SNR-availability-based optical network provisioning

We review recently proposed metrics, Q availability and signal-to-noise ratio (SNR) availability, based on statistical performance of optical signals, for modulation format assignment in network provisioning. These metrics assign a modulation format aiming to maximize spectral efficiency while satisfying the specified service availability. Q availability is suitable for tunable modulations with a discrete data rate based on M-ary quadrature amplitude modulations (mQAMs), while SNR availability is more suitable for fine-tunable modulations such as time-domain hybrid mQAM or a probabilistically shaped signal as well as discrete mQAMs. We also present a new guideline, to the best of our knowledge, on how to estimate network capacity without full network simulations when fine-tunable modulations are provisioned using SNR availability. We apply this guideline on three different network topologies and show 18.7% to 35.7% capacity gains with probabilistically shaped signal over mQAMs. SNR availability serves as a useful metric for provisioning in future optical networks adopting fine-tunable modulations.