A pipelined scheduler which allows easy implementation and control and
further fair scheduling among input lines of a crossbar high speed switch
fabric is discussed. By means of a round-robin communication scheme, a
systematically ordered sequence of visits to time slots can be obtained
regardless of whether the number of scheduler modules is even or odd by
framing the time axis and using a priority matrix to reserve future time
slots. Further, a Carry Over Round-robin Pipelined Scheduler (CORPS)
achieves scalability to a large number of ports. Moreover, CORPS achieves
one scheduling decision per line per slot, by scheduling packets in
future slots. It is well suited to the support of Quality of Service
traffic, since the choice of the queues to be scheduled is arbitrary.
CORPS limits itself to resolve, in a fair way, the contention for output
ports.