Low Margin QoT-Aware RMLSA with Circuit Invigoration in Elastic Optical Networks

In Elastic Optical Networks (EON), the literature usually measures QoT (Quality of Transmission) by the Optical Signal-to-Noise Ratio (OSNR) or estimated maximum transparent reach of the modulation technique adopted by the circuit. This paper evaluates the Quality of Transmission (QoT) margins adopted in traditional Routing, Modulation Level, and Spectrum Assignment (RMLSA) algorithms that quantify QoT through the maximum transparent reach of the modulation techniques. A RMLSA algorithm is proposed that categorizes the minimum margins that must be adopted for the establishment of new circuits, based on their expected degeneration and the impact it will have on the already established optical circuits. Simulation results show that the proposed minimum margins associated with circuit invigoration present better results than algorithms that propose a fairer margin or evaluate QoT through the maximum transparent reach. The proposal showed a reduction of up to 89% of bandwidth blocking rate and with a runtime performance similar to the simpler algorithms that evaluate QoT by distance.