Age of Information Optimization in Distributed Sensor Networks with Half-Duplex Channels

TL;DR

This paper analyzes and optimizes the Age of Information in distributed sensor networks with half-duplex channels using an ALOHA-based protocol, deriving optimal policies for various network topologies.

Contribution

It provides closed-form expressions and optimal transmission policies for AoI minimization in distributed networks with different topologies.

Findings

Optimal transmission probabilities improve information freshness.

Closed-form solutions for d-regular topologies.

Effective adaptive policies for star topologies.

Abstract

Motivated by cooperative distributed networks in which users dynamically alternate between transmit and receive modes under half-duplex constraints, this paper studies the Age of Information (AoI) in a distributed multi-user network using an ALOHA-based protocol. We derive closed-form expressions for the average AoI and formulate an optimization problem over transmission probabilities. After proving the convexity of the problem, we leverage the derived optimality conditions to characterize optimal policies for general network graphs, obtain closed-form solutions for $d$-regular topologies, and derive tractable optimality conditions for star topologies. Numerical results confirm that the proposed mechanism can effectively and adaptively determine user-specific optimal transmission probabilities across varying network topologies. These findings contribute to the design of adaptive and efficient distributed networks with enhanced information freshness.