Genetic algorithm for virtual topology design on MLR WDM networks

For the mixed-line-rate (MLR) wavelength-division multiplexing (WDM) networks, each wavelength of fiber can provide different transmitting rates (in 10/40/100 Gbps) by using different modulation types. Since the MLR-WDM is becoming the key and a cost-efficient technique for the network upgrading, the problem for constructing an efficient virtual topology becomes an important issue. In this paper, the Virtual Topology Design (VTD) problem on MLR-WDM network is considered. Given the physical backbone network and traffic demand matrix between nodes of the network, the goal of the VTD problem is to determine which node-pairs to be connected by establishing lightpaths, the actual routes of the lightpaths, the transmitting rates of lightpaths, and the assigned wavelengths of lightpaths such that the total cost of deployed transceivers can be minimized. Since the VTD problem on MLR-WDM network is a hard problem, in the paper, a heuristic algorithm (HA) and a genetic algorithm (GA) are proposed to solve it. Experimental results indicate that the proposed GA is robust for this problem.