Optimal Wavelength Converter Placement in Wavelength-Routed Optical Networks by Simulated Annealing

Abstract

Wavelength-routed all-optical networks have emerged as a popular architectural solution for wide area networks and are being conceived for future broad-band communications. Call connection probability in such networks depend on the number of WDM wavelengths employed and on the capability for wavelength conversion at network nodes. Equipping all the network nodes with wavelength converters to reduce the blocking probability is not a cost effective solution due to the high cost of wavelength converters. Hence only some of the nodes are to be equipped with wavelength converters. The objective of this paper is to address the optimal placement of wavelength converters among the network nodes. Here “placement” refers to providing a network node with wavelength conversion capability. This paper uses simulated annealing to determine the location of the converters in order to achieve minimum blocking probability. It is observed that this method significantly reduces the number of blocking probability calculations and has been applied to a six hop path and to the ′14 nodes NSFNET. The results are verified with the published literature. This method achieves optimal and near-optimal solutions at low computational expense and minimum programming requirement.