网页设计课程网站外文文献翻.docx
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网页设计课程网站外文文献翻.docx
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网页设计课程网站外文文献翻
毕业设计(论文)
外文文献翻译
专业
计算机科学与技术
学生姓名
王岩
班级
B计算机081
学号
0810704124
指导教师
唐拥政
信息工程学院
Networklayeredprioritymappingtheory
AbstractIntheearlydaysoftheInternetlayereddesign,theinformationbetweenlayersdidnotexchangeinlargeamountfrequently.WiththerapidgrowthoftheInternet,theemergenceofmanytechnologiessuchasservicedatapartition,multi-connectionandmulti-pathhasmadeitpossibletofrequentlyexchangecomplexinformationbetweenlayers.Withregardtothesechanges,thispaperintroduces“networklayeredprioritymapping(NLPM)”forfutureInternetdevelopment.TheNLPMaimstomaximizethesatisfactionoftheInternetusers.TheNLPMisdesignedtodifferentiatepriorityoftheinformationondifferentlayersandintegratetheinformationusingprioritymapping.WithNLPM,networkservicescanbedeliveredmoreefficiently;networkutilizationsuchastheutilizationofconnection,pathandchannelcanalsobeimproved.Modelanalysis,NSsimulationandprototypeimplementationhaveprovedtheefficiencyofNLPM.
1Introduction
LayeredstructureisthebasicdesignmethodofInternet.IntheearlydaysofInternet,theinteractionbetweenthelayerswassimpleinviewofthepoornetworkinfrastructureonlowlayerandthesimpleserviceonhighlayer.Besides,therewasnounifiedformfortheinteractionbetweenlayersastheinitiallayeringwasadhocmodel.Asnewnetworkservicesareconstantlyemergingandgrowingmoreandmorecomplex,thesimplelayereddesigncannotmeetthedemandoffuturenetworkdevelopment.Thereforetherehaveemergedservicepartition,multi-connection,multi-path,andmulti-channelondifferentInternetlayers.Fortheapplicationlayer,thenetworkservicesaregrowingdiversifiedwhilethecontentofservicesisgrowingincreasinglycomplex.Asaresult,onenetworkserviceusuallyconsistsofanumberoflogicallyindependentcomponents.Partitionofthecomplexservicewillimproveservicerobustnessandflexibility.Forthetransportlayer,aservicewithmulti-connectionisneededastheservicecanbepartitionedintomanydifferenttypesofpartitioned-services.Multi-connectioncanensuretheefficiencyoftheend-to-endtransmissionfordifferenttypesofpartitioned-services.Besides,itcanflexiblysupporttheservicepartitionandimprovethetransmissionthroughput.Forthenetworklayer,manynewtechnologiesonnetworkaccessareemergingwiththeexplosiveincreaseofInternetusers.Thesetechnologiesenableend-to-endmulti-pathcommunicationandprovidemoreoptionsforhighlayermulti-connection.Forthelinklayer,differentnetworkusesdifferentphysicalchannel.Tosupportthemulti-networks,terminalsneedtoswitchbetweendifferentchannels.Theabove-mentionedtechnologiesshowthatsignificantchangeshaveoccurredoneverylayeroftheInternetstructure.Twoofthemostsignificantchangesaremulti-connectionandend-to-endmulti-path.Servicepartitionreliesonmulti-connection;multi-channeliscloselyinterconnectedwithmulti-path.PlentyofstudieshaveshownthatthecurrentTCPthroughputistoolowrelativetoavailablebandwidthprovidedbylowerlayer[1].Theadventofmulti-connectionhasgreatlyimprovedthethroughput.Therehavebeenalotofresearchesonmulti-connectionandtheseresearchescanbedividedintothreecategories:
designofmulti-connectionprotocol[1,2],multi-connectionapplications[3,4]andtheoreticalanalysisofmulti-connectionperformance[5,6].End-to-endmulti-pathisanemergingresearch.AtthetimeTCPwasdesigned,multi-pathofendhostswasbeyondthekenofresearchinviewoftheexpensivenetworkinterfacedevices.Withrapideconomicdevelopment,theincreasingemphasisonend-to-endtransferefficiencyhasbroughtmulti-pathinthepurviewoftransportlayer[7–9].Multi-connectionandend-to-endmulti-pathtransferhavebeenwidelyresearchedasillustratedabove.Buttheseresearcheshavetheirlimitationsbecausetheydidnotfullyconsidertheneedsofusers.Forexample,currentmulti-connectionresearchessimplypartitionservicedataintoblockswithfixedsize[1,4];currentmulti-pathresearchesonlyrandomlychooseoneavailablepathtosendapplicationdatawithoutconsiderationinhowtopartitiontheservicedataefficientlyandhowtooptimizethepathtomaximizethesatisfactionofusers.Moreover,asfarasweknow,noresearchhasyetcombinedmulticonnecttechnologyandmulti-pathtechnology.Inresponsetotheabove-mentionedlimitationsofcurrentresearches,thispaperintroducesNLPMbasedonthecurrentInternetlayereddesign.NLPMusessatisfactionofusersasevaluationcriteria.ItskeyideaistostandardizethedescriptionoftheInternetlayerinformation(suchaspartitionedservice,connectionandpath)withmatrixandtoprocesstheexchangeofinformationbetweenlayerswithmapping.Withthisnewdesign,thenetworkservicescanbedeliveredmoreefficientlyandtheutilizationofnetworkcanbeimproved.Finally,itisworthmentioningthatthenewgenerationnetworkresearchisthemostpopulartopicnowadays,suchas3G,4G,NGN,NGI,sourceaddressvalidationarchitecture[10]anduniversitynetwork[11].Asaninterfacetechnologyresearchbetweennetworklayers,theworkofthispapercanbeappliedtothecurrentandothernewgenerationnetworkresearchesgivenitsstrongscalability.
