说明：  WCDMA的基本信令流程有：RRC连接建立、RAB建立流程、UE起始呼叫建立、UE终止呼叫建立、PS域连接、切换
(WCDMA the basic signaling processes are: RRC connection is established, RAB establishment process, UE initial call setup, UE terminated call setup, PS domain connection, switch)