Fresh Data Collection for UAV-Assisted IoT Based on Aerial Collaborative Relay

Low-latency data delivery in sparse deployment scenarios is a challenging problem. The emergence of unmanned aerial vehicle (UAV)-assisted Internet of Things (IoT) provides a viable path to solve this problem. In the existing UAV-assisted IoT system, UAVs usually complete data collection through task collaboration, but there is no data relay transmission between UAVs. The main bottleneck of this mode is that the UAV responsible for the edge region of the ground sensor network needs to fly a long distance to send data to the base station, which will seriously affect the age of information (AoI) performance of the system. Therefore, in this work, we design a UAV-assisted IoT data collection mechanism based on an aerial collaborative relay and propose an AoI-sensitive data collection (ADC) scheme. In this scheme, we design a generalized AoI expectation (GAE) function to achieve iterative optimization of UAV flight paths. Extensive experimental results have shown that the proposed data collection scheme requires less deployment preparation time while obtaining better AoI performance than existing data collection schemes.