(jié)點處的接口。8、OTMoverheadsignal(OOS):TheOOSistheinformationstructureusedfortransportofOTMnon-associatedoverheadovertheopticalsupervisorychannel.Thenon-associatedoverheadconsistsoftheopticaltransmissionsectionoverhead,opticalmultiplexsectionoverheadandopticalchannelnon-associatedoverhead.Itischaracterizedbyitsframestructure,bitrateandbandwidth.OTM開銷信號（OOS）：OOS是用于在光監(jiān)控信道上進行OTM非聯(lián)合開銷傳送的信息結(jié)構(gòu)。非聯(lián)合開銷由光傳輸段開銷、光復(fù)用段開銷和光信道非聯(lián)合開銷組成。它由其幀結(jié)構(gòu)、比特率及帶寬規(guī)范。9、opticalsupervisorychannel(OSC):ThephysicalcarrieroutsideoftheamplifierbandthatprovidestransportoftheOTMoverheadsignal.光信道監(jiān)控信道（OSC）：提供OTM開銷信號傳送的放大器帶外物理載波。10、OTUk,ODUkandOPUkoverheadassignment:Theassignmentofoverheadintheopticalchanneltransport/data/payloadunitsignaltoeachpartisdefinedinFigure5-1.OTUk、ODUk和OPUk開銷分配：光信道傳送/數(shù)據(jù)/凈荷單元信號到每一部分中的開銷分配如下。圖5.111、OpticaltransportnetworkinterfacestructureTheopticaltransportnetworkasspecifiedinITU-TRec.G.872definestwointerfaceclasses:-Inter-domaininterface(IrDI);-Intra-domaininterface(IaDI).ThebasicsignalstructureisshowninFigure6-1.光傳送網(wǎng)絡(luò)接口結(jié)構(gòu)ITU-TG.872建議中規(guī)范的光傳送網(wǎng)絡(luò)定義了兩種接口類型：域間接口（IrDI）和域內(nèi)接口（IaDI）。圖6.112、opticaltransportnetwork（OTN）:atransportnetworkboundedbyopticalchannelaccesspoints.AnOpticalTransportNetwork(OTN)iscomposedofasetofOpticalNetworkElementsconnectedbyopticalfibrelinks,abletoprovidefunctionalityoftransport,multiplexing,routing,management,supervisionandsurvivabilityofopticalchannelscarryingclientsignals,accordingtotherequirementsgiveninITU-TG.872.光傳送網(wǎng)絡(luò)（OTN）：一種由光信道接入點約束的傳送網(wǎng)絡(luò)。根據(jù)ITU-TG.872建議給定的要求，OTN由一組通過光纖鏈路連接的、能夠提供攜帶客戶信號的傳送、復(fù)用、路由發(fā)現(xiàn)、管理功能、監(jiān)控和生存性功能的光網(wǎng)元組成。13、accesspoint（AP）:A"referencepoint"thatconsistsofthepairofco-located"unidirectionalaccess"points,andthereforerepresentsthebindingbetweenthetrailterminationandadaptationfunctions接入點（AP）：由一對共點“單向接入”點組成的“參考點”。所以，接入點代表蹤跡終結(jié)和適配功能之間的綁定關(guān)系。OTN學(xué)習(xí)筆記214、ODUkpath(ODUkP):Theopticalchanneldataunitkpath(ODUkP)istheinformationstructureusedtosupporttheend-to-endODUktrail.ODUk通道（ODUkP）：ODUkP是用于支持端到端ODUk蹤跡的信息結(jié)構(gòu)。15、ODUkTCM(ODUkT):TheopticalchanneldataunitkTCM(ODUkT)istheinformationstructureusedtosupporttheTCMtrails.Upto6TCMsublayersaresupported.ODUkTCM（ODUkT）：ODUkT是用于支持TCM蹤跡的信息結(jié)構(gòu)。最多可以支持6個TCM子層。