An efficient cell-scheduling algorithm for multicast ATM switching systems

We propose an efficient multicast cell-scheduling algorithm, railed multipl e-slot cell-scheduling algorithm, for multicast ATM switching systems with input queues. Cells in an input-queueing system are usually served based on the first-in-first-out (FIFO) discipline, which may have a serious head-of -line (HOL) blocking problem, Our algorithm differs from previous algorithm s in that we consider the output contention resolution for multiple time sl ots instead of the current time slot only. Like window-based scheduling alg orithm, our algorithm allows cells behind an HOL cell to be transmitted pri or to the HOL cell in the same input port. Thus, HOL blocking can he allevi ated, We have illustrated that the delay-throughput performance of our algo rithm outperforms most of those algorithms that consider only the output co ntention resolution for the current time slot. We also present a simple and efficient architecture for realizing our algorithm, which can dramatically reduce the time complexity, Wt believe that the proposed architecture is v ery suitable for multicast asynchronous transfer mode (ATM) switching syste ms with input queues.