15 February 2018


SACCH stands for Slow associated control channel GSM. 

It is related to the traffic channel or SDCCH.

On the forward link, it is used to send regularly changing information like: 
  • Transmit power channel 
  • Broadcast messages
  • Specific timing advance instruction for each user
On the reverse link, it carries information about 
  • Received signal strength 
  • Quality of TCH and BCH
  • Measurement results from neighboring cells
  • It is used to inform the base of power measurements made by the mobile of signal strength in the adjacent cells
  • It is transmitted during the total 13th frame of every dedicated control channel multi-frame
  • SACCH exchanges control information between the base station and mobile station a call or call set up