A Novel Link Failure Detection and Switching Algorithm for Dissimilar Redundant UAV Communication

• Main Authors: Yan Han Lau, Marcelo H. Ang
• Format: Article
• Language: English
• Published: MDPI AG 2021-06-01
• Series: Drones
• Subjects: UAV; medicines drone delivery; long-range communication; beyond visual line of sight (BVLOS); networks; dissimilar redundancy
• Online Access: https://www.mdpi.com/2504-446X/5/2/48

Unmanned Aerial Vehicles (UAVs) used for humanitarian applications require simple, accessible and reliable components. For example, a communication system between UAV and the Ground Control Station (GCS) is essential in order to monitor UAV status; various communication protocols are available in the industry. Such systems must be simple for non-technical personnel (e.g., healthcare workers) to operate. In this study, a novel link failure detection and switching algorithm was proposed for a dissimilar redundant UAV communication system designed for long-range vaccine delivery in rural areas. The algorithm would ease the workload of the operators and address a research gap in the design of such algorithms. A two-layer design is proposed: A baseline layer using the heartbeat method, and optimisations to speed up local failure detection. To dynamically tune the heartbeat timeout for the algorithm’s baseline without intervention from ground operators, the modified Jacobson’s algorithm was used. Lab simulations found that the algorithm was generally accurate in converging to an optimal value, but has less satisfactory performance at poor or unpredictable connectivity, or when link switches get triggered frequently. Improvements have been suggested for the algorithm. This study contributes to ongoing research on ensuring reliable UAV communication for humanitarian purposes.