A Tractable Analysis of Positioning Fundamentals in Low-Power Wide Area Internet of Things

This paper studies positioning fundamentals in low-power wide area (LPWA) Internet of Things (IoT), where those devices with locations known operate as anchors. A tractable model is developed to analyze localizability of target devices. A random scenario is investigated, where anchors are randomly distributed. The model first studies the positioning of a target which can be anywhere. Then, from the point of view of system level, target randomness is further considered so that the study can be conducted over the whole network area. The model has no limitations on area shape but can consider any arbitrary polygonal one. It incorporates the ability for participating anchors to coordinate transmissions, and the interference effect on positioning is theoretically investigated. The model is then extensively validated in comparison with simulations, and the effects of a set of parameter settings are investigated. Compared to the existing positioning performance studies targeting deterministic scenarios, the proposed model considers location randomness through distance distributions using a powerful probabilistic distance-based tool from geometric probability. The model considers both interference and system-related parameter settings, investigating anchor transmission coordination and traffic load, which reveals how participating anchors in general impact positioning performance in LPWA IoT.