# Age of Actuation in a Wireless Power Transfer System

## TL;DR

This paper introduces the Age of Actuation (AoA) metric in wireless power transfer systems, analyzing its behavior and advantages over the traditional Age of Information (AoI) for timely actuation based on status updates.

## Contribution

It proposes and analytically characterizes the new AoA metric, demonstrating its generality and relevance for goal-oriented communication systems with energy transfer.

## Key findings

- AoA is more general than AoI for actuation timing
- Analytical expressions for AoA are derived
- Numerical evaluations confirm the benefits of AoA

## Abstract

In this paper, we study a model relevant to semantics-aware goal-oriented communications. More specifically, observations from an external process are transmitted through status updates to a battery-powered receiver. From these updates, the receiver is informed about the status of the process and if there is sufficient energy, uses them to perform an actuation to achieve a goal. We consider a wireless power transfer model where the destination receives energy from a dedicated power transmitter and occasionally from the data transmitter. We provide the analysis for the Age of Information (AoI). Furthermore, we propose a new metric, namely the \textit{Age of Actuation (AoA) which is relevant when the receiver utilizes the status updates to perform actions in a timely manner}. We analytically characterize the AoA and we show that is a more general metric than AoI. We provide the optimization problems for both metrics, and we numerically evaluate our analytical results.