Fault-tolerance analysis of one-sided crosspoint switching networks

The fault-tolerance capability of one-sided crosspoint networks is analyzed with respect to crosspoint faults. Because of the correspondence between one-sided crosspoint networks and multiple-bus interconnection networks, the analysis also applies to multiple-bus configurations, where M buses are used to interconnect N processors. Upper bounds are established on the size of a fault set to sustain a given level of connectivity. Two modes of operation are considered, namely, nonblocking and rearrangeable. A complete nonblocking switch matrix with N ports has N² /2 crosspoints. It is shown that at most N/2-1 faulty crosspoints can be tolerated in the case of nonblocking operation