16、opticalchannelcarrier(OCC[r]):TheopticalchannelcarrierrepresentsatributaryslotwithintheOTM-n.TwoOCCstructuresaredefined:OCCwithfullfunctionality(OCC):TheOCCconsistsoftheOCCPayload(OCCp)andOCCOverhead(OCCo).TheOCCpcarriestheOCh_CI_PLDandisassignedtoawavelength/frequencyslotoftheWDMgroup.TheOCCocarriestheOCh_CI_OHandistransportedwithintheOOSinformationstructure.OCCwithreducedfunctionality(OCCr):TheOCCconsistsoftheOCCPayload(OCCp).TheOCCpcarriestheOCh_CI_PLDandisassignedtoawavelength/frequencyslotoftheWDMgroup.Non-associatedoverheadisnotsupported.光信道載波（OCC）：OCC表示OTM-n中的支路時隙。定義了兩種結(jié)構(gòu)的OCC：完全功能OCC（OCC）：OCC由OCC凈荷（OCCp）和OCC開銷（OCCo）組成。OCCp攜帶OCh_CI_PLD，并且被安排在WDM組的一個波長/頻率位置。OCCo攜帶OCh_CI_OH，并且在OOS信息結(jié)構(gòu)中傳送。簡化功能OCC（OCCr）：OCCr由OCCp組成。OCCp攜帶OCh_CI_PLD，并且被安排在WDM組的一個波長/頻率位置。不支持非聯(lián)合開銷。18、opticalcarriergroupofordern(OCG-n[r]):nopticalchannelcarriersoccupyingfixed,definedpositionsinanOTMpayloadaretermedanopticalcarriergroup(OCG[r]).TwoOCGstructuresaredefined:OCGwithfullfunctionality(OCG-n):TheOCG-nconsistsofuptonOCCpayload(OCCp)andOCCOverhead(OCCo).OCGwithreducedfunctionality(OCG-nr):TheOCG-nrconsistsofuptonOCCpayload(OCCp).Non-associatedoverheadisnotsupportedn階光載波組（OCG-n）：在OTM凈荷中占據(jù)固定、限定位置的n個光信道載波是用于描述光載波組的術(shù)語。定義了兩種結(jié)構(gòu)的OCG：完全功能OCG（OCG-n）：OCG-n由最多n個OCCp和OCCo組成。簡化功能OCG（OCG-nr）：OCG-nr由最多n個OCCp組成。不支持非聯(lián)合開銷。19、opticalphysicalsectionofordern(OPSn):alayernetworkthatprovidesfunctionalityfortransmissionofamulti-wavelengthopticalsignalonopticalmediaofvarioustypes(e.g.,G.652,G.653andG.655fibre).Notethata"multi-wavelength"signalincludesthecaseofjustoneopticalchannel.ItcombinesthetransportfunctionalityoftheOMSandOTSlayernetworkswithouttheirsupervisoryinformation.OPSncapacitiesforn=0andn=16aredefined.n階OPS（OPSn）：為各種類型光介質(zhì)（即G.652、G.653和G.655光纖）提供多波長光信號傳輸功能的層網(wǎng)絡(luò)。注意：這里的“多波長”信號包括一個光信道的情況。它將OMS和OTS層網(wǎng)絡(luò)的傳送功能，并且不包括它們的監(jiān)控信息。定義了n=0和n=16的OPSn容量。20、TheinformationstructurefortheOTNinterfacesisrepresentedbyinformationcontainmentrelationshipsandflows.TheprincipalinformationcontainmentrelationshipsaredescribedinFigures6-2,6-3and6-4.TheinformationflowsareillustratedinFigure6-5.ForsupervisionpurposesintheOTN,theOTUk/OTUkVsignalisterminatedwhenevertheOChsignalisterminated.OTN接口的信息結(jié)構(gòu)由基本信息包含關(guān)系和信息流表示。在圖6-2、6-3和6-4中描述了這種基本信息包含關(guān)系。在圖6-5中，描述了相應(yīng)的信息流。