Highly Dense Elastic Optical Networks Enabled by Grouped Routing With Distance-Adaptive Modulation

We propose highly spectrally efficient grouped-routing networks with distance-adaptive modulation. The proposed scheme can realize highly dense wavelength-division-multiplexing networks under the constraint of the spectrum narrowing caused by optical-node traversals. Its effectiveness is confirmed by extensive computer simulations using 400-Gbps dual-polarization QPSK, 8QAM, and 16QAM signals. The fiber-utilization efficiency is improved by 18.0%.