TCH分配失败处理流程

TCH分配失败处理流程定义-TCH分配失败（含切换）指占用SDCCH后对TCH的呼叫中所有分配TCH信道失败的总次数。统计的为“切入的HandoverFailure+AssignmentFailure”消息。（溢出包括主叫和被叫占用SDCCH后试图建立TCH失败的情况，不包括非常早分配时指派TCH信道用做SDCCH的情况，包括各种切换和直接重试情况。）定义-TCH分配失败(含切换）(TCH_CALL_REQ-MS_TCH_SUCC_SEIZ_ASSIGN_CMPLT)fromP_NBSC_TRAFFIC+(-MSC_O_SDCCH_TCH-BSC_O_SDCCH_TCH-CELL_SDCCH_TCH+MSC_I_TCH_TCH_AT+MSC_I_SDCCH_TCH_AT-MSC_I_TCH_TCH-MSC_I_SDCCH_TCH+BSC_I_TCH_TCH_AT+BSC_I_SDCCH_TCH_AT-BSC_I_TCH_TCH-BSC_I_SDCCH_TCH+CELL_TCH_TCH_AT+CELL_SDCCH_TCH_AT-CELL_TCH_TCH-CELL_SDCCH_TCH)FromP_NBSC_HO定义-详细说明TCH_CALL_REQNumberofTCHrequestsfornormalassignment(successful+unccessful)WhentheRadioResourceManagerreceivesaTCHrequestinacallattempt.MSSUCCTCHSEIZUREFORASSIGNMENTCOMPLETENumberoftimeswhenaMSissuccessfullyontheTCHafteranASSIGNMENT_COMPLETEmessage.WhenanASSIGNMENT_COMPLETEmessageisreceivedfromtheMSviaBTStoTCH.TheTCHisreservedandtheMSismovedfromtheSDCCHtotheTCH.Thiscounterisupdatedonlywhenacallisestablishedforthefirsttime,notduringhandovers.ThiscounterisnotupdatedwithsoftwaresFACCHcallsetupbecauseofSDCCHcongestion,directedretryprocedureinBSC,TCHassignmenttosuperreuseTRXinIUOanddirectaccesstosuperre-useTRXinIUO.TCH分配失败形成的主要原因TCH信道拥塞基站硬件故障（含天馈质量）或硬件故障导致的无线资源有效性下降基站传输故障或闪断内外部干扰致信号质量低弱覆盖致信号质量低与话务负荷和功率控制等相关参数设置不合理TCH分配失败处理流程TCH分配失败主要处理方案覆盖合理性调整

天线调整或改造TCH容量的增加拥塞严重，应扩容或建新站，DCS1800系统使用网络频率质量的提升频率修改或整网频率规划，ZERM;弱覆盖增加新站或天线调整基站硬