圖6-2OTM-n.m基本信息包含關(guān)系圖6-3OTM-0.m基本信息包含關(guān)系圖6-4OTM-nr.m基本信息包含關(guān)系圖6-5信息流關(guān)系舉例（略）21、Figure7-1showstherelationshipbetweenvariousinformationstructureelementsandillustratesthemultiplexingstructureandmappings(includingwavelengthandtimedivisionmultiplexing)fortheOTM-n.圖7-1表示各種信息結(jié)構(gòu)之間的關(guān)系，并且也表明了OTM-n的復(fù)用結(jié)構(gòu)和映射結(jié)構(gòu)（包括波長和時分復(fù)用）。圖7-1（1）圖7-1左上部分圖7-1（2）圖7-1左中部分圖7-1（2）圖7-1左下部分圖7-1（3）圖7-1中間部分圖7-1（4）圖7-1右半部分我理解的OTN大概是這樣的：第一步，將客戶光信號變成電信號；第二步，形成OPUk信號；第三步，形成ODUk信號；第四步，形成OTUk信號；第五步，形成OCh或OChr信號；第六步，由OCh形成（實際是復(fù)用）OMSn或由OChr形成OPSn信號（并且以O(shè)TM-0.m或OTM-0形式傳送），并且完成電光變換（這一步有疑問，需要繼續(xù)學(xué)習(xí)）；第七步，由OMSn信號形成OISn信號（并且以O(shè)TM-n.m形式傳送）。OTN學(xué)習(xí)筆記4：36、Theopticalchannelwithfullfunctionality(OCh)structureisconceptuallyshowninFigure10-1.Itcontainstwoparts:OChoverheadandOChpayload完全功能光信道（OCh）結(jié)構(gòu)概念性地示于圖10-1中。它包含兩個部分：OCh開銷和OCh凈荷。37、Theopticalchannelwithreducedfunctionality(OChr)structureisconceptuallyshowninFigure10-2.Itcontains:OChrpayload.簡化功能光信道（OChr）結(jié)構(gòu)概念性地示于圖10-2中。它包含OCh凈荷。38、TheOTUk[V]conditionstheODUkfortransportoveranopticalchannelnetworkconnection.TheOTUkframestructureiscompletelystandardized.TheOTUkVisaframestructurethatisonlyfunctionallystandardized(i.e.,onlytherequiredfunctionalityisspecified).ThecompletelystandardizedOTUkframestructureasdefinedinthisRecommendationisshowninFigureII.1.OTUkVwiththesameoverheadbyteallocationastheOTUk,butuseofanalternativeFECasshowninFigureII.2.OTUkVwiththesameoverheadbyteallocationastheOTUk,butuseofasmaller,alternativeFECcodeandtheremainderoftheOTUkVFECoverheadareafilledwithfixedstuffasshowninFigureII.3.OTUkVwithalargerFECoverheadbyteallocationastheOTUk,anduseofanalternativeFECasshowninFigureII.4.OTUkVwithnooverheadbyteallocationforFECasshowninFigureII.5.OTUkVwithadifferentframestructurethantheOTUkframestructure,supportingadifferentOTUoverhead(OTUkVoverheadandOTUkVFEC)asshowninFigureII.6.OTUkVwithadifferentframestructurethantheOTUkframestructure,supportingadifferentOTUoverhead(OTUkVoverhead)andwithnooverheadbyteallocationforFECasshowninFigureII.7.OTUk[V]為使ODUk在光信道網(wǎng)絡(luò)連接上傳送提供條件。OTUk幀結(jié)構(gòu)完全標(biāo)準(zhǔn)化。OTUkV是一個功能標(biāo)準(zhǔn)化的幀結(jié)構(gòu)（即僅僅規(guī)范了要求的功能）。在本建議做定義了完全功能OTUk，如圖Ⅱ.1。具有與OTUk相同開銷字節(jié)分配的、應(yīng)用交替FEC的OTUkV幀結(jié)構(gòu)如圖Ⅱ.2。具有與OTUk相同開銷字節(jié)分配的、應(yīng)用較小、交替FEC編碼和由固定字節(jié)填充的OTUkVFEC開銷區(qū)余部的OTUkV幀結(jié)構(gòu)如圖Ⅱ.3。