400Gb/s Real-time Trials on Commercial Systems for Next Generation Networks

We report the results of a field trial carrying 400-Gb/s real-time dual-carrier PDM-16QAM signals over a 550-km-long commercial system. After the examination of the propagation nonlinear noise statistics nature, we analyze the accuracy of a performance prediction model based on Gaussian nonlinear distortions on the lab replica of on-the-field conditions. Further on, we demonstrate the compatibility of 400-Gb/s real-time dual-carrier PDM-16QAM signals with legacy systems based on a 50-GHz channel grid, yielding 4 b/s/Hz of spectral efficiency over 550-km transmission. In the last part of the paper, we review recently published field trials employing real time 400Gb/s dual-carrier PDM-16 QAM channels and discuss the potential of such transponders to further increase spectral efficiency beyond 4 b/s/Hz forming super-channels and to be configured by software according to traffic demand.