BLOCKING PROBABILITY EVALUATION OF WDM LIGHTWAVE NETWORKS

Abstract

In recent years, Wavelength Division Multiplexing (WDM) technology has emerged as the transmission and switching mechanism for future optical networks, where wavelength is routed without electrical conversions. There are two types of optical circuit switched networks: Wavelength Selective networks and Wavelength Interchange networks. Wavelength Interchange networks involve wavelength conversion. Wavelength conversion techniques are found to give.better blocking performance. This dissertation discusses three different network simulation topologies viz.,30- node MESH ,16- node RING and14-node NSFNET . For these we have implemented the routing and wavelength selection algorithms of First Fit and Random.. Simulation results of these three topologies are obtained by using the wavelength selective first fit, wavelength selective random and wavelength interchange first fit algorithms. We have generated the blocking rates of each algorithm. After comparing the results, we found that the wavelength interchange first fit algorithm gives large improvement in blocking performance. The software has been written in C++ language and runs successfully under the UNIX environment.