Adaptive subcarrier-distribution algorithm for routing and spectrum allocation in OFDM-based elastic optical networks

In this paper, we have proposed the adaptive subcarriers-distribution routing and spectrum allocation (ASD-RSA) algorithm, which is the first elastic optical network routing and spectrum allocation algorithm based on distributed subcarriers. It allocates lightpaths to request adaptively and proved to achieve much lower bandwidth blocking probability than traditional routing and spectrum allocation algorithms based on centralized subcarriers with integer linear programming and dynamic simulation methods. Additionally, the ASD-RSA algorithm performs the best with three alternate routing paths; this character will decrease the calculating amount of both alternate routing path searching and spectrum allocation immensely in large networks.