Interference and Spatial Throughput Characterization through Practical 3D Mapping in Dense Indoor IoT Scenarios

Ultra-dense Internet of Things (IoT) networks in the unlicensed bands are subject to significant interference due to their high deployment density and attacks from malicious users. The interference has a non-uniform distribution, when examined in 3D space which leads to the need of volumetric monitoring for precise estimation of spectrum utilization. This paper analyzes the indoor spectrum occupancy for two promising IoT standards - LoRa and WiFi, through 3D interference maps and spatial throughput (ST) analysis produced using an automated measurement tool. The system is implemented through software-defined radio (SDR) platforms. Fading impacts the interference distribution not only in a single plane but also in height. In addition, the experimental results show that the received interference power within an area (measured in m
²
) and a volume (in m
³
), and consequently the ST, vary dynamically. Thus, the worst-case interference rather the mean value, needs to be considered in realistic dense scenarios for beyond 5G IoT networks.