Wimax宽带无线接入技术

TianJingUniversityChenmiao2011年3月14日,WimaxforBroadbandWirelessAccess,2,Outline,1.WhatisWiMAX2.802.16Introduction3.802.16dReferenceModel4.802.16dMACHighlights5.802.16dPHYHighlights6.802.16Networkarchitecture7.802.16Scenarios,3,1.WhatisWiMAX?,WorldwideInteroperabilityforMicrowaveAccess(WiMAX)isthecommonnameassociatedtotheIEEE802.16standards.ThesestandardsareissuedbytheIEEE802.16subgroupthatoriginallycoveredtheWirelessLocalLooptechnologieswithradiospectrumfrom10to66GHz.,4,ComparedwithWifi:higherthroughputQoSandenhancedsecurityservicesgoodscalabilityfortheentirenetwork,5,2.IEEE802.16x-Introduction,6,7,3.802.16dReferenceModel,8,9,MAClayerisconnection-oriented,mappingtothePSonthebusinessandassociatedwithdifferentlevelsofQoS.WhenanPSisinstalledintothesystem,itcanprovidethebusinessflow.WhenthePStoCompletetheregistration,theconnectionassociatedwiththetraffictoprovidetherequestedbandwidthguarantee.Whentheuserservicerequirementschange,maycreateanewconnection.,4.802.16dMACHighlights,10,Aconnectionnotonlydefinesthemappingwiththeconvergencelayer,butalsodefinethebusinessflow,businessflowdefinedinthePDUtransmittedonthisconnectiontheQoSparameters.ProvidesatrafficuplinkanddownlinkoftheQoSmanagementmechanism.,11,4.1ServiceSpecificConvergenceSublayer(CS),CSsub-layerismainlyresponsibleforthecompletionofexternalnetworkdatabetweenthedataandtheCPSsub-layermapping.Itallfromtheconvergencelayerserviceaccesspoint(CSSAP)receivedexternaldataintothenetworkandmappedtoMACSDU,andthroughtheMACServiceAccessPoint(MACSAP)senttotheCPSsub-layer.Inthisprocess,CSsub-layerontheexternalnetworkdataclassifythemwiththeappropriateMACserviceflowIDandtheconnectionidentifierCIDSFIDtheassociation,andalsoperformloadheadercompressionPHS.,12,4.2MACCommonPartSublayer(CPS),CPSsub-layerprovidesthecoreMAClayerfunctions,includingsystemaccess,bandwidthallocation,connectionestablishmentandmaintenanceetc.CPSsub-layerthroughtheMACSAPCSfromdifferentsub-layerreceivesthedata,theformationofMACSDU.MACSDUcanbesplit,butalsowiththeotheroneormoreMACSDUintoanewMACPDU,accordingtoclassificationofMACconnectionstoensureQoS.,13,4.3PrivacySublayer(PS),MAClayercontainsaseparateoptionalsecuritysub-layertoprovideauthentication,keyexchangeandencryption.802.16byencryptingtheconnectionbetweenthePSandBSprovideconfidentialaccesstothefixedbroadbandwirelessnetworkcapacity,inadditiontotherelevantBStrafficthroughencryptedagainstunauthorizedaccess,andgaveoperatorsapowerfulanti-theftfunctions.,14,5.802.16dPHYHilights,15,OFDMphysicallayersupportforframe-basedtransmission.Onecontainsadownlinksubframeandanuplinksub-frame.OFDMphysicallayersupportforframe-basedtransmission.Onecontainsadownlinksubframeandanuplinksub-frame.Uplinksub-framefromtheinitialrangingandbandwidthrequestforthecompetitiveslot,andoneormoreoftheSSemissionbydifferentupstreamphysicallayerPDUcomposition.,16,802.16dOFDMphysicallayerusing256subcarriers,OFDMAphysicallayer2048subcarriers,thesignalbandwidthisvariablefrom1.2520MHz.Intermsofmultipleaccessmethods,802.16dintheuplinkusingTDMA(TimeDivisionMultipleAccess),downbyTDM(TimeDivisionMultiplexing)tosupportmulti-usertransmission.AnotherwaymultipleaccessOFDMA,the2048sub-carrierasanexample,thesystemwillalltheavailablesubcarriersaredividedinto32subchannels,eachsubchannelcontainsseveralsub-carriers.Multi-usermultipleaccessandfrequencyhoppinginasimilarwayusingtoachieve,butFHoftheunitasasub-channelfrequencydomain,timedomaininunitsof2or3symbolperiods.,17,OFDMPHYTDDFrameStructure,18,OFDMPHYFDDFrameStructure,19,FDDMAPsTimeRelevance,frame,Broadcast,FullDuplexCapableUser,HalfDuplexT,erminal#1,HalfDuplexT,erminal#2,UPLINK,DOWNLINK,DLMAP,ULMAP,DLMAP,ULMAP,20,6.802.16Networkarchitecture,21,22,R1:AirinterfaceR2:CustomerInterfaceR3:WimaxaccessnetworkandcorenetworkinterfacesR4:ASNandASNInterfaceR5:WimaxroamingcorenetworkinterfacesR6:TheinterfacebetweentheBSandtheGWR7:ControlandbearerinterfacesR6:TheinterfacebetweentheBSandtheBS,23,ASNfunctionASNfunctionistomanagetheIEEE802.16airinterfaceforWiMAXtoprovideuserswithwirelessaccess.Keyfeaturesincludethefollowing:(1)Findthenetwork,selecttheCSN/NSP(accordingtopolicyconstraints,selectabasestation,accesstowirelessaccessservices);(2)Inthebasestationandlayer2connectionbetweentheMSS(3)IntheProxyMobileIP(PMIP)mode,theAAAmessagetotheusercontroltheownershipofNSP,tohelpcompletetheauthentication,authorizationandaccountingbusiness(4)MSShelptoestablishhigh-levelandlayer3connections,IPaddressallocation(5)RadioResourceManagement(6)ASNaccordingtotheclassificationstructurewithinthemobilitymanagement,includingalltypesofswitching,24,ASNreferencemodel,25,ASN-GWfunctionaldecomposition,26,ASN-GWfunctions:(1)LocationmanagementandpagingbetweenASN(2)Onlinewirelessloadbalancing,usedtodeterminetheswitch,andofflinewirelessstatisticsfornetworkoptimization(3)ASNprovisionallistofuserinformationandencryptionkeys,similartothefunctionofVLR.(4)Authenticationkeygenerationanddistribution(5)AndBScollaboration,establishmentandmanagementofmobiletunnel(6)Session/mobilitymanagement(client)(7)QoSandpolicyenforcement,27,CSNfunctionCSNprovidesIPconnectivityfortheuser.CSNcanberouters,AAAagentorserver,userdatabase,Internetgatewaydeviceandothercomponents,CSNcouldserveasanewnetworkofthenewentitycanalsousesomeoftheexistingnetworkequipmentCSNfunction.(1)Sessionconnectionfortheuser,IPaddressassignedtotheterminal.(2)Internetaccess(3)SystemparametersbasedonuserQoSandAdmissionControl(4)AAAproxyorserver(5)mobilitymanagementbetweentheASNs,28,7.802.16Scenarios,802.16dprovidedfixedandnomadicservices.802.16eadditiontoprovidingthefirsttwobusinesses,alsooffersportablesimplemobilityandfullmobileservices,29,ApplicationMode(1)-PMP,1.PMPapplicationmodelisacommonlyusedformofaccessnetworkapplications,networkstructureischaracterizedbysimplicity.2.ApplicationmodeandformofxDSLandothersimilarcableaccess,therefore,istheidealchoiceofacablereplacementprogram.,30,Meshapplicationmodeischaracterizedbymeshstructurecanbedeployedflexiblyaccordingtoactualconditions,toachievetheflexibilityofthenetworkextension.Sofarfromthebackbonenetworkforthesuburbs,theareacoveredbyhardwire,themodelcanbeusedtoexpandcoverage,dependingontheirregulatorytouchbaseradius,coveringareas.,ApplicationMode(2)-Mesh,31,ApplicationMode(3)-backhaul,WiMAXhotspotmodelthemainfeaturesofthereturnisthereturnasabusinessapplication,usingwirelesstransmission.Andcomparedtotraditionalwiredbackhaulmode,characterizedbyclear,thetraditionalpost