Eecient Algorithms for Scheduling Data Broadcast

With the increasing acceptance of wireless technology, mechanisms to eeciently transmit information to wireless clients are of interest. The environment under consideration is asymmetric in that the information server has much more bandwidth available, as compared to the clients. It has been proposed that in such systems the server should broadcast the information periodically. A broadcast schedule determines what is broadcast by the server and when. This paper makes the simple, yet useful, observation that the problem of broadcast scheduling is related to the problem of fair queueing. Based on this observation, we present a log-time algorithm for scheduling broadcast, derived from an existing fair queueing algorithm. This algorithm signiicantly improves the time-complexity over previously proposed broadcast scheduling algorithms. Modiication of this algorithm for transmissions that are subject to errors is considered. Also, for environments where diierent users may be listening to diierent number of broadcast channels, we present an algorithm to coordinate broadcasts over diierent channels. Simulation results are presented for proposed algorithms.