软切换 宏分集:"Macro diversity" is a operation state in which a User Equipment simultaneously has radio links with two or more UTRAN access points for the sole aim of improving quality of the radio connection or providing seamless handover. 活动集:“ Active Set” Set of radio links simultaneously involved in a specific communication service between an User Equipment and a UTRAN access point 硬切换流程(RNC内)1. Radio Link Setup Request 2. Radio Link Setup Response 3 ALCAP ub Data Transport Bearer Setup 4. Downlink Synchronisation 5.Uplink Synchronisation 6.DCCH : Physical Channel Reconfiguration 7. Radio Link Failure Indication 8. DCCH : Physical Channel Reconfiguration Complete 9. Radio Link Deletion Request 10. Radio Link Deletion Response 11. ALCAP Iub Data Transport Bearer Release 前向切换(Forward Handover)是UE发起的切换包括CELL UPDATE和URA UPDATE过程。其中,URA UPDATE过程只用于处于URA_PCH状态的UE进行URA重选,以及检查RRC连接是否正常。 对于CELL_FACH和CELL_PCH状态的UE 小区重选 处于SA(Service Area) 定时器T305超时此定时器在广播的系统信息中定义 对于CELL_PCH和URA_PCH状态的UE 需要上传数据时(进入CELL_FACH状态) 当在PCCH上接收到寻呼消息时,发起小区更新 CELL UPDATE过程还可用来重建RLC实体不可恢复的错误(丢失连接),以及监视RRC连接的状态。