A genetic algorithm for solving virtual topology reconfiguration problem in survivable WDM networks with reconfiguration constraint

In wavelength division multiplexing (WDM) networks, the performance of the virtual topology designed for a pre-specified traffic pattern can be improved by performing virtual topology reconfiguration. Simultaneously, the provision of survivability of WDM networks is important, because the transmission of huge data should be protected when fiber fails. Thus, the combination of survivability and reconfiguration is an important issue on WDM networks. In this paper, the virtual topology reconfiguration problem (VTRP) in survivable WDM networks with reconfiguration constraint is studied. Given the physical topology, dedicated path-protection virtual topology and a new traffic demand matrix, the goal of VTRP is to reconfigure current virtual topology under the pre-specified reconfiguration constraint so that the objective cost can be minimized. The object cost of VTRP is the average weighted propagation delay (AWPD). Because designing a polynomial time algorithm to find the optimal solution of VTRP is impractical, in this paper, a genetic algorithm (GA) is proposed to solve this problem. Experiment results reveal that the objective cost can be decreased effectively by using the proposed genetic algorithm. (C) 2008 Elsevier B.V. All rights reserved,