LTE_用戶面介紹

1、HUAWEI TECHNOLOGIES CO., LTDHuawei Confidential Security Level: LTELTE用戶面介紹用戶面介紹HUAWEI TECHNOLOGIES CO., LTD.Huawei Confidential Page 2l用戶面簡介用戶面簡介l包數(shù)據(jù)匯聚層（包數(shù)據(jù)匯聚層（PDCP）l無線鏈路層（無線鏈路層（RLC）l媒體接入層（媒體接入層（MAC）HUAWEI TECHNOLOGIES CO., LTD.Huawei Confidential Page 3用戶面簡介HUAWEI TECHNOLOGIES CO., LTD.Huawei Conf

2、idential Page 4用戶面在用戶面在E-UTRANE-UTRAN的位置的位置 HUAWEI TECHNOLOGIES CO., LTD.Huawei Confidential Page 5控制面和用戶面的協(xié)議棧控制面和用戶面的協(xié)議棧User-plane protocol stackcontrol-plane protocol stackHUAWEI TECHNOLOGIES CO., LTD.Huawei Confidential Page 6L2L2的下行結(jié)構(gòu)的下行結(jié)構(gòu)HUAWEI TECHNOLOGIES CO., LTD.Huawei Confidential Page 7L2

3、L2的上行結(jié)構(gòu)的上行結(jié)構(gòu)HUAWEI TECHNOLOGIES CO., LTD.Huawei Confidential Page 8包數(shù)據(jù)匯聚層（PDCP）HUAWEI TECHNOLOGIES CO., LTD.Huawei Confidential Page 9PDCPPDCP在協(xié)議棧中的位置在協(xié)議棧中的位置User-plane protocol stackcontrol-plane protocol stackHUAWEI TECHNOLOGIES CO., LTD.Huawei Confidential Page 10PDCPPDCP層的架構(gòu)層的架構(gòu)HUAWEI TECHNOLOGI

4、ES CO., LTD.Huawei Confidential Page 11PDCP PDCP 層的功能層的功能p- header compression and decompression of IP data flows using the ROHC protocol, at the transmitting and receiving entity, respectively;p- transfer of data (user plane or control plane). This function is used for conveyance of data between us

5、ers of PDCP services;p- maintenance of PDCP sequence numbers for radio bearers mapped on RLC AM;p- in-sequence delivery of upper layer PDUs at handover;p- duplicate elimination of lower layer SDUs at handover for radio bearers mapped on RLC AM;p- ciphering and deciphering of user plane data and cont

6、rol plane data; p- integrity protection and integrity verification of control plane data;p- timer based discard;p- duplicate discarding.HUAWEI TECHNOLOGIES CO., LTD.Huawei Confidential Page 12PDCPPDCP層功能層功能( (控制面控制面) )HUAWEI TECHNOLOGIES CO., LTD.Huawei Confidential Page 13PDCPPDCP層功能層功能( (用戶面用戶面) )

7、HUAWEI TECHNOLOGIES CO., LTD.Huawei Confidential Page 14RoHC (Robust header compression)RoHC (Robust header compression)Profile IdentifierUsage:Reference0 x0000No compressionRFC 49950 x0001RTP/UDP/IPRFC 3095, RFC48150 x0002UDP/IPRFC 3095, RFC48150 x0003ESP/IPRFC 3095, RFC48150 x0004IPRFC 3843, RFC48

8、150 x0006TCP/IPRFC 49960 x0101RTP/UDP/IPRFC 52250 x0102UDP/IPRFC 52250 x0103ESP/IPRFC 52250 x0104IPRFC 5225HUAWEI TECHNOLOGIES CO., LTD.Huawei Confidential Page 15加密功能加密功能l加密用戶面數(shù)據(jù)和控制面數(shù)據(jù)：加密用戶面數(shù)據(jù)和控制面數(shù)據(jù)：p控制面：PDCP PDU的數(shù)據(jù)部分和MAC-I部分（message authentication code ）被加密；如果控制面數(shù)據(jù)沒有完整性保護，則MAC-I部分仍然存在，但是值設(shè)置為0；p用戶面

9、：PDCP PDU的數(shù)據(jù)部分被加密；p加密的算法和密鑰都是高層設(shè)置的，加密的激活也是由高層來做的；HUAWEI TECHNOLOGIES CO., LTD.Huawei Confidential Page 16完整性保護功能完整性保護功能l完整性保護應用于控制面數(shù)據(jù)完整性保護應用于控制面數(shù)據(jù)p包括完整性保護和完整性驗證p完整性保護的算法和密鑰都是高層設(shè)置的，它的激活也是由高層來做的；HUAWEI TECHNOLOGIES CO., LTD.Huawei Confidential Page 17PDCPPDCP的丟包處理：的丟包處理：lPDCP實體收到上層遞交的一個PDCP SDU，就會為這個S

