UAV-Based Relay System for IoT Networks With Strict Reliability and Latency Requirements

In hazardous Internet of Things (IoT) environments with the unlinked control server, unmanned aerial vehicles (UAVs) swarm is leveraged to relay commands with strict reliability and latency requirements. This letter optimizes the number of UAVs and their positions and decides on the IoT-to-UAV associations and radio resource allocation while allowing IoT association with multiple UAVs using orthogonal frequency division multiple access. The problem is formulated as a mixed-integer nonlinear program and linearization is proposed. A clustering-based approach providing low-complexity sub-optimal solutions is presented. Simulation results demonstrate the significance of multiple paths utilization in achieving high reliability with minimal resources.