A distributed strategy for dynamic routing and wavelength assignment in ASON network

As one of the core technology of ASON (automatically switched optical network), the dynamic routing and wavelength assignment algorithm is the key for ASON to reflecting its intelligence. In this paper, a new distributed heuristic algorithm based ant colony optimization for dynamic RWA (routing and wavelength assignment) that is adapted to the environment of ASON networks was put forward. The route selecting and the wavelength assignment process were combined with as whole using multilayer-graph model. The algorithm implements in distributed way using local information stored in a "pheromone matrix" and will be refreshed on the way of searching path. Compare with "shortest-path+first-fit" algorithms, it can reduce communication overhead cost of networks and the simulation computing showed lower blocking probability and more balanced wavelength resource assignment.