cubin_Andrew_Zalesky_thesis

TeletrafficPerformanceModelsforAll-OpticalNetworksandtheirAnalysisbyAndrewL.ZaleskySubmittedintotalfulfilmentoftherequirementsforthedegreeofDoctorofPhilosophyDepartmentofElectricalandElectronicEngineeringUniversityofMelbourneAustralia2006AbstractThisthesisisabouttheperformancemodellingandevaluationofall-opticalswitchingtechniquesforthewavelength-divisionmultiplexedlayer.Weclas-sifyanall-opticalapproachtoswitchingaseitheropticalburstswitching(OBS),opticalcircuitswitching(OCS)oropticalpacketswitching.ThescopeofthisthesisisconfinedtoOBSandOCSaswellashybridapproachesthatarederivedbycombiningthetwotoallowforapolymorphicopticallayer.WedevelopteletrafficperformancemodelsforseveralformsofOCSandOBS,including:•Wavelength-routing;•DistributivelyandcentrallycontrolledvariantsofdynamicOCS,wherewedefinedynamicOCSasanyformofOCScapableofstatisticallymultiplexingwavelengthcapacityonatleastamillisecondtimescale;•Time-slottedformsofdynamicOCS;•OBSwithlimitedandfullwavelengthconversion;and,•OBSwithdeflectionrouting.Allthemodelswedevelopareopen-looplossmodelseitherforabackbonenetworkorastand-alonelink.Ourgenericmodelforabackbonenetworkconsistsofedgeroutersatwhichpacketsareenqueuedandacoreofopticalcross-connectsthatareinterconnectedviawavelength-divisionmultiplexedlinks.Weparticularisethisgenericmodelbyspecifyinghowpacketsareswitchedfromoneedgeroutertoanother.Fortheparticularmodelsweidevelop,wederiveanalyticalapproximationsforthethreeimportanttele-trafficperformancemeasuresof:end-to-endblockingprobability;thepre-transmissionqueuingdelaydistributionexperiencedbyapacketenqueuedatanedgerouter,orthemeanofthisdistributionifthedistributionitselfistoodifficulttoaccuratelyapproximate;and,wavelengthcapacityutilisation.Computersimulationisusedtoverifytheaccuracyofeachapproximation.Assuch,wedividethetaskofperformanceevaluationintothreesteps:modeldevelopment,modelanalysisandanalysisverification.Mostchaptersinthisthesisaredevotedtoimplementingthissimplethree-steprecipeforaparticu-larswitchingtechnique.TheexceptionsareChapters3,8and10.Chapter3isdevotedtothecross-layeroptimisationofthelogicaltopology,androutingandwavelengthassignmentinawavelength-routednetwork,whileChap-ter10proposesanewapproximationforblockingprobabilityinoverflowlossnetworks.AndinChapter8,weuseourperformancemodelstoquan-tifyhowwellOBSstacksupagainstOCSfromateletrafficist’sviewpoint.Weseethatatwodimensionaldelay/blockingplotcanbedividedintofourquadrantscorrespondingtoOBS-onlyandOCS-onlyquadrants,anOBSorOCSquadrantandaquadrantencompassingunattainabledelay/blocking.WeareabletodeterminewhichofOBSorOCSshouldbeusedtoachieveaprescribeddelay/blockingwhilemaximisingutilisation.Wealsoseethatsacrificinganassuranceofnoblockingateachopticalcross-connectwiththeuseofOBSisnotasattractiveinopticalnetworksasitsanalogueoftell-and-gowasinATMnetworks.Themaincontributionofthisthesisisacomprehensivesuiteofapproximationsandexactanalyticalresultsthatcanbeusedfordimensioningandquantitativeevaluation.Wepresentseveralsuchapplicationsandnumericalexamplesattheendofeachchapter.iiDeclarationThisistocertifythat:(i)Thethesiscomprisesonlymyoriginalwork(ii)Dueacknowledgementhasbeenmadeinthetexttoallothermaterialused(iii)Thethesisislessthan100,000wordsinlength,exclusiveoftable,maps,bibliographies,appendicesandfootnotesSignatureDateiiiivPrefaceThisthesispresentsmuchoftheworkIhaveundertakenduringmythreeandahalfyearPhDcandidature.ThecontentofeachchapteriscloselyalignedwithoneormoreresearchpapersthatIhaveco-authoredduringmycandidature.Therefore,muchofthecontentofthisthesishasalreadybeenpeerreviewed.Inmostchapters,Ihavepresentedfewernumericalresultsthaninthecorrespondingresearchpapers.Furthermore,Ihaveincludedsubstantiallymorebackgroundinthisthesis.TheorderofchaptersalmostcorrespondstothechronologicalorderinwhichIhavepursuedmyresearch.TheonlyexceptionisthatChapter8andChapter10shouldhavebeenswapped.IdecidedagainstthisthoughtoimprovethecontinuitybetweenChapter8,whichquantifieshowwellOBSstacksupagainstOCS,andtheprecedingchapters,whichfocuseitheronOBSorOCS.ThestructureandorganisationofeachchapterbeyondChapter3issimi-lar.Atypicalchapterinthisthesisbeginswiththedevelopmentofanetworkorstand-alonelinkmodelforacertainopticalswitchingtechnique.Then,usingtheanalyticalapproachtoperformanceevaluation,approximationsforotherwisecomputationallyintractableteletrafficperformancemeasuresarederived.Finally,theaccuracyofeachapproximationisverifiedwithcom-putersimulation.Assuch,atypicalchaptercomprisesthreeparts:modeldevelopment,modelanalysisandanalysisverification.Alltheperformancemodelsdevelopedinthisthesisareopen-looplossmodels.Therehasbeeninterestrecentlyin“closingtheloop”bymodellingthepresenceofaretransmissionprotocol.Closedloopmodelsarenotcon-sideredinthisthesis.vChapters4and5applythisthree-partapproachtoOBS,whileChapters6and7toOCSandChapter9toopticalhybridswitching.Chapter8isaculminationofthefourprecedingchaptersinthatitreliesonthemodelsdevelopedinthesechapterstoquantifyhowwellOBSstacksupagainstOCS.TheexceptionsareChapters2,3and10.InChapter2,Ioutlineth