Conference Paper

The utilization of hybrid Erbium-doped fiber (EDF)/Raman amplifiers enables to extend the reach of optical channels and, consequently, reduce the number of expensive 3R regenerators required in long-haul optical networks. However, hybrid amplifiers are costlier than the widely deployed EDF amplifiers (EDFAs). Therefore, it is critical to place them only at selected fiber spans of the network such that their number is also kept to a minimum. Hybrid amplifier placement is a complex task in mesh networks due to the diverse optical channels (i.e., with different source and destination nodes) traversing each fiber span. This paper proposes an optimal method to solve the problem of placing hybrid amplifiers in mesh networks. It builds on the approximation that noise adds up incoherently along the transmission path to derive an integer linear programming (ILP) model that determines the minimum number and location of hybrid EDF/Raman amplifiers required to reach a target set of feasible optical channels (i.e., without intermediate 3R regenerators). A comprehensive set of network simulations using a reference optical network provides evidence that the proposed method outperforms existing approaches.