Multifiber Shared-Per-Wavelength All-Optical Switching: Architecture, Control and Performance

A new wavelength converter sharing strategy for multi-fiber optical switches, namely shared-per-wavelength, which employs wavelength converters with fixed wavelengths on input is presented. The aim is to reduce switch costs by using simpler optical components and low complexity space switching matrices. Practical implementations of both the well known shared-per-node and the new shared-per-wavelength schemes are presented, as well as the related scheduling algorithms to manage optical packet forwarding in synchronous scenario. An analytical model to evaluate the performance of the shared-per-node architecture is also provided. The proposed architectures are compared in terms of performance and number of optical components employed. Results show the accuracy of the model in the range of interest for switch design. Moreover, the shared-per-wavelength approach is shown to save a large number of SOA gates with respect to the shared-per-node one when the number of fibers per interface is suitably not too high. In these cases, the shared-per-wavelength architecture requires a number of wavelength converters higher than the shared-per-node, but simpler, being their inputs tuned on a single wavelength.