An extension to the enhanced Gaussian noise model in optical bus considering various links spectrum

Abstract

Physical layer impairment modeling has considerably influenced optical networking in optimizing resource allocation for fulfilling a required quality of transmission. Among these impairments, the modeling of optical fiber non-linearity has enjoyed widespread applications by vendors and network operators, giving rise to the two well established Gaussian noise (GN) and enhanced Gaussian noise (EGN) models. In this work, we introduce an extension to the EGN model for a point-to-point bus transmission, where a demand is not typically routed over a single link. More specifically, we assume that a lightpath is routed over a bus and multiple interferers occasionally add and drop along the links, resulting in a mixture of coherent and incoherent non-linear propagation. We propose a mathematical formulation in the optical bus scenario, taking into account the spectrum variation of the links along the bus. To more accurately address their mutual statistical correlation in non-linear interference estimation, we make use of extra lightpath information. Along with presenting the new formulation, we modify the non-linear link function to include the spectrum variation of a lightpath links. The exploited optical bus topology is capable of approximating a real network lightpaths to enable design optimization of optical networks. Our numerical results show approximately 0.4 dB and 0.6 dB improvements versus the GN and EGN models in long bus scenarios with moderate number of channels and lightpaths, and around 0.3 dB minimum improvement.