【正文】 包 ,但 SGW的 UE上下文中又沒(méi)有下行用戶面的 TEID,表示當(dāng)前沒(méi)有和 UE建立用戶面連接 ,則 SGW緩存下行分組數(shù)據(jù)包 ,并查詢目前服務(wù) UE的是哪個(gè)MME(SGSN) (2a)SGW向 MME(SGSN)發(fā)下行數(shù)據(jù)到達(dá)通知消息 ,請(qǐng)求用戶面連接 (2b)MME(SGSN)向 SGW發(fā)下行數(shù)據(jù)到達(dá)通知確認(rèn)消息 (3)如果 UE注冊(cè)到 MME,則 MME向 UE注冊(cè) TA的所有 eNodeB發(fā)尋呼消息 (4)如果 eNodeB收到 MME的尋呼消息 ,則開始尋呼 UE (5)一旦收到 EUTRAN的尋呼消息 ,UE發(fā)起” UE觸發(fā)的服務(wù)請(qǐng)求過(guò)程” (6)如果 ISR是激活的 ,當(dāng) EUTRAN收到尋呼響應(yīng) ,SGW向 MME發(fā)停止尋呼消息 ? 切換過(guò)程 RRC連接狀態(tài)的 UE在 EUTRAN中進(jìn)行移動(dòng)的一般原則如下 在 EUTRAN中 ,網(wǎng)絡(luò)控制 UE的移動(dòng) ,網(wǎng)絡(luò)決定 UE該進(jìn)入哪個(gè)小區(qū) ,哪個(gè)頻點(diǎn)或哪個(gè) RAT。 MME正式確認(rèn) UE駐留在某個(gè) TA中，并為該 UE生成上下文 SGW發(fā)生成默認(rèn)承載請(qǐng)求消息 ,要求 SGW為該 UE生成一個(gè)默認(rèn)承載 EPS承載列表中建立一個(gè)新的條目 ,并向 PGW發(fā)送生成默認(rèn)承載請(qǐng)求消息 ,要求 PGW為該 UE生成一個(gè)默認(rèn)承載 EPS承載列表中建立一個(gè)新的條目 ,開始在外部 PDN網(wǎng)絡(luò)和 SGW之間轉(zhuǎn)發(fā)用戶面 PDU,并生成一個(gè)新的計(jì)費(fèi) ID,開始計(jì)費(fèi)。包括以下參數(shù)： ? UE的 IMSI，舊的 GUTI以及附加 GUTI：舊 GUTI可以由 PTMSI和 RAI(routing area identity)導(dǎo)出。 RRC連接重配置消息中包括測(cè)量配置，移動(dòng)控制，無(wú)線資源配置（包括 RB， MAC主配置和物理信道配置）等消息以及所有相關(guān)的專用 NAS信息和安全配置信息。 ? UE identity, as provided in message 3 is echoed in RRC Contention Resolution message – HARQ feedback is transmitted only by the UE which detects its own UE identity U E e N BR a n d o m A c c e s s P r e a m b l e1R a n d o m A c c e s s R e s p o n s e2S c h e d u l e d T r a n s m i s s i o n3C o n t e n t i o n R e s o l u t i o n4? RRC連接釋放過(guò)程 ? 由 EUTRAN發(fā)起 ,要求一個(gè)處于 RRC連接狀態(tài)的 UE釋放 RRC連接 ,包括釋放已建立的無(wú)線承載 (RB)和所有無(wú)線資源 ? RRC連接重配置過(guò)程 ? EUTRAN通過(guò)向 UE發(fā) RRC連接重配置消息 ,發(fā)起 RRC連接重配置過(guò)程。 ? If the size of the message allows it, the initial NAS message (or something allowing to build the initial NAS message in eNB) can be included。 ? Sent on DLSCH, and intended for one or multiple UEs – 3) (MSG. 3) RRC Connection Request in uplink: ? Uses HARQ。 UE收到 RRC連接建立消息后，根據(jù)消息中的信元進(jìn)行以下操作： ? （ 1）根據(jù) radioResourceConfigDedicated信元進(jìn)行無(wú)線資源配置過(guò)程 ? （ 2）填寫 RRC連接建立完成消息 ? ? UE通過(guò) PUCH/UL_SCH/DCCH向 EUTRAN發(fā) RRC連接建立完成消息 ,進(jìn)入 RRC連接狀態(tài) ,結(jié)束本次RRC連接建立過(guò)程 An example of a possible connection flow UE eNB MME Power ON, measurements, cell selection BCCH/BCH: MasterInformationBlock BCCH/BCH: SystemInformation (SIB1) BCCH/BCH: SystemInformation (SIB2) RACH: preamble_id PDCCH: UL grant CCH: SRB0: RRCConnectionRequest (STMSI) CCH: SRB0: RRCConnectionSetup (STMSI, CRNTI) DCCH: SRB1: RRCConnectionSetupComplete (CRNTI, NAS_info) S1: INITIAL UE MESSAGE S1: INITIAL CONTEXT SETUP REQUEST (UE cap) DCCH: SRB1: Security Mode Command DCCH: SRB1: Security Mode Complete DCCH: SRB1: RRCReconfigurationRequest DCCH: SRB1: RRCReconfigurationComplete Random Access Procedure – Contention Based (Initial Access Example) The four steps of the RACH procedures are: – 1) (MSG. 1) Random Access Preamble on RACH in uplink: ? 