Dynamic window-constrained scheduling for multimedia applications

This paper describes an algorithm, called Dynamic Window-Constrained Scheduling (DWCS), designed to meet the service constraints on packets from multiple, network-bound media streams with different performance objectives. Using only two attributes, a deadline and a loss-tolerance per packet stream, DWCS: (1) can limit the number of late packets over finite numbers of consecutive packets in loss-tolerant or delay-constrained heterogeneous traffic streams, (2) does not require a-priori knowledge of the worst-case loading from multiple streams to establish the necessary bandwidth allocations to meet per-stream delay and loss-constraints, and (3) can exhibit both fairness and unfairness properties when necessary. In fact, DWCS can perform fair-bandwidth allocation, static priority (SP) and earliest-deadline first (EDF) scheduling. We show the effectiveness of DWCS using a streaming video application, running over ATM.