Patent ID: 7231221

Claim:
A communication system, comprising: a central control station that broadcasts beacon messages on a communication channel; and at least one remote terminal that accesses a communication channel based on the beacon messages; wherein the beacon messages provide timing references for the at least one remote terminal, signal a remote terminal that data is waiting in the control station, enable a remote terminal to request access to the communication channel, and are configured such that access to the communication channel by a terminal is controlled according to a grouping of the terminal into a respective beacon group; remote terminals of a beacon group are permitted to send channel access request messages during an access window following a beacon message corresponding to the beacon group; the access window includes a plurality of consecutive time slots, and remote terminals are allocated to respective time slots and send channel access request messages during their allocated time slots; and an allocated time slot, a remote terminal, and a data-pending indication in a beacon message correspond to one another.