ACO-based routing and spectrum allocation in flexible bandwidth networks

Optical networks with flexible bandwidth provisioning are a very promising networking architecture. It enables efficient resource utilization and supports heterogeneous bandwidth demands. In this paper, we focus on the dynamic routing and spectrum allocation (RSA) problem which emerges in such networks and propose a novel dynamic RSA algorithm by means of ant colony optimization (ACO). In our proposed algorithm, ants are launched to modify the routing table according to the length and the spectrum fragmentation information along the path. A simulation study is performed considering five algorithms in terms of blocking probability: WDM-based RWA approach, KSP-based RSA approach, Slot-based RSA algorithm, and our proposed ACO-based RSA approach. We then compare the deterioration degree of blocking probability by adding more types of line rate. Simulation results indicate that our proposed ACO-based RSA approach achieves lower blocking probability, complexity, and higher adaptability to more line rates mixture.