OSNR-aware dynamic lightpath allocation in Raman-amplified networks

A dynamic lightpath allocation algorithm that considers the impact of Raman amplification on the quality of the signal is proposed. To do so, an exhaustive theoretical model that includes fiber attenuation, Rayleigh scattering, stimulated Raman scattering (gain and depletion of channels and pumps) and spontaneous Stokes and anti-Stokes scattering caused by Distributed Fiber Raman Amplifiers (DFRAs) is used to quantify the Optical Signal to Noise Ratio (OSNR) of the lightpaths found by the lightpath allocation algorithm. The performance of the proposed algorithm was evaluated by means of computer simulation. Results show that, due to the rigorous modeling of the Raman amplification, the blocking probability of the proposed lightpath algorithm can be several orders of magnitude higher than that of classical Routing and Wavelength Assignment (RWA) algorithms or previous OSNR-aware algorithms applying a much simpler model for the signal power propagation of DFRAs. We expect these results help network operators to better design and operate their future Raman-amplified dynamic networks.