Modeling and Simulation of Wavelength-Routed optical Networks

All-optical Wavelength Division Multiplexing (WDM) networks providing extremely large bandwidths are among the most promising solutions to the increasing need for high-speed data transport. A lightpath has a specific route and one or more wavelengths through which the information is routed from the source to the destination node. In wavelength-routed optical networks, data are transmitted solely in the optical domain along lightpaths from source to destination without being converted into the electronic form and each lightpath is allowed to use the same wavelength on all the links along its path. This restriction is known as the wavelength continuity constraint. And it leads to an issue called as blocking in networks. Optical wavelength conversion with suitable Routing and wavelength assignment (RWA) can increase the performance and capacity of optical networks by eliminating this restriction and relaxing the wavelength continuity constraint. In this research, we analyze the problem of placing a limited number of wavelength converters in a mesh network using Weighted Maximum Segment Length (WMSL) converter placement algorithm. It employs Least-Loaded Routing and First-Fit (LLR-FF) RWA algorithm. It is tested on varying number of nodes in network and its respective blocking probabilities are calculated. The proposed algorithm provides the minimum blocking probability on optimal wavelength converters placement.