看LOG学4G(19)--切换请求消息(注解）.docx

看1OG学4G(19)-切换请求消息、(注解)#4G#无线网络#1RC#handover一、4G网络切换流程处于RRC连接状态的终端(UE)向相邻小区移动时，UE会话从服务小区转移到另一个服务小区，最终与新eNodeB建立新连接。切换首先由服务eNodeB根据终端(UE)周期性上报的RRC测量报告来确定是否发起切换过程。当选定目标小区进行切换决策时，服务小区eNB还从其邻区列表和切换类型(即X2或S1切换)中选择H标eNodeB小区。如与目标eNodeB的X2链路已建立且可用，则执行X2切换，否则执行S1切换。切换过程中服务eNodeB通过X2链路向目标eNodeB发送切换请求(HandoverRequest)；当目标eNodeB接纳终端切入时回送“HandoverRequestACknoW1edge”消息；收到允许切换消息后，服务eNodeB再通过包含“TargetCe11”的RRC重配置消息通知终端(UE)执行切换。切换流程如下图所示：MMESGWX2APHandoverRequest×2APHandoverRequestAcknow1edgeHandoverCommandK2APSNTransferStatusendforforwardingSourceeNodeBTargeteNodeBTQCkingAreaUpdateReSpOnseC和老康一.学5G图14G网络内部切换流程Beginforwardingdown1inkdatafromsourcetodestinationeNodeBS1APPathSwitchRequestS1APPathSwitchAcknow1edgeX2APUEContextRe1easeTrackingAreaUpdateRequestModifyBearerReQUesCModifyBearer二、切换请求消息(HaiIdOVerReqIIeSt)是由服务eNodeB通过X2链路向目标eNodeB发送请求消息，其中包括终端(UE)在服务eNodeB中X2ID,切换原因，目标小区的P1MN和ID,终端在目标小区中eRAB建立以及RRC内容。消息结构如下：图2.4G网络中切换请求内容三、切换请求实例(部分注释)无线网络中做为目标小区切换请求是终端切入的第一条消息，只有允许切换入才回复“HandoverRequestACknOW1edge”消息，否则将回复“HandoverRequestRejectu。TimeeN0eBce11RNTIDATAIDMsgtiameDiredionFrameNo2019X>Miq2WM2385539145201W)M109:21226423855391453237832378X2X2201W)7-1109212265238553914532378X2201907-1109:212270238553914532378UU201907-1109212270238553914532378S1Handoverrequest*f>RecedeHandoverrequestacknowtedge令SendSnstatustransfer0ReceiveRfcconftecttonrecofinQurationco.DRecewePatswitchrequestSendPathswitchrequestacknw<edoeDRecede2019071109212273238553914532378S12O1AO71109212273238553914532378X2Ucomx1r*1caMSend201MM1o92122732385621452O1M711O92122772385539143201907-110W122792385539145201907-110W12792385539145201907-110&2123182385539145201907-110921231823855391452019-07-110921232123855391452O195110921264823S55391457787878787a7878Rrcc<xnctMrecocfgurat>n令SendRrccocinectKHirecocitgvrat>nco.RecedeMeasurementreportDRecetveMeasurementreport0RecefeMeaMirementreponQRecedeRfccotiiiectkMireeoofiguraQonSendRr(XOaMCtkMireconfiguQtkmc1DRecetveMeaMiremen1report，Rcwt717721723723762762765682Q1M7-11092126482395539145»378X2HaMMreqU81÷SdW2O1X7110/212649238灰，S14532378X2HandoverrequestackoweOge»Receive69201M7-110W12649238553914532378UURrccxmnecttonrecof1hauratwnOSend69IDt=IHUPinffi3tin9MessagtDProcCodeO:X2AP1han(JChge网3bonHHandovtrRtwstPProtoco11EsptO*1agQ1racAc1ronPrnt=ODsRVCCOp31)nPossWPrst«DCSGMemeCShIPStaIusPresentODm1t)1nornaoPrese1OQCa11Reaxd-UE-IdPresent1ue.S.TMS1nfo.1dPreset=OQrees1SrcCeJnfoResemOQSpdai.UPresn1OO0d.N.UX2APjD=564管罪专康一起学为图3.4G网络中切换入和切换出请求3.1HandoverRequest消息实例X2apMsgt=1uinitiatingMessageProcCode=O:X2AP_id_handoverPreparationHandoverRequest(切换请求)protoco1IEstOptF1agsIraceActivationPresent=OsRVCCOperationPossib1ePresent=OcSGMembershipStatusPresent=Omobi1ity1nformationPresent=Oca11_Record_UE_IdPresent=1(UE通信记录ID二是）ue_S_TMSI_1nfo_IdPrcsent-Oreest_SrcCe11_1nfoPrcsent=OSpccia1UePrescnt=Oo1d_eNB_UE_X2APD=564(UE原eNB中X2APID=564)CaUSe(原因)=1UradioNetwork=O:TX2AP_CauseRadioNetwork_Root_handover_desirab1e_for_radio.reasons(无线原因)targetedIJD(目标小区ID)tOptF1agsiE_ExtensionsPresent=Op1MNJdentity(P1MNID)nocts=3data=64fI1(HEX)eUTRANce11Identifier(eUTRAN小区ID)numbits=28data=010111100010000000111001OOO1(BIT)gUMMEID(终端gUMMEI)IOptF1a过iE_ExtensionsPresent=0gU_Group_IDtOptF1agsiE_ExtensionsPresent=0P1MNdentity(P1MNID)nocts=3data=64fI1(HEX)mME_Group_IDnocts=2data=37OO(HEX)mME_Codenocts=1data=03(HEX)uE_Context1nformation(UE上下文信息)IOptF1agsSubscriberprofi1eIDforRFPPresent=0handoverRestriction1istPresent=0IocationReportingInformationPresent=0iE_ExtensionsPrescnt=0mME_UE_SIAPJD=2785058307uESecurityCapabi1itiesIOptF1agsiE_ExtensionsPresent=0encryption1gorithmsnumbits=16data=eOOO(HEX)integrityProtectionA1gorithmsnumbits=16data=eOOO(HEX)aS_SecurityInformationtOptF1agsiE_ExtensionsPresent=key_eNodeB_starnumbits=256data=d1aa471920ff3e6873507ae5c8057395fd994bb6ac8cdb6bfbe606c5a396206(HEX)nextHopChainingCount=3UEaggregateMaximumBitRate(终端聚合最大速率)tOptF1agsiE_ExtensionsPresent=0UEaggregateMaximumBitRateDown1ink=300000000UEaggregatcMaxiniumBitRateUp1ink=4000。OOooe_RABs_ToBeSetup_1ist(eRAB建立列表)n=1e1emOJtOptF1agsd1_ForwardingPresent=1iE_ExtensionsPresent=0e_RAB_ID=5e_RAB_1eve1_QoS_Parameters（e_RAB的QOS参数）tOptF1agsgbrQosInformationPresent=OiE_ExtensionsPresent=OqCI=9a11ocationAndRctentionPrioritytOptF1agsiE_ExtensionsPresent=Opriority1eve1=15（优先级=15）pre_empiionCapabi1ity=O:TX2AP_Pre_emptionCapabi1ity_Root_sha11_not_trigger_pre_emption（预清空能力=O不启用）pre_emptionVu1nerabi1ity=1:TX2AP_Pre_emptionVuInerabi1ity_Root_pre_emptab1ed1_Forwarding=O:TX2AP_D1_Forwarding_Root_d1_forwardingProposedu1_GTPtunne1Endpoint（上行GTP端点）tOptF1agsiE_ExtensionsPresent=Otransport1ayerAddrcss（传输层地址）numbits=32data=06IcO17c