Multi-hop scheduling algorithms in switches with reconfiguration latency

Optical switching fabrics (OSF) are receiving increasing attention in the design of high speed packet switches, due to their excellent properties in terms of available bandwidth and reduced power consumption. However, most optical devices suffer a reconfiguration latency each time input/output connections are modified; unfortunately, this latency may not be negligible with respect to the packet transmission time, and can adversely affect performance, especially delay and throughput. The multi-hop approach, i.e., sending packets to the final destination port exploiting transmission to intermediate ports, was shown to be a promising way to control the tradeoff between delay and throughput. In this paper, we examine the multi-hop approach when using a logical interconnections based on multidimensional regular topologies. We discuss not only the scheduling problem for these topologies, but also the design of routing and queueing schemes. Performance are analyzed by simulation.