Wavelength requirements of all-optical networks

All-optical networks are emerging as a clear choice for wide area networks. With newer developments in optical switching technology, all-optical networks are becoming feasible. The authors discuss a wavelength division multiple access (WDMA) network with optical switches at each node. The number of wavelengths available for a WDMA is limited. The authors focus on the permutation routing problem and present a lower bound on the number of wavelengths as a function of the size of the network. They also construct network topologies to derive upper bounds on the number of wavelengths