Deterministic lightpath scheduling and routing in elastic optical networks

A huge torrent of information being generated from various heterogeneous applications and services is passing to and from the Internet backbone. Accommodating such heterogeneity and preserving the quality of service (QoS) of each traffic profile is a challenging task for operators. The heterogeneous traffic profile (HTP) considered in this work includes permanent lightpath demands (PLDs) and scheduled lightpath demands (SLDs). We propose various distance adaptive routing and spectrum assignment (DA-RSA) heuristics to resolve resource conflict among these two traffic profiles in elastic optical networks (EONs) under a full sharing environment. Conventionally, preemption was the only technique to resolve such conflict and ensure QoS for HTPs. Since excessive preemption leads to poor performance and lowers the degree of customer satisfaction, this work aims at reducing the preemption of demands. In order to do this, we propose to utilize bandwidth splitting as an alternative solution in such situations. Moreover, an integrated solution consisting of splitting and preemption is also proposed. We call this new integration as flow-based preemption. The simulation results demonstrate that utilizing splitting in place of preemption yields significant improvement in terms of all metrics of interest. Moreover, flow-based preemption is proved to be superior in performance than the only splitting-based solution. To the best of our knowledge, this is the first work addressing resource conflicts under a full-sharing environment by focusing on resource utilization at the link and node level. We believe that proposed heuristics support network operators to smoothly orchestrate network resources in the presence of such HTPs.