Performance of Scheduling Algorithms in Multi-Stage Optical Packet Switches with Sparse Wavelength Converters

This paper describes the scheduling algorithms to control the optical packet forwarding in a multi-stage switch based on the broadcast-and-select principle. The aim of control algorithms is to fully exploit switch resources while avoiding contention in the wavelength and space domains. A multi-stage switch based on the shared per node wavelength conversion scheme is considered in a synchronous context. An analytical model is provided to calculate the packet loss probability in relation to different reference traffic scenarios. Results show how the sharing of wavelength converters impacts on node performance depending on the scheduling algorithm applied, and provide a meaningful support for optical packet switch design.