Extra Group Network: a cost-effective fault-tolerant multistage interconnection network

Extra Group Networks, a class of fault-tolerant multistage interconnection networks, are introduced. An EGN-m of size N is designed to have m+1 unique-path multistage-networks of size N/m. This approach of constructing the network allows that an EGN-m can provide full-access capability in the presence of multiple faults, up to m , in any stage. EGNs can also maintain the permutation capability of the unique-path multistage-network of size N in the presence of any single fault. It is shown that EGNs are more cost-effective than other previously proposed fault-tolerant multistage-interconnection networks with a similar fault-tolerant capability