2Networklayeredprioritymapping
2.1Satisfactionofusers
TheInternetisdesignedforusersandhencethesatisfactionofusersshouldbethekeycriteriatoevaluatetheInternettechnology.Wecanformulatesuchevaluativecriteriainutilityfunction[12].Letthevectorsdescribetheservicedeliveredtothei’thusersi,containingallrelevantmeasuresofthedeliveredservice.ThenwemaketheutilityfunctionUimaptheserviceintothesatisfactionofusers.Withthisformulation,thegoalofnetworkdesigncanbeconvertedtomaximizingthesumoftheutilities.WecallthisquantityVthetotalutilityofanarchitectureV=_iUi(si).Shenker[12]foundthattraditionalInternetdataserviceswereelastictraffic.Accordingtothistrafficcharacter,theutilityofserviceisthemonotonicallyincreasingfunctionofnetworkcapability,suchasbandwidth.Themarginalutilitydecreasesasnetworkcapabilityincreases.Thisisthecharacterofconcavefunctionandwedeemutilityfunctionasconcavefunctioninthepaper.
2.2DesignthoughtofNLPM
NLPMistheinstantiationof“mapping”inInternet.Itscoreideaistodifferentiatethepriorityof
networkinformationondifferentlayersandcombinetheinformationbyprioritymappingsothattheInternetservicecanbedeliveredmoreefficiently.Likea“mapping”,NLPMhasthreeelements:
image,
inverseimageandmappingfunction.Imageandinverseimagerepresentthenetworkinformation.Mappingfunctionincludesmappingformandmappingmechanism.Mappingformgivesthenumberoftheimageandinverseimage,suchasone-to-one,one-to-many,many-to-oneandmany-to-many.Mappingmechanismintegratesthenetworkinformationondifferentlayersbyoptimizingthenetworkconnectionandpath.
2.3Mappingformmodel
Mappingfunctionincludesmappingformandmappingmechanism.Inthissection,wefocusonmappingformandinsubsection2.4wewillanalyzethemappingmechanism.Theformofmappingfunctionisbasedonthe0-1mappingmatrix.Wewillillustrateasfollowstheroleandsignificanceofthe0-1mappingmatrixinNLPM.Firstly,thepositionof_1_whichisdeterminedbyitssubscript,inthematrixrepresentsthecorrespondencebetweenimageandinverseimage.Inthe0-1mappingmatrix,thecolumnrepresentsimageandtherowrepresentsinverseimage.Secondly,the0-1mappingmatrixcanrepresentmappingform.Iftherearemorethanone_1_sinsomecolumnvector,thereexistsamany-to-onemapping.Iftherearemorethanone_1_sinsomerowvector,thereexistsaone-to-manymapping.Takethetwomappingmatrixesinprevioussectionasanexample.AllvectorsintherowsandcolumnsinmatrixAhaveone_1_,sothemappingisone-to-one.ThefirstcolumnandthesecondrowvectorofmatrixHhavetwo_1_s,sothemappingismany-to-many.Finally,theweightα={1,2,3,...}for_1_representsthemappingpriority.Therearetwo_1_sinthesecondrowofH,representingthattherearetwopathsforoneconnection.
2.4Mappingfunctionmodel
Afterobtainingamappingformaccordingtoaspecificservice,weturntotheanalysisofthemapping
mechanism.Weapplythefollowingsixqueueingmodelstoanalyzethemappingmechanismofcurrent
networkandNLPM.M1isthecurrentmulti-connectionsingle-pathmodel,whichcanbeconsidered
anM/M/1queuewithmultiplenon-prioritycustomers.M2istheprioritymulti-connectionsingle-path
model,whichcanbeconsideredanM/M/1queuewithmultipleprioritycustomers.M3isthenon-prioritymulti-connectionmulti-pathmodel,whichcanbeconsideredanM/M/Nqueuewithmultiplenon-prioritycustomers.M4isthebindingprioritymulti-connectionmulti-pathmodel,whichcanbeconsideredmultipleindependentM/M/1queues.LikeM4,M5isusedhereonlytoshowadifferentbindingrelationship.M6istheoptimalprioritymulti-connectionmulti-pathmodel,whichcanbeconsideredanM/M/Nqueuewithmultipleprioritycustomers.
2.5Applicationofmappingfunction
Thissectiongivesanapplicationofthemappingfunction,anapplicationindataretransmissionfor
connection-orientedtransportprotocol.Themappingformisone-to-manyandthemappingmechanism
isbasedonthepriorityofretransmissiontime.In[13]weshowanotherapplicationofmappingfunction
whichdealswiththepathselectionproblem.
2.6Imageandinverseimagemodel
Wehaveanalyzedthemappingfuncti
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