Two expansible multistage interconnection networks

Two new construction methods for multistage interconnection networks (MINs) are proposed. These methods provide low overhead in enlarging the size of MIN scheme and they have the same features as those of MIN schemes by typically designed method. The first proposed method proves that, in enlarging the size of MIN scheme, the full access interconnection property and the self-routing ability are also available in the enlarged scheme and the hardware and reconstruction overhead is low. However, the requests to be accepted by the MIN scheme depend not only on the configuration of MIN but also on another mechanism in the first proposed method. It results in low success probability for any request. The second proposed method releases this disadvantage. The following are the features of our two proposed schemes: (1) The full-access interconnection property; (2) Simple and distributed self-routing ability; (3) The least hardware cost; (4) Low reconstruction overhead.