A greedy strategy of data dissemination over multi-channel in mobile computing environments

Wireless data broadcast is very suitable for delivering information to large user population. In this paper, we concentrate on data scheduling algorithm over multiple channels in mobile computing environments. First, we formulate the average expected delay of multiple channels considering data items´ access frequencies, variable length, and different bandwidth of each channel. Second, we propose a GREEDY algorithm, a multi-channel data allocation method that rationally allocates data items to different channels in order to minimize the MCAED. So far as we know, this is the first model that considers changing situations, e.g. item frequencies, length or available bandwidth. Considering these situations, we propose a REGULATING algorithm, a multichannel balancing method that improves system performance. Within each channel, the Log-Time algorithm which supposed to be optimal in single channel is adopted. The performance evaluation shows that the GREEDY algorithm significantly reduces the average expected waiting time and obtains a near-optimal solution under varieties of circumstances.