Performance of scheduling algorithms minimizing the packet loss in optical switches equipped with limited range and shared wavelength converters

This paper compares some optical packet switching architectures that use the wavelength conversion technique to solve the packet contention problem. The architectures are equipped with shared and limited-range wavelength converters. We evaluate for these architectures 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 we propose an algorithm able to reach good performance with a complexity O(M), M being the number of wavelengths used.