Energy-efficient routing and bandwidth allocation in OFDM-based optical networks

This paper introduces a novel routing and bandwidth allocation strategy for orthogonal frequency-division multiplexing (OFDM)-based elastic optical networks, aiming to optimize the network operational expenditures in terms of energy consumption. Based on the previously reported analytical bit error rate model for an OFDM-based optical transmission line, an optimization problem is formulated to allocate a set of lightpaths according to realistic network topologies, where the routing path, modulation level, bandwidth, and optical transceiver power of each lightpath are jointly determined for achieving minimum power consumption. To reduce computational complexity, a suboptimal iterative flipping method for solving the above NP-complete optimization problem is proposed, which achieves better performance than a simulated annealing scheme while consuming considerably fewer search iterations.