Toward efficient, reliable, and autonomous optical networks: the ORCHESTRA solution [Invited]

Optical networks have historically been designed to be operated statically. Connections are overprovisioned so that they remain uninterrupted over several (e.g., 10) years, using high physical-layer margins to cover the evolution of the physical conditions and modeling uncertainties. As a first step, we can increase the efficiency without sacrificing network reliability by removing uncertainties and reducing long-term margins, observing and adjusting them at intermediate periods. This requires certain automation steps in monitoring and data processing. Increasing the efficiency further, and thus further reducing the margins, comes at a trade-off in reliability, and should be done according to service classes and the level of network automation. The ORCHESTRA network makes use of coherent optical transponders as software-defined optical performance monitors (soft-OPMs) to improve the optical network observability. ORCHESTRA developed digital signal processing (DSP) OPM algorithms and a hierarchical monitoring plane to carry and process physical-layer monitoring data. ORCHESTRA uses data analytics methods to understand the physical-layer conditions and feed cross-layer optimization algorithms. ORCHESTRA closes the observe-decide-act control loop, automating the mechanisms required to trade efficiency for reliability.