The PAGCH is used by the network to assign radio resources to the mobile for a packet transfer. The PPCH is used by the network to page the mobile in order to establish a downlink packet transfer. The PRACH is used by the MS to initiate uplink access to the network. PCCCH is composed of packet random access channel (PRACH), used for random access, packet paging channel (PPCH), used for paging, and packet access grant channel (PAGCH), used for access grant. When it is not present in the cell, the common control signaling for GPRS is handled on the GSM common control channels (CCCH). The PCCCH is present in the cell only if the PBCCH is present in the cell. 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.

Gprs multislot class