MAIN ACHIEVEMENTS (ESR2):
ESR2 Li Zhang’s work at DTU mainly focused on the atmospheric turbulence time-variant channels modelling and prediction. At Orange Labs in Lannion, the topic was fiber Raman amplifiers modelling. Orange Labs provided a standard numerical model for Raman amplifiers modelling and performance evaluation and this model served as a benchmark for ESR2’s work. ESR2’s work proposed an accurate and efficient neural networks-based tool to model and learn the complex physical effects inside the fiber.
ESR2 also worked on network topology and this continued at Telecom Italia Mobile. Telecom Italia developed an open-source tool (MoleNetwork) to generate backbone and metrocore and metrocore aggregation topologies. Based on this MoleNetwork tool ESR2’s work aimed to improve the generation of metrocore aggregation topologies from the point of view of practical applications and more efficient generation.
Of note is the new neural networks-based solver in the C-band with backward-pumped and bidirectional-pumped schemes. The outlook for the next generation of fiber-optic communication systems operating over ultra-wide band, Raman amplifiers are attractive solutions due to their broad bandwidth, and the ability to provide arbitrary gain profiles in a controlled way. Crucial to optimizing Raman amplifiers over large bandwidths is the proper allocation of pump powers and wavelengths. The new neural networks-based solver could be used to foresee the impact of Stimulated Raman Scattering on the fiber span of a C+L or S+C+L-band system and to design the distributed Raman amplifiers to compensate for this effect. Also, this new neural networks-based solver could be used to optimize wide-bandwidth (C+L- or S+C+L-band) Raman amplifiers to properly select multiple pump wavelengths and powers for desired gain profiles. It is an effective way for Raman amplifier modelling and performance evaluation before the real fiber Raman amplifiers are fabricated.
Key results are published here:
ESR3 Lareb Zar Khan and ESR4 Abdennour Ben Terki at SSSA worked on Work Package 3.
MAIN ACHIEVEMENTS (ESR3):
Computational complexity reduction of ML models will impact not just optical networks but the world of AI. AI/ML-based data centres consume one order of magnitude more power than traditional data centres which means that larger ML models consume high power. Our work on computational complexity reduction of ML models can be used to minimize the carbon footprint, analysing and predicting equipment failures, vendor-agnostic solutions for alarm management, and developing ML-based algorithms for failure prediction; there are contributors in maintaining a stable network operation, minimizing downtime. The potential here is to revolutionize optical network management, reducing operational costs and enhancing service provisioning. This contributes to advancing automation and optimization technologies.
The potentials of machine learning (ML) have been investigated to enhance control and management functionalities for optical networks, even assuming multi-band optical networks. Such functionalities span from resource allocation strategies accounting for transmission performance to (soft-)failure management. Several ML models have been proposed, demonstrated, and tested even experimentally. First, reinforcement learning and deep reinforcement learning techniques have been proposed to optimize routing and spectrum assignment in multi-band optical networks, while accounting for transmission performance in wide-band transmission systems in the presence of Stimulated Raman Scattering (SRS). Then, failure management (e.g., failure identification) assisted by neural networks (NNs) has been studied facing with issues coming from live networks (e.g., data scarcity associated to specific failures). ML models have been proposed, also relying on generative AI techniques such as data augmentation. A specific attention has been also given to the NN-complexity reduction to create sustainable networks even in terms of power consumption. Overall, activities in WP3 demonstrated that ML can actually empower control and management functionalities revolutionizing optical networks control and operation.
Key results have been published in:
MAIN ACHIEVEMENTS (ESR4):
ESR4’s work focused on applying Reinforcement Learning (RL) and Deep Reinforcement Learning (DRL) to enhance RSA in multi-band optical networks. This research leveraged the Generalized Gaussian Noise (GGN) model to simulate physical layer impairments accurately, crucial for assessing Quality of Transmission (QoT) and optimizing network performance. Results showed that RL and DRL strategies adapt dynamically to network conditions, effectively minimizing blocking probability and improving throughput across various network topologies compared to k-Shortest Path and First-Fit (k-SP FF) strategy. Then, a multi-stage ML technique has been proposed and demonstrated to infer with high accuracy the type, severity, and localization of failures in an experimental testbed based on commercial equipment.
Key results have been published in:
ESR5 Mariano Devigili and ESR6 Prasunika Khare at UPC worked on Work Package 4.
MAIN ACHIEVEMENTS (ESR5):
ESR5 Mariano Devigili‘s work focused mainly on the applications of OCATA: an optical layer digital twin. In particular, the applications investigated were failure management (i.e. failure detection, identification and severity estimation), quality of transmission estimation for lightpath provisioning (e.g., design of models and algorithms supporting the establishment of optical connections) and finally optical amplifier control (e.g., algorithms for the control and the optimization of optical amplifiers). Regarding the investigation on failure management, a journal paper titled, “Applications of the OCATA time domain digital twin: from QoT estimation to failure management” was published in the Journal of Optical Communications and Networking (JOCN), Open Access here. Elsewhere, part of the work done on QoT estimation for lightpath provisioning was presented orally at the Optical Fiber Communication Conference (OFC) 2024.
Key results have been published in:
MAIN ACHIEVEMENTS (ESR6):
ESR6 Prasunika Khare developed software for multiband optical networks. ESR6 simulated the optical light path propagation using 4th order Runge-Kutta method and then generated the symbols/constellation to study the linear and non-linear effects in C+L+S optical system. ESR6 introduced SSMS, a multiband optical fiber simulator entirely developed in MATLAB. SSMS solves the generalized nonlinear Schrödinger equation relying on the 4th order Runge-Kutta method in Interaction Picture (RK4IP) with adaptive step size approach and compare it with the widely used split-step Fourier method (SSFM). Then, ESR6 proposed digital twin models based on deep neural networks that propagate optical constellation features, related to RO1 and putting in to practice TO1. Remarkable accuracy is shown for optical C+L+S bands.
Alongside failure management, WP4 worked on the OCATA optical layer digital twin and investigated its applications e.g. light path provisioning and optical amplifier control. These applications if verified will enable effective network optimization, accurate failure management, thereby reducing the network margins and loads. The societal implications would consist in a more efficient and sustainable infrastructure supporting Internet. WP4 has also worked on Adaptive Neural Network-based models for C+L+S band scenario. The proposed adaptive neural network-based model is able to provide a more efficient and accurate way to handle highly non-linear optical network transmission. MB optical transmission is considered the next technological evolution in optical WDM transport capable of dealing with 5G and beyond in a cost-effective manner. Hence, a revolution to optical network management.
Key results have been published in: