【導(dǎo)讀】LTE系統(tǒng)主要信令流程。TD-S/L系統(tǒng)總體分析對比。TD-LTE系統(tǒng)架構(gòu)與協(xié)議特點。LTE借鑒TD-SCDMAIu-PS進行定義。X2口相當于Iur，S1相當于Iu. X2口支持小區(qū)間負荷信息交互，輔助執(zhí)行ICIC. LTE借鑒TD-SCDMA，分層相同。各協(xié)議具體功能不同。協(xié)議棧在接入網(wǎng)側(cè)分布于NodeB. 支持固定數(shù)據(jù)分段，通過調(diào)整分。段的數(shù)量適配底層傳輸速率。用戶面和控制面都存在，除實現(xiàn)。頭壓縮功能外，還要實現(xiàn)加密和。采用多址方式不同，物理層的設(shè)計存在諸多差異，信道與信號的表現(xiàn)。接，UTRAN內(nèi)沒有任何有關(guān)此UE的信。息；通過非接入層標識如IMSITMSI或。P-TMSI等標志來區(qū)分UE；時，UE才從空閑模式轉(zhuǎn)移到連接模。TD-LTE未定義專用信道，取消CELL_DCH狀態(tài)。狀態(tài)越少，轉(zhuǎn)移越簡單，狀態(tài)功能越復(fù)雜；狀態(tài)越多，狀態(tài)轉(zhuǎn)移越復(fù)雜，狀態(tài)功能越簡單?；鹃g切換類似于SRNS重定位。和CS域分別定義流。TD-LTE支持NAS和RRC信令的合并傳輸，可降低連接建立時延。TD-SCDMA建立業(yè)務(wù)承載之前需要經(jīng)過7條NSA信令交互，TD-LTE只。若切換失敗，TD-LTE系統(tǒng)終端發(fā)起RRC連接重建過程，TD-SCDMA使。定義QCI,核心網(wǎng)下發(fā)QCI及其伴隨屬性,接入網(wǎng)負責保證

　　

【正文】 le a s e C o m p le t e 1 5 . A L C A P I u d a t a t r a n s p o r t b e a r e r r e le a s e 1 6 . R a d io L in k D e l e t io n R e q u e s t 1 7 . R a d io L in k D e le tio n R e s p o n s e 1 8 . A L C A P I u b d a t a t r a n s p o r t b e a r e r r e le a s e 1 9 . R e le a s e ( S C C P ) 2 0 . R ele a s e C o m p le t e ( S C C P ) C o m m u n ic a t i n g 62 ? ? TDLTE ENB間的切換 ENB間切換的四種可能 – 服務(wù) MME和 SGW均不發(fā)生變化 – 服務(wù) MME不變而 SGW改變 – 服務(wù) MME改變而 SGW不變 – 服務(wù) MME和 SGW均改變 ENB是否存在 X2接口 – 無 X2接口 ? 經(jīng) SGW間接前轉(zhuǎn)分組數(shù)據(jù) – 有 X2接口 ? 經(jīng) X2接口直接前轉(zhuǎn)分組數(shù)據(jù) 63 TDLTE 基站間切換（ 1） 64 TDLTE 基站間切換（ 2） UE Source eNB Target eNB MME Source Gateway 65 TDLTE 系統(tǒng)間切換 切換準備 UE Source eNodeB Target RNC Source MME Source Target Target SGSN Serving GW Serving GW PDN GW HSS Uplink and DownlinkUser Plane PDUs 1. Handover Initiation 2. Handover Required 3. Forward Relocation Request 4. Create Session Request 4a. Create Session Response 5. RelocationRequest 5a. Relocation Request Acknowledge 6. Create Indirect Data Forwarding Tunnel Request 6a. Create Indirect Data Forwarding Tunnel Response 7. Forward Relocation Response 8. Create Indirect Data Forwarding Tunnel Request 8a. Create Indirect Data Forwarding Tunnel Response 66 (A) TDLTE UE Source eNodeB Target RNC Source MME Target SGSN Source Serving GW Target Serving GW PDN GW HSS Uplink and Downlink User Plane PDUs 1. Handover Command 2. HO from EUTRAN Command 4. UTRAN Iu Access Procedures 4a. Handover to UTRAN Complete Sending of uplink data possible Downlink User Plane PDUs If Direct Forwarding applies Via Target SGSN in case Direct Tunnel is not used If Indirect Forwarding applies. 