具有象OTUk一樣的較大FEC開銷字節(jié)分配的、應(yīng)用應(yīng)用交替FEC的OTUkV幀結(jié)構(gòu)如圖Ⅱ.4。沒有FEC開銷字節(jié)分配的OTUk，如圖Ⅱ.5。具有與OTUk幀結(jié)構(gòu)不同的、支持不同OUT開銷（OTUkV開銷和FEC開銷）的OTUkV，如圖Ⅱ.6。具有與OTUk幀結(jié)構(gòu)不同的、支持不同OUT開銷（OTUkV開銷）和沒有FEC開銷字節(jié)分配的OTUkV，如圖Ⅱ.7。39、TheOTUksignalmusthavesufficientbittimingcontentattheONNI.Asuitablebitpattern,whichpreventsalongsequenceof"1"sor"0"s,isprovidedbyusingascrambler.Theoperationofthescramblershallbefunctionallyidenticaltothatofaframesynchronousscramblerofsequencelength65535operatingattheOTUkrate.Thegeneratingpolynomialshallbe1+x+x3+x12+x16.Figure11-3showsafunctionaldiagramoftheframesynchronousscrambler.Thescramblershallberesetto"FFFF"(HEX)onthemostsignificantbitofthebytefollowingthelastframingbyteintheOTUkframe,i.e.,theMSBoftheMFASbyte.Thisbit,andallsubsequentbitstobescrambled,shallbeaddedmodulo2totheoutputfromthex16positionofthescrambler.ThescramblershallruncontinuouslythroughoutthecompleteOTUkframe.Theframingbytes(FAS)oftheOTUkoverheadshallnotbescrambled.ScramblingisperformedafterFECcomputationandinsertionintotheOTUksignal.在ONNI處，OTUk必須具有豐富的定時比特信息。通過應(yīng)用擾碼器，提供表示為長“1”或“0”序列的合適比特圖案。在功能上，擾碼器的運行應(yīng)該與工作在OTUk速率的、序列長度為65535的幀同步擾碼器相同。生成多項式應(yīng)該是1+x+x3+x12+x16。圖11-3給出了同步擾碼器的功能圖。在OTUk幀結(jié)構(gòu)中，在跟隨最后成幀字節(jié)后字節(jié)的最有效比特（即MFAS字節(jié)的MSB）時擾碼器應(yīng)該復(fù)位為“FFFF”（16進制）。該比特及所有被擾碼的序列比特應(yīng)該與擾碼器x16位置的輸出模二加。擾碼器應(yīng)該連續(xù)運行輸出全部OTUk幀。OTUk開銷的成幀字節(jié)（FAS）應(yīng)該不擾碼。應(yīng)該在FEC計算和插入到OTUk信號后進行擾碼。40、TheODUk(k=1,2,3)framestructureisshowninFigure12-1.Itisorganizedinanoctet-basedblockframestructurewithfourrowsand3824columns.ThetwomainareasoftheODUkframeare:-ODUkoverheadarea;-OPUkarea.Columns1to14oftheODUkarededicatedtoODUkoverheadarea.ODUk（k=1,2,3）幀結(jié)構(gòu)示于圖12-1。它被安排成4行和3824列的塊狀幀結(jié)構(gòu)。ODUk幀的兩個主要區(qū)域為ODUk開銷區(qū)域和OPUk區(qū)域。ODUk的的第1到第14列為ODUk開銷區(qū)域。41、TheOPUk(k=1,2,3)framestructureisshowninFigure13-1.Itisorganizedinanoctet-basedblockframestructurewithfourrowsand3810columns.ThetwomainareasoftheOPUkframeare:-OPUkoverheadarea;-OPUkpayloadarea.Columns15to16oftheOPUkarededicatedtoOPUkoverheadarea.Columns17to3824oftheOPUkarededicatedtoOPUkpayloadarea.OPUk（k=1,2,3）幀結(jié)構(gòu)示于圖13-1。它被安排成4行和3810列的塊狀幀結(jié)構(gòu)。OPUk幀的兩個主要區(qū)域為OPUk開銷區(qū)域和OPUk凈荷區(qū)域。OPUk的的第15到第16列為OPUk開銷區(qū)域。OPUk的的第17到第3824列為OPUk凈荷區(qū)域。