YD-T 1159-2016光波分复用（WDM）系统测试方法

ICS33.040.20

M33

YYD/DT1159—2016

CommunicationsIndustryStandardofthe

People’sRepublicofChina

YD/T1159—2016

TestmethodsofopticalWavelengthDivision

Multiplexing(WDM)system

光波分复用（WDM）系统测试方法

（EnglishTranslation）

Issuedate:2016-04-05Implementationdate:2016-07-01

IssuedbyMinistryofIndustryandInformationTechnologyofthePeople’sRepublicofChina

YD/T1159—2016

Foreword

ChinaCommunicationsStandardsAssociation(CCSA)isinchargeofthisEnglishtranslation.

IncaseofanydoubtaboutthecontentsofEnglishtranslation,theChineseoriginalshall

beconsideredauthoritative.

ThispartisdraftedinaccordancewiththerulesgivenintheGB/T1.1-2009Directivesfor

standardization–Part1:Structureanddraftingofstandards.

Attentionisdrawntothepossibilitythatsomeoftheelementsofthispartmaybethesubject

ofpatentrights.Theissuingbodyofthisdocumentshallnotbeheldresponsiblefor

identifyinganyorallsuchpatentrights.

ThispartwasproposedandpreparedbyCCSA.

YD/T1159—2016

TestmethodsofopticalWavelengthDivision

Multiplexing(WDM)system

1Scope

Thisdocumentspecifiesthetestmethodsofthetechnicalindicatorsandperformance

requirementsoftheopticalwavelengthdivisionmultiplexing(WDM)system.Thisdocument

mainlyincludessystemconfigurationandtestreferencepointdefinition,opticaltransport

unittest,mainpathinterfacetest,opticalwavelengthdivisionmultiplexer/demultiplexer

test,opticalamplifiertest,dispersioncompensatortest,FECtest,dynamicpowercontrol

andgainequalizationtest,OADMtest,monitoringchanneltest,transmissionfunctionand

performancetest,networkmanagementsystemfunctionverification,WDMtemperaturecycletest

andAPRfunctionverification,etc.

Thisdocumentappliestoopenopticalwavelengthdivisionmultiplexing(WDM)systemswith

singlechannelratesof2.5Gbit/s,10Gbit/s,40Gbit/sand100Gbit/s.Forintegratedoptical

wavelengthdivisionmultiplexing(WDM)systems,itcanalsobeimplemented.

2Normativereferences

Thefollowingreferenceddocumentsareindispensablefortheapplicationofthisdocument.

Fordatedreferences,onlytheeditioncitedapplies.Forundatedreferences,thelatest

editionofthereferenceddocument(includinganyamendments)applies.

GB/T16850Basicspecificationforopticalfibreamplifiertestmethods

GB/T20440-2006Technicalrequirementsfordensewavelengthdivision

multiplexer/demultiplexer

YD/T1060-2000TechnicalrequirementsforWDMSystems-32×2.5Gbit/spart

YD/T1259-2003TechnicalspecificationforopticalsafeprocedureforWDMSystems

YD/T1274-2003TechnicalrequirementsforWDMSystems-160×10Gbit/sand80×10Gbit/spart

YD/T1339-2005TestmethodsformetropolitanopticaltransportnetworkWDMring

YD/T1383-2005TechnicalrequirementsforWDMelementmanagementsystem

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YD/T1159—2016

YD/T1960-2009TechnicalRequirementsforUltraLongHaulN×10Gbit/sWDMSystems

YD/T1991-2009TechnicalRequirementsforN×40Gbit/sWDMSystems

YD/T2147-2010TestmethodsforN×40Gbit/sWDMSystems

YD/T2485-2013TechnicalRequirementsforN×100Gbit/sWDMSystems

YD/T2489-2013Testmethodsforreconfigurableopticaladddropmultiplexing(ROADM)equipment

