GNPy model of the physical layer for open and disaggregated optical networking [Invited]

• Published in: Journal of optical communications and networking Vol. 14; no. 6; pp. C92 - C104
• Main Author: Curri, Vittorio
• Format: Journal Article
• Language: English
• Published: Piscataway Optica Publishing Group 01.06.2022; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Computer networks; Data transmission; Hauling; Modelling; Multiplexers; Nonlinear optics; Optical communication; Optical network units; Optical noise; Optical polarization; Optical propagation; Optical signal processing; Random noise; Software; Software-defined networking; Wavelength division multiplexing
• ISSN: 1943-0620; 1943-0639
• DOI: 10.1364/JOCN.452868

Networking technologies are fast evolving to support the request for ubiquitous Internet access that is becoming a fundamental need for the modern and inclusive society, with a dramatic speed-up caused by the COVID-19 emergency. Such evolution needs the development of networks into disaggregated and programmable systems according to the software-defined networking (SDN) paradigm. Wavelength-division multiplexed (WDM) optical transmission and networking is expanding as physical layer technology from core and metro networks to 5G x-hauling and inter- and intra-data-center connections requiring the application of the SDN paradigm at the optical layer based on the WDM optical data transport virtualization. We present the fundamental principles of the open-source project Gaussian Noise in Python (GNPy) for the optical transport virtualization in modeling the WDM optical transmission for open and disaggregated networking. GNPy approximates transparent lightpaths as additive white and Gaussian noise channels and can be used as a vendor-agnostic digital twin for open network planning and management. The quality-of-transmission degradation of each network element is independently modeled to allow disaggregated network management. We describe the GNPy models for fiber propagation, optical amplifiers, and reconfigurable add/drop multiplexers together with modeling of coherent transceivers from the back-to-back characterization. We address the use of GNPy as a vendor-agnostic design and planning tool and as physical layer virtualization in software-defined optical networking.