Freshness-in-air: An AoI-inspired UAV-assisted wireless sensor networks

The Age-of-Information (AoI) metric has emerged as a performance measurement metric for evaluating time-sensitive wireless communications systems. Maintaining the freshness and reliability of data is critical in time-critical wireless networks, where outdated information can have significant consequences. Moreover, short packet transmissions are used in wireless sensor networks (WSNs) to maintain energy efficiency and low latency. This paper proposes a theoretical model that utilizes the AoI metric and finite block length information theory to estimate information freshness in an unmanned aerial vehicle (UAV)-assisted WSN. This network includes multiple sensing nodes and relies on short-packet communication for transmission. In this paper, closed-form expressions for average AoI (AAoI) and the block error rate are derived. Furthermore, the optimal altitude and block length that ensures the freshness of received information at the destination is determined. The results of the analysis provide valuable insights into the performance characteristics of UAV-assisted WSNs and have important implications for the design and optimization of such systems.