Lower bounds for WSNB multi-log2N switching networks

Multi-log(2)N switching networks are one of propositions for high-speed and high-capacity electronic and photonic switches. These networks have recently been studied for strictly nonblocking and rearrangeable nonblocking operations in case of unicast connections. Wide-sense nonblocking conditions of these networks were considered only for multicast connections. In this paper lower bounds for wide-sense nonblocking conditions of multi-log(2)N switching networks with unicast connections are considered. For some algorithms required number of planes is the same as in strict-sense nonblocking switching networks. We also prove, that for switching networks with odd number of stages the lower bound for wide-sense nonblocking operation is greater than the necessary and sufficient conditions for rearrangeable switching networks.