湖南移动TDLTE切换优化指导手册_Nokia_最终版

湖南移动TD-LTE切换优化指导手册2015年2月目录1概述32系统内切换成功率相关KPI指标52.1切换成功率指标定义52.2切换成功率相关统计项52.2.1站内切换统计项52.2.2站间X2切换统计项62.2.3站间S1切换统计项72.2.4切换统计项-邻区级82.2.5切换失败的常见问题93切换问题的定位和分析93.1切换问题的定位93.2切换问题的原因分析113.3切换问题处理流程图113.3.1切换整体分析133.3.2切换Top小区分析133.3.3小区故障排查143.3.4切换准备失败问题分析143.3.5切换执行失败问题分析153.3.6终端类问题163.3.7个性问题单独分析163.4切换问题优化方案163.4.1高负荷拥塞优化163.4.2邻区优化183.4.3参数优化193.4.4干扰优化193.4.5覆盖优化194切换问题典型案例20附录一：网管取指标方法：22附录二：切换相关参数231 概述TD-LTE系统的切换大致可以分为站内切换，站间同频切换，站间异频切换和系统间切换等，其中站间切换又可以分为基于S1切换和基于X2切换2种情形。 本文暂时只涉及TD-LTE系统内、同一EPC下的数据业务切换，典型切换过程如下：Figure 1 TD-LTE切换过程示意图 TD-LTE切换的触发事件通常包括以下几种情况，其中的测量量即可以是RSRP也可以是RSRQ，一般采用RSRP：A1：服务小区测量值大于门限值A2：服务小区测量值小于门限值A3：邻小区测量值优于服务小区测量值一定门限值A4：邻小区测量值大于门限值A5：服务小区测量值小于门限1，同时邻小区信道质量大于门限2B1：表示异系统邻区质量高于一定门限B2：表示服务小区质量低于一定门限并且异系统邻区质量高于一定门限 同频切换通常用到A3切换算法(better cell)和A5切换算法(cell edge):A3 切换算法进入条件离开条件其中：Mn为该邻区的测量结果，不考虑计算任何偏置Ofn 为该邻区频率特定的偏置Ocn(CIO)为该邻区的小区特定偏置Ms 为没有计算任何偏置下的服务小区的测量结果Ofs 为服务频率上频率特定的偏置.Ocs 为服务小区的小区特定偏置Hys 为该事件的滞后参数。Off 为该事件的偏移参数，正值增加难度，负值降低难度A5 切换算法UE 将：进入条件1进入条件2离开条件1离开条件2其中：Ms为该服务小区的测量结果，没有计算任何偏置。Mn 为该邻区的测量结果，没有计算任何偏置。Ofn 为该邻区频率的频率特定偏置Ocn为该邻区的小区特定偏置Hys为该事件的滞后参数Thresh1为该事件的门限参数（即a5-Threshold1）Thresh2为该事件的门限参数（即a5-Threshold2） 异频切换通常使用A2+A3或A2+A5的算法，因为异频切换需要用到异频测量，会影响本UE吞吐量性能，用A2/A1分别作为触发异频测量的开关，并通过RRC_Reconficutation消息通知相应的测量配置变化。2 系统内切换成功率相关KPI指标2.1 切换成功率指标定义切换成功率=(站内切换成功次数+站间X2切换成功次数+站间S1切换成功次数)/ (站内切换尝试次数+站间X2切换尝试次数+站间S1切换尝试次数)站内切换成功率=站内切换成功次数/站内切换尝试次数=sum(M8009C7)/sum(M8009C6)站间X2切换成功率=站间X2切换成功次数/站间X2切换准备次数=sum(M8014C7)/sum(M8014C0)站间S1切换成功率=站间S1切换成功次数/站间S1切换准备次数=sum(M8014C19)/sum(M8014C14)2.2 切换成功率相关统计项2.2.1 站内切换统计项网管统计项有：Counter ID Name in tableNE Counter NameM8009C0TOT_NOT_START_HO_PREPTotal not started Handover preparationsM8009C1TOT_HO_DECISIONTotal Handover decisionsM8009C2INTRA_ENB_HO_PREPIntra eNB Handover preparationsM8009C3FAIL_ENB_HO_PREP_ACFailed Intra eNB Handover preparations due to Admission ControlM8009C5FAIL_ENB_HO_PREP_OTHFailed Intra eNB Handover preparations due to other reasonsM8009C6ATT_INTRA_ENB_HOAttempted intra eNB HOM8009C7SUCC_INTRA_ENB_HOSuccessful intra eNB HOM8009C8ENB_INTRA_HO_FAILTotal intra eNB HO failures due to timerM8009C12ENB_HO_DROP_RLFAILIntra eNB HO drops due to RL failureM8009C13ENB_HO_DROP_OTHERFAILIntra