YD/T2649-2013TestmethodsforN×100Gbit/sWDMSystems

ITU-TG.692OpticalInterfacesforMultichannelSystemswithOpticalAmplifiers

ITU-TG.783Characteristicsofsynchronousdigitalhierarchy(SDH)equipmentfunctionalblocks

ITU-TG.783,Amendment3Characteristicsofsynchronousdigitalhierarchy(SDH)equipment

functionalblocks,Amendment3

ITU-TG.825Thecontrolofjitterandwanderwithindigitalnetworkswhicharebasedonthe

synchronousdigitalhierarchy(SDH)

ITU-TG.8251Thecontrolofjitterandwanderwithintheopticaltransportnetwork(OTN)

ITU-TG.959.1OpticalTransportNetworksPhysicalLayerInterfaces

IETFRFC2544BenchmarkingMethodologyforNetworkInterconnectDevices

IEC61290-10Opticalamplifiers-Testmethods:Multichannelparameters

IEC61290-11Opticalamplifiers-Testmethods:Polarizationmodedispersionparameter

3Abbreviationsandacronyms

Thisdocumentusesthefollowingabbreviationsandacronyms:

3R:Re-amplification,ReshapingandRetiming

AIS:AlarmIndicationSignal

APR:AutomaticPowerReduction

ASE:AmplifiedSpontaneousEmission

BBE:BackgroundBlockError

BBER:BackgroundBlockErrorRatio

BDI:BackwardDefectIndication

BER:BitErrorRatio

BERT:BitErrorRatioTesting

BIAES:BackwardIncomingAlignmentErrorSecond

CSF:ClientSignalFail

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DEG:Degraded

DFB:DistributedFeedBack

DGD:DifferentialGroupDelay

EDFA:Er-dopedFibreAmplifier

ES:ErroredSecond

ESC:ElectricSupervisoryChannel

EVM:ErrorVectorMagnitude

EXC:Excessive

FEBBE:FarEndBackgroundBlockError

FEBBER:FarEndBackgroundBlockErrorRatio

FEC:ForwardErrorCorrection

FEES:FarEndErroredSecond

FESES:FarEndSeverelyErroredSecond

FESESR:FarEndSeverelyErroredSecondRatio

FEUAS:FarEndUnavailableSecond

FOADM:FixedOpticalAdd-DropMultiplexer

IAES:IncomingAlignmentErrorSecond

IL:InsertLoss

ISOL:Isolation

LCK:Locked

LOF:LossofFrame

LOM:LossofMultiframe

LOS:LossofSignal

LTC:LossofTandemConnection

MPI:MainPathInterface

MPI-SM:MultichannelSourceMainPathInterfaceReferencePoint

MPI-RM:MultichannelReceiveMainPathInterfaceReferencePoint

MSIM:MultiplexStructureIdentifierMismatch

OA:OpticalAmplifier

OADM:OpticalAdd-DropMultiplexer

OBA:OpticalBoosterAmplifier

OCI:OpenConnectionIndication

ODU:OpticalDataUnit

ODUk:OpticalDataUnit-k

OLA:OpticalLineAmplifier

OMA:OpticalModulationAmplitude

OMU:OpticalMultiplexerUnit

OPA:OpticalPre-amplifier

OSC:OpticalSupervisoryChannel

OSNR:OpticalSignal-to-NoiseRatio

OTN:OpticalTransportNetwork

OTU:OpticalTransportUnit

OTUk:OpticalTransportUnit-k

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PLM:PayloadMismatch

PM:PathMonitoring

PMD:PolarizationModeDispersion

PRBS:PseudoRandomBinarySequence

R:ClientInterfaceSourceReferencePoint

RFA:RamanFiberAmplifier

ROADM:ReconfigurableOpticalAdd-DropMultiplexer

RM:MultichannelReceiveReferencePoint

Rn:Then-thChannelReceiveReferencePoint

Rx:OpticalReceiver

S:ClientInterfaceReceiveReferencePoint

SDH:SynchronousDigitalHierarchy

SES:SeverelyErroredSecond

SESR:SeverelyErroredSecondRatio

SM:SectionMonitoring

SM:MultichannelSourceReferencePoint

Sn:Then-thChannelSourceReferencePoint

SOA:Semiconductoropticalamplifier

