Feasibility of Standalone TDoA-based Localization Using LoRaWAN

Abstract

The growing need for localization has created an array of alternative approaches to GNSS, based on Wi-Fi, Bluetooth, Ultra-Wideband, etc. Long Range Wide Area Network (LoRaWAN) is one such technology that has garnered tremendous attention due to its low power and long-range capabilities. Many attempts to achieve localization using LoRaWAN have been made till now, based on a variety of techniques such as Angle of Arrival (AoA), Time Difference of Arrival (TDoA), Received Signal Strength Index (RSSI). In this paper, we present a novel, standalone localization approach by developing a collaborative, TDoA-based methodology using LoRaWAN. The server determines the target node location by means of TDoA measurements from the target node to the gateways. The introduction of an additional stationary node allows the synchronization of the gateways without utilizing GNSS, either inbuilt or external. The cooperation between target node, synchronization node and server, is the innovative feature which makes this approach attractive for GNSS-free localization. Further, we explore the effects of timing resolution, time-on-air, and duty cycle constraints on the localization error. Finally, the distribution of error in a triangle of gateways situated approximately 8.6 kilometers apart is simulated in ideal Line of Sight (LoS) conditions, showing the maximum error to be around 23 meters.

Design of a Multi-Standard UWB-LoRa Antenna Structure and Transceiver Board for High-Accuracy and Long-Range Localization Applications

“…Previous research has realized localization attempts via LoRa technology, mostly using the Time Difference of Arrival (TDoA) method [7,15,16], which requires at least three gateways to infer the location of the object. For example, in [16], a number of sets of messages sent via the target sensor were used to calculate the TDoAs of these messages and perform location estimation at the gateway level, the authors assessed the efficiency of the performance of the localization and the results indicated that the localization error was greatly affected by the noise of the received timestamps at the base stations.…”

“…Furthermore, LoRaWAN networks have a high capacity and can handle millions of messages from thousands of gateways. However, despite these advantages, this technology is still not suitable for gateways to locate mobile sensors precisely and as often as is necessary [7]. Indeed, to ensure the low consumption of power, LoRa sensors send data with low packet rate [8,9], that is, typically one or two packets are sent per day.…”