Energy-Efficient UAV-Assisted Cluster-Based Control Messages Relay System in IoT Networks

Due to their flexibility and ease of deployment, Unmanned Aerial Vehicles (UAVs) play pivotal roles in providing different services in modern wireless communication systems, especially in hazardous industrial areas where fixed base stations cannot be deployed. This paper addresses control messages relaying from the server to IoT devices through UAVs while strictly adhering to time and energy constraints. In contrast to the conventional method, we do not restrict the messages to be relayed only by the UAV, however, we propose allowing the control messages to be relayed by cluster heads (CHs) using more energy-efficient short-range communication. We first formulate the problem as a multi-objective optimization problem where we aim at deploying the minimum number of UAVs to relay control messages to all the IoT devices within their deadline requirement while minimizing the energy consumption of the IoT devices. We decide on the CHs selection, UAV deployment, IoT-to-UAV, and IoT-to-CH associations. We then propose an energy-efficient cluster-based approach to provide fast and efficient solutions in real-time IoT networks. Simulation results demonstrate the efficiency of the proposed approach and the significance of adopting cluster-based methods in relay systems.