Energy Efficiency Analysis in Adaptive FEC-Based Lightpath Elastic Optical Networks

In this paper, an energy efficiency (EE) analysis for elastic optical networks (EONs) considering the adaptive allocation of the transmitted power, spectrum bandwidth, modulation format and forward error correction (FEC) type has been proposed. The trade-off between the FEC coding types and the optical layer EE (OL-EE) was investigated considering the capacity of information transmission and power consumption. The power consumption model considers elements involved in the lightpath establishment, namely transmitter, receiver, bandwidth-variable optical crossconnect (BV-OXC), optical amplifiers and network control. Numerical examples have demonstrated EE increasing for the lightpaths when adaptive FEC coding is deployed; furthermore, the EE varies with the distance of the optical network nodes and hop count. In this sense, it is observed that the EE decreases with the increasing of FEC energy per bit consumption; however, an operation region is verified in which the overall EE network with FEC is superior to the system without FEC coding. After this point, the increases in the FEC energy per bit consumption will affect negatively the EE metric. For instance, with the proposed OL-EE model it is possible to determinate the maximum energy consumption allowed to the FEC codes without OL-EE system degradation.