10、DU啟動一個Discard_Timerl當一個PDCP SDU的Discard_Timer超期時，UE就會丟棄這個PDCP SDU以及由它生成的PDCP PDU。如果這個PDCP PDU已經(jīng)傳遞到底層的話，就向底層發(fā)一個丟棄指示命令HUAWEI TECHNOLOGIES CO., LTD.Huawei Confidential Page 18PDCP Reordering windowPDCP Reordering windowHUAWEI TECHNOLOGIES CO., LTD.Huawei Confidential Page 19無線鏈路層（RLC）HUAWEI TECHNOLOGIE

11、S CO., LTD.Huawei Confidential Page 20RLCRLC在協(xié)議棧中的位置在協(xié)議棧中的位置User-plane protocol stackcontrol-plane protocol stackHUAWEI TECHNOLOGIES CO., LTD.Huawei Confidential Page 21RLCRLC的結(jié)構(gòu)的結(jié)構(gòu)HUAWEI TECHNOLOGIES CO., LTD.Huawei Confidential Page 22TM TM 實體實體HUAWEI TECHNOLOGIES CO., LTD.Huawei Confidential Page

12、 23UM UM 實體實體HUAWEI TECHNOLOGIES CO., LTD.Huawei Confidential Page 24AM AM 實體實體HUAWEI TECHNOLOGIES CO., LTD.Huawei Confidential Page 25RLCRLC層的功能層的功能lTransfer of upper layer PDUs;lError correction through ARQ (only for AM data transfer);lConcatenation, segmentation and reassembly of RLC SDUs (only f

13、or UM and AM data transfer);lRe-segmentation of RLC data PDUs (only for AM data transfer);lIn sequence delivery of upper layer PDUs (only for UM and AM data transfer);lDuplicate detection (only for UM and AM data transfer);lRLC SDU discard (only for UM and AM data transfer);lRLC re-establishment;lPr

14、otocol error detection and recovery.HUAWEI TECHNOLOGIES CO., LTD.Huawei Confidential Page 26 Segmentation / Concatenation/ Re-segmentationlSegmentation就是分段，LTE中它只在UM的發(fā)送實體或者AM實體的發(fā)送側(cè)執(zhí)行。當由MAC層指示的總的RLC PDU大小小于RLC SDU時，RLC實體就會根據(jù)此情況對RLC SDU執(zhí)行分段操作，讓生成的RLC PDU能適配進去。lConcatenation就是串接，LTE中它只在UM的發(fā)送實體或者AM實體的發(fā)送

15、側(cè)執(zhí)行。當由MAC層指示的總的RLC PDU大小大于RLC SDU時，RLC層就會根據(jù)此情況對RLC SDU執(zhí)行串接操作，讓一個RLC SDU和其他RLC SDU或者其他RLC SDU的分段串聯(lián)起來，讓生成的RLC PDU能適配進去。lRe-segmentation就是重分段，LTE中它只在AM實體的發(fā)送側(cè)執(zhí)行。RLC AM實體支持ARQ重傳，當重傳的RLC PDU無法適配到由MAC層指示的總的RLC PDU大小時，RLC層就會根據(jù)此情況對重傳的RLC PDU執(zhí)行分段操作，讓生成的RLC PDU分段能適配進去。HUAWEI TECHNOLOGIES CO., LTD.Huawei Confid

16、ential Page 27 RLC AMRLC AM的的ARQARQ功能功能lRLC AM實體的發(fā)送側(cè)發(fā)送RLC數(shù)據(jù)PDUs到對端RLC AM實體，對端接收側(cè)接收到RLC數(shù)據(jù)PDUs，并在以下兩種情況下發(fā)送狀態(tài)報告給發(fā)送側(cè)p收到發(fā)送側(cè)發(fā)來的Pollingp檢測到RLC數(shù)據(jù)PDU接收失敗l發(fā)送側(cè)在以下兩種情況會進行重傳p收到接收側(cè)發(fā)來的狀態(tài)報告指示有數(shù)據(jù)包未接收成功p本發(fā)送側(cè)底層發(fā)來的HARQ發(fā)送失敗指示HUAWEI TECHNOLOGIES CO., LTD.Huawei Confidential Page 28 RLC AMRLC AM的狀態(tài)報告的狀態(tài)報告l發(fā)送方觸發(fā)(通過在RLC PDU

17、中置Polling位為1來觸發(fā)）p最后一個包，發(fā)方buffer中沒有數(shù)據(jù)pT_Poll_Retransmit定時器超時(Polling觸發(fā)后沒有收到回應)p每發(fā)送完P(guān)oll_PDU個PDU后將P為置為1 （PDU個數(shù)觸發(fā)）p每發(fā)送完P(guān)oll_Byte個字節(jié)后將P為置為1 （Byte位觸發(fā)）l接收方觸發(fā)p檢測到接收的RLC數(shù)據(jù)PDU錯誤時，觸發(fā)狀態(tài)報告HUAWEI TECHNOLOGIES CO., LTD.Huawei Confidential Page 29RLC的丟包功能的丟包功能l當收到高層丟棄指示命令丟棄特定的RLC SDU時，UM或AM RLC實體的發(fā)送端應該丟棄指示的RLC SDU