系統(tǒng)間切換 切換執(zhí)行 5. Relocation Complete 6. Forward Relocation Complete Notification 6a. Forward Relocation Complete Acknowledge 7. Modify Bearer Request For Serving GW relocation Steps 7, 8 and 9, and the following User Plane path, will be handled by Target Serving GW 8. Modify Bearer Request 8a. Modify Bearer Response 9. Modify Bearer Response Uplink and Downlink User Plane PDUs (Via Target SGSN if Direct Tunnel is not used) 10. Routeing Area Update procedure 11. Delete Session Request 11b. Release Resources (B) 11a. Delete Session Response 12. Delete Indirect Data Forwarding Tunnel Request 12a. Delete Indirect Data Forwarding Tunnel Response 13. Delete Indirect Data Forwarding Tunnel Request 13a. Delete Indirect Data Forwarding Tunnel Response67 68 TDLTE 基于 X2的切換過程 UE Source eNodeB Target eNodeB MME Serving GW PDN GW Downlink and uplink data Handover preparation Handover execution Forwarding of data Downlink data Uplink data 1 Path Switch Request Downlink data Handover pletion 2 User Plane Update Request 3a Update Bearer Request (A) 3b Update Bearer Response 4 User Plane Update Response 5. End marker 5. End marker 6 Path Switch Request Ack 7 Release Resource 8. Tracking Area Update procedure TDLTE 基于 S1的切換過程 69 TDLTE 基于 S1的切換過程 70 TDLTE 基站內(nèi)切換 Source UE eNB 71 active time） TDLTE 基站內(nèi)切換對比 UE Node B RNC Communicating Measurement Report Radio Link Adding Request Radio Link Adding Response Decision to HO LO OP ERQ (AAL2_EST_REQ) ECF(AAL2_EST_CFM) 1 1 voice data（ to old Physical Channel Reconfiguration SYNC_UL (to new cell) FPACH (from new cell) Physical Channel Reconfiguration Complete (via new cell) cell） voice data（ to new cell, after Radio Link Restoration Radio Link Deletion Request (for old cell) Radio Link Deletion Response LO OP REL (AAL2_REL_REQ) RLC(AAL2_REL_CFM) 1 1 Communicating 72 TDLTE 目 錄 TDS/L系統(tǒng)總體分析對比 開機注冊過程 TDLTE系統(tǒng)架構(gòu)與協(xié)議特點 TDLTE主要信令流程 位置更新過程 連接建立過程 切換控制過程 尋呼信令過程 小區(qū)初搜過程 隨機接入過程 73 TDLTE TDS系統(tǒng)尋呼概述 Paging type 2 PICH DATA FP PCH Pbitmap PAGING PCCH:PAGING TYPE 1 Idle或連接狀態(tài) UE PAGING DCCH:PAGING TYPE 2 MTC過程 74 TDLTE LTE尋呼過程 網(wǎng)絡(luò)發(fā)起，多個接收方 (PCCH) UE EUTRAN Paging PCCH/RLCTM/無 PDCP PCH(無 HARQ)/PDSCH 75 TDLTE 目 錄 TDS/L系統(tǒng)總體分析對比 開機注冊過程 TDLTE系統(tǒng)架構(gòu)與協(xié)議特點 TDLTE主要信令流程 位置更新過程 連接建立過程 切換控制過程 尋呼信令過程 小區(qū)初搜過程 隨機接入過程 76 1 2 3 TDLTE TDS系統(tǒng) UE小區(qū)搜索步驟 搜索 DwPCH ? DwPCH對應(yīng)于 4個基本 Midamble 擾碼與基本 midamble鑒別 控制復(fù)幀同步 ? 擾碼與基本 Midamble一一對應(yīng) ? 比較 DwPTS與 PCCPCH Midamble 的相對相位 4 讀取 BCH 77 TDLTE UE小區(qū)初搜實現(xiàn)過程 DwPTS 同步 ICS . 4 載波 調(diào)整 同步 調(diào)整 增益 調(diào)整 ICS . 1 搜索 DwPTS 大致位置 ICS . 2 當前小區(qū) SYNC _ DL 碼編號 ICS . 3 SYNC _ DL 碼確認及 其接收時 刻 載波頻偏粗調(diào) ICS . 5 UE 同時接收到 的 SYNC _ DL 碼 及其主徑位置 ICS . 6 載波頻偏 粗估計 ICS . 7 載波頻偏 粗調(diào)策略 ICS . 8 Basic midamble 碼確認 ICS . 9 確認當前小區(qū) Basic Midamble 碼 ICS .10 載波頻偏精調(diào) ICS .11 ICS .12 JD 載波頻偏 精估計 載波頻偏 精調(diào)策略 ICS .13 BCH 交織幀確 信道估計 ICS .14 定 計算 SYNC _ DL 調(diào)制相位 ICS .16 確定 BCH 交織塊位置 ICS .15 78 TDLTE UE小區(qū)初搜實現(xiàn) 在鎖定的某個頻點上接 Possible location of DwPTS 收一個子幀長度數(shù)據(jù) 特征窗確定 DwPCH粗略位置 Symbol級 5ms GP S YN C GP SYNC: 4symbols GP: 2symbols Power ratio = ((Pi+Pi+1)+(Pi+6+P