Broadcast Channels (BCH)
  • Frequency correction channel (FCCH)
  • the “lighthouse” of a BTS
  • Synchronization channel (SCH)
  • PLMN/base identifier of a BTS plus
  • synchronization information (frame number) 
  • Broadcast control channel (BCCH)
  • to transmit system information 1-4, 7-8 (differs in
  • GSM 900, GSM 1800, and PCS 1900)
CBCH and CCCH
  • CBCH (Cell Broadcast Channel)
  • transmits cell broadcast messages
  • PCH (Paging Channel)
  • carries PAG_REQ message
  • AGCH (Access Grant Channel)
  • SDCCH channel assignment
  • RACH (Random Access Channel)
  • communication request from MS to BTS