Joint Task Offloading and UAV Deployment for Collaborative HAP-UAV Systems

In emergency scenarios such as natural disasters, unmanned aerial vehicles (UAVs) are widely employed to provide communication and computation services when ground infrastructure fails. However, UAVs face limitations in resources. High Altitude Platforms (HAPs), operating in the stratosphere, offer a promising solution with their wide coverage and substantial payload capacity. This paper proposes a collaborative task offloading scheme that combines UAVs and HAPs to minimize task delays, considering task types and the mobility of ground devices, which are typically overlooked. We jointly optimize UAV deployment and task scheduling, modeling deployment as a maximum clique problem and task scheduling as a device-UAV matching problem solved by a stable matching algorithm. Numerical simulations demonstrate the effectiveness of the proposed solution.