Multipoint Overlapping Optical Networks

Coherent transmission has drastically evolved in the last decade to provide high flexibility to reach a great spectral efficiency. This yields a point-to-point capacity close to the Shannon's limit. In this work, we present a Multipoint Overlapping Optical Network in a multi-transmitter to single-receiver context to rather boost the network capacity. It overlaps two optical signals partly reusing network resources, here frequency slots of 12.5GHz width. We show that a joint DSP based on multi-stage parallel interference cancellation efficiently compensates Inter-Channel Interference up to 39% spectrum overlap with 1 dB SNR penalty in PDM-QPSK signals. We introduce an additional parameter, extending the Gaussian Noise model, to account for the residual ICI penalties after mitigation. This parameter is shown to be independent of the signal power and its value depends on the chosen overlapping. We validated both experimentally and by simulations the proposed model extension. Finally, with such a model, we study the network gains bring by the MOON architecture. We investigate networking scenarios assuming either 2-slot or 3-slot of overlapping resulting in ~20% or ~40% of overlapping. We demonstrate a gain up to 17% for 3-slot overlapping in the Italian network.