400 Gb/s real-time trial using rate-adaptive transponders for next-generation flexible-grid networks [invited]

We experimentally demonstrate real-time error-free transmission for longer than 65 h using a 400G rate-adaptive flexible-grid transponder in a metro regional Telecom Italia multivendor environment. Transmission over a G.652 field link and G.655 E-LEAF path with legacy dense wavelength division multiplexing equipment and co-propagating commercial coherent 40G and 100G channels was successfully achieved with a spectral efficiency of 5.33 b/s/Hz.