校园无线网路技术与应用发展(PPT 82页)-英文版.ppt

2019/11/28,1,校園無線網路技術與應用發展,Sheng-TzongCheng鄭憲宗.tw.tw,2019/11/28,成大資訊鄭憲宗,2,Outline,無線區域網路IEEE802.11無線應用通訊協定WAP,2019/11/28,成大資訊鄭憲宗,3,無線區域網路通訊協定WirelessLocalAreaNetwork(IEEE802.11),2019/11/28,成大資訊鄭憲宗,4,無線區域網路標準-IEEE802.11,SpecifiesasingleMediumAccessControl(MAC)sublayerand3PhysicalLayerSpecifications.Stationscanoperateintwoconfigurations:Ad-hocmodeInfrastructuremodeThreePHYspecificationsFrequencyHoppingSpreadSpectrum(FHSS).DirectSequenceSpreadSpectrum(DSSS).InfraredPHY.,2019/11/28,成大資訊鄭憲宗,5,IEEE802.11規範,IEEEProject802Charter:Local40%:60%(2005),2019/11/28,成大資訊鄭憲宗,35,全球無線通訊用戶成長,2019/11/28,成大資訊鄭憲宗,36,預估未來WAP手機的佔有率,2019/11/28,成大資訊鄭憲宗,37,2019/11/28,成大資訊鄭憲宗,38,2019/11/28,成大資訊鄭憲宗,39,手持型元件之延革,2019/11/28,成大資訊鄭憲宗,40,2019/11/28,成大資訊鄭憲宗,41,bringtheinternetcontentandadvancedservicesto後PC時代之userscreateaglobalwirelessprotocoltoworkacrossdifferingwirelessnetworktechnologiesenableapplicationstoscaleacrossavarietyoftransportoptionsanddevicetypes,WhatsWAPfor?,2019/11/28,成大資訊鄭憲宗,42,WhatisdefinedinWAP?,Micro-BrowserScriptingtoenhanceMScapabilitiesWTA/WTAIfortelephonefunctionality(e.g.callchains)ContentFormatsbusinesscard(vCard)calendarevent(vCalendar)LayeredTelecommunicationStack,2019/11/28,成大資訊鄭憲宗,43,Comparison,2019/11/28,成大資訊鄭憲宗,44,2019/11/28,成大資訊鄭憲宗,45,GoalsforWTP(WAPv1.1),acommoninterfacetophysicaltransportmechanismsprovideaport-basedabstractinterfacetoupperlayerprotocolsallowapplicationsdesignedindependentfromspecifictransportsextensibletoavarietyofdigitalwirelessnetworksandfuturetransportoptions,2019/11/28,成大資訊鄭憲宗,46,GoalsforWTP(cont.),supportsconnection-oriented,transaction,anddatagrammodesoptimizefornarrowtomediumbandwidthchannelstobecapableofimplementationinalowmemoryfootprint,suitableforstandardorlow-IQhandsets,2019/11/28,成大資訊鄭憲宗,47,RequirementsforWTP,WTP/Cprovidesareliableconnection-orientedservicetotheupperlayerWTP/Tprovidesareliabletransaction-orientedservicesuitableforwebbrowsingWTP/Dprovidesadatagramservicelightweight:implementablein=10Kb(lowmemory/computationalneeds),2019/11/28,成大資訊鄭憲宗,48,WTP/Dfeatures(WDPinWAPv1.2),WTP/D(Datagram)providesaconnection-less,unreliabledatagramserviceWTP/DisreplacedbyUDPwhenusedoveranIPnetworklayer.usestheServicePrimitiveT-UnitData.req.ind,2019/11/28,成大資訊鄭憲宗,49,WAPv1.2,2019/11/28,成大資訊鄭憲宗,50,WTP/Tfeatures(WTPinWAPv1.2),WTP/T(Transaction)providesreliabledatatransferbasedonrequest/replyparadigmnoexplicitconnectionsetuporteardowndatacarriedinfirstpacketofprotocolexchangeseekstoreduce3-wayhandshakeoninitialrequest,2019/11/28,成大資訊鄭憲宗,51,WTP/Tfeatures(cont.),supportsretransmissionoflostpacketsselective-retransmissionsegmentation/re-assemblyportnumberaddressing(specifictoWTP/T)flowcontrolmessageoriented(notstream)supportsanAbortfunctionforoutstandingrequests,2019/