Impairment aware evolutionary programming algorithm for transparent optical networks

In this paper the effect of Four Wave Mixing (FWM) and amplifier spontaneous emission (ASE) noise are considered while solving the dynamic routing and wavelength assignment (DRWA) problem in optical networks using wavelength division multiplexing (WDM). The proposed Evolutionary programming algorithm uses a fitness function that is comprised of the number of hops, path cost, variance contributions due to FWM crosstalk, amplifier noise, and different beat noises of the receiver, to solve the DRWA problem. The set up time of a requested lightpath is reduced by pre-computing the FWM crosstalk products and the static FWM noise power per link and storing these in an offline database. These are retrieved during the setting up of a lightpath and evaluated online taking the dynamic parameters like cost of the links into consideration.