lte接入专题优化.pptx

湖北电信CD级无线人才培训教材 LTE接入优化接入流程接入相关参数接入相关KPI接入常用优化方法典型接入失败案例分析内容随机接入的5种场景EPCeNodeBUEIdle状态下有数据或信令发送，发起service reques过程1. RA Preamble2. RA Response3. RRCConnectionRequest4. RRCConnectionSetup建立 SRB15. RRCConnectionSetupComplete(包含Service Reques消息）6. Initial UE message(包含Service Reques消息）7. Authentication建立EPS 默认承载随机接入流程（1）随机接入流程（2）EPCeNodeBUE8. S1-AP: Initial Context Setup Request9. UECapabilityEnquiry10. UECapabilityInfomation11. UE Capability Info Indication12. SecurityModeCommand13. SecurityModeComplete14. RRCConnectionReconfiguration建立SRB2 和DRB15. RRCConnectionReconfigurationComplete16. S1-AP: Initial Context Setup Response随机接入流程（3）EPCeNodeBUEFirst Uplink DataFirst Downlink Data更新承载检测到User Inactivity17. UE Context Release Request (Cause)更新承载18. UE Context Release Command19. RRC Connection Release20. UE Context Release CompleteUEeNB L1eNB L2eNB L3EPSRandom Access Preamble1Sent on PRACH with RA-RNTI Random Access Response2RAP sent on PDSCH, addressed by PDCCH using RA-RNTIScheduled Transmission3Data sent on PUSCHContention resolution4CR sent on PDSCH, addressed by PDCCH using TC/C-RNTI基于竞争的随机接入—冲突解决eNodeBUE0123基于非竞争的随机接入—专用前导eNodeBUEMsg0: PDCCH orderDedicated Preamble ID, Mask IndexMsg1: Random Access PreambleDedicated preambleMsg2: RA Responsesent on PDSCHMsg3: Contention requirementData or padding内容接入流程接入相关参数接入相关KPI接入常用优化方法典型接入失败案例分析接入相关参数Cell High-speed Attribute小区高速移动属性Ncs Used to Generate PRACH Preamble用于生成PRACH前导的循环位移参数NcsLogical Root Sequence Start Number Used to Generate PRACH Preamble用于生成PRACH前导的逻辑根序列起始索引号Number of Non-dedicated Random Access Preambles竞争随机接入前导个数Size of Random Access Preambles Group A前导组A中的前导个数Threshold of Selecting Preamble Group选择随机接入前导组的门限（消息的长度）Message Power Offset for Group B 组B配置的功率余量the Initial RB Number for Random Access Preambles 随机接入前导的起始RB号PRACH Configuration Index PRACH配置索引Initial Power for Preamble of PRACH PRACH前导初始发射功率Power Ramping Step for PRACH PRACH的功率攀升步长Max retransmit number for PRACH PRACH前导最大重传次数TTI Window Size for PRACH