Employing Intelligent Aerial Data Aggregators for the Internet of Things: Challenges and Solutions

Internet-of-Things (IoT) devices equipped with temperature and humidity sensors and cameras are increasingly deployed to monitor remote and human-unfriendly areas (e.g., farmlands, forests, rural highways, and electricity infrastructures). Aerial data aggregators such as autonomous drones provide a promising solution for collecting sensory data of IoT devices in human-unfriendly environments, enhancing network scalability and connectivity. The flexibility of a drone and favorable line-of-sight connection between the drone and IoT devices can be exploited to improve data reception at the drone. This article first discusses challenges of the drone-assisted data aggregation in IoT networks, such as incomplete network knowledge at the drone, limited buffers of the IoT devices, and lossy wireless channels. Next, we investigate the feasibility of onboard deep-reinforcement-learning-based solutions to allow a drone to learn its cruise control and data collection schedule online. For deep reinforcement learning in a continuous operation domain, deep deterministic policy gradient (DDPG) is suitable to deliver effective joint cruise control and communication decision, using its outdated knowledge of the IoT devices and network states. A case study shows that the DDPG-based framework can take advantage of the continuous actions to substantially outperform existing non-learning-based alternatives.