百科解释
Separate/Stand-alone Dedicated Control CHannel -- 独立专用控制信道 SDCCH - Stand-alone Dedicated Control Channel This channel is used in the GSM system to provide a reliable connection for signalling and SMS (Short Message Service) messages. The SACCH (Slow Associated Control Channel) is used to support this channel. SDCCH SDCCH的全称是独立专用控制信道（Stand-Alone Dedicated Control Channel），用在分配TCH之前呼叫建立过程中传送系统信令。例如登记和鉴权在此信道上进行。上行和下行信道，点对点方式传播。一般进行的信令交互主要利用SDCCH信道承载，SDCCH信道的分配也称立即指配过程。有时还会进行短信传输。