SQM:SequenceNumberMismatch

SSF:ServerSignalFail

TCM:TandemConnectionMonitoring

TTI:TrailTraceIdentifier

Tx:OpticalTransmitter

UAS:UnavailableSecond

VCAT:VirtualConcatenation

VcPLM:VirtualConcatenationPayloadMismatch

WDM:WavelengthDivisionMultiplexing

WSS:WavelengthSelectiveSwitch

4WDMsystemconfigurationandtestreferencepointdefinition

4.1OpenWDMsystem

OpenWDMsystemaddsOTUbeforeOMU,convertsSDH,OTNorEthernetandotherservicewavelengths

intowavelengthsrequiredbyITU-TG.694.1standardspecification(thetransmittingend

functionofOTU),andatthesametimeaddsOTUafterODU,ThewavelengthrequiredbytheITU-T

G.694.1standardisconvertedintoSDH,OTNorEthernetandotherservicewavelengths(the

receivingendfunctionofOTU).

ThereferenceconfigurationoftheopenWDMsystemisshowninFigure1.Inthefigure,OTU

isopticalwavelengthconversionunittoachieve3Rfunctions,re-amplification,re-shaping

andre-timing.OMUisanopticalmultiplexingunit,whichimplementsmultiplewavelength

multiplexingfunction.OAisanopticalamplifier(includingadispersioncompensationunit),

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whichrealizestheopticaldomainamplificationofthesignal.ODUisanopticaldemultiplexing

unit,whichrealizesthedemultiplexingfunctionofmultiplewavelength.Tx/Rxisthe

client-sideopticalinterface.

Figure1ReferenceconfigurationofopenWDMsystem

4.2IntegratedWDMsystem

ThereferenceconfigurationoftheintegratedWDMsystemisshowninFigure2.Tx/Rxisan

SDHterminaltransmitterandreceiverwithanopticalinterfacespecifiedbyITU-TG.692,or

anOTNterminaltransmitterandreceiverwithanopticalinterfacespecifiedbyITU-TG.959.1.

Figure2ReferenceconfigurationofintegratedWDMsystem

4.3WDMsystemtestreferencepointdefinition

Figure1andFigure2define6systemexternalreferencepointsand2systeminternalreference

points.TheyareS,MPI-SM,RM,SM,MPI-RM,R,SnandRn.SandRarethereferencepointsof

theinterfacebetweentheWDMsystemandtheclientsystem.MPI-SM,RM,SMandMPI-RMarethe

referencepointsofthemainopticalchanneloftheWDMsystem.SnandRnarethereferencepoints

ofOTUbetweenOMUandODUintheWDMsystem.Atthesametime,nismarkedasthenominal

centerwavelengthcorrespondingtothecurrentreferencepoint.RefertoYD/T1060-2000,YD/T

1274-2003,YD/T1991-2009andYD/T2485-2013fortheparametersandspecificindexrequirements

ofrelatedreferencepoints.Thespecificmeaningsofthesereferencepointsareasfollows:

-Srepresentsthereferencepointoftheopticalfiberconnectionaftertheoutputinterface

oftheclientsignaltransmitter.

-SnrepresentsthereferencepointoftheopticalfiberconnectionaftertheOTUisconnected

totheoutputinterfaceoftheOMU.

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-MPI-SMrepresentsthereferencepointoftheopticalfiberconnectionaftertheOAoptical

outputinterfacebehindtheOMU.

-RMrepresentsthereferencepointoftheopticalfiberconnectionbeforetheOAinput

interface.

-SMrepresentsthereferencepointoftheopticalfiberconnectionaftertheOAoutput

interface.

-MPI-RMrepresentsthereferencepointoftheopticalfiberconnectionbeforetheOAinput

interfaceonthefrontoftheODU.

-RnrepresentsthereferencepointoftheopticalfiberconnectionbeforetheODUinput

interfaceconnectedtotheOTU.

