WDM Concept ponents.ppt

ponentsEE8114CourseNotesPart1:WDMConceptEvolutionoftheTechnologyWhyWDM?works(withoutaddingfibers)Transparency:Eachopticalchannelcancarryanytransmissionformat(differentasynchronousbitrates,analogordigital)Scalability–BuyandinstallequipmentforadditionaldemandasneededWavelengthroutingandswitching:WavelengthisusedasanotherdimensiontotimeandspaceWavelengthDivisionMultiplexingEachwavelengthislikeaseparatechannel(fiber)TDMVsWDMEx:WavelengthDivisionMultiplexingPassive/bine,distribute,isolateandamplifyopticalpoweratdifferentwavelengthsWDM,CWDMandDWDMWDMtechnologyusesmultiplewavelengthstotransmitinformationoverasinglefiberCoarseWDM(CWDM)haswiderchannelspacing(20nm)–lowcostDenseWDM(DWDM)hasdensechannelspacing()whichallowssimultaneoustransmissionof16+wavelengths–worksusedjusttwowavelengths,1310nmand1550nmToday'sDWDMsystemsutilize16,32,64,128ormorewavelengthsinthe1550nmwindowEachofthesewavelengthprovideanindependentchannel(Ex:eachmaytransmit10Gb/sdigitalorSCMAanalog)Therangeofstandardizedchannelgridsincludes50,100,200and1000GHzspacingWavelengthspacingpracticallydependson:laserlinewidthopticalfilterbandwidthITU-TStandardTransmissionDWDMwindows