Abstract:
The analysis of link characteristics is critical to the design of the wireless sensor network (WSN) protocol, but this design is typically established on a binary model that considers only two link states, connection and disconnection. Unreliable links in the transition area are ignored, yet these links have unstable communication performance and experience highly dynamic changes. If these links are not considered in the protocol design, problems will arise, such as high-power consumption of the WSN and long network delays. To address this issue, we designed a LoRa-based communication system. In a test, we studied the characteristics of unreliable links in both land and sea scenarios, and analyzed the influence of the LoRa physical-layer parameters on the communication performance. Specifically, we established relationship models of the link quality with the received signal strength indication and the signal-to-noise ratio for a large number of data tested on land and at sea. We also optimized the spread factor and bandwidth to improve the performance of unreliable links.