Routing, modulation and spectrum allocation of dynamic anycast based on ant colony optimization in elastic optical networks

Abstract

Elastic optical networks (EONs) using optical orthogonal frequency division multiplexing (O-OFDM) technique are considered to be promising optical networks due to their ability to achieve flexible spectrum management. This paper studies dynamic anycast in EONs. The rapid growth of service demand has brought enormous challenges to the network environment, resulting in the increase of blocking rate. In order to reduce the traffic blocking rate, we propose a spectrum-aware ant colony optimization (SA−ACO) algorithm to optimize the anycast transmission problem in EONs and improve the spectrum utilization in the network. Different from the traditional anycast allocation algorithm, the proposed SA−ACO algorithm can adapt to the real-time changes of the system. We add bandwidth factor into the node pseudo-random selection rule, and add a weight factor to weigh the impact of bandwidth on the system. In the found candidate path set, the link distance and link spectrum availability are processed to find the optimal path suitable for the current service transmission. In terms of pheromone update, we delay the secretion of ant pheromone, and secrete pheromone on the path where the relatively optimal solution is located in the solution space found by the ant colony. Through extensive simulation experiments, we evaluate the performance of the algorithm. By comparing with the reference algorithms in previous literature, our proposed algorithm significantly outperforms other methods in reducing bandwidth blocking probability performance.