A Parallel Algorithm for Traffic Control Problems in Three-Stage Connecting Networks

A parallel heuristic algorithm for traffic control problems in three-stage connecting networks is presented in this paper. A three-stage connecting network consists of an input crossbar switching stage, an intermediate crossbar switching stage, and an output crossbar switching stage. The goal of our algorithm is to quickly and efficiently find a conflict-free switching assignment for communication demands through the network. The algorithm requires n² × m processing elements for the network composed of n input/output switches and m intermediate switches, where it runs not only on a sequential machine, but also on a parallel machine with maximally n² × m processors. The algorithm was verified by 1100 simulation runs with the network size from 10² × 7 to 50² × 27. The simulation results show that the algorithm can find a solution in nearly constant time with n² × m processors.