Logical Channels

Within GPRS there are a number of new logical channels, similar to the existing ones, but these are only for GPRS. (NB These logical channels have been standardized.) The new logical channels have been mapped onto the physical channels that have been assigned for packet data, the physical channels denoted as Packet Data Channels (PDCH), the logical channels that are mapped onto these are : Packet Common Control Channels PRACH : Packet Random Access Channel (Uplink) PPCH : Packet Paging Channel (Downlink) PAGCH : Packet Access Grant Channel (Downlink) PTCCH : Packet Timing advance Control Channel (Up/downlink) PNCH : Packet Notification Channel (Downlink) Broadcast Channel PBCCH : Packet Broadcast Control Channel (Downlink) Packet Traffic Channels PDTCH : Packet Data Traffic Channel (Up/downlink) PACCH : Packet Associated Control Channel (Up/downlink)