LoRaWAN performances for underground to aboveground data transmission

The aim of this paper is to discuss the usability of the LoRa transmission technology together with the LoRaWAN protocol for underground monitoring activities. In particular, the paper focuses on the transmission performances in different conditions (i.e., different antennas, different Spreading Factors and different burial depths), for an underground-to-aboveground (UG2AG) communication. The theoretical achievable value for RSSI is calculated and is then compared with the real values achieved by means of field measurements. While the obtained results on field are slightly worse than the theoretical ones, due to additional unpredictable losses and attenuation, their trends are consistent with the estimated ones and demonstrate the feasibility of UG2AG LoRaWAN transmission channels. Such a kind of system may be crucial in several application scenarios, like for example environmental monitoring or smart agriculture, where the real-time, remote acquisition of underground parameters at different depths is required