An efficient algorithm for virtual-wavelength-path routing minimizing average number of hops

Abstract—In this paper, we present a novel heuristic algorithm for routing and wavelength assignment in virtual-wavelength-path (VWP) routed wavelength-division multiplexed optical networks. We are the first to take up the approach of both minimizing the net-work cost, as well as maximizing the resource utilization. Our algo-rithm not only minimizes the number of wavelengths required for supporting the given traffic demand on any given topology, but also aims to minimize the mean hop length of all the lightpaths which in turn maximizes the resource utilization. The algorithm initially assigns the minimum hop path to each route and then performs efficient rerouting to reduce the number of wavelengths required while also trying to minimize the average hop length. To further reduce the network cost, we also propose a wavelength assignment procedure for VWP routed networks which minimizes the number of wavelength converters required. Our algorithm has been tested on various topologies for different types of traffic demands and has been found to give solutions much better than previous standards for this problem. Index Terms—Network cost, resource utilization, routing and wavelength assignment (RWA), virtual-wavelength-path (WPM) routed network, wavelength conversion, wavelength-division multiplexed (WDM) optical network. I