Autonomous Raman amplifiers in multi-band software-defined optical transport networks

Abstract

A controller architecture for managing multi-band Raman amplification within software-defined optical transport networks is presented. In the perspective of optical fiber network softwarization and disaggregation, this work provides an operative description of a system capable of autonomously handling Raman amplification on a single fiber span, achieving the working point requested by the control plane in terms of mean gain and tilt. The developed architecture is composed of two software modules: the Raman design unit (RDU) and the Raman controller unit (RCU). First, the RDU defines the nominal optimal working point designing the power level configuration of the Raman card pumps according to the required amplification constraints without considering any channel spectral load. Then, due to the telemetry feedback, the RCU performs a tracking operation of the mean gain towards the target one, linearizing the problem at the nominal optimal working point. The fiber physical parameters needed by the controller for correct operation of the system are extracted through a conceived probing procedure. The proposal shows a high degree of adaptability of the defined Raman amplifier to the particular in-field scenario in which it is deployed, also counteracting spectral load modifications. The behavior of the described system is validated by means of an experimental session, confirming the effectiveness of the controller architecture design and the high accuracy achieved in terms of performance.