Underwater to above water LoRa transmission: Technical issues and preliminary tests

The aim of this paper is to discuss the usability of Long Range (LoRa) communication technology for the transmission of data collected under fresh water to a Gateway positioned outside water. The technical feasibility of the LoRa transmission channel is discussed from a theoretical point of view, focusing on the definition of the link budget for the proposed scenario. The operation of a prototypal LoRa sensor node is then tested in a real scenario, analyzing the performances according to the different Spreading Factors (SF). Actual data transmission is achieved at a depth of 30 cm, thus suggesting the usage of such a technology for real time monitoring applications in environments, like swimming pools, rivers or fish farms.