Adaptive Buffer Sensitive Scheduling for Transmitting Video Streams in a Mobile Multimedia System

1 The work described in this paper was partially supported by a grant from the Research Grants Council of Hong Kong SAR, China [Project No. CityU 1097/99E]. Abstract In this paper, we propose the Adaptive Buffer Sensitive (ABS) algorithm for scheduling the transmission of video packets from multiple video streams in a mobile multimedia system. Two important considerations in the design of the ABS are: (1) to maximize the mobile network bandwidth utilization and at the same time to minimize the impact of transient overloading on video playback; and (2) to minimize the impact of a video playback by other video requests. The second objective is very important to mobile multimedia systems since the clients may request videos with great differences in workload characteristics. In the ABS, the allocation of network bandwidth to serve client requests is divided into two phases. Firstly, each client receives equal share of network bandwidth or at least enough bandwidth to support the average playback of its requested video. Secondly, the extra bandwidth after the first allocation will be distributed to clients based on its playback status, i.e., buffer playback duration, to deal with the problem of transient overloading. A selective packet transmission scheme is adopted in ABS to deal with heavy overloading situation.