Dynamic Routing and Wavelength Assignment with Power Consideration in WDM Networks

One of the most important technical problems in optical WDM network is the dynamic routing and wavelength assignment (dynamic RWA) problem, which is to set up lightpaths and assign wavelengths dynamically in order to establish a channel between optical source and destination nodes. Previous studies have solved many variations of the dynamic RWA problem under the assumption of ideal conditions regarding the power of a signal, i.e. signal attenuation on a fiber and saturation of optical amplifier are not taken into account. In practical network environment, capability of connection establishment in RWA problem should be smaller than this ideal case. In this paper, we investigate the dynamic RWA problem taking account of degradation of routed signals by optical components, and propose a new routing algorithm with power consideration. The proposed algorithm can reduce forced termination probability of connections due to the above power constraints. With a computer simulation, we evaluate the proposed algorithm by comparing it with an existing routing algorithm.