Adaptive FEC-based lightpath routing and wavelength assignment in WDM optical networks

Forward error correction (FEC) has been widely used in optical communication systems to compensate for the degradation of the received optical signal to noise ratio (OSNR). Current optical networks tend to use the same type of FEC for all the lightpaths even though lightpaths with higher OSNRs can be established by FECs with lower overhead. This paper proposes an adaptive approach to choose the most efficient FECs for different lightpaths based on their individual OSNRs. An Integer Linear Programming (ILP) model and a simple waveplane-based heuristic algorithm considering shuffled lightpath demand sequences are developed to tackle the routing and wavelength assignment (RWA) problem. The simulation results indicate that compared to the non-adaptive case, using the proposed adaptive FEC selection scheme can significantly reduce the required FEC overhead. Apart from being far more tractable, the proposed heuristic approach performs almost as well as the ILP model.