Connectivity is the major driver in the modern “information society”, where the range of data-driven applications is exploding, and new information-based value chains are rapidly emerging. Optical networks are the backbone of the global communication infrastructure, interconnecting billions of people and a huge number of various autonomous devices, control systems, and machines. Optical systems’ development incites the skyrocketing growth in the demand for data exchange and harnessing, fuelled by webbased services such as ultra-HD streaming, cloud services, 5G proliferation, fostering the changes in the digital world, and shaping the structure of the modern society. The demand growth is especially pronounced in the access and metro links, where data rates largely exceeding the current <1 Tb/s will be required. Moreover, the COVID-19 – with the huge number of people working from home – has intensified the pressure on the optical networks. Also, features such as the financial cost of the system elements, latency, dynamic reconfigurability, and energy consumption gain progressively more importance for the new generation of access and metro networks. The Doctorate Network NESTOR will answer the How? When? and Where? coherent optical transceiver will be deployed in metroaggregation optical networks to meet the demand for new cost-efficient solutions. NESTOR will also address the Who? by providing advanced training to 10 Fellows - from a new generation of engineers - with PhD projects significantly expanding the flexibility and capacity of access/metro networks. NESTOR harnesses the complementary expertise of the top academic groups (Aston, PoliTO, UPC, SSSA, and TU/e) and core telecom industry (Infinera, BT, Orange, SM-Optics, VPI and Ericsson). NESTOR will provide Fellows with a uniquely broad education ranging from recent advances in ML&AI to real-world telecom engineering, which will enable them to design and implement high-capacity access and metro networks.

One major goal in this project is to develop an analytical formulation,as well as a stochastic Monte-Carlo (MC) simulator, that allow us to study in a rigorous way the impact of in-band crosstalk, both incoherent and coherent, originated in CDC ROADMs in the performance of flexible grid networks, considering 16-QAM and 64-QAM 400 Gbps signals.On a network-side perspective, the emergence of modulation formats with higher-order constellations and, consequently, with stricter performance margins has increased the importance of physical impairment awareness in the network planning process. Thus, it is essential to incorporate the effects of in-band crosstalk, along with other effects, in an impairment-aware routing and spectrum assignment (RSA) framework. This framework should be able to efficiently provision paths and spectrum for superchannels based on M-QAM carriers in a CDC-ROADM network, while using the physical model as a performance validation tool for candidate optical paths

This project aims at developing and analysing models for the statistical characterisation of ICXT in MCFs, proposing techniques for mitigating those effects in MCF-based networks, and using those achievements in the development of ICXT-aware algorithms for routing, spectrum and core assignment (RSCA) in MCF-based elastic optical networks (EONs). The project focuses on the theoretical and simulation studies of the statistical characteristics of ICXT in MCF and techniques for mitigating its impact on MCF-based networks. These studies are complemented by the experimental demonstration of the main outcomes of the theoretical and simulation studies. The project takes advantage of the expertise on experimental work and system design on MCF technology of NICT (National Institute of Information and Communications Technology, from Japan) combined with the experience of IT (Optical Communications Group at Lisbon site of Instituto de Telecomunicações) on theoretical modelling and analysis of optical fibre telecommunication systems and networks.