Enabling Multi-Node Underwater Image Transmission with a LoRa Mesh Network

Abstract

Underwater communication is essential for applications such as marine research, environmental monitoring, and infrastructure inspection. However, traditional methods like acoustic, Radio Frequency signals, and optical signaling are often expensive, power-intensive, and can negatively impact marine life–particularly due to water’s permeability. To address these challenges, this study details a low-cost, low-power underwater communication system built on a multi-hop LoRa mesh network. The system utilizes Seeeduino LoRaWAN boards with RHF76-052AM modules, submerged in polycarbonate containers and powered by Lithium Polymer batteries. A mesh topology on the application layer routes byte-converted data packets across multiple submerged nodes, which are then reassembled at the final receiver, with upwards of 3 nodes. System performance was validated in a controlled underwater environment by testing packet transmission across multiple Spreading Factors (SF7-SF12), with signal quality and link strength quantified using the Received Signal Strength Indicator (RSSI) metric. These results confirm the viability of LoRa for multi-node underwater networks, establishing it as an effective, scalable, and eco-friendly alternative for low-bandwidth data transmission in aquatic environments.