NB-IOT技术及优化目录1.NB-IOT关键技术...............................................................................................51.1强覆盖:.................................................................................................51.2低成本:.................................................................................................51.3小功耗:.................................................................................................71.4大连接:.................................................................................................82.NB-IOT帧结构..................................................................................................92.1下行物理层结构........................................................................................92.2上行物理层结构......................................................................................102.3上行资源单元RU....................................................................................113.NB-IOT网络架构.............................................................................................123.1CP和UP传输方案..................................................................................133.2CP和UP方案传输路径对比.....................................................................143.3CP和UP协议栈对比..............................................................................143.3.1CP方案的控制面协议栈.................................................................143.3.2UP方案的控制面协议栈.................................................................152.4状态转换...............................................................................................154.信令流程........................................................................................................184.1CP传输方案端到端信令流程.....................................................................184.2RRC连接建立过程..................................................................................204.3UP传输方案端到端信令流程....................................................................224.4RRC挂起流程(SuspendConnectionprocedure)...................................244.5RRC恢复流程(ResumeConnectionprocedure)....................................254.6CP/UP方案网络协商流程.......................................................................265.覆盖优化........................................................................................................285.1弱覆盖..................................................................................................285.2SINR差.................................................................................................285.3重叠覆盖问题点......................................................................................285.4覆盖指标要求:........................................................................................286.重选优化........................................................................................................286.1重选时延统计方法:................................................................................296.2判断小区重选是否成功:.........................................................................296.3重选成功率统计:.....................................................................................