18、(只有在該SDU還沒有被映射到RLC數(shù)據(jù)PDU時)HUAWEI TECHNOLOGIES CO., LTD.Huawei Confidential Page 30媒體接入層(MAC)HUAWEI TECHNOLOGIES CO., LTD.Huawei Confidential Page 31MACMAC在協(xié)議棧中的位置在協(xié)議棧中的位置User-plane protocol stackcontrol-plane protocol stackHUAWEI TECHNOLOGIES CO., LTD.Huawei Confidential Page 32MACMAC層的功能層的功能MAC func

19、tionUEeNBDownlinkUplinkMapping between logical channels and transport channelsXXXXXXMultiplexingXXXXDe-multiplexingXXXXError correction through HARQXXXXXXTransport Format SelectionXXXPriority handling between UEsXXXPriority handling between logical channels of one UEXXXLogical Channel prioritisation

20、XXScheduling information reportingXXHUAWEI TECHNOLOGIES CO., LTD.Huawei Confidential Page 33通道和映射通道和映射DL Channel mappingUL Channel mappingHUAWEI TECHNOLOGIES CO., LTD.Huawei Confidential Page 34MACMAC層的主要過程和操作層的主要過程和操作l隨機接入過程隨機接入過程 Random access procedurel斷續(xù)接收斷續(xù)接收DRXl調(diào)度調(diào)度 Schedulingl混合混合ARQ重傳重傳HARQH

21、UAWEI TECHNOLOGIES CO., LTD.Huawei Confidential Page 35RACHHUAWEI TECHNOLOGIES CO., LTD.Huawei Confidential Page 36隨機接入的場景隨機接入的場景l(fā)Initial access from RRC_IDLE;lInitial access after radio link failure;lUL data arrival during RRC_CONNECTED requiring random access procedure; E.g. when UL synchronisatio

22、n status is non-synchronised or there are no PUCCH resources for SR available.lHandover requiring random access procedure;lDL data arrival during RRC_CONNECTED requiring random access procedure; E.g. when UL synchronisation status is “non-synchronised”;All for contention base RA; last two for non-co

23、ntention based RAHUAWEI TECHNOLOGIES CO., LTD.Huawei Confidential Page 37隨機接入過程隨機接入過程 競爭RA 非競爭RA HUAWEI TECHNOLOGIES CO., LTD.Huawei Confidential Page 38DRXHUAWEI TECHNOLOGIES CO., LTD.Huawei Confidential Page 39DRXDRX概念和一些定義概念和一些定義lDRXpStop monitoring PDCCH during some period of time. lPurpose of D

24、RXpDRX functionality for RRC-CONNECTED allowing for optimised configurations that allow good UE power savings and network optimisations, for UEs introducing the possibility for better UE stand-by times without the need for going to RRC-IDLE mode to reach the goal. lOn duration TimerpUE每次從DRX醒來后維持醒著的

25、時間,UE在該段時間內(nèi)搜索PDCCHlInactivity TimerpUE在醒著時每次成功解碼HARQ初始發(fā)送的PDCCH后保持active的時間lActive TimepUE從DRX醒來后保持醒著的總時間lHARQ RTT TimerpUE預期DL Retransmission到達的最少間隔時間lDRX Retransmission TimerpUE預期接收DL Retransmission的時間lDRX cycle lengthpDRX cycle length一旦配置/重配置就固定，即不會因為active time大于on duration而變化。1R2-075009 SamsungH

26、UAWEI TECHNOLOGIES CO., LTD.Huawei Confidential Page 40DRXDRX操作的圖例操作的圖例p HUAWEI TECHNOLOGIES CO., LTD.Huawei Confidential Page 41SchedulingHUAWEI TECHNOLOGIES CO., LTD.Huawei Confidential Page 42調(diào)度調(diào)度l目的目的p調(diào)度的好壞對于系統(tǒng)的性能影響很大，對于LTE十分重要 p最好的利用時/頻/空/功率資源用于不同的UEs和不同的業(yè)務(wù)，保證各種業(yè)務(wù)的Qos，提高系統(tǒng)的容量l基本調(diào)度原則基本調(diào)度原則peNB負責上下行調(diào)度，上下行是不同的調(diào)度器負責 p調(diào)度器需要考慮的因素包括業(yè)務(wù)的Qos，業(yè)務(wù)量以及相關(guān)的無線承載，無線條件以及UE能力等p給于UE的UL-