Internet of Underground Things ESP8266 WiFi Coverage Study

[EN] The Internet of Underground Things (IoUT) is a novel concept regarding Internet of Things (IoT). It could have countless applications, particularly in agriculture as buried devices do not interfere with the machinery. Furthermore, wireless communication among buried and above ground devices would allow a significant cost reduction as wires would not need to be deployed and wires would not be destroyed by machinery or impede the correct performance of the activities performed by the workers of the field. In this paper, we perform a WiFi coverage study of ESP8266 nodes placed both underground and above ground so as to assess the current lack of knowledge in IoUT and the performance of low-cost controller boards for IoUT applications. Tests were performed with ESP8266 nodes buried at depths of 10 cm, 20 cm, 30 cm and 40 cm in a field located in an area of citrus fields. A node programmed as an AP (Access Point) was placed at several distances at a height of 50 cm. Results showed that the coverage was better for the node buried at a depth of 20 cm.