Implementation of a Hybrid FiWi System Using FSO, VLC and mm-Waves Toward 6G Applications

This letter presents an experimental investigation that integrates various technologies, such as fiber-wireless (FiWi), free-space optics (FSO), and visible light communication (VLC), as a network physical layer solution to meet the requirements for 5G and beyond scenarios. The implemented architecture is centered on the concept of a centralized radio access network (C-RAN), utilizing 20 km of optical fiber followed by an FSO link as the fronthaul of the network, with a focus on last-mile applications. In the access network, a 2-meters reach 5G New Radio (NR) mm-wave link operating at 39 GHz was simultaneously deployed with a VLC transmission utilizing quadrature amplitude modulation (M-QAM) at 550 MHz. The experimental results demonstrate a satisfactory coexistence among these technologies, achieving a total data throughput of 4.92 Gbit/s. The proposed architecture underwent evaluation based on the root mean square error vector magnitude (EVM (RMS)) requirements specified in the 3rd Generation Partnership Project (3GPP) Release 18.