A Stochastic Fault-tolerant Routing Algorithm in Hyper-star Graphs

A hyper-star graph HS(2n, n) is promising as a generic topology for interconnection networks of parallel processing systems because it has merits of a hypercube and a star graph. This paper proposes an O(n log n) algorithm that constructs a faultfree path between a pair of non-faulty nodes in HS(2n, n) with faulty nodes. For each node and each distance, the algorithm first calculates an estimated value of the probability of existence of a non-faulty minimal path to an arbitrary destination node with the distance from the node. Then it tries to construct a fault-free path based on the estimated values. In addition, we conduct a computer experiment to show its effectiveness.