电子信息-外文文献译文

XXXX学院毕业设计（论文）外文参考文献译文本2012届原文出处ANovelCross-layerQuality-of-serviceModelForMobileADhocNetwork毕业设计(论文)题目基于COMNETIII的局域网的规划与设计院（系）电气与电子信息学院专业名称电子信息工程学生姓名学生学号指导教师ANovelCross-layerQuality-of-serviceModelForMobileADhocNetworkLeichunWang,ShihongChen,KunXiao,RuiminHuNationalEngineeringResearchCenterofMultimediaSoftware,WuhanUniversityWuhan430072,Hubei,chinaEmail:[e-mail]:Thedivided-layerprotocolarchitectureforMobileadhocNetworks(simplyMANETs)canonlyprovidepartialstack.ThisleadstotreatdifficultiesinQoSguaranteeofmultimediainformationtransmissioninMANETs,thispaperproposesAcross-layersQoSModelforMANETs,CQMM.InCQMM,acorecomponentwasaddednetworkstatusrepository(NSR),whichwasthecenterofinformationexchangeandshareamongdifferentprotocollayersinthestack.Atthesametime,CQMMcarriedoutallkindsofunifiedQoScontrols.ItisadvantageousthatCQMMavoidsredundancyfunctionsamongthedifferentprotocollayersinthestackandperformseffectiveQoScontrolsandoverallimprovementsonthenetworkperformances.Keyword:Cross-layersQoSModel,MobileAdhocNetworks(MANETs),NetworkStatusRepository(NSR),QoSControls.1introductionWiththerapiddevelopmentofmultimediatechnologiesandthegreatincreaseofhisbandwidthforpersonalcommunication,videoandvideoservicesbegintobedeployedinMANETs.DifferentfromstaticnetworksandInternet,multimediacommunicationsinMANETssuchasVoiceandVideoservicesrequirestrictQoSguarantee,especiallythedelayguarantee.Inaddition,communicationamongdifferentuserscanbeintegratedserviceswithdifferentQoSrequirements.TheseleadtogreatchallengesinQoSguaranteeofmultimediacommunicationinMANETs.Therearetwomainreasonsinthese:1)MANETsrunsinatypicalwirelessenvironmentwithtime-varyingandunreliablephysicallink,broadcastchannel,anddynamicandlimitedbandwidthandsoforth.Therefore,itcanonlyprovidelimitedcapabilityfordifferentiatedserviceswithstrictQoSrequirements[1].2)Itisdifficultthattraditionalflowprojectandaccesscontrolmechanismareimplementedbecauseofmobility,multiplehopsandself-organizationofMANETs.Atpresent,mostresearchesonQoSbasedontraditionaldivided-layerprotocolarchitectureforMANETsfocusonMACprotocolsupportingQoS[2],QoSroutingprotocol[3]andadaptiveapplicationlayerprotocolwithQoSsupport[4],andsoon.Itisavoidlessthattherewillbesomeredundanciesonfunctionsamongthedifferentprotocollayersinthestack.ThiswillincreasethecomplexityofQoSimplementationandcausesomedifficultiesinoverallimprovementonthenetworkperformances.Therefore,itisnotsuitableforMANETswithlowprocessingabilityInrecentyears,thecross-layersdesignbasedonthepartialprotocollayersinMANETswasputforward.[1]proposedthemechanismwithQoSguaranteeforheterogeneousflowMAClayer.[5,6,7,8]didsomeresearchesonimplementingvideocommunicationwithQoSguaranteebyexchangeandcooperationofinformationamongafewlayersinMANETs.ThesecanimproveQoSinMANETs’communicationtosomeextent.However,MANETsismuchmorecomplexthanwiredsystemandstaticnetwork,andimprovementsonQoSguaranteedependonfullcooperationamongalllayersintheprotocolstack.Therefore,itisdifficultforthedesigntoprovideefficientQoSguaranteeforcommunicationandoverallimprovementsonthenetworkperformancesinMANETs.TomakegooduseoflimitedresourcesandoptimizeoverallperformancesinMANETs,thispaperproposesanovelcross-layerQoSmodel,CQMM,wheredifferentlayerscanexchangeinformationfullyandunifiedQoSmanagementsandcontrolscanbeperformed.Therestofthepaperisorganizedasfollows.CQMMisdescribedinsection2indetail.Insection3,weanalyzeCQMMbythecomparisonwithDQMM.Thesection4concludesthepaper.2.ACROSS-LAYERQOSMODELFORMANETS-CQMM2.1ArchitectureofCQMMInMANETs,presentresearchesonQoSaremostlybasedontraditionaldivided-layerprotocolarchitecture,wheresignalsandalgorithmssupportingQoSaredesignedandimplementedindifferentlayersrespectively,suchasMACprotocolsupportingQoSindatalinklayer[9],routingprotocolwithQoSsupportinnetworklayer[10.11],andsoforth.ItcanbesummarizedasADivided-layerQoSModelforMANETs,DQMM(seefig.1).InDQMM,differentlayersintheprotocolstackaredesignedandworkindependently;thereareonlystaticinterfacesbetweendifferentlayersthatareneighboringinlogic;andeachprotocollayerhassomeQoScontrolssuchaserrorcontrolinlogiclinklayer,congestioncontrolinnetwork,etc.Ontheonehand,DQMMcansimplifythedesignofMANETsgreatlyandgaintheprotocolswithhighreliabilityandextensibility.Ontheotherone,DQMMalsohassomeshortcomings:1)duetotheindependentdesignamonghedifferentprotocollayers,therearesomeredundancyfunctionsamongthedifferentprotocollayersinthestack,2)itisdifficultthatinformationisexchangedamongdifferentlayersthatarenotneighboringinlogic,whichleadstosomeproblemsinunifiedmanagements,QoScontrolsandoverallimprovementsonthenetworkperformances.Fig.1Therefore,itisnecessarythatmoreattentionarefocusedonthecooperationamongphysicallayerdatalinklayer,networklayerandhigherwhenattemptingtooptimizeperformancesofeachoflayerinMANETs.Forthisreason,wecombineparametersdispersedindifferentlayersanddesignanovelcross-layerQoSmodel,CQMM,toimprovetheQoSguaranteeandtheoverallnetworkperformances.ThearchitectureofCQMMisprovidedinfig2Fromfig.2,itcanbeseenthatCQMMk