LTE專有承載建立，修改，釋放組網(wǎng)和接口圖:LTE中用戶數(shù)據(jù)傳輸流程:Application/ServiceLayerULTrafficFlowAggregatesDLTrafficFlowAggregatesUE.UL-TFTL-TFTfRB-IDRB-ID屋1-TEIDeNNBeBRadioBearerDL-TFT、UE.UL-TFTL-TFTfRB-IDRB-ID屋1-TEIDeNNBeBRadioBearerDL-TFT、DL-TFT.S5/S8-TEI'飛ServingGPDNGWS1BearerS5/S8BearerEPS承載是什么？我理解就是UE到PGW的一個(gè)用戶數(shù)據(jù)傳輸通道。EPS承載ID作用？唯一的標(biāo)識(shí)EPS承載。MME分配。EPSRBID和EPSbearerID是一對(duì)一的，對(duì)應(yīng)關(guān)系E-NodeB維護(hù)。

承載建立場(chǎng)景：EPS專有承載建立目的是為了滿足用戶特定的QOS(核心網(wǎng)提供)需求，建立之前必須有缺省的EPS承載。通過(guò)網(wǎng)絡(luò)側(cè)觸發(fā)數(shù)據(jù)承載建立流程，其觸發(fā)條件可以是IP多媒體子系統(tǒng)(IMS)會(huì)話中的策略與計(jì)費(fèi)規(guī)則功能實(shí)體(PCRF)交互、初始附著時(shí)移動(dòng)性管理實(shí)體(MME)指示，或是由UE請(qǐng)求，從而方便未來(lái)很多由網(wǎng)絡(luò)端發(fā)起的業(yè)務(wù)的QoS及策略控制。建立的信令流程:UEMMFServingGWPDNGWPCRF（A）IP-CANSessionModification——————————,q2.CreateBearerRequestCreateBearerRequestBearerSetupRequest/.SessionManagementRequest.5.RRCConnectionReconfigurationUEMMFServingGWPDNGWPCRF（A）IP-CANSessionModification——————————,q2.CreateBearerRequestCreateBearerRequestBearerSetupRequest/.SessionManagementRequest.5.RRCConnectionReconfigurationRRCConnectionReconfigurationCompleteBearerSetupResponseDirectTransfer,[9.SessionManagementResponse10.CreateBeare/esponse11_CreateBearer（B）Response12.IP-CANSession,Modification-關(guān)鍵信令消息字段：PCCdecisionprovision：QosPolicy（動(dòng)態(tài)PCC時(shí)才需要）CreateBearerRequest：IMSI,PTI（只用于UE請(qǐng)求的承載資源修改流程），EPSBearerQoS,TFT,S5/S8TEID（給專有承載新分配的），ChargingId,LBI（連接的EPS承載ID，即默認(rèn)承載的ID）,ProtocolConfigurationOptions（用于在UE和PGW之間傳輸應(yīng)用級(jí)參數(shù)，透明傳輸在MME和SGW）CreateBearerRequest：IMSI,PTI,EPSBearerQoS,TFT,S1-TEID,LBI,ProtocolConfigurationOptionsSessionManagementRequestNAS消息發(fā)給UE：PTI,TFT,EPSBearerQoSparameters（excludingARP）,ProtocolConfigurationOptions,theEPSBearerIdentityandtheLinkedEPSBearerIdentity(LBI)BearerSetupRequest發(fā)給E-NODEB：EPSBearerIdentity,EPSBearerQoS,SessionManagementRequest,S1-TEID5.RRCConnectionReconfiguration：RadioBearerQoS,SessionManagementRequest,EPSRBIdentity(透?jìng)鱊AS消息)BearerSetupResponse：EPSBearerIdentity,S1-TEIDSessionManagementResponse(DirectTransfer)：UE的nas層建立此消息，攜帶EPSBearerIdentitySessionManagementResponse：E-nodeB轉(zhuǎn)發(fā)這個(gè)上行NAS傳輸給MMECreateBearerResponse(消息7和9都收到之后發(fā)送):EPSBearerIdentity,S1-TEIDCreateBearerResponse：EPSBearerIdentity,S5/S8-TEID承載修改場(chǎng)景1：PGW發(fā)起的，由于QOS更新觸發(fā)的承載修改流程。(A)..UpdateBearerrequ1.IP-CANSessionModificationJ jestMMEPDNGWServingGWPCRF信令流程:MMEPDNGWServingGWPCRFeNodeB條UpdateBearerRequest4.BearerModifyRequest/SessionManagementRequest|5.RRCConnectionReconfigurationRRCConnectionReconfigurationComplete一7.-Bearer.ModifqResponse8.DirectTransfer 9.SessionManagementResponse■10.UpdateBearerResponse11.UpdateBearerresponse12.IP-CANSession(B)Modifications: :上關(guān)鍵信令消息字段：UpdateBearerRequest：PTI(用于UE發(fā)起的修改流程)，EPSBearerIdentity,EPSBearerQoS,APN-AMBR,TFT

