On the Peak AoI of UAV-assisted IoT Networks: A Stochastic Geometry Approach

TL;DR

This paper analyzes the peak age of information in UAV-assisted IoT networks using stochastic geometry, revealing how device clustering and resource splitting impact information freshness.

Contribution

It introduces a stochastic geometry-based framework to evaluate PAoI in UAV-assisted IoT networks with resource sharing and clustering.

Findings

Increasing correlated devices can improve PAoI at low data rates.

Time-splitting causes higher interference but has limited impact on PAoI.

Shorter transmission distances in clustered areas enhance communication quality.

Abstract

In this paper, we analyze the peak age of information (PAoI) in UAV-assisted internet of thing (IoT) networks, in which the locations of IoT devices are modeled by a Mat\'{e}rn cluster process (MCP) and UAVs are deployed at the cluster centers to collect the status updates from the devices. Specifically, we consider that IoT devices can either monitor the same physical process or different physical processes and UAVs split their resources, time or bandwidth, to serve the devices to avoid inter-cluster interference. Using tools from stochastic geometry, we are able to compute the mean activity probability of IoT devices and the conditional success probability of an individual device. We then use tools from queuing theory to compute the PAoI under two load models and two scenarios for devices, respectively. Our numerical results show interesting system insights. We first show that for a low data arrival rate, increasing the number of correlated devices can improve the PAoI for both load models. Next, we show that even though the time-splitting technique causes higher interference, it has a limited impact on the mean PAoI, and the mean PAoI benefits more from the time-splitting technique. This is because of the nature of UAV communication, especially at places where devices (users) are spatially-clustered: shorter transmission distances and better communication channels, comparing the links established by the cluster UAV and serving devices (users) to links established by interferers.