Quality of transmission impact on routing and wavelength assignement rules in hybrid optical networks

Transmission quality is being a very important issue in optical communication systems. As an optical signal propagates along a lightpath connecting a source node to a destination node in the network, the quality of transmission is degraded due to transmission impairments introduced by long-haul optical components. Consequently, the signal's bit error rate (BER) at the destination node can become unacceptably high. It is, thus, necessary to find an efficient method to estimate these impairments penalties and to evaluate the optical links transmission quality. In this paper, an analytic expression of the Q-factor is presented. To the best of our knowledge, this is the first time that the Q-factor estimation is presented in details considering four main impairments referred to as chromatic dispersion (CD), polarization mode dispersion (PMD), optical signal to noise ratio (OSNR) and nonlinear phase (Phi
_NL
).