Routing and wavelength assignment in a satellite optical network based on ant colony optimization with the small window strategy

Ant colony optimization (ACO) with the small window strategy is put forward to solve the routing and wavelength assignment problem in satellite optical networks. The intersatellite distance, link duration, and wavelength idle ratio are introduced as the heuristic functions, and the small window strategy is used to promote the convergence speed. By calculating the intersection of idle wavelengths on adjacent links, the algorithm can accomplish routing selection and wavelength assignment on a single ant. The results show that, compared with the Dijkstra+FF algorithm, the blocking probability of ACO can decrease by 50% at most, and improvement of the resource utilization ratio can reach 45%.