Downlink wireless packet scheduling with deadlines
Next- generation cellular wireless communication networks aim to provide a variety of quality- of- service ( QoS)- sensitive packet- based services to downlink users. Included among these are real- time multimedia services, which have stringent delay requirements. Downlink packet scheduling at the base station plays a key role in efficiently allocating system resources to meet the desired level of QoS for various users. In this paper, we employ dynamic programming ( DP) to study the design of a downlink packet scheduler capable of supporting real- time multimedia applications. Under well- justified modeling reductions, we extensively characterize structural properties of the optimal control associated with the DP problem. We leverage intuition gained from these properties to propose a heuristic scheduling policy, namely, Channel- Aware Earliest Due Date ( CA- EDD), which is based on a " quasi-static" approach to scheduling. The per- time- slot implementation complexity of CA- EDD is only O(K) for a system with K downlink users. Experimental results show that CA- EDD delivers up to 50 percent of performance gains over benchmark schedulers. CA- EDD achieves these performance gains by using channel and deadline information in conjunction with application layer information ( relative importance of packets) in a systematic and unified way for scheduling.
packet scheduling dynamic programming (dp) wireless systems cross-layer design multimedia communication quality of service (qos)