Time and bandwidth aware traffic balancing in elastic optical networks – A two dimensional approach

Abstract The time scheduled traffic in spectrally efficient elastic optical networks (EONs) is periodic and exhibits non uniform pattern, in both, the time as well as the requested bandwidth. In time domain, it remains heavy during the office hours and slacks during the non-office hours; while in the bandwidth domain, it is distributed non-uniformly along the network links and also, may vary from few Gbps to hundreds of Gbps. This inefficient utilization of spectral resources results in increased blocking of connection requests. Hence, to address the problem of traffic unevenness in time and bandwidth domains in the EONs, traffic balancing based routing and spectrum assignment (TBRSA) strategies for scheduled traffic are proposed in this manuscript. Traffic balancing is on the basis of service level agreements (SLA) between the clients and the network service providers. The characteristics of traffic and the advanced features of EONs have been exploited to perform the traffic balancing. The proposed strategies have been compared with the existing benchmark strategy. The metrics of comparison are bandwidth blocking probability (BBP), spectrum utilization ratio (SUR), fragmentation index (FI) and a newly introduced metric, spectrum time utilization ratio (STUR). From the simulation results, it has been conclusively established that the proposed traffic balancing based RSA strategies outperform the benchmark strategy in all the parameters of interest.