-Rrepresentsthereferencepointoftheopticalfiberconnectionbeforetheinputinterface

oftheclientsignalreceiver.

5Opticaltransportunittest

5.1IntegratedOTUopticalparametertest

5.1.1Transmitterinterfaceparametertest

5.1.1.1Receiversensitivity

5.1.1.1.1Definition

Thereceiversensitivityistheminimumvalueoftheaveragereceivedopticalpoweratthe

referencepointSwhenthebiterrorratereaches1.0E-12.

5.1.1.1.2Testconfiguration

ThetestconfigurationisshowninFigure3.Thetestinstrumentsareserviceanalyzer,optical

powermeter,spectrumanalyzer,andopticaladjustableattenuator.Theserviceanalyzercan

selectOTNorEthernetanalyzeraccordingtotheserviceinterface.

(a)Single-channelinterface

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(b)Multi-channelinterface

Figure3Transmitterreceiversensitivity/overloadpowertestconfiguration

5.1.1.1.3Testprocedure

Theteststepsareasfollows:

a)ConnectthetestconfigurationasshowninFigure3,selectthecorrespondingtest

configurationaccordingtothesingle-channelormulti-channelinterfacetype,andconfirm

thattheserviceanalyzerandtheRnpointreceivetheappropriateopticalpower.

b)AdjusttheerrorcodeoftheadjustableopticalattenuatorAtotheserviceanalyzerto

displayabout1.0E-7.Theerrorratemonitoringtimeisrelatedtothesignalrate.Theamount

ofmonitoreddatashouldbeatleastanorderofmagnitudehigherthantheamountofdata

requiredtogeneratethespecifiederrorrate.

c)AdjusttheadjustableopticalattenuatorA,andtesttheopticalpowervaluecorresponding

tothereferencepointSwhentheerrorcodeisdisplayedas1.0E-8,1.0E-9,1.0E-10,1.0E-11.

d)Accordingtotheextrapolationmethod(suchastheleastsquaremethod,etc.),drawthe

receivedopticalpowerandbiterrorrateonthedoublelogarithmicgraphpaper(theordinate

shouldtaketwologarithmstoindicatethebiterrorrate.theabscissaindicatestheoptical

power)Correspondingtothecurve,theopticalpowercorrespondingtoBER=1.0E-12isthe

receivingsensitivity.

5.1.1.1.4Note

Notethefollowingitems:

a)InthecaseofEthernetserviceinterface,theconversionmethodbetweenthebiterrorrate

andthepacketlossrateundertheuniformdistributionoferrorscanbeusedforcalculation.

Packetlossrate＝1-(1-BER)n,nisthenumberofbitsintheEthernetframe.WhentheEthernet

analyzersupportstheBERTmode,youcanalsodirectlyusetheBERTmodetotestthebiterror

rate.

b)Undercertainconditions,suchasbatchtest,itcanalsodirectlyrecordtheopticalpower

valuewhentheanalyzererrorrateis1.0E-12.Oruseacriticalerror-freejudgmentmethod

torecordtheopticalpowervalue.Themonitoringtimeisnotlessthan4minforthe40Gbit/s

ratesignalandnotlessthan2minforthe100Gbit/sratesignal.

c)Forasingle-channelinterface,useanopticalpowermetertotestthepowervalue.For

amulti-channelinterface,useanopticalspectrumanalyzertotestthepowervalue.

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d)Takingintoaccounttheactualapplicationscenario,theconfigurationshowninFigure3

(a)canalsobeusedtotestthesensitivityofthemulti-channelinterface.Atthistime,

thetestresultistheapproximatereceivingsensitivityofallchannels.

e)Beforetheteststarts,thewavelengthandpowerparametersofthespectrumanalyzershould

becalibrated,andthecalibrationresultsshouldbecomparedwiththemulti-wavelengthmeter

andopticalpowermeter.

f)ForOTUwithFECfunction,theFECfunctionmustworknormallyduringthetest.

g)RefertoYD/T2649-2013informativeappendixAforthedifferencebetweenaverageoptical

powerreceivingsensitivityandOMAsensitivityanditsspecificanalysis.

