Age of Information for Constrained Scheduling with Imperfect Feedback

TL;DR

This paper develops scheduling algorithms for multi-user status update systems that account for imperfect feedback and transmission constraints, achieving near-optimal age of information performance.

Contribution

It introduces a novel AoI analysis under zero feedback and Bernoulli traffic, deriving bounds and designing policies with performance guarantees.

Findings

Derived a closed-form lower bound for AoI with zero feedback.

Proposed a rate splitting and modular arithmetic policy achieving the bound.

Developed a drift-plus-penalty policy with performance guarantees.

Abstract

This paper considers a downlink system where an access point sends the monitored status of multiple sources to multiple users. By jointly accounting for imperfect feedback and constrained transmission rate, which are key limited factors in practical systems, we aim to design scheduling algorithms to optimize the age of information (AoI) over the infinite time horizon. For zero feedback under the generate-at-will traffic, we derive a closed-form lower bound of achievable AoI, which, to the best of our knowledge, reflects the impact of zero feedback for the first time, and propose a policy that achieves this bound in many cases by jointly applying rate splitting and modular arithmetic. For zero feedback under the Bernoulli traffic, we develop a drift-plus-penalty (DPP) policy with a threshold structure based on the theory of Lyapunov optimization and provide a closed-form performance guarantee. Furthermore, we extend the design of this DPP policy to support general imperfect feedback without increasing the online computational complexity. Numerical results verify our theoretical analysis and the AoI advantage of the proposed policies over state-of-the-art policies.