Reconfigurable Intelligent Surfaces for Outdoor Visible Light Communications

The increasing dependence on light-emitting diode (LED)-based lighting is raising the interest in using visible light communication (VLC) to provide wireless coverage in outdoor scenarios, given its merits which include operating on huge unlicensed spectrum and minimizing the radio frequency (RF) interference. However, since line-of-sight (LOS) components dominate VLC signal reception, the performance of VLC systems is highly dependent on maintaining LOS and avoiding link blockages caused by user mobility. Interest in the utilization of reconfigurable intelligent surfaces (RISs) in VLC systems has been growing recently, as they offer solutions for improving the link robustness by pro-viding spatial diversity. This work discusses the use of RISs in outdoor VLC systems, highlighting use cases for the RIS-assisted VLC in the unmanned aerial vehicle networks, vehicle-to-everything applications, and streetlight-based communication systems. In addition, it evaluates using simulations the impact of considering RISs on the outdoor VLC system performance in terms of link outage, before discussing possible directions for future research.