TD-LTE切换优化指导手册V2

湖南移动TD-LTE切换优化指导手册湖南移动TD-LTE切换优化指导手册2015年2月湖南移动TD-LTE切换优化指导手册1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..............................................103.3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....................................................19湖南移动TD-LTE切换优化指导手册24切换问题典型案例........................................................20附录一：网管取指标方法：.....................................错误!未定义书签。附录二：切换相关参数.........................................错误!未定义书签。湖南移动TD-LTE切换优化指导手册31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：Figure1TD-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(bettercell)和A5切换算法(celledge):A3切换算法进入条件SAEGWMMETargeteNBSAEGWMMESAEGWMMESAEGWMME=Datainradio=Signalinginradio=GTPtunnel=GTPsignaling=S1signaling=X2signalingBeforeHandoverHandoverPreparationRadioHandoverLatePathSwitching湖南移动TD-LTE切换优化指导手册4OffOcsOfsMsHysOcnOfnMn离开条件OffOcsOfsMsHysOcnOfnMn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11ThreshHysMs进入条件22ThreshHysOcnOfnMn离开条件11ThreshHysMs离开条件22ThreshHysOcnOfnMn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湖南移动TD-LTE切换优化指导手册5Hys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：CounterIDNameintableNECounterNameM8009C0TOT_NOT_START_HO_PREPTotalnotstartedHandoverpreparationsM8009C1TOT_HO_DECISIONTotalHandoverdecisionsM8009C2INTRA_ENB_HO_PREPIntraeNBHandoverpreparationsM8009C3FAIL_ENB_HO_PREP_ACFailedIntraeNBHandoverpreparationsduetoAdmissionControlM8009C5FAIL_ENB_HO_PREP_OTHFailedIntraeNBHandoverpreparationsduetootherreasonsM8009C6ATT_INTRA_ENB_HOAttemptedintraeNBHO湖南移动TD-LTE切换优化指导手册6M8009C7SUCC_INTRA_ENB_HOSuccessfulintraeNBHOM8009C8ENB_INTRA_HO_FAILTotalintraeNBHOfailuresduetotimerM8009C12ENB_HO_DROP_RLFAILIntraeNBHOdropsduetoRLfailureM8009C13ENB_HO_DROP_OTHERFAILIntraeNBHOdropsduetootherfailure统计方法：2.2.2站间X2切换统计项网管统计项有：CounterIDNameintableNECounterNameM8014C0INTER_ENB_HO_PREPIntereNBHandoverpreparationsM8014C2FAIL_ENB_HO_PREP_TIMEFailedIntereNBHandoverpreparationsduetotimerM8014C3FAIL_ENB_HO_PREP_ACFailedIntereNBHandoverpreparationsduetotargeteNBadmissioncontrolM8014C5FAIL_ENB_HO_PREP_OTHERFailedIntereNBHandoverpreparationsduetootherreasonM8014C6ATT_INTER_ENB_HOAttemptedintereNBHOM8014C7SUCC_INTER_ENB_HOSuccessfulintereNBHOM8014C8INTER_ENB_HO_FAILIntereNBHOfailuresduetotimer湖南移动TD-LTE切换优化指导手册7统计方法：2.2.3站间S1切换统计项网管统计项：CounterIDNameintableNECounterNameM8014C14INTER_ENB_S1_HO_PREPIntereNBS1-HandoverpreparationsM8014C15INTER_S1_HO_PREP_FAIL_TIMEFailedIntereNBS1-HandoverpreparationsduetotimerM8014C16INTER_S1_HO_PREP_FAIL_NORRFailedIntereNBS1-HandoverpreparationsduetotargeteNBadmissioncontrolM8014C17INTER_S1_HO_PREP_FAIL_OTHERFailedIntereNBS1-HandoverpreparationsduetootherreasonM8014C18INTER_ENB_S1_HO_ATTAttemptedintereNBS1-HOM8014C19INTER_ENB_S1_HO_SUCCSuccessfulintereNBS1-HOM8014C20INTER_ENB_S1_