Patent Document ID: 20030086420
Application ID: 09882139
Patent Flag: 0

Claim One:
1. An N×N circular expander for serving a connection request to route k incoming signals, k&lE;N, and for enabling conditionally nonblocking switching, the circular expander comprising a switch defined by a set of connection states and having an array of N input ports with N distinct input addresses and an array of N output ports with N distinct output addresses wherein the k incoming signals arrive at k distinct input ports determining k active input addresses and are destined for corresponding k distinct output ports determining k active output addresses, the switch accommodating every combination of concurrent connections, point-to-point or multicast, subject to the following constraint: if the input ports i and j are connected to the output ports p and q, respectively, then &par;i−j&par; N &lE;&verbar;p−q&verbar;, where &par;i−j&par; N &equals;min &lcub;&verbar;i−j&verbar;, N−&verbar;i−j&verbar;&rcub; is the distance between i and j on the discretized circle size N, and control circuitry, coupled to the switch, for routing the incoming signals from the k distinct input ports to the corresponding k distinct output ports by activating one of the connection states such that the activated one of the connection states accommodates the connection request.