42、TheOTMoverheadsignal(OOS)consistsoftheOTS,OMSandOChoverhead.Theformat,structureandbitrateoftheOOSisnotdefinedinthisRecommendation.TheOOSistransportedviaanOSC.Dependingonanoperator'slogicalmanagementoverlaynetworkdesign,generalmanagementcommunicationsmayalsobetransportedwithintheOOS.Therefore,theOOSforsomeapplicationsmayalsotransportgeneralmanagementcommunications.Generalmanagementcommunicationsmayincludesignalling,voice/voicebandcommunications,softwaredownload,operator-specificcommunications,etcOTM開銷信號（OOS）由OTS、OMS和OCh開銷組成。OOS的形式、結(jié)構(gòu)和比特率不在本建議中定義。OOS通過OSC傳送。與涉及網(wǎng)絡(luò)設(shè)計的操作人員邏輯管理有關(guān)的，通用管理通信可以在OOS中傳送。所以，一些應(yīng)用的OOS也可以傳送通用管理通信。通用管理通信可能包括信令、語音/語音頻帶通信、軟件下載、操作者特定通信等。OTN學(xué)習(xí)筆記543、AnoverviewofOTS,OMSandOChoverheadispresentedinFigure15-1.AnoverviewofOTUk,ODUkandOPUkoverheadispresentedinFigures15-2and15-3.OTS、OMS和OCh開銷示于圖15-1。OTUk、ODUk和OPUk示于圖15-2和15-3。44、OPUkOHinformationisaddedtotheOPUkinformationpayloadtocreateanOPUk.Itincludesinformationtosupporttheadaptationofclientsignals.TheOPUkOHisterminatedwheretheOPUkisassembledanddisassembled.TheOPUkoverheadconsistsof:payloadstructureidentifier(PSI)includingthepayloadtype(PT),overheadassociatedwithconcatenationandoverhead(e.g.,justificationcontrolandopportunitybits)associatedwiththemappingofclientsignalsintotheOPUkpayload.TheOPUkPSIandPToverheadlocationsareshowninFigure15-23.OnebyteisallocatedintheOPUkoverheadtotransporta256-bytepayloadstructureidentifier(PSI)signal.Thebyteislocatedinrow4,column15oftheOPUkoverhead.Aone-bytepayloadtypesignalisdefinedinthePSI[0]byteofthepayloadstructureidentifiertoindicatethecompositionoftheOPUksignal.SevenbytesarereservedintheOPUkoverheadformappingandconcatenationspecificoverhead.OPUkmappingspecificoverheadarelocatedinrows1to3,columns15and16andcolumn16row4.Inaddition,255bytesinthePSIarereservedformappingandconcatenationspecificpurposes.Theuseofthesebytesdependsonthespecificclientsignalmapping.將OPUkOH信息加入到OPUk信息凈荷上以創(chuàng)建一個OPUk。它包括支持客戶信號適配的信息。在建立和分解OPUk的地方，要終結(jié)OPUkOH。OPUkOH由包括凈荷類型（PT）的凈荷結(jié)構(gòu)指示符（PSI）、具有級聯(lián)有關(guān)的開銷及與客戶信號適配成OPUk凈荷有關(guān)的開銷（調(diào)整控制和調(diào)整機會比特）組成。OPUkPSI和PT的位置示于圖15-23。為了傳送一個256字節(jié)凈荷結(jié)構(gòu)指示符（PSI）信號，在OPUk中定義了1個字節(jié)。該字節(jié)定位于OPUk開銷的第4行和第15列。為了指示OPUk信號的補償，單字節(jié)凈荷類型在凈荷結(jié)構(gòu)指示符的PSI[0]字節(jié)定義。在OPUk開銷中預(yù)留7個字節(jié)用于映射和級聯(lián)特定開銷。OPUk映射特定開銷定位在第1到第3行和第15到第16列、第4行和第16列。此外，在PSI中預(yù)留255字節(jié)用于映射和級聯(lián)特定開銷。這些字節(jié)的應(yīng)用與特定客戶映射有關(guān)。