Optical Path Design Method for Reducing Maximum Spectrum Slot Number by Selecting Alternative Routes and Using GNPy

For cost-effective transport services, we need to efficiently utilize spectrum resources in optical networks. Currently, we need to carefully design optical resources including routing, modulation format and slot assignment in order to improve of the efficiency of optical resources. In this paper, we propose a routing, modulation, and spectrum allocation (RMSA) method in optical networks in consideration of transmission quality and transmission parameters by GNPy. In the proposed method, the spectrum utilization of the optical network can be improved by selecting the route with the smaller spectrum slot number when searching for the route for optical path. We take into account the change of the required generalized signal-to-noise ratio (GSNR) and frequency bandwidth of the optical path due to the change of the modulation mode. Here, we utilize GNPy to estimate the transmission quality. In this way, we can obtain more realistic and highly efficient optical path design in consideration of requirements in operational optical networks. We evaluate the performance of the proposed method for optical networks in a simulation. In numerical examples, we show that our proposed method improves the efficiency of spectrum utilization. It also shows the effect of parameters on the performance and calculation time of the proposed method.