A linear lightwave Benes network

The authors consider linear lightwave networks with a single waveband that have N inputs, each with a transmitter, and N outputs, each with a receiver, interconnected by optical links, broadcast stars, and wavelength-independent 2*2 switches. The transmitters and receivers can tune to C different wavelengths. The authors describe a rearrangeably nonblocking network that is a modification of the Benes network and uses transmitters that are fixed tuned and switches with two states. The network uses (1+o(1))N/log/sub 2/(N/C) switches, which is shown to be nearly the minimum number. It is also shown that, if C=o(log N), then a rearrangeably nonblocking network requires (1+o(1))Nlog/sub 2/N switches even if the switches have more than two states.>