Patent ID: 7016345

Claim:
A method for implementing a class of N×N expanders each serving a connection request to route m incoming signals, m≦N and for enabling the service of any connection request in a nonblocking way on the condition that the connection request is compliant to certain constraints, the method for each of the expanders comprising: configuring 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 m incoming signals arrive at m input ports determining m active input addresses and are destined for a total of n, m≦n≦N, distinct output ports determining n active output addresses, and wherein said constraints on the connection request are that: (1) the m active input addresses are consecutive upon a rotation of the ordering of the N input addresses, and (2) for any two active input addresses i and j and any two active output addresses p and q such that i is being connected to p and j is being connected to q, if i precedes j with respect to the rotated ordering, then p<q, and routing the incoming signals from said m input ports to said n distinct output ports by activating one of the connection states such that the activated one of the connection states accommodates the connection request subject to said constraints on the connection request, said class excluding (i) those having a switch constructed from a banyan network of expander cells prepended with a shuffle exchange and (ii) those having a switch constructed from the shuffle-exchange network of expander cells prepended with the shuffle exchange.