At the 50th European Conference on Optical Communication (ECOC 2024), held from 22nd to 26th September, Professor Marco Ruffini, a CONNECT Principal Investigator and Professor at Trinity College Dublin, was invited to present his research on bandwidth-efficient fronthaul technology for Beyond 5G (B5G) networks. His talk, titled “Coexistence of Analogue Radio and Digital Coherent Transmission Over Access/Metro Networks for Bandwidth-Efficient Fronthaul Beyond 5G,” explored how different signal types can coexist within the same fibre network infrastructure.
This research is part of the ECO-eNET project, which focuses on foundational research into emerging transmission technologies for 6G networks. The ECO-eNET project aims to create a new confluent edge network that integrates optical and radio transport to scale network efficiency and capacity. The project combines photonic radio, fixed wireless, and free space optical transmission to create an edge mesh network, with protocols that unify radio intelligent controllers and transport software-defined networking to deliver high-capacity signals over fibre and wireless links.
As part of this project, Professor Ruffini’s research demonstrated the coexistence of Analogue Radio-over-Fibre (RoF) and Digital Coherent Optical signals on converged metro and Passive Optical Networks (PON). By using RF generation through optical heterodyning, his team was able to transmit 5.8 Gb/s millimetre-wave (mmWave) signals alongside 400 Gb/s coherent optical signals, all within the bandwidth of a Reconfigurable Optical Add-Drop Multiplexer (ROADM) channel.
Wide coverage and high-speed performance for 6G mobile services hinge on achieving cost-effective connectivity between central offices and remote units (RUs). To support this objective, three key advancements have been demonstrated in this work. The first advancement centers on generating analog Radio over Fiber (ARoF) signals and a secondary carrier remotely, which are subsequently combined at the receiver via optical heterodyning, employing a simplified envelope detector to reconstruct the RF signal. The second improvement emphasizes the seamless transmission of these signals across a converged, fully transparent metro and access network, ensuring efficient data flow across the network layers. Lastly, the integration of ARoF signals into the Reconfigurable Optical Add-Drop Multiplexer (ROADM) channel of an existing Digital Coherent Optical (DCO) signal has been achieved, with little to no increase in fiber bandwidth usage. These advancements mark significant progress toward fulfilling the connectivity needs of future 6G networks.
Professor Ruffini’s presentation at ECOC 2024 highlights his contributions to this important research, providing valuable insights into how current networks can evolve to meet the demands of next-generation technologies.