Adaptive Control of Optical Amplifier Operating Point Using VOA and Multi-Objective Optimization

One of the challenges concerning dynamic optical networks is to increase the level of network automation to allow capabilities devoid of any human intervention. The adaptive control of optical amplifiers operating point (ACOP) is an effort to enable the network control and management to have “plug-and-play” capabilities. ACOP approaches aim to autonomously define the gain of the amplifier after changes in the amplifier input power. The straight-forward implementation of ACOP approaches is as an application running above a software-defined network controller. Some ACOP approaches were recently proposed, and the latest approaches can define the gains minimizing both the linear and nonlinear interference in the optical signal. Nevertheless, these proposed approaches only use the information concerning the individual amplifier conditions to select its gain. In this paper, we propose a novel approach to minimize the nonlinear interference (NLI) impact in ACOP approaches by considering the use of a VOA in the output of each amplifier deployed in an optical link. Moreover, we propose a new global ACOP approach based on multi-objective optimization that can define both the gains of the amplifiers and the losses of the VOAs, aiming to maximize the OSNR and minimize the OSNR ripple of the entire link considering the NLI. The results showed that the proper deployment of the VOA increases the number of solutions with good quality of transmission and that this consideration is more beneficial in the cases where the amplifiers in the link are operating in points with high noise figure. The results showed that the proposed global ACOP approach returns better solutions than the state-of-the-art ACOP approaches considering two commercial amplifier models.