On The Age Of Information In Status Update Systems With Packet Management

TL;DR

This paper analyzes the age of information in a status update system with packet management, modeling the system with queuing theory and proposing new metrics to optimize information freshness.

Contribution

It introduces a queuing model for status updates with packet discarding and proposes the peak age metric to better evaluate information freshness.

Findings

Derived expressions for average age of information.

Proposed the peak age metric for maximum age analysis.

Demonstrated benefits of packet management in reducing age.

Abstract

We consider a communication system in which status updates arrive at a source node, and should be transmitted through a network to the intended destination node. The status updates are samples of a random process under observation, transmitted as packets, which also contain the time stamp to identify when the sample was generated. The age of the information available to the destination node is the time elapsed since the last received update was generated. In this paper, we model the source-destination link using queuing theory, and we assume that the time it takes to successfully transmit a packet to the destination is an exponentially distributed service time. We analyze the age of information in the case that the source node has the capability to manage the arriving samples, possibly discarding packets in order to avoid wasting network resources with the transmission of stale information. In addition to characterizing the average age, we propose a new metric, called peak age, which provides information about the maximum value of the age, achieved immediately before receiving an update.