University of Teramo
In this paper, the authors study the Energy-efficient Impairment-constrained Regenerator Placement (EIRP) problem with the objective of minimizing the total energy consumption in optical networks with mixed line rates. The destination of each path is guaranteed to receive the data correctly from the source based on the regenerator placement. They first provide the problem definition of EIRP and show that the EIRP problem is NP-complete. They then formulate the problem as a Mixed Integer Linear Program (MILP) and give results for small scale problems. Two heuristic approaches, named High Line Rate First (HLRF) and Reroute Only (RO), are presented.