Exploiting Blockage in VLC Networks Through User Rotations

Visible Light Communication (VLC) has attracted significant attention over the past decade. Although numerous research studies have been performed to improve the data rate of VLC links, an important fact has been largely neglected:
human bodies that host VLC receivers could block their Line-of-Sight (LOS) downlinks
, and thus, degrade the system performance greatly. In this paper, we propose a system that can significantly improve the robustness for VLC networks by avoiding performance degradation due to blockage. A novel user-in-the-loop mechanism is designed in which users (including human bodies and VLC receivers) are guided by the network to rotate themselves to improve the system performance and the individual user experience. Both our simulation and experimental results demonstrate that the proposed user-in-the-loop mechanism can improve the system throughput and user fairness on average by 48% and 14%, respectively. For individual users, the average gain in throughput can reach up to 135%. Furthermore, to make the system more practical, two lightweight heuristics are designed and implemented which can achieve similar gains while reducing the computational complexity by 99%.