“…However, these impairments can be integrated into the constraint model as OSNR penalties, as detailed in [29,30]. A similar approximation can also be found in [29][30][31][32], which has been verified as a feasible way to evaluate the quality of optical signals in an online IA-RWA algorithm. An extended Dijkstra algorithm based on [29,30] is implemented in the PCE, which is capable of computing the route and wavelength, minimizing the path cost, and fulfilling both the wavelength continuity constraint and the OSNR requirement.…”