Design and analysis of strictly nonblocking WDM optical-switching networks

Two novel strictly nonblocking crossbar-like WDM networks are proposed and used to design what we believe to be new classes of Clos-type networks. The proposed Clos-type networks are based on two design methods, namely, the wavelength-interconnected and the fiber-interconnected methods. The proposed designs enforce wavelength conversion strictly between two prespecified and fixed wavelengths, thus eliminating the need for expensive wide-range wavelength converters. Analysis of hardware complexity shows that the proposed designs can achieve up to 30% reduction in overall cost compared with best-known WDM switching networks while using a smaller number of stages.