短語詞組短語Access Channel overload control arithmetic 接入信道過載控制算法slow access control channel 慢接入控制信道access on control channel 接入控制信道Access Control Channel 接入控制信道fast access control channel 快接入控制信道facch fast access control channel 快接入控制信道channel access control 信道接入控制 返回 access channel control