Nonlinear cumulated phase as a criterion to assess performance of terrestrial WDM systems

Through extensive numerical studies, we showed that the cumulated nonlinear phase can be considered as a relevant parameter to assess the performance of N /spl times/ 40 Gbit/s terrestrial systems, after calibration. This can be of high interest for constraint based-routing algorithms in Ultra-Long haul transparent networks: indeed, a node could decide, with the knowledge of the nonlinear phase and OSNR evolution, whether a path should be regenerated or not.