Energy Efficient Routing and Spectrum Assignment With Regenerator Placement in Elastic Optical Networks

In this paper, we present a dynamic energy efficient routing and spectrum assignment algorithm with regenerator placement (RP) capability for elastic optical networks. In this algorithm, a virtual graph is considered for a given network topology graph, whereby the cost functions of virtual graph is computed according to the energy consumption of the corresponding links and intermediates routers. Furthermore, the arrived connection request is served by finding the most energy-efficient path among the possible candidate paths. Then, the quality of transmission (QoT) of the selected path is evaluated in terms of bit error rate. If the estimated QoT is higher than a predetermined threshold, the designated path is assigned to the incoming request, otherwise, the RP algorithm is utilized to place a regenerator at the most energy-efficient position. In addition, the demanded transmission rate and required QoT are fulfilled by assessing different modulation formats and selecting appropriate modulation format in terms of power consumption and blocking probability (BP). We evaluate the proposed algorithms through extensive numerical simulations. The results of simulations reveal that the proposed algorithms have better performance than other existing schemes in terms of network total energy consumption and acceptable BP.