L.C. Souza, A.C. Sodré Jr.
Inatel - Instituto Nacional de Telecomunicações,
Keywords: 6G, fiber-optics, PoF, remote powering, RoF
Summary:We propose a novel approach for energy transmission in beyond fifth-generation (B5G) networks using the power-over-fiber (PoF) technique, which could be integrated with the next-generation centralized radio access network (C-RAN) architecture. In this context, a radio- and power-over-fiber (RPoF) system takes place in order to enable a remotely optically powered fronthaul. The proposed PoF system employs three main components aiming to transport electrical power to remote locations: a high-power source responsible for generating high-power light; an optical fiber as the light transmission medium; a photovoltaic power converter (PPC), which performs the optical-to-electrical (O/E) conversion. In order to enable the simultaneous data and power transmission, two scenarios could be implemented: the shared scenario, in which a single optical fiber is used for both transmissions and the dedicated scenario, in which data and high-power signals are individually transmitted through dedicated fibers. The primary advantage of the shared scenario is the weight and cost reduction due to the use of a single optical fiber and the possibility of multiplexing the optical power into existing single-mode fibers (SMFs) available at the current communication network architectures. On the other hand, in the dedicated scenario, it is possible to employ a single SMF for data transmission and several multimode fibers (MMFs) for power transmission, all bundled in a hybrid optical fiber cable, achieving higher electrical power. Other types of optical fiber could also be used, such as double-clad fibers (DCFs), multi-core fibers (MCFs), and photonic crystal fibers (PCFs). Regarding the data transmission, the radio-over-fiber (RoF) technique is employed, which aims to transmit multiple radio frequency (RF) signals modulated onto optical carriers over low-loss optical fibers. In a C-RAN architecture, the baseband unit (BBU) processing hardware is moved from the base stations (BSs) to a common central location, known as central office (CO), which is connected to a large number of BSs by means of optical fiber links, known as fronthaul. In addition, an optical backhaul link connects the 5G network core to the CO. Therefore, both RoF and PoF transmitters are placed in the CO, enabling simultaneous data and power transmission in a shared or dedicated scenario, giving rise to an RPoF system. A hybrid Fiber/Wireless (FiWi) system is also proposed for taking advantage of both optical and wireless communications in a unique technological solution. Wireless technology is used to extend the reach of the fiber optic network and provide connectivity to mobile devices. The combination of fiber optic and wireless technologies in B5G systems makes it possible to deliver faster and more reliable connectivity with lower latency and higher capacity than previous generations of mobile networks. In conclusion, the proposed RPoF system holds great potential for enabling new applications and services that were not feasible before, paving the way for the next era of mobile networks.