On the Importance of Dynamic FOV Receivers for Dense Indoor Optical Wireless Networks

The increased density of fixed and mobile wireless devices in indoor settings introduces novel challenges related to the deployment of multi-user access points (APs). Network “densification” includes the adoption of many replicated APs in order to meet aggregate demands divided up across the system. However, the close proximity of APs can create interference. Directional optical channels have been proposed to improve signal isolation between adjacent APs.In this paper we explore the use of controlled dynamic field of view (D-FOV) as a way to isolate resources. Specifically, we study (a) system resource reuse, (b) receiver scope, and (c) interference mitigation. Analysis and simulation show performance gains in overall system performance, and user SNR/SINR. We also show that D-FOV enables improved resource reuse, making full use of spatial diversity while mitigating interference effects on user devices. We validate results using data collected in a network and lighting testbed implementation. Results of the experimentation show good correspondence to the analysis and reveal the associated trade-offs that occur when moving between the span of narrow to wide FOVs.