市场营销--全球无线区域网路市场销售值(PPT 137页)-英文版

来自@vnu.edu.tw来自CharacteristicsIEEE802.11WirelessLANArchitectureProtocolPHYMACRoamingNetworkImplementAntennaSecurityWEPIEEE802.1X802.11Future802.11a,b,g802.11vsBluetooth来自WEPIEEE802.1X802.11Future802.11a,b,g802.11vsbluetooth来自ChipsetIntersil,Lucent（Agere）TaiwanNo.1来自(nooneshouldbeabletoreadmydata),privacy(nooneshouldbeabletocollectuserprofiles),safety(lowradiation)Transparencyconcerningapplicationsandhigherlayerprotocols,butalsolocationawarenessifnecessary来自(economicaltoscale)Ad-hocnetworkswithoutplanningpossible(Almost)nowiringdifficulties(e.g.historicbuildings,firewalls)Morerobustagainstdisastersoruserspullingaplug来自(10vs.100[0]Mbit/s)Manyproprietarysolutions,especiallyforhigherbit-rates,standardstaketheirtimeProductshavetofollowmanynationalrestrictionsifworkingwireless,ittakesalongtimetoestablishglobalsolutions(IMT-2000)SecurityEconomy来自(walls,furnitureetc.)simple,cheap,availableinmanymobiledevicesnolicensesneededsimpleshieldingpossibleinterferencebysunlight,heatsourcesetc.manythingsshieldorabsorbIRlightlowbandwidthExample:IrDA(InfraredDataAssociation)interfaceavailableeverywhereRadiotypicallyusingthelicensefreeISMbandat2.4GHzexperiencefromwirelessWANandmobilephonescanbeusedcoverageoflargerareaspossible(radiocanpenetratewalls,furnitureetc.)verylimitedlicensefreefrequencybandsshieldingmoredifficult,interferencewithotherelectricaldevices•Examples:HIPERLAN,Bluetooth来自2001--15BillionDollar2004--31BillionDollar2003~200640%•測•来自中国最大的资料库下载全球無線區域網路市場銷售值、量預估•。••資料來源：CahnersIn-Stat；工研院經資中心ITIS計劃整理来自:Cahner’sIn-StatGroup2001来自ExtendedServiceSetESSAd-hocnetworksIndependentBasicServiceSetNetwork（IBSSNetwork)来自–ArchitectureofaninfrastructurenetworkStation(STA)–terminalwithaccessmechanismstothewirelessmediumandradiocontacttotheaccesspoint•BasicServiceSet(BSS)–groupofstationsusingthesameradiofrequency•AccessPoint–stationintegratedintothewirelessLANandthedistributionsystem•Portal–bridgetoother(wired)networks•DistributionSystem–interconnectionnetworktoformonelogicalnetwork(EES:ExtendedServiceSet)basedonseveralBSS来自–Architectureofanad-hocnetwork•Directcommunicationwithinalimitedrange–Station(STA):terminalwithaccessmechanismstothewirelessmedium–BasicServiceSet(BSS):groupofstationsusingthesameradiofrequency•YoumayuseSDMorFDMtoestablishseveralBSS.来自–Protocolarchitecture来自(PhysicalMediumDependent)modulation,coding•PLCP(PhysicalLayerConvergenceProtocol)clearchannelassessmentsignal(carriersense)•PHYManagementchannelselection,PHY-MIB•StationManagementcoordinationofallmanagementfunctionsMACaccessmechanismsfragmentationencryptionMACManagementSynchronizationroamingpowermanagementMIB(managementinformationbase)来自(2.4GHz),1IR:FHSS(FrequencyHoppingSpreadSpectrum)spreading,despreading,signalstrength,1Mbit/satleast2.5frequencyhops/s,two-levelGFSKmodulationDSSS(DirectSequenceSpreadSpectrum)DBPSKmodulationfor1Mbit/s(DifferentialBinaryPhaseShiftKeying),DQPSKfor2Mbit/s(DifferentialQuadraturePSK)preambleandheaderofaframeisalwaystransmittedwith1Mbit/s,restoftransmission2(oroptionally1)Mbit/schippingsequence:Barkercode(+–++–+++–––)max.radiatedpower1W(USA),100mW(EU),min.1mWInfrared850-950nm,diffuselight,10mrangecarrierdetection,energydetection,synchronization来自来自79Channels,1MHzEachChangesfrequency(Hops)atleastevery0.4secondsSynchronizedhoppingrequiredFrequency2.400GHz2.483GHz123456789来自•2Mbpsdataratewithoutcomplexmodulationschem