Dedicated Control Channels 

*  Stand alone Dedicated Control Channel (SDCCH)  

         <1>  Used for signaling purposed: call setup, location update, IMSI 

                 attach – detach. 

         <2>  Used to send / receive SMS in idle mode.  

*  Slow Associated Control Channel (SACCH) 

         <1>  Always allocated with traffic channel to transmit measurement 

                 reports. 

         <2>  DL: Commands from the network to the MS to adjust its power, 

                 Timing advance (TA). 

         <3>  UL: information about the MS own power, received signal 

                 strength, quality and SS for neighbor cells. 

         <4>  Used to send SMS in active mode. 

*  Fast Associated Control Channel (FACCH) 

         <1>  Transmits handover information.