Information Freshness and Packet Drop Rate Interplay in a Two-User Multi-Access Channel

TL;DR

This paper studies the trade-off between information freshness and packet drop rate in a two-user multi-access channel, providing analytical insights into their interplay and validating results through simulations.

Contribution

It introduces a combined analysis of deadline-constrained delivery and information freshness in a two-user setup, deriving explicit expressions for throughput, drop probability, and AoI.

Findings

Lower AoI increases packet drop rate for user 1.

Analytical expressions accurately predict system performance.

Trade-off exists between information freshness and packet reliability.

Abstract

In this work, we combine the two notions of timely delivery of information in order to study their interplay; namely, deadline-constrained packet delivery due to latency constraints and freshness of information at the destination. More specifically, we consider a two-user multiple access setup with random access, in which user 1 is a wireless device with a queue and has external bursty traffic which is deadline-constrained, while user 2 monitors a sensor and transmits status updates to the destination. For this simple, yet meaningful setup, we provide analytical expressions for the throughput and drop probability of user 1, and an analytical expression for the average Age of Information (AoI) of user 2 monitoring the sensor. The relations reveal that there is a trade-off between the average AoI of user 2 and the drop rate of user 1: the lower the average AoI, the higher the drop rate, and vice versa. Simulations corroborate the validity of our theoretical results.