Wireless Underground Sensor Network Path Loss Models for Durian Tree

In order to maintain plant growth and protect brackish water of durian tree, wireless underground sensor networks (WUSNs) are applied. In this study, path loss models were formulated based on the curve-fitting for LoRa WSN at the banana garden in Nakornchaisri district of Thailand. Additionally, there were deterministic large-scale models based on a measurement campaign at a frequency of 433 MHz. The path loss between the transmitter node and the receiver node was modeled and derived based on the received signal strength indicator (RSSI) measurements. We investigated how soil contents affected the path loss models especially sandy loam for durian planting. The results show that the proposed path loss model with topping attenuation factor (TAF) outperforms especially for underground-to-underground communication (UG2UG) comparing with conventional models.