Analysis of LoRa Link Quality for Underwater Wireless Sensor Networks: A Semi-empirical Study

With increasing concerns in aquatic environment, modern and cost-effective real-time sensing and monitoring systems are in great demand. The LoRa technology provides a novel communication solution for underwater wireless sensor networks (UWSNs), especially for shallow water applications. However, the link characteristics of LoRa in underwater environment have not yet been comprehensively studied. This paper reports our experimental investigation of the link quality of three channels in UWSNs with the objective to evaluate the feasibility of deploying LoRa for the underwater wireless communications. The preliminary results reveal that the underwater-to-overwater (UW2OW) and overwater-to-underwater (OW2UW) channels exhibit highly symmetric performance at the same vertical position. However, the link quality for the underwater-to-underwater (UW2UW) channel varies with the depth when the horizontal inter-node distance (HID) is fixed. These field data can serve as a benchmark before deploying underwater sensor nodes for the LoRa-based WUSN s.