Preemptive maximum stretch optimization scheduling for wireless on-demand data broadcast

On-demand broadcast is an attractive data dissemination method for mobile and wireless computing. We need an on-demand broadcast scheduling algorithm which can balance individual and overall performance, at the same time avoid the starvation of data items, and scale in terms of client population, database size, and data size in heterogeneous settings. As stretch is regarded as a fair performance metric for variable-sized data requests, in this paper, we propose a new preemptive, heuristic online scheduling algorithm, called PRS for on-demand broadcast system to optimize the worst case stretch across all criteria. We have done a series of simulation experiments to evaluate the performance of our algorithm as compared with other recently proposed methods under a range of scenarios. The experimental results show that our algorithm can substantially reduce the maximum stretch without jeopardizing the overall system performance.