5.1.1.2Overloadpower

5.1.1.2.1Definition

Theoverloadpoweristhemaximumacceptablevalueoftheaveragereceivedopticalpowerat

thereferencepointSwhenthebiterrorratereaches1.0E-12.

5.1.1.2.2Testconfiguration

ThetestconfigurationisshowninFigure3.Thetestinstrumentsareserviceanalyzer,optical

powermeter,spectrumanalyzer,andopticaladjustableattenuator.Theserviceanalyzercan

selectOTNorEthernetanalyzeraccordingtotheserviceinterface.

5.1.1.2.3Testprocedure

Theteststepsareasfollows:

a)ConnectthetestconfigurationasshowninFigure3,selectthecorrespondingtest

configurationaccordingtothesingle-channelormulti-channelinterfacetype,andconfirm

thattheserviceanalyzerandtheRnpointreceivetheappropriateopticalpower.

b)AdjusttheerrorcodeoftheadjustableopticalattenuatorAtotheopticalpowervalue

ofSpointisoverloadpowervalue.Whentheserviceanalyzerhasnobiterrororthebiterror

rateislessthanorequalto1.0E-12,therecordedoverloadpowerislessthanthecurrent

powervalue.

c)Whenitisnecessarytotesttheaccuratevalueofoverloadpower,theattenuationvalue

ofadjustableopticalattenuatorAcanbefurtherreduceduntilthebiterrorrateisclose

tobutlessthan1.0E-12.

5.1.1.2.4Note

Inadditiontothenotesinsection5.1.1.1.4,alsonotethefollowingitems:

a)Ifthetransmissionpowerofserviceanalyzercannotreachtheoverloadpower,optical

amplifier(suchasEDFA,SOA,etc.)canbeusedtoincreasethepowervalue(noiseoutsidethe

signalpassbandneedstobefiltered).

b)Ifthereisnoopticalamplifiercondition,thecurrentmaximumtestablevaluecanbe

recordedandthetestlimitconditionsshouldbeindicated.

5.1.1.3Reflectioncoefficient

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5.1.1.3.1Definition

Thereflectioncoefficientistheratioofthereflectedopticalpowerandtheinputoptical

poweratthereferencepointS.

5.1.1.3.2Testconfiguration

ThetestconfigurationisshowninFigure4.Thetestinstrumentisopticalreflection(return

loss)analyzer.

Figure4Opticalreflectioncoefficienttestconfigurationoftransmitterport

5.1.1.3.3Testprocedure

Theteststepsareasfollows:

a)Setthewavelengthoftheopticalreflection(returnloss)analyzertotheappropriate

receivingwindow(1310nmor1550nm)accordingtotheactualsignalwavelengthatpointS,and

calibratetheopticalreflection(returnloss)analyzer.

b)ConnectthetestconfigurationasshowninFigure4,andconfiguretheOTUtothepower-off

state,recordthetestresultaftertheanalyzerresultisstable.

5.1.1.4Averagetransmitopticalpower

5.1.1.4.1Definition

Theaveragetransmitpoweristheaveragepowercoupledtothefiberbythetransmitterat

thereferencepointSn.

5.1.1.4.2Testconfiguration

ThetestconfigurationisshowninFigure5.Thetestinstrumentsaresignalgeneratorand

opticalpowermeter.ThesignalgeneratorcanbeselectedasSDH,OTNorEthernetanalyzer

accordingtotheserviceinterface.

Figure5Transmitteraveragetransmitpowertestconfiguration

5.1.1.4.3Testprocedure

Theteststepsareasfollows:

a)ConnectthetestconfigurationasshowninFigure5,andsetOTUtonormalworkingstate.

b)Aftertheresultoftheopticalpowermeterisstable,recordthetotalpowervalueonthe

opticalpowermeter.

