A high performance cell scheduling algorithm in broadband multicast switching systems

A multicast cell scheduling algorithm with input queue is proposed in ATM multicast switching systems. Therefore, HOL blocking may occur due to the FIFO input queueing discipline. To avoid HOL blocking, our algorithm relaxes the strict FIFO queueing discipline for the input queue to increase its throughput, but the cell sequence order is still preserved. In our cell scheduling algorithm, every multicast cell is only watched once, but in the window policy every cell will be watched more than two times in average. The simulated result shows that our proposed scheme has a high performance with respect to the cell loss probability, required buffer size, and the waiting delay. Moreover, our proposed algorithm can obtain a maximum throughput of almost 0.997 and is independent of the switch size and input load. The time complexity of our proposed scheme is also analyzed. Hence, our cell scheduling algorithm is an efficient scheme for an ATM switching system.