Multi-Level Round-Robin Multicast Scheduling with Look-Ahead Mechanism

In this paper, we propose a multi-level round-robin multicast scheduling (MLRRMS) algorithm with look-ahead (LA) mechanism for N×N input-queued switches. Fan-out splitting is applied, where a multicast cell can be transferred to all its destinations over any number of cell times. The scheduler constructs the Traffic Matrix before each cell transmission based on the fan-out vectors of the cells in the queues. A scheduling pointer independently moves on each column of the Traffic Matrix in a round-robin fashion and returns the decision to the Decision Matrix. The sync procedure is carried out to reduce the unnecessary transmissions of a cell. The look-ahead mechanism is executed to reduce the head-of-line blocking problem resulting in increased the throughput and reduced cell delay.