Scheduling Scalable Multimedia Streams for 3G Cellular Broadcast and Multicast Services

摘要

The cdma2000 1timesevolution-data-only (EV-DO) mobile communication system provides broadcast and multicast services (BCMCS) to meet an increasing demand for multimedia data services. Currently, broadcast and multicast streams are scheduled using a slot-based static algorithm which cannot support dynamic environments where broadcast content is added or removed online. We propose a dynamic packet-scheduling algorithm that works with a retransmission scheme to enable a scalable and adaptive service across the cdma2000 1timesEV-DO BCMCS environments. Since it is integrated with earliest deadline first real-time scheduling, the proposed algorithm not only adapts efficiently to dynamic contexts but also satisfies the real-time requirements of broadcast streams. Furthermore, by exploiting the fine granular scalability features of the MPEG-4 Part 2 standard, our scheme can avoid abrupt playback quality degradation by protecting the base layer using a retransmission technique and can also adapt more flexibly to an environment in which the resource requirements of video streams change dynamically. Simulation results show a significant improvement in average playback quality while quantitatively validating the efficiency of our approach.