Average AoI in Pinching Antenna-assisted WPCNs with Probabilistic LoS Blockage

TL;DR

This paper investigates the average age of information in a wireless powered IoT network with a pinching antenna, deriving formulas and optimizing antenna placement to improve update freshness under probabilistic LoS blockage.

Contribution

It provides a closed-form analysis of AoI in PA-assisted WPCNs and proposes an optimization method for antenna placement to minimize AoI.

Findings

Optimal PA position is closest to the IoT device.

PA-based systems outperform fixed-antenna systems.

Results extend to multi-IoT FDMA scenarios.

Abstract

This paper analyzes the age of information (AoI) for a pinching antenna (PA)-assisted wireless powered communication network (WPCN) with probabilistic line-of-sight (LoS) blockage. AoI is a key metric for evaluating the freshness of status updates in IoT networks, and its optimization is crucial for ensuring the performance of time-critical applications. To facilitate analysis and gain useful insights, we consider a representative scenario, where an IoT device harvests energy from a base station (BS) equipped with a PA and transmits data packets to it. The IoT device harvests energy via the PA until its capacitor is fully charged, then transmits status updates using all stored energy. We derive closed-form expressions for the average AoI by analyzing the capacitor charging time, transmission success probability, and inter-arrival time of successful updates. To minimize the average AoI, we formulate an optimization problem of PA position, and propose a one-dimensional search to solve it. The simulation results show that the optimal PA position is the one closest to the IoT device, and this conclusion can be extended to the multi-IoT devices frequency division multiple access (FDMA) scenario. The PA-based systems significantly outperform the conventional fixed-antenna systems.