無線局域網(wǎng)技術(shù)走勢

September8,2003TechnologyDirectionsfor802.11WLAN

UbiquitousWirelessBroadband

CraigBarratt,Ph.D.,President&CEOAtherosOverviewInnovatorin802.11a,a/b,b/g,anda/b/gchipsetsBestclientsforrangeandthroughputaccordingtopublicationreviewsUniversalwirelessaccesswithdualband,multimodeproductsOver200Atheros-basedproductsonmarketworldwideLeadinglaptopandretailvendorsuseembeddedmultimodeWLANfromAtherosAdvancedsecuritywithAES,CCX,WPA;certifiedinternationaloperation;QualityofServiceFirstdigital

CMOSOFDMradios-1999First802.11a

chipsets-2001FirstWi-Fi

audio/videoproducts-2001FirstDSRC

automotiveapplications-2002First802.11a/b

chipsets-2002Firstcertified802.11a/b/g

andb/gchipsets-2003Firstwirelessasfastaswired(SuperG)-2003SomeofOurCustomers…ProliferationofWLANandOFDM3rdGenOFDM802.11a802.11a/b

802.11a/g/bdesignsTheavailabilityoflowcost,robust,standards-basedWLANproductswillinfluencethehomeentertainment,publicaccess,andtelematicsmarketsenormously.ConsumerElectronicsWLANHotSpotsVehicularApplicationsWLANinConsumerElectronicsPortabledevices(Camera,Camcorder,MobileTablet,Laptop)BatterypoweredlowpowerconsumptionSmallsmallformfactorSingleroomrangefeasibleandsufficientFixeddevices(Settopbox,TV,DVD,MediaCenter)LinepoweredcanhavehigherpowerassumptionLargerlargerformfactorWholehouserangefeasibleanddesiredSatellite,Cable,DSLConnectionSTB/Home

GatewayTV’sStereo’sPC’sCamcorderWirelessLANHotSpotsHotSpotgrowthnowdriveninternationallybytelecomcarriersGreatestgrowthinJapanwithNTTaggressivelyrollingout802.11aand802.11bdualmodeaccesspointsandexpandingWLANto4.9GHzSource:IDC,Corp.Reports802.11TechnologyComparison802.11802.11b802.11g802.11aStandardApprovedJuly1997Sept1999June,2003Sept1999AvailableSpectrum83.5MHz83.5MHz83.5MHz125MHzFrequenciesofOperationinChina2.400-2.4835GHz2.400-2.4835GHz2.400-2.4835GHz5.725-5.85GHzNon-OverlappingChannels333513-24(US)ModulationTechnologyFHSSDSSSCCKCCK,OFDMOFDMDataRateperChannel1,21,2,5.5,111,2,5.5,6,9,11,12,18,

24,36,48,546,9,12,18,

24,36,48,54MaxUDPThroughput

(1500byte)1.7Mbps7.1Mbps19.5Mbps*30.7MbpsMaxTCP/IPThroughput(1500byte)1.6Mbps5.9Mbps14.4Mbps*24.0Mbps*Withany802.11bstationinthenetwork,CTS-onlymode.ImportantIEEEWorkingGroups802.11eQualityofServiceEDCFparameterizedQoSandHCFpolling-basedQoS802.11iSecurityRobustSecureNetwork:(1)AESEncryption,(2)EAPAuthentication802.11hDFS/TPCRadardetectionandavoidanceforEuropeanoperation802.11fInter-AccessPointProtocolCommunicationbetweenAPsforroamingandhandover802.11kRadioResourceManagementImprovedphysicallayermanagementandreporting802.11nHighThroughputWLANExtendingWLANdataratesbeyond108MbpsTheAdventofMultimode802.11a/b/gTheStandardsBattlesareOverUniversalconnectivityisthewatchwordofthedayComprehensiveprotocolsupportWorldwidetuningrange,2.3–2.5GHz,4.9–5.9GHzLine-speedAESandWPAencryptionforfast,secureconnectionsParadigm-shiftenhancementstorangeandthroughputCostreductioncurveunprecedentedinwirelesscommunicationsEvolutionintheWi-FiMarket802.11bhasbecomealegacymarketwithalmostallnewproductscomingtomarketwithmultimodeb/ganda/b/g802.11bb/ga/b/gPCOEMb/ga/b/gRetailTowardaSecureWirelessNetworkIndustryConvergenceonAESEncryptionandEAPAuthenticationEncryptionstandardshaveprogressedfromWEP,toTKIP,andfinallytoAESAuthenticationprotocolshaveprogressedfrom802.1x,toEAP,tovendor-specificimplementationssuchasLEAPandPEAPWi-FiProtectedAccess(WPA)isthecurrentstate-of-the-art.WPAmandatesTKIPencryptionandEAPauthentication.WPA2upgradesencryptiontoAES.CloselymonitoringChinesestandardsGB15629.11andGB15629.1102

forWAPIcomplianceThroughputandRangeEnhancementsExtendstheEfficiencyandReachofWirelessConnectionsLargeframes,compression,andpacketburstingdramaticallyimprovethroughput<-100dBmReceiveSensitivityisclosetocellular,20dBbetterthanWi-Fispec

DeliversSeamlessInteroperabilityFullyinteroperablewithstandard802.11a,802.11b,and802.11gtrafficLine-of-SightRange(meters)Standard11gAtherosRangeExtended11a/g790mForOffices:EliminatesDeadSpotsForHomes:Single-APCoverageForPublicAccess:CoverLargerAreasWhitherWLAN?802.11DataThroughput3G90Mbps1Mbps100m500mRange(Indoor)802.11withRangeExtensionWirelessLANandcellularhavetraditionallyhaddifferentapplicationsandusagemodels

Localareanetwork(<100m)Metroareanetwork(~500m)Wideareanetwork(>500m)TheShapeofWLANConvergenceCordless(DECT,CT-2)Cellular(GSM,CDMA)WLAN(802.11a/b/g)??VoiceDataLocalAreaWideAreaTechnologyComparison:802.11&3G802.11a/g3GScopeofStandardL1,L2Voice/DataL1–L7Voice/DataAvailableSpectruminChina200+MHz175MHzSupportedDataRates6-54Mbps384kbps-2MbpsChannelBandwidth20MHz5MHzSpectralEfficiency(Maximum)2.7bps/Hz0.4bps/HzCoverageRange(Radius)100m-1km2-3kmSystemCapacity/Cell(Maximum)54Mbpsxkm218Mbpsxkm2InfrastructureCost/CellRMB20,000RMB2,000,000TerminalCostRMB400RMB4,000WLANMovesBeyond“Local”TowardLong-Range,Metropolitan-AreaCoverage12kmpoint-to-pointlinks@36MbpshavebeendemonstratedRequiresincreasedtransmitpower,antennadirectionalityProtocolmodificationsarealsopossibleFarterminal,12.5kmawayPhotoscourtesyofMicroelectronicsTechnology,Inc.WLANImplicationsforChinaWi-FiIsaTrueTelecommunications