45、ODUkOHinformationisaddedtotheODUkinformationpayloadtocreateanODUk.Itincludesinformationformaintenanceandoperationalfunctionstosupportopticalchannels.TheODUkOHconsistsofportionsdedicatedtotheend-to-endODUkpathandtosixlevelsoftandemconnectionmonitoring.TheODUkpathOHisterminatedwheretheODUkisassembledanddisassembled.TheTCOHisaddedandterminatedatthesourceandsinkofthecorrespondingtandemconnections,respectively.將ODUkOH加入到ODUk信息凈荷，以便形成一個ODUk。它包括支持光信道的維護和操作功能信息。ODUkOH由專用端到端ODUk通道和六級級聯(lián)監(jiān)視組成。ODUk通道OH在ODUk接入和接出的地方終結(jié)。TCOH（級聯(lián)開銷）分別在相關(guān)級聯(lián)連接的源和宿處被加入和終結(jié)。46、OTUkOHinformationispartoftheOTUksignalstructure.Itincludesinformationforoperationalfunctionstosupportthetransportviaoneormoreopticalchannelconnections.TheOTUkOHisterminatedwheretheOTUksignalisassembledanddisassembled.OTUkOH信息是OTUk信號結(jié)構(gòu)的一部分。它包括通過一個或多個光信道連接支持傳送的操作功能信息。OTUkOH在OTUk信號接入和接出的地方被終結(jié)。47、OChOHinformationisaddedtotheOTUktocreateanOCh.Itincludesinformationformaintenancefunctionstosupportfaultmanagement.TheOChOHisterminatedwheretheOChsignalisassembledanddisassembled.OChOH信息被加入到OTUk，以便創(chuàng)建一個OCh。它包括用于支持故障管理的維護功能的信息。OChOH在OCh信號接入和接出的地方被終結(jié)。48、OMSOHinformationisaddedtotheOCGtocreateanOMU.Itincludesinformationformaintenanceandoperationalfunctionstosupportopticalmultiplexsections.TheOMSOHisterminatedwheretheOMUisassembledanddisassembled.OMSOH信息被加入到OCG，以便創(chuàng)建一個OMU。它包括用于支持光復(fù)用段維護和操作功能的信息。OMSOH在OMU信號接入和接出的地方被終結(jié)。49、OTSOHinformationisaddedtotheinformationpayloadtocreateanOTM.Itincludesinformationformaintenanceandoperationalfunctionstosupportopticaltransmissionsections.TheOTSOHisterminatedwheretheOTMisassembledanddisassembled.OTSOH信息被加入到信息凈荷，以便創(chuàng)建一個OTM。它包括用于支持光傳輸段維護和操作功能的信息。OTSOH在OTM信號接入和接出的地方被終結(jié)。50、COMMSOHinformationisaddedtotheinformationpayloadtocreateanOTM.Itprovidesgeneralmanagementcommunicationbetweennetworkelements.COMMSOH信息被加入到信息凈荷，以便創(chuàng)建一個OTM。它在網(wǎng)元之間提供一般的管理通信。51、ntenancesignalsincludeOTSmaintenancesignals(OTS-PMI),OMSmaintenancesignals(OMS-FDI-P,OMS-FDI-OandOMS-PMI),OChmaintenancesignals(OCh-FDI-P,OCh-FDI-OandOCh-OCI),OTUkmaintenancesignals(OTUk-AIS),ODUkmaintenancesignals(ODUk-AIS,ODUk-OCIandODUk-LCK)andClientmaintenancesignal.OTS-PMIisgeneratedasanindicationthattheOTSpayloaddoesnotcontainanopticalsignal.OMS-FDI-PisgeneratedasanindicationofanOMSserverlayerdefectintheOTSnetworklayer.OMS-FDI-Oisgeneratedasani