Efficient Wake-Up Strategy: UAV-Enabled Opportunistic Sensing in IoT Networks

This paper proposes an unmanned aerial vehicle (UAV)-enabled wake-up radio (WuR) and data collection strategy for an Internet of Things (IoT) network. The considered model involves employing UAVs to awaken IoT devices from an ultralow power sleep mode through the transmission of WuR signals. Diverging from traditional methods where all IoT devices engage in data collection post-wake-up, the proposed framework centers on a more streamlined strategy. In the system model, a single UAV continuously traverses a specific region without hovering for the sake of waking-up nearby IoT devices. Specifically, solely IoT devices identifying valuable or unusual information transmit data back to the UAV upon a successful wake-up, which we refer to as opportunistic sensing. Hence, for reliable communication, it becomes important to determine the optimal height and velocity of the UAV while traversing the IoT region so as to maximize the probability that the UAV successfully wakes-up enough IoT devices to cover the field, followed by successful data collection of valuable sensed information. To this end, the paper proposes a low-complexity, fast in convergence, simple to implement efficient method to solve the non-convex optimization problem. The proposed algorithm relies on multidimensional bisection method, and is specifically tailored to determine the UAV's velocity and height, along with optimizing the device density. The numerical results in the paper validate the superior performance of the proposed algorithm when compared to conventional baselines.