Utilizing Link Characterization for Improving the Performance of Aerial Wireless Sensor Networks

Characterization of communication links in Aerial Wireless Sensor Networks (AWSN) is of paramount importance for achieving acceptable network performance. Protocols based on an arbitrary link performance threshold may exhibit inconsistent behavior due to link behavior not considered during the design stage. It is thus necessary to account for factors that affect the link performance in real deployments. This paper details observations from an extensive set of experiments designed to characterize the behavior of communication links in AWSN. We employ the widely used TelosB sensor platform for these experiments. The experimental results highlight the fact that apart from the usual outdoor environmental factors affecting the link performance, two major contributors to the link degradation in AWSN are the antenna orientation, and the multi-path fading effect due to ground reflections. Based on these observations, we propose a Link Aware Protocol for AWSN (LAAWN) that takes into account the effect of these potential sources of performance degradation. This paper details the design and performance evaluation of our proposed LAAWN protocol. We evaluated the LAAWN protocol in two real-world use cases namely delay-tolerant and real-time AWSN. The simulation results show that on average, LAAWN improves the overall network performance by reducing the percentage of dropped packets from about 34% to less than 4% for an AWSN that requires real-time data transfer.