Wavelength Rotation Graph Algorithm Based on Physical Impairment Constraints in Optical Networks

Abstract

As the network is converting to transparent optical networks, the impact of physical layer impairments on transmission performance can't be ignored. The impairments will decrease the quality of signals. To find a lightpath with high quality of transmission (QoT), this paper adds impairment constraints to the routing and wavelength algorithm based on wavelength rotation graph (WRG-RWA) and proposes impairment aware WRG-RWA algorithm. The constraints consider amplified spontaneous emission noises and polarization mode dispersion which are the most important liner impairments. The new algorithm estimates the impact of the impairments after the route is selected, and selects another route when the previous one fails in comparing with the constraints. By simulating, the new algorithm has preferably improvement on blocking probability and wavelength efficiency by contrast with the WRG-RWA algorithm and the impairment aware FF algorithm. The simulation results show the new algorithm can effectively decrease the blocking probability of transmission and improve the performance of optical networks.