Fragmentation aware Routing and Spectrum Assignment algorithm for Elastic Optical Networks

Routing and Spectrum Assignment is a key issue in Elastic Optical Networks (EON). Under dynamic traffic conditions, spectrum fragmentation of the frequency resources reduces the spectrum utilization efficiency, and hence degrades the service blocking probability. To address this problem, this paper proposes an improved fragmentation aware routing and spectrum assignment algorithm (FA-RSA) for EON by considering the spectrum fragmentation in the routing decision and spectrum allocation phase. Theoretical analysis and numerical simulation results show that compared with the traditional Random-Fit (RF) and First-Fit (FF) algorithm, the improved algorithm can significantly reduce the blocking probability and improve spectrum utilization.