Outage and Rate Analysis for Industrial Internet of Things in Multitier Visible Light Communication Networks Inside Finite 3-D Space

In this article, downlink multitier visible light communication (VLC) networks in the Industrial Internet of Things (IIoT) are studied in terms of outage probability and achievable rate. The industrial VLC network is modeled as a multitier network in a finite space under limited receiver field of view (FOV), in which access points (APs) of each tier at their own height follow a Poisson point process (PPP) distribution. Random interference between different tiers in the multitier network and the boundary effects in a finite space lead to difficulties in analysis, so we propose a new stochastic geometric-based analytical framework to tackle this problem. Our analytical expressions precisely capture the impact of typical IIoT device's FOV and position in a finite space on the outage probability and average achievable rate. For a typical IIoT device which is far away from the boundary, the boundary effect is found to be negligible. Finally, the analytical results are verified by simulations. We observe that the changes in the FOV and the number of APs mainly affect interference and cell coverage, and further influence the network performance of multitier VLC networks. We also investigate how the other network parameters influence performance metrics, emphasizing that reasonable parameter settings can yield better VLC network performance.