Outdoor sports tracking by means of hybrid GPS-LoRaWAN localization

In this paper, we propose a hybrid LoRaWAN/GPS solution for the tracking of athletes performing outdoor sport activities. The combination of the two technologies has the main purpose of optimizing power consumption by limiting GPS usage and providing a continuous people tracking even in case of GPS-denied areas, for example when walking through woods and forests. In this case, GPS is replaced by LoRaWAN connectivity which, besides acting merely as a data transmission technology, thus sending the user's position to a remote server, is also used to estimate such position. To this aim, different localization techniques are evaluated, testing a simple technique based on preliminary area mapping and presenting a data fusion technique to improve the positioning accuracy. To demonstrate the feasibility of the proposed approach, a prototypical tracker was set up, integrating a GPS module with a LoRa transceiver. Then, field tests were performed correlating the positions along a pre-defined path, acquired by means of a GPS module, with the Received Signal Strength Indication (RSSI) values related to the LoRaWAN transmission. Acquired values suggest the usability of these parameters to estimate the user's position in case of lack of GPS coverage.