第1页共39页编号:时间:2021年x月x日书山有路勤为径,学海无涯苦作舟页码:第1页共39页CSFB问题小区分析“三步法”第2页共39页第1页共39页编号:时间:2021年x月x日书山有路勤为径,学海无涯苦作舟页码:第2页共39页版本号:V1.0.0网络优化中心第3页共39页第2页共39页编号:时间:2021年x月x日书山有路勤为径,学海无涯苦作舟页码:第3页共39页目录1CSFB概述.................................................................................................................................41.1CSFB组网架构............................................................................................................41.2CSFB总体流程............................................................................................................42CSFB业务流程..........................................................................................................................52.1主叫业务流程..............................................................................................................52.1.1信令流程..........................................................................................................52.1.2关键字段..........................................................................................................62.2被叫业务流程..............................................................................................................72.2.1信令流程..........................................................................................................72.2.2关键字段..........................................................................................................82.3联合位置更新流程.....................................................................................................102.3.1信令流程........................................................................................................102.3.2关键字段........................................................................................................113CSFB问题分析流程................................................................................................................143.1快速定位问题出现阶段.............................................................................................143.24G寻呼阶段问题分析...............................................................................................143.2.1问题分析流程.................................................................................................143.2.2各环节分析要点.............................................................................................153.34G释放阶段问题分析...............................................................................................173.3.1问题分析流程.................................................................................................173.3.2各环节分析要点.............................................................................................183.42G接入阶段问题分析...............................................................................................193.4.1问题分析流程.................................................................................................193.4.2各环节分析要点.............................................................................................194CSFB案例............................................................................................