An Age of Information Characterization of Frameless ALOHA

TL;DR

This paper characterizes the peak age of information in frameless ALOHA, revealing how protocol parameters affect AoI and showing that maximizing throughput can degrade AoI performance.

Contribution

It provides an exact Markovian analysis of AoI in frameless ALOHA considering variable contention durations, which was not addressed in prior work.

Findings

Maximum contention period length impacts average peak AoI.

Maximizing throughput may lead to AoI degradation.

The analysis offers insights into protocol parameter optimization.

Abstract

We provide a characterization of the peak age of information (AoI) achievable in a random-access system operating according to the frameless ALOHA protocol. Differently from previous studies, our analysis accounts for the fact that the number of terminals contending the channel may vary over time, as a function of the duration of the previous contention period. The exact characterization of the AoI provided in this paper, which is based on a Markovian analysis, reveals the impact of some key protocol parameters such as the maximum length of the contention period, on the average peak AoI. Specifically, we show that setting this parameter so as to maximize the throughput may result in an AoI degradation.