Investigation of Outage Probability and AP Placement for Mobile Users in Indoor VLC System Design

Providing optical wireless data access with the visible spectrum is a commercial reality. Products are available for point-to-point or point-to-multipoint solutions. However, there remain many important questions about how to successfully achieve "dual-use" systems in which both lighting and communications functions are realized. In particular, the necessary placement of lights for lighting and the characteristic of light signals to be out-of-view creates trade-offs especially when mobile devices can change their position, height, and orientation requiring cooperation with neighboring access points (APs). In this paper, we investigate outage probability for Visible Light Communication (VLC) links in a system in which these dimensions are varied. We propose a probabilistic model characterizing where to deploy indoor VLC access points considering the impact of handover delay and user velocity. Our model demonstrates the trade-offs that lie within this problem and we also provide a closed form upper bound on outage probability that guarantees outage-free regions for devices attempting handover. The model is used to demonstrate the impact of different VLC access point cell separations and to show how user device velocity impacts outage probability.