A Penalty-Based Routing and Spectrum Assignment in Fragmented Elastic Optical Network Spectrum

Routing and spectrum assignment (RSA) has been an area of keen interest in Elastic Optical Networks (EONs). Improper resource provisioning causes fragmentation in the network spectrum, which leads to inefficient spectrum utilization. It also causes an increase in blocking of the new connection requests. Fragmentation management techniques are complicated and costly. There is a need to operate the network in a fragmented state without worsening the performance. In this work, we present a penalty-based routing and spectrum assignment technique to mitigate fragmentation effects. We also propose a best-effort routing and spectrum assignment if the demanded spectrum resources are not available. The simulation results show that the proposed techniques perform better in terms of resource blocking ratio and network spectrum utilization.