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1、ComputerCommunications23(2000)1336±1348www.elsevier.com/locate/comcomTraf®cshapingforMPEGvideotransmissionoverthenextgenerationinternetM.F.Alama,M.Atiquzzamanb,*,M.A.KarimcaElectro-OpticsProgram,UniversityofDayton,Dayton,OH45469-0245,USAbDepartmentofElectricalandComput
2、erEngineering,UniversityofDayton,Dayton,OH45469-0226,USAcDepartmentofElectricalandComputerEngineering,UniversityofTennessee,Knoxville,TN37996-2100,USAAbstractTheInternetEngineeringTaskForce(IETF)hasproposedtheGuaranteedService(GS)intheIntegratedServicesmodelwith®rmdela
3、yandbandwidthguarantees.Inthispaper,westudytheeffectsofatokenbuckettraf®cshaperatthesourceonthetransmissioncharacteristicsofMotionPictureExpertsGroup(MPEG)compressedvideostreamsovertheGS.Wedevelopananalyticalmodelofthetraf®cshaper,andalsocarryoutnumericalsimulationofth
4、etransmissionperformanceusingMPEGtracedatafromseveraldifferentvideosequences.Theanalyticalmodelandthenumericalsimulationresultsareinexcellentagreement.Ourstudyprovidesatechniquetodeterminethetokenbucketparametersthathavetobespeci®edwhilesettingupaGS¯ow.Ourstudyrevealst
5、hatthetraf®cshapingprocessgivesanendapplicationawiderangeof¯exibilityincontrollingthedelay.Bychoosingappropriatetokenbuckettraf®cshaperparameters,delaycanbereducedsigni®cantlywithouttheneedtoreservecostlynetworkresourcesforlessdelay-sensitiveapplications,whiletime-crit
6、icalapplica-tionsmayspecifytherequiredtokenbucketparametersforminimumdelay.q2000ElsevierScienceB.V.Allrightsreserved.Keywords:Qualityofservice;Tokenbuckettraf®cshaping;Internetvideo;MPEG;Integratedservices1.Introductiondesignedtosupportreal-timeapplicationslikevideo-co
7、nferencing,whichisbasedonvariable-bit-rate(VBR)Present-dayInternetProtocol(IP)providesaservicethatcompressedvideotransmission.TheCLService[2]canbecharacterizedasabest-effortservice.CurrentIPprovidesaservicewhichcloselyapproximatesthebehaviornetworkelementstreatalltraf®
8、cequallywithoutanyvisibletoapplicationsreceivingbest-effortserviceundermechanismforprovidingprioritytothepacketscarry