When there is no PBCCH in the cell, the information needed by the mobile to access the network for a packet transfer is broadcast on BCCH. This information is used by the mobile in order to access the network. The PBCCH broadcasts information relative to the cell in which the mobile camps and information on the neighbor cells.
The presence of PBCCH in the cell is optional. Packet broadcast control channel (PBCCH). The different packet data logical channels are: In addition, the GSM common control channels (BCCH, CCCH, and RACH) may be used to access the network and establish packet transfer. Three subtypes of control channels have been defined for GPRS: broadcast, common control, and associated. Two types of logical channels have been introduced, namely traffic channels and control channels.
GPRS, like GSM, uses the concept of logical channels mapped on top of the physical channels.