UpdateBearerRequest：PTI,EPSBearerIdentity,EPSBearerQoS,TFT,APN-AMBRSessionManagementRequest發(fā)送給UE：PTI,EPSBearerQoSparameters(包括ARP),TFT,APN-AMBR,EPSBearerIdentity，這個(gè)過(guò)程UE不應(yīng)該拒絕。發(fā)送BearerModifyRequest給E-Nodeb：EPSBearerIdentity,EPSBearerQoS,SessionManagementRequest,UE-AMBRRRCConnectionReconfiguration：RadioBearerQoS,SessionManagementRequest,EPSRBIdentityBearerModifyResponse：EPSBearerIdentity，EnodeB告訴MME該EPS承載能否被建立DirectTransfer(SessionManagementResponse)：EPSBearerIdentity，NAS層創(chuàng)建BearerResponse：EPSBearerIdentity11.UpdateBearerResponse：EPSBearerIdentity承載修改場(chǎng)景2：HSS發(fā)起的，由于用戶簽約信息QOS更新觸發(fā)的承載修改流程。PS：這里更新的QOS信息是用戶簽約信息(HSS發(fā)起的InsertSubscriber口2七2，插入的就是用戶簽約信息)。信令流程:eNodeBMMEServingGWPDNGWPCRFHSSeNodeBMMEServingGWPDNGWPCRFHSS1.InsertSubscriberdata1aInsertSubscriberdataAck2a.UECtxtUpdate2b.ModifyBgarerCommand(A)ModifyBearerCommand(A)PCEFInitiatedIP-CAN

jSessionModification],5.UpdateBearerRequest6.ProcedureasinTS23.401,steps3to10ofFigure-1orsteps3to8ofFigure5.4.3-17.UpdateBearer(B);Response--8.-Provision-Ack^關(guān)鍵信令消息字段:1.InsertSubscriberData：IMSI,SubscriptionData(EPSsubscribedQoS(QCI,ARP),subscribedUE-AMBRandAPN-AMBR)1a.InsertSubscriberDataAck：IMSI2a.UEContextModificationProcedureeNB MMEUECONTEXTMODIFICATIONREQUESTUECONTEXTMODIFICATIONRESPONSEtheSecurityKeyIE.theSubscriberProfileIDforRAT/Frequencypriority!.theUEAggregateMaximumBitRateIE.theCSFallbackIndicatorIE.theUESecurityCapabilitiesIE.theCSGMembershipStatusIE.theRegisteredLAIIE..如果修改的UE-AMBR,觸發(fā)S1-APUEContextModificationProcedure；如果修改的QCI,ARP,APN-AMBR,并且有激活的PDN連接觸發(fā)2b2b.ModifyBearerCommand：EPSBearerIdentity,EPSBearerQoS,APN-AMBR.ModifyBearerCommand：EPSBearerIdentity,EPSBearerQoS,APN-AMBR5.UpdateBearerRequest：EPSBearerIdentity,EPSBearerQoS,TFT,APN-AMBR承載修改場(chǎng)景3：PGW發(fā)起的，非QOS更新觸發(fā)的承載修改流程。這個(gè)流程用于為激活的默認(rèn)承載或者專有承載更新TFT（與承載相對(duì)應(yīng)，提供包過(guò)濾功能來(lái)選擇對(duì)應(yīng)的專有承載），或者用于更新APN-AMBR（需要，PGW協(xié)商后應(yīng)用的ANP-AMBR會(huì)經(jīng)過(guò)SGW,MME,E-NodeB通知給UE）。

MME ServingGW PDNGW PCRF(A).2UpdateBearerReqi1.IP-CANSessionModificationM1LlestI信令流程:eNodeB,3.UpdateBearerRequest.4.DownlinkNASTransport信令流程:eNodeB.5.DirectTransferDirectTransferUplinkNASTransportUpdateBearerResponse9.UpdateBearerRespo)nse10.IP-CANSessioModification./*---n.(B)關(guān)鍵信令的消息字段：UpdateBearerRequest：PTI,EPSBearerIdentity,APN-AMBR,TFTUpdateBearerRequest：PTI,EPSBearerIdentity,APN-AMBR,TFTDownlinkNASTransport(SessionManagementConfiguration)：TFT,APN-AMBRandEPSBearerIdentity(如果APN-AMBR修改,MME有可能決定修改UE-AMBR，則MME會(huì)發(fā)起S1-APUEContextModificationProcedure)DirectTransfer(SessionManagementRequest)DirectTransfer(SessionManagementResponse)UplinkNASTransport(SessionManagementResponse)UpdateBearerResponse：EPSBearerIdentityUpdateBearerResponse：EPSBearerIdentity承載刪除場(chǎng)景1：沒(méi)有動(dòng)態(tài)PCC應(yīng)用時(shí)，一些QOS策略(比如，當(dāng)前一些優(yōu)先級(jí)高的用戶業(yè)務(wù)帶寬不能滿足,通過(guò)釋放優(yōu)先級(jí)低的用戶承載資源來(lái)滿足)可能觸發(fā)此流程；或者從3GPP到非3GPP網(wǎng)絡(luò)切換時(shí)可能觸發(fā)；對(duì)于一個(gè)緊急的PDN連接，當(dāng)這個(gè)連接在配置的周期內(nèi)無(wú)報(bào)文傳輸或者是被動(dòng)態(tài)PCC觸發(fā)時(shí)，會(huì)觸發(fā)此流程。作用：刪除一個(gè)專有承載；刪除該P(yáng)DN連接下的所有承載（通過(guò)刪除默認(rèn)承載）。