5.1.1.4.4Note

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Theopticalpowermeterselectsthecorrectwavelengthwindow.

5.1.1.5Centerfrequency(wavelength)andoffset

5.1.1.5.1Definition

Thecenterfrequency(wavelength)istheactualcenterfrequency(wavelength)oftheoptical

signalemittedatthereferencepointSn.Centerfrequency(wavelength)offsetisthedifference

betweenthenominalcenterfrequencyandtheactualcenterfrequency(wavelength),which

includestheeffectsofopticalsourcechirp,signalbandwidth,SPMbroadening,temperature

andaging.

5.1.1.5.2Testconfiguration

ThetestconfigurationisshowninFigure6.Thetestinstrumentsaresignalgeneratorand

multi-wavelengthmeter.ThesignalgeneratorcanselectSDH,OTNorEthernetanalyzeraccording

totheserviceinterface.

Figure6Transmittercenterfrequencytestconfiguration

5.1.1.5.3Testprocedure

Theteststepsareasfollows:

a)ConnectthetestconfigurationasshowninFigure6.

b)Setthefrequency(wavelength)rangedisplayedbythemulti-wavelengthmeter,andrecord

thecenterfrequency(wavelength)valueatthepeakvalue.

c)Thedifferencebetweenthetestcenterfrequency(wavelength)andthenominalcenter

frequency(wavelength)isthecenterfrequency(wavelength)offset.

5.1.1.5.4Note

Notethefollowingitems:

a)Thetestprocesscanflexiblyselectwavelengthorfrequencyastheunit.

b)Thespectrumanalyzerwhichwavelength/frequencyiscalibratedwithamulti-wavelength

meter,thetestaccuracyofthespectrumanalyzerisatleastanorderofmagnitudehigher

thantheaccuracyrequiredbythetestresult,canalsotestthecenterfrequency/wavelength,

andthetestmethodisthesameasthatofthemulti-wavelengthmeter.

c)Themulti-wavelengthmeterissettobroadbandworkingmodeduringthetest.

d)Amulti-wavelengthmetercanbeconnectedtotheMPI-SMpointtotestthecenterfrequency

ofallconfiguredwavelengthsatonetime.

e)Forsomedouble-peakormulti-peakmodulationcodespectrum,theaveragevalueofthe

double-peakormulti-peakcenterfrequency/wavelengthisusedtocalculatethecenter

frequency/wavelengthofthespectrum.

5.1.1.6Extinctionratio

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5.1.1.6.1Definition

Extinctionratioistheratiooftheaverageopticalpoweroflogic"1"totheaverageoptical

poweroflogic"0"underthefullmodulationconditionandtheworstreflectioncondition.

5.1.1.6.2Testconfiguration

ThetestconfigurationisshowninFigure7.Thetestinstrumentsaresignalgeneratorand

communicationsignalanalyzer.ThesignalgeneratorcanbeselectedasSDH,OTNorEthernet

analyzeraccordingtotheserviceinterface.

Figure7Transmitterextinctionratio/eyepatternmasktestconfiguration

5.1.1.6.3Testprocedure

Theteststepsareasfollows:

a)ConnectthetestconfigurationasshowninFigure7.

b)Adjusttheopticalattenuatortothedynamicrangeoftheinputopticalpowerofthe

communicationsignalanalyzer.

c)Adjustthecommunicationsignalanalyzer,recordtheextinctionratiovaluefromthemeter

afterthewaveformisstable.

5.1.1.6.4Note

Notethefollowingitems:

a)Thefilteroftheinternalreferencereceiverofthecommunicationsignalanalyzerisclosed

duringthetest.

b)Calibratetheanalyzerbeforethetest.

c)Forsignalsbasedonphasemodulation(suchasDPSK,P-DPSK,RZ-DQPSK,PM-QPSK,etc.),this

parameterisnotapplicable.

5.1.1.7Transmissionpulseshape(eyepatterntemplate)

5.1.1.7.1Definition

Thetransmittedsignalwaveformspecifiestheopticalpulseshapecharacteristicsofthe

transmitterintheformofaneyediagramtemplate,includingrisetime,falltime,pulse

overshootandoscillation.

