Two-phase scheduling for reducing delay variance in space-division packet switches

Several scheduling algorithms have been proposed to resolve transmission conflict in space-division packet switches. These algorithms do not consider the queueing delay of the backlog packets in the input adaptors. Consequently, some packets may wait a long time before they are switched, while others do not. The authors propose a two-phase scheduling method to reduce the delay variance. The simulation results show that this method can significantly reduce the delay variance, especially when the traffic load is heavy.