Light Path Optimization Implementation for Survivable Routing and Wavelength Assignment in Optical Networks

Abstract

In this paper, establishing a light path setup in WDM network done by implementing an ant-based mechanism Ant Colony Optimization (ACO) algorithm used for providing survivable routing in WDM network. The major problem in survivable routing WDM network is routing wavelength and assignment (RWA) problem, It sets up light path by routing and assigning a wavelength to each connection such that no light path use the same wavelength on same link .Our study aims to develop an routing and optimize the light path setup for survivable routing based upon the bit transmission to which supports data transfer supports to run continuously thus it can provide dynamic path. By adopting a new routing table structure and keeping a number of mobile agents in the network to cooperatively explore the network states and continuously update the routing tables, our new ant algorithm can efficiently support the ants' foraging tasks of route selection and wavelength assignment in WDM networks. Each path in the network is assigned by feasibility value. This feasibility value is calculated by considering the metrics such as bandwidth availability, path length and number of free wavelengths. When an ant is launched in the network by its node, it moves towards random destination to gather information such as bandwidth availability, path length and free wavelengths in that path. The value of path load is dynamically updated by the mobile agents in the load table. Using NS-2 simulation we show that the proposed ant based routing achieves better channel utilization and throughput with reduced delay, when compared with the normal routing. Optimization of light path performance is measured by varying the CBR traffic sending rate and flows.