5.1.1.7.2Testconfiguration

ThetestconfigurationisshowninFigure7.Thetestinstrumentsaresignalgeneratorand

communicationsignalanalyzer.ThesignalgeneratorcanbeselectedasSDH,OTNorEthernet

analyzeraccordingtotheserviceinterface.

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5.1.1.7.3Testprocedure

Theteststepsareasfollows:

a)ConnectthetestconfigurationasshowninFigure7.

b)Adjusttheopticalattenuatortothedynamicrangeoftheinputopticalpowerofthe

communicationsignalanalyzer.

c)Adjustthecommunicationsignalanalyzer,turnonthefiltercorrespondingtothesignal

undertest.Afterthewaveformisstable,usethecorrespondingeyepatterntemplatestored

inthecommunicationsignalanalyzertoachievewaveformalignmentthroughadjustment.

d)Afterthewaveformsamplingpointshaveaccumulatedatleast1000times,saveandrecord

theresults.

5.1.1.7.4Note

Notethefollowingitems:

a)Thetesteyediagramsignalrateis40Gbit/s(including43Gbit/s)andbelow.

b)Whenusingademultiplexertotesttheeyediagramforamulti-channelinterface,the

additionalinsertionlossintroducedbythesplittermaycausethepoweroftheopticalsignal

receivedbythecommunicationsignalanalyzertobetoolowandaffecttheeyediagramtest

results.

c)Whenmulti-channelinterfacetestingeyediagrams,theclocksynchronizationsignalofthe

communicationsignalanalyzershouldbeusedasmuchaspossiblewiththededicatedhigh-speed

outputclocksignalofthemulti-channelsignal(nottheinstrumentclocksignal).

d)Thisparameterisnotapplicabletotheeyepatternmasksofsignalsbasedonphasemodulation,

suchasDPSK,P-DPSK,RZ-DQPSKandPM-QPSK,etc.

e)Communicationsignalanalyzersgenerallydonotsupporttheclockrecoveryfunctionofthe

40Gbit/sopticalinterface,andthesynchronizationsignalisprovidedbytheelectrical

interfaceofthedeviceundertestoraspecial40Gbit/sclockrecoverymodule.

f)Fornon-intensitymodulatedsignalswitharateof40Gbit/sandabove,relatedparameters

suchasconstellationdiagramandEVMcanbetested.Thespecifictestmethodistobestudied.

5.1.1.8Sidemodesuppressionratio

5.1.1.8.1Definition

Thesidemodesuppressionratioistheratiooftheaverageopticalpowerofthemain

longitudinalmodetotheopticalpowerofthemostsignificantsidemodeunderthefull

modulationconditionundertheworstemissioncondition.

5.1.1.8.2Testconfiguration

ThetestconfigurationisshowninFigure8.Thetestinstrumentsaresignalgeneratorand

spectrumanalyzer,andthesignalgeneratorcanselectSDH,OTNorEthernetanalyzersaccording

totheserviceinterface.

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Figure8Transmitterspectrumtestconfiguration

5.1.1.8.3Testprocedure

Theteststepsareasfollows:

a)ConnectthetestconfigurationasshowninFigure8,settheworkingmodeofthespectrum

analyzertoDFBandtheresolutionbandwidthto0.1nmorless.

b)Setthewavelengthrangedisplayedbythespectrumanalyzerandadjusttheamplitudescale

ofthespectrumanalyzersothatthemainlongitudinalmodeandsidemodearedisplayedon

thescreenwithappropriateamplitude.

c)Adjusttheverticalcursor,recordtheaveragepeakopticalpowerofthemainlongitudinal

modeandthelargestsidemoderespectively,andcalculatethedifferencebetweenthetwopowers

(dBm)toobtainthesidemodesuppressionratio.Forspectrumanalyzersthatsupportautomatic

measurementofsidemodesuppressionrati