Lisbon is set to become a global hub for fiber optic innovation with the deployment of the world’s largest multicore fiber (MCF) terrestrial testbed. The pioneering initiative, known as the LUMIRing project (Lisbon Underground Multicore Fiber Ring), is a landmark step in next-generation communications infrastructure.
The testbed is being installed along the Yellow Line of the Lisbon Metro, creating a rare opportunity to test fiber optics in a live underground environment.
The tests will be conducted inside the tunnels of an operating metro line, exposing the cables to vibrations, temperature fluctuations, humidity, noise, and constant movement. This setup offers unmatched conditions to validate new optical cables and multicore fibre technologies in real-world scenarios, at a scale not found anywhere else in the world.
Monitoring will be centralized at the IT-Iscte Optical Communications Laboratory, which serves as both the entry point of the network and the hub for data collection. The multicore fiber cable features 144 strands with 74 multicore fibers, which, when interconnected, can span 728 kilometers, the equivalent of 28 full loops of the 26 km metro ring between Odivelas and Largo do Rato.
Within the next few months, the testbed will become fully operational and open to the international scientific community. To date, this represents the longest deployed terrestrial multicore fiber ring anywhere in the world.
By enabling companies and researchers to test new components, equipment, and applications in a real-world environment, the platform promises to accelerate development cycles and strengthen Lisbon’s role in the global innovation ecosystem.
The project is led by Adolfo Cartaxo, together with Tiago Alves and João Rebola, researchers in the Optical Communication Systems and Networking group at the Instituto de Telecomunicações (IT), branch of Iscte.
Developed in close partnership with Metropolitano de Lisboa, whose support is crucial to the success of the project, and supported by Heraeus Covantics, a German leader in high-purity quartz products for fiber optic manufacturing, LUMIRing also counts on key contributions from Telcabo, responsible for installing the optical fiber cable, and Tratos Cavi, an Italian group manufacturing the optical fibre cable.
Valued at €2.3 million- including €588,000 in European funding from the Lisbon 2030 Programme (financed by CCDR-LVT) and additional resources from Iscte - the project represents a major investment in Europe’s digital future.
The project's link: