Hybrid RF/VLC Systems: A Comprehensive Survey on Network Topologies, Performance Analyses, Applications, and Future Directions

Abstract

Wireless communications refer to data transmissions in unguided propagation media through the use of wireless carriers such as radio frequency (RF) and visible light (VL) waves. The rising demand for high data rates, especially, in indoor scenarios, overloads conventional RF technologies. Therefore, technologies such as millimeter waves (mmWave) and cognitive radios have been adopted as possible solutions to overcome the spectrum scarcity and capacity limitations of the conventional RF systems. In parallel, visible light communication (VLC) has been proposed as an alternative solution, where a light source is used for both illumination and data transmission. In comparison to RF links, VLC links present a very high bandwidth that allows much higher data rates. VLC exhibits also immunity to interference from electromagnetic sources, has unlicensed channels, is a very low power consumption system, and has no health hazard. VLC is appealing for a wide range of applications including reliable communications with low latency such as vehicle safety communication. Despite the major advantages of VLC technology and a variety of its applications, its use has been hampered by its cons such as its dependence on a line of sight connectivity. Recently, hybrid RF/VLC systems were proposed to take advantage of the high capacity of VLC links and better connectivity of RF links. Thus, hybrid RF/VLC systems are envisioned as a key enabler to improve the user rates and mobility on the one hand and to optimize the capacity, interference and power consumption of the overall network on the other hand. This paper seeks to provide a detailed survey of hybrid RF/VLC systems. This paper represents an overview of the current developments in the hybrid RF/VLC systems, their benefits and limitations for both newcomers and expert researchers. INDEX TERMS Radio frequency (RF), visible light communication (VLC), hybrid RF/VLC, wireless fidelity (Wi-Fi), hybrid networks, hybrid RF/VLC environments.

Semantic Modeling of a VLC-Enabled Task Automation Platform for Smart Offices

“…This makes it necessary to resort to new communication technologies. One of the technologies that has gained much popularity in recent years is VLC [13]. VLC has emerged as an alternative solution, in which a light source is used simultaneously for lighting and data transmission.…”

“…The obtained results of the conducted experiments confirm the improvement in the energy consumption of the proposed system. Moreover, many studies have been conducted on VLC to improve its functionality [13,44]. However, the use of VLC for providing IoT services has not been extensively studied [14].…”

“…Nevertheless, these technologies present some drawbacks, such as Electromagnetic Interference (EMI), a limited frequency spectrum, and, in some cases, a lower data rate [5]. These problems have pushed the investigation of new wireless communication technologies, such as Visible Light Communication (VLC) [13]. VLC uses the existing light in an environment (e.g., Light Emitting Diode (LED) lights) for transmitting data, exploiting the bandwidth of visible light, which is almost ten times wider and completely different from that of conventional wireless access technologies [14].…”

Novel Path Counting-Based Method for Fractal Dimension Estimation of the Ultra-Dense Networks

“…In such cases, it is necessary to represent the structure of the network, at both the physical and logical levels, which would allow to evaluating the network properties. The properties of typical structures used to build traditional communication networks, e.g., star, bus, and tree topologies, are quite clear and well-known [19]. However, with a large number of nodes, such structures are used together, which represents a challenge in determining the network properties.…”

Secure Precoding and User Association for Multiuser Hybrid RF/VLC Systems

“…All the numerical results can be reproduced using the MATLAB code and data files available at: https://github.com/isabella-gomes/Data-JPUA namely, strong dependence on line-of-sight (LoS), small coverage area, instability of the link quality, and interference of other sources of light [4]. In this sense, by considering the capability of supporting high mobility and the superior performance in non-LoS scenarios offered by RF systems, makes it a natural step forward to combine both technologies to obtain the benefits of both, thus leading to remarkable gains in terms of system connectivity and throughput [5].…”