Age of information with packet management

Abstract

We consider a system in which random status updates arrive at a source node, and should be transmitted through a wireless network to the intended destination node. The status updates are samples of a random process, transmitted as packets, containing the time stamp to identify the moment the sample was generated. The time it takes to successfully transmit a packet to the destination is modeled as an exponentially distributed service time. The status update age at the receiver is the time elapsed since the last received update was generated. In this paper, we analyze the age in the case that the source node has the capability to manage the arriving samples and decide which packets will be transmitted to the destination. In addition to the average age, we investigate the average of a new metric, called peak age, which provides information about the maximum value of the Age, achieved immediately before receiving an update.

Optimal Transmission Policies for Energy Harvesting Age of Information Systems with Battery Recovery

“…We are interested in two particular performance metrics: i) the probability of the AoI hitting a predetermined upperbound, denoted by A max , and ii) the average AoI. Influenced by the term peak-age violation probability introduced in [21], the first performance metric is referred to as the peak-age hitting probability and is used to model the case where the information becomes useless (or less relevant to the system) after its age reaches A max . This is in fact the case in several possible application areas of AoI; for instance, proximity sensors, or time-correlated data used for online learning with small time-windows.…”

Closed-Form Expression for the Average Age of Information in a Multi-Source M/G/1 Queueing Model

“…The average AoI for an M/M/1 last-come first-served (LCFS) queueing model with preemption was analyzed in [8]. In [11], the authors proposed peak AoI as an alternative metric to evaluate the information freshness. The average AoI and average peak AoI for different packet management policies in an M/M/1 queueing model were derived in [12].…”

“…The two most commonly used metrics for evaluating the AoI of a source at the destination are the average AoI and average peak AoI [5], [10], [11]. Next, we introduce these two metrics for the considered system model.…”

LUPMAC: A cross-layer MAC technique to improve the age of information over dense WLANs

“…In [2], [9], [11]- [13] the authors study the AoI in different simple queuing systems with multiple classes of service, modeling the channel as a single server. For example, in [2] the authors derive a lower bound for the AoI given any service distribution in a simple queuing system with only one server.…”

“…The AoI will continue to have this characteristic sawtooth behaviour, and it is possible to reconstruct its curve by interpolating between the various samples when packets are received. Then it is possible to reconstruct various metrics; for example, it is possible to reconstruct the average AoI by calculating the integral over time of the curve as a sum of trapezoids and dividing over the elapsed time [11].…”