11/28,成大資訊鄭憲宗,52,WirelessSessionProtocol,WSP/BprovidesupperlayerswithsessionservicesandmanagementWSP/BProvidessemanticsandmechanismsbasedonHTTP1.1WSPprovidesmeansto:establishareliablesessionfromclienttoserveragreeoncommonlevelofprotocolfunctionalitybycapabilitynegotiationcompactencodingsuspendandresume,2019/11/28,成大資訊鄭憲宗,53,WSPfeatures,HTTP1.1functionalityExchangeofclientandserversessionheadersInterruptmechanismfortransactionsinprocessContentPushfromservertoclientNegotiationformultiple,simultaneousasynchronoustransactions,2019/11/28,成大資訊鄭憲宗,54,WTLSRecordProtocol,4recordprotocolclients:ThehandshakeprotocolThechangecipherspecprotocolThealertprotocolTheapplicationdataprotocolWTLSconnectionstate:theoperatingenvironmentforrecordprotocolcompression/encryptionalgorithmMACalgorithm-keys,2019/11/28,成大資訊鄭憲宗,55,RecordProtocolUsage,HandshakeprotocolNegotiatesecureattributesofasecuresessionauthentication,securityparametersettingsChangecipherspecprotocolSignaltransitionsincipheringstrategiessentbeforeverifyingfinishedmessageAlertprotocolconveytheseverityofthemessageandadescriptionofthealert,2019/11/28,成大資訊鄭憲宗,56,WirelessApplicationEnvironment(WAE),AnInternet(WWW)programmingmodelVendor-controlledMMIInitialfocusonphonesSlowbearersSmallmemoryLimitedCPUSmallscreenLimitedinputmodel,2019/11/28,成大資訊鄭憲宗,57,WAEComponents,ArchitectureApplicationmodelBrowser,Gateway,ContentServerWML(WirelessMarkupLanguage)DisplaylanguageWMLScriptScriptinglanguageContentFormatsDataexchange,2019/11/28,成大資訊鄭憲宗,58,WAEIn-DeviceArchitecture,2019/11/28,成大資訊鄭憲宗,59,WML,Tag-basedbrowsinglanguage:Screenmanagement(text,images)Datainput(text,selectionlists,etc.)Hyperlinks&navigationsupportSyntax:W3CXML(SGMLderivative)InheritstechnologyfromHDMLandHTML,2019/11/28,成大資訊鄭憲宗,60,WML(cont.),CardmetaphorUserinteractionsaresplitintocardsNavigationoccursbetweencardsStatemanagementandvariablesReducenetworktrafficResultsinbettercachingExplicitinter-cardnavigationmodelHyperlinksUIEventhandlingHistory,2019/11/28,成大資訊鄭憲宗,61,WMLExample,Welcome!Entername:speed:FastSlow,2019/11/28,成大資訊鄭憲宗,62,WMLScript,Scriptinglanguage:Procedurallogic,loops,conditionals,etc.Optimizedforsmall-memory,small-cpudevicesDerivedfromJavaScriptIntegratedwithWMLPowerfulextensionmechanismReducesoverallnetworktraffic,2019/11/28,成大資訊鄭憲宗,63,WMLScript(cont.),Bytecode-basedvirtualmachineStack-orienteddesignROM-ableDesignedforsimple,low-impactimplementationCompilerinnetworkBetternetworkbandwidthuseBetteruseofterminalmemory/cpu,2019/11/28,成大資訊鄭憲宗,64,2019/11/28,成大資訊鄭憲宗,65,2019/11/28,成大資訊鄭憲宗,66,2019/11/28,成大資訊鄭憲宗,67,WAPGateway,2019/11/28,成大資訊鄭憲宗,68,WAPApplicationServer,2019/11/28,成大資訊鄭憲宗,69,2019/11/28,成大資訊鄭憲宗,70,WAPPushTechnology,2019/11/28,成大資訊鄭憲宗,71,WAP怎麼了？,歐洲在兩年內至少應有10億隻WAP手機，實際上只有六百萬之使用量(accordingtoIDC)T-Mobile:1%o