Consecutiveness Loss-Aware Routing and Spectrum Assignment Algorithm in Flexible Bandwidth Optical Networks

Routing and spectrum assignment (RSA) problem has become a research hotspot in flexible bandwidth optical networks. In this paper, we propose a novel RSA algorithm based on consecutiveness loss, i.e. Consecutiveness Loss-Aware Routing and Spectrum Assignment algorithm (CLA-RSA). A metric (consecutiveness loss) which quantifies the consecutiveness damage of spectrum brought by connection request is proposed to choose optimal route and spectrum assignment scheme. Numeric results show that CLA-RSA performs better in blocking probability than First Fit and Maximize Common Large Segment algorithm (MCLS). Also, our algorithm can effectively decrease spectrum fragmentation and enhance spectrum consecutiveness.