Multistage Shared-Per-Wavelength Optical Packet Switch: Heuristic Scheduling Algorithm and Performance

This paper describes an optical switch architecture based on the shared-per-wavelength strategy for contention resolution in the wavelength domain. This strategy impacts on wavelength converters requirements and switch organization, by allowing to obtain cost saving. The general sharing concept is first introduced and the related practical solution as a multistage switch architecture is presented and thoroughly analyzed in terms of performance, control and cost perspectives. Heuristic scheduling to manage packet forwarding in a synchronous context is developed and discussed in terms of computational complexity. A simple accurate analytical model is developed and validated against simulation to numerically evaluate packet loss performance of the shared-per-wavelength switch. The main achievement of the work is represented by the proposal of a feasible approach which leads to remarkable cost saving in terms of optical gates and wavelength converters under the conditions outlined.