Age of Information Under Frame Slotted ALOHA-Based Status Updating Protocol

TL;DR

This paper introduces a frame slotted ALOHA protocol for status updates in wireless networks, demonstrating through stochastic geometry analysis that it reduces average Age of Information and stabilizes age performance, especially in dense deployments.

Contribution

It develops an analytical framework for FSA-based status updating, showing its advantages over traditional slotted ALOHA in terms of AoI reduction and stability in Poisson networks.

Findings

FSA significantly decreases average AoI in dense networks.

FSA stabilizes AoI by reducing variance.

Converting slotted ALOHA to FSA always reduces average AoI.

Abstract

We propose a frame slotted ALOHA (FSA)-based protocol for a random access network where sources transmit status updates to their intended destinations. We evaluate the effect of such a protocol on the network's timeliness performance using the Age of Information (AoI) metric. Specifically, we leverage tools from stochastic geometry to model the spatial positions of the source-destination pairs and capture the entanglement amongst the nodes' spatial-temporal attributes through the interference they caused to each other. We derive analytical expressions for the average and variance of AoI over a typical transmission link in Poisson bipolar and cellular networks, respectively. Our analysis shows that in densely deployed networks, the FSA-based status updating protocol can significantly decrease the average AoI and in addition, stabilizes the age performance by substantially reducing the variance of AoI. Furthermore, under the same updating frequency, converting a slotted ALOHA protocol into an FSA-based one always leads to a reduction in the average AoI. Moreover, implementing FSA in conjunction with power control can further benefit the AoI performance, although the particular values of framesize and power control factor must be adequately tuned to achieve the optimal gain.