Enabling Fiber-Wireless Technologies For Radio Communications In Millimeter-Wave and Terahertz-Wave Bands In IMT-2030 and Beyond

Radio communications in high-frequency bands are crucial for providing high-speed and low-latency services. Research efforts are being made worldwide; however, several bottlenecks still exist, such as high free-space loss, weak penetration, and limited coverage, making the deployment of high-frequency radio communications challenging. To attain sustainable development goals, cost-effective, high-speed, and energy-efficient communication infrastructure should be developed. Photonic technology and its convergence with radio counterparts are promising for high-frequency radio communications. In this paper, we present key fiber-wireless technologies, including a high-speed fiber-wireless bridge system for fixed wireless access and emergency communications, transparent relay and routing of radio signals for coverage extension, and simultaneous generation, transmission, and reception of multiple radio signals in different frequency bands, to overcome the bottlenecks. For each technology, we present the system concept and proof-of-concept demonstration. The achieved results reveal the potential of the proposed solutions and can pave the way for the deployment of radio access networks in the millimeterwave and terahertz-wave bands in IMT-2030 and beyond.