6 bits to carry: a 5 bit random ID, and 1 bit to indicate information on size of message 3 limited by radio conditions. – 2) (MSG. 2) Random Access Response in downlink: ? semisynchronous (within a flexible window) with message 1。 on request from the MME, eNB sends pages to the UE during UE’s DRX up wake time – At PDCP/RLC/MAC level: ? UE monitors L1/L2 control signalling channel to see if any transmission over the shared data channel has been allocated to the UE ? UE reports channel quality and feedback information to eNB ? DRX/DTX period can be configured according to UE activity level for UE power saving and efficient resource utilization. This is under control of eNB (RRC). ? DRX = Discontinuous Reception。 eNB processes these requests – UE and eNBcan transmit and/or receive data to/from each other。 – UE can perform handover (intereNB, intraeNB, interRAT) under eNB control。LTE 典型信令過(guò)程 Software Architecture 3類 NAS信令流程 ? 1. 會(huì)話管理相關(guān) ? 2. 位置管理相關(guān) ? 3. 鑒權(quán)管理相關(guān) UE eNB MME SGW PGW RRC: RRC Connection setup plete NAS: Attach Request NAS:PDN connectivity request S1AP: Initial UE message Authentication and NAS security procedure HSS S6a: Update Location request S6a: Update Location answer S11: Create bearer request S5: Create bearer request S5: Create bearer response S11: Create bearer response S1AP: Initial Context setup request NAS: Attach accept NAS: Activate Default EPS bearer request NAS: Attach Request NAS:PDN connectivity request RRC: RRCConnectionReconfiguration NAS: Attach accept NAS: Activate Default EPS bearer request RRC: RRCConReconfigComplete S1AP: Initial Context setup response RRC: UL information Transfer NAS: Attach plete NAS: Activate Default EPS bearer accept S1AP: Uplink NAS Transport NAS: Attach plete NAS: Activate Default EPS bearer accept UE initiated Detach Procedure UE eNB MME SGW PGW HSS RRC: RRC Connection setup plete NAS: Detach request S1AP: Initial UE message NAS: Detach request Authentication and NAS security S11: Delete session request S5: Delete session request S5: Delete session response S11: Delete session response S1AP: Downlink NAS transport NAS: Detach accept RRC: DLInformation transfer NAS: Detach accept Radio and S1 Release S6a: TDelay purge timer expires S6a: Purge UE request S6a: Purge UE answer MME Se rv i n g G W PDN G W 2 . NAS: Se rv i c e Re q u e s t 1 . NAS: Se rv i c e Re q u e s t 7 . S1 AP: I n i ti a l Co n te x t Se tu p Co m p l e te 3 . Au th e n ti c a t i o n HSS 4 . S1 AP: I n i ti a l Co n te x t Se tu p Re q u e s t 5 . Rad i o Be a r e r Es t a b l i s h m e n t 6 . Upl i n k D a ta 8 . Upd a t e Be a r e r Re q u e s t 1 2 . Upd a te Be a re r Re s p o n s e UE e Nod e B 1 1 . Upd a te Be a re r Re s p o n s e PCR F (A ) 1 0 . P C E F I n it ia t e d I P C A N S e s s ion M o d if i c a t ion 9 . Upd a t e Be a r e r Re q u e s t UE Tri