信令流程:UEeNodeBMME11SGSN11ServingGWPDNGWPCRFHSSIP-CANSessionModification.2.DeleteBearerRequestg.DetachReq-5.RRCConne(uest一一一,————一--.4b.Deactivate?tionReconfigure)tionReconfigure6b.Deactivate3a.DeleteBearerRequestrerRequesteyerResponseBearerRequationitioncompletBearerResp(EPSBearer8a.Deletease-3bDeleteBeaeste)nse6a.RRCConnec >7a.DirectTran*_7c--DeiachAcc6,11.Signalling/er7b.Deactivate —源t >當(dāng)nnectionReleContextAcceptBearerRespons8b.DeleteBej9.DeleteBearerReq(B))onse10.IP-CANSession_Modification__1L關(guān)鍵信令消息的字段：DeleteBearerRequest：PTI,EPSBearerIdentity,Causes(為RATchangedfrom3GPPtoNon-3GPP時(shí)，會(huì)刪除該P(yáng)DN連接的所有承載)3a.DeleteBearerRequest：PTI,EPSBearerIdentity,Cause時(shí)會(huì)發(fā)送4a.DetachRequest：UE的最后一個(gè)PDN連接已經(jīng)釋放，不是ISR或者到非3GPP網(wǎng)絡(luò)的切換，會(huì)觸發(fā)此消息。如果UE是IDLE狀態(tài)，MME會(huì)pageUE4b.S1-APDeactivateBearerRequest：EPSBearerIdentity5.RRCConnectionReconfiguration：EPSRadioBearerIdentity,theNASDeactivateEPSBearerContextRequestmessage6a.RRCConnectionReconfigurationComplete6b.DeactivateBearerResponse：EPSBearerIdentity

7a.DirectTransfer(DeactivateEPSBearerContextAccept)：EPSBearerIdentity8a.DeleteBearerResponse：EPSBearerIdentity9.DeleteBearerResponse：EPSBearerIdentity承載刪除的場(chǎng)景2：MME發(fā)起的承載刪除。只能刪除專有承載，如果要?jiǎng)h除默認(rèn)承載的話MME使用UE或者M(jìn)ME請(qǐng)求PDN連接斷開(kāi)。觸發(fā)條件：異常的無(wú)線資源限制，無(wú)線環(huán)境不能讓E-NodeB繼續(xù)維持分配的GBR承載連接已發(fā)的無(wú)線承載釋放。信令流程：UE eNodeB MME ServingGW PDNGW PCRFRadioBearerReleaseRadioBearerReleaseIndicationofB孽rerReleaseDeleteBearerCommand3.DeleteBearerCommand(A)4.PCEFInitiatedIP-CANSessionModification "5.DeleteBearerRequest4.DeleteBearerRequestProcedureasinTS23.401,Figure-1,betweenstep4andstep7DeleteBearerResponseDeleteBearer(B)

Response-關(guān)鍵信令消息的字段：0.radiobearersrelease：(比如：異常的無(wú)線資源限制，無(wú)線環(huán)境不能讓E-NodeB繼續(xù)維持分配的GBR承載連接)BearerReleaseRequest/InitialContextSetupComplete/HandoverRequestAck/UEContextResponse/PathSwitchRequest：EPSBearerIdentityDeleteBearerCommand：EPSBearerIdentityDeleteBearerCommand：EPSBearerIdentity

UE申請(qǐng)承載資源修改:此流程UE可能是為了一個(gè)數(shù)據(jù)流的特別QOS需求，發(fā)起承載資源修改（比如分配或者釋放資源）；或者是沒(méi)修改QOS,只是更新了packetfilter，也可以發(fā)起。如果UE發(fā)起的承載資源修改請(qǐng)求被網(wǎng)絡(luò)側(cè)接受，會(huì)觸發(fā)專有承載的激活，承載修改或者PGW發(fā)起的去激活流程。前提是UE已經(jīng)和PGW有了PDN連接。信令流程:UEeNodeBMMEServingGWPDNGWPCRFUEeNodeBMMEServingGWPDNGWPCRFRequestBearerResourceModification| N IBearerResourc%Command3.BearerResourceCo(A)4.PCEFInitiatedIP-CANSessionModification,begin—3.BearerResourceCo(A)4.PCEFInitiatedIP-CANSessionModification,begin— /mmandDedicatedbeareractivationasperFigure5.4.1-1,fromstep2to11;orBearermodificationprocedureasperFigure-1,fromstep2to11,orasperFigure5.4.3-1,fromstep2to9;or^DedicatedbearerdeactivationprocedureasperFigure-1,fromstep2to9.-CANPCEFInitiatedIP-CANSessionModificati