Performance of Scheduling Algorithms in Optical Packets Switches with Limited-Range Wavelength Converters

This paper evaluates the performance of an optical packet switching architecture that uses the wavelength conversion technique to solve the packet contention problem. The architecture, referred to as shared per node (SPN), is equipped with limited-range wavelength converters shared per node. We evaluate for this architecture the performance of the optimum scheduling algorithm by resolving an integer linear programming problem. Unfortunately the optimum scheduling algorithm has a high time complexity and it cannot be adopted for optical packet switches requiring packet scheduling time in the order of 10/100 ns. For this reason we propose some scheduling algorithms allowing the best optimum scheduling performance to be reached in low computation time. In particular an algorithm, based on heuristic rules, is proposed able to reach good performance with a complexity O(M),M being the number of wavelengths used.