Real-time 400 Gbps/carrier WDM transmission over 2,000 km of field-installed G.654.E fiber.

We combine erbium-doped fiber amplifier (EDFA) and backward distributed Raman amplifier (DRA) to achieve the real-time wavelength division multiplexing (WDM) transmission of 400 Gbps/carrier polarization division multiplexing (PDM) 16 quadrature amplitude modulation (QAM) signals over 2,000 km of terrestrial field-deployed cut-off shifted fiber (CSF) compliant with ITU-T G.654.E.

Field trial of distance-adaptive optical transmission with digital in-band OSNR estimation.

We present a feasible distance-adaptive optical transmission system that selects the optimum modulation format by referencing the estimated optical signal to noise ratio (OSNR) information transmitted from an opposing transceiver via a feedback channel. A modulation format free time-domain-multiplexed pilot sequence enables OSNR estimation and feedback channel transmission. Thanks to a feedback channel transmission, this system does not need to pass through a control plane in optimizing scheme.