Optimizing Peak Age of Information in Mobile Edge Computing

Recently, information freshness in real-time monitoring systems has received increasing attention. Age of Information (AoI) has emerged as a metric for measuring the information freshness. In many applications, the information embedded in an update packet needs to be computed before delivering to a destination. Mobile edge computing (MEC) can efficiently accomplish the computing process. In the MEC system, transmission process and computation process are coupled together, jointly affecting freshness. In this paper, we consider minimizing the average peak AoI (PAoI) in an MEC system, where each update is received and computed by an edge server before delivering to the destination. We consider the generate-at-will source model and study when to generate a new update. We prove that the fixed threshold policy is optimal for arbitrary transmission time and computation time distributions. Our numerical simulation results not only validate the theoretical findings, but also demonstrate the behaviors of the average PAoI versus the mean transmission time and the mean computation time.