eNB HO drops due to other failure统计方法：2.2.2 站间X2切换统计项网管统计项有：Counter IDName in tableNE Counter NameM8014C0INTER_ENB_HO_PREPInter eNB Handover preparationsM8014C2FAIL_ENB_HO_PREP_TIMEFailed Inter eNB Handover preparations due to timerM8014C3FAIL_ENB_HO_PREP_ACFailed Inter eNB Handover preparations due to target eNB admission controlM8014C5FAIL_ENB_HO_PREP_OTHERFailed Inter eNB Handover preparations due to other reasonM8014C6ATT_INTER_ENB_HOAttempted inter eNB HOM8014C7SUCC_INTER_ENB_HOSuccessful inter eNB HOM8014C8INTER_ENB_HO_FAILInter eNB HO failures due to timer统计方法：2.2.3 站间S1切换统计项网管统计项：Counter IDName in tableNE Counter NameM8014C14INTER_ENB_S1_HO_PREPInter eNB S1-Handover preparationsM8014C15INTER_S1_HO_PREP_FAIL_TIMEFailed Inter eNB S1-Handover preparations due to timerM8014C16INTER_S1_HO_PREP_FAIL_NORRFailed Inter eNB S1-Handover preparations due to target eNB admission controlM8014C17INTER_S1_HO_PREP_FAIL_OTHERFailed Inter eNB S1-Handover preparations due to other reasonM8014C18INTER_ENB_S1_HO_ATTAttempted inter eNB S1-HOM8014C19INTER_ENB_S1_HO_SUCCSuccessful inter eNB S1-HOM8014C20INTER_ENB_S1_HO_FAILInter eNB S1-HO failures due to timer统计方法：2.2.4 切换统计项-邻区级切换是由源小区向目标小区转移的过程，很多时候会由于目标小区故障造成切换失败，下面是针对邻区的相关统计项：Counter ID Name in tableNE Counter NameM8015C0INTRA_HO_PREP_FAIL_NBFailed Intra eNB HO preparations per neighbour cellM8015C1INTRA_HO_ATT_NBIntra eNB HO attempts per neighbour cellM8015C2INTRA_HO_SUCC_NBIntra eNB HO successes per neighbour cellM8015C4INTRA_HO_DROPS_NBIntra eNB HO drops per neighbour cellM8015C5INTER_HO_PREP_FAIL_OTH_NBNumber of failed Inter eNB Handover preparations per neighbour cell relationshipM8015C6INTER_HO_PREP_FAIL_TIME_NBFailed Inter eNB Handover preparations per neighbour cell due to expir. of guard timer TX2RELOCprepM8015C7INTER_HO_PREP_FAIL_AC_NBFailed Inter eNB Handover preparations per neighbour cell due to admission control in the target eNBM8015C8INTER_HO_ATT_NBNumber of Inter eNB Handover attempts per neighbour cell relationshipM8015C9INTER_HO_SUCC_NBNumber of successful Inter eNB Handover completions per neighbour cell relationshipM8015C10INTER_HO_FAIL_NBNumber of Inter eNB Handover failures per cause per neighbour cell rela