TD-LTE切换优化指导书

TD-LTE切换优化指导书

目录

1

切换概述 ............................................................................................................................. 5 1.1

切换流程介绍 ............................................................................................................ 5 1.1.1 切换流程图 ..................................................................................................... 5 1.1.2 切换分类介绍 .................................................................................................. 7 1.2

前台信令解析 ............................................................................................................ 9 1.2.1 测量控制 ....................................................................................................... 10 1.2.2 测量报告 ....................................................................................................... 10 1.2.3 终端测量机制 ................................................................................................ 10 1.2.4 测量报告内容 ................................................................................................ 11 1.2.5 切换命令 ....................................................................................................... 12 1.2.6 在目标小区随机接入（MSG1） ................................................................... 12 1.2.7 基站回应随机接入响应（RAR） .................................................................. 13 1.2.8 终端反馈重配完成，切换结束 ...................................................................... 13

2

切换优化整体思路 ............................................................................................................ 15 2.1 2.2 2.3 3

测量报告发送后未收到切换命令............................................................................. 17 目标小区MSG1发送异常情况 ............................................................................... 19 接收RAR异常情况 ................................................................................................ 20

切换相关常用参数汇总 ..................................................................................................... 20 小区参考信号的功率 ......................................................................................................... 20 中心UE的PDSCH与小区RS的功率偏差 ..................................................................... 21 小区选择所需要的最小接收水平 ...................................................................................... 22 测量时的RSRP层3滤波系数 ......................................................................................... 22 EVENT IDENTITY ............................................................................................................ 23 小区个体偏移 .................................................................................................................... 23 TIME TO TRIGGER ......................................................................................................... 24 HYSTERESIS ................................................................................................................. 25 事件上报次数 .................................................................................................................... 25 事件上报周期 .................................................................................................................... 26

最大上报小区 .................................................................................................................... 26 4

切换优化常见问题及案例 ................................................................................................. 27 4.1

漏配邻区 ................................................................................................................. 27 4.1.1 前台分析漏配邻区的现象 .............................................................................. 27 4.1.2 漏配邻区带来的影响 ..................................................................................... 33 4.1.3 漏配邻区处理方法 ......................................................................................... 34 4.2

无线环境引起的切换异常 ....................................................................................... 34 4.2.1 上行干扰引起的目标测接入困难 ................................................................... 34 4.2.2 环境复杂引起的切换问题 .............................................................................. 42

5

非正常情况引起的切换问题案例 ...................................................................................... 53 5.1

版本问题引起的切换异常 ....................................................................................... 53 5.1.1 高通LOG问题现象 ...................................................................................... 53 5.1.2 该问题带来的影响 ......................................................................................... 55 5.1.3 研发初步定位 ................................................................................................ 57 5.2

不同厂商切换差异 .................................................................................................. 57 5.2.1 问题现象 ....................................................................................................... 57 5.2.2 问题分析 ....................................................................................................... 57 5.2.3 问题总结 ....................................................................................................... 60

图目录

图 1-1 切换流程图 ............................................................................................................................. 5 图 1-2 站内切换信令流程图 .............................................................................................................. 7 图 1-3 X2口切换信令流程图 ............................................................................................................. 8 图 1-4 S1口切换信令流程图 ............................................................................................................. 9 图 2-1 正常切换信令，CNT采集 ...................................................................................................... 9 图 2-2 重配消息中的测量控制（RRC CONNECT RECONFIGRATION） ..................................... 10 图 2-3 a3时间报告示意图 ............................................................................................................... 11 图 2-4 测量报告内容 ....................................................................................................................... 12 图 2-5 切换命令 ............................................................................................................................... 12 图 2-6 MSG1 ................................................................................................................................... 13 图 2-7 MSG2 ................................................................................................................................... 13 图 2-8 切换执行过程 ....................................................................................................................... 14 图 2-9 MSG3 ................................................................................................................................... 14 图 3-1 切换问题分析整体思路 ......................................................................................................... 16 图 3-2 发送测量报告后未收到切换命令处理流程 ............................................................................ 18 图 4-1 多次测量报告现象 ................................................................................................................ 28 图 4-2 第一个测量报告内容 ............................................................................................................ 28 图 4-3 第四次测量报告内容 ............................................................................................................ 28 图 4-4 切换命令 ............................................................................................................................... 29 图 4-5 源小区测量控制信息 ............................................................................................................ 30 图 4-6 漏配邻区引起的掉话 ............................................................................................................ 31 图 4-7 第一个测量报告内容 ............................................................................................................ 31 图 4-8 源小区测量控制信息 ............................................................................................................ 32 图 4-9 SINR ..................................................................................................................................... 33 图 4-10 流量 .................................................................................................................................... 33 图 4-11 上行干扰问题点 .................................................................................................................. 35 图 4-12 上行干扰引起的问题现象 ................................................................................................... 36 图 4-13 上行干扰引起的问题现象2 ................................................................................................ 37

图 4-14 上行干扰引起的问题3........................................................................................................ 38 图 4-15 上行干扰问题验证 .............................................................................................................. 38 图 4-16 上行干扰引起的集中掉话区域 ............................................................................................ 39 图 4-17 正常GPS后台查询图形 ..................................................................................................... 40 图 4-18 异常GPS后台查询图形 ..................................................................................................... 40 图 4-19 GPS失步闭塞小区配置 ...................................................................................................... 42 图 4-20 覆盖引起的切换失败点1 .................................................................................................... 43 图 4-21 失败点RSRP ..................................................................................................................... 44 图 4-22 失败点信令 ......................................................................................................................... 44 图 4-23 覆盖引起的切换失败点2 .................................................................................................... 45 图 4-24 失败点信令 ......................................................................................................................... 45 图 4-25 失败点RSRP ..................................................................................................................... 46 图 4-26 覆盖引起的切换失败点3 .................................................................................................... 46 图 4-27 失败点信令 ......................................................................................................................... 47 图 4-28 失败点RSRP ..................................................................................................................... 47 图 5-1 切换命令 ............................................................................................................................... 54 图 5-2 事件上报 .............................................................................................................................. 54 图 5-3 切换前后RLM Report1 ...................................................................................................... 54 图 5-4 切换前后RLM Report2 ...................................................................................................... 55 图 5-5 华为与我司切换命令差异 ..................................................................................................... 58 图 5-6 收到切换命令后在我司接入信令 .......................................................................................... 58 图 5-7 前台发送的重建立消息 ......................................................................................................... 59 图 5-8 后台收到重建立消息 ............................................................................................................ 60

1

1.1

1.1.1

切换概述

切换流程介绍

切换流程图

图 1-1 切换流程图

UESource eNBTarget eNBEPC1. MeasurementControl(RRCConnection Reconfiguration)Packet dataUL allocation（PDCCH）2. Measurement ReportPacket data3. HO Request4. HO Request Ack5. RRC Connection Reconfiguration(HO Command)Deliver buffered packets to T_eNB6. SN Status TransferBuffer packets from S_eNB7. Random Access Preamble 8. Random Access Response 9. RRC Connection Reconfiguration Complete(HO Confirm)Path Switch10. Release ResourceFlush DL BufferRelease Resources

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