Protocol Design for Irregular Repetition Slotted ALOHA With Energy Harvesting to Maintain Information Freshness

TL;DR

This paper proposes a method to improve information freshness in energy-harvesting IoT devices using an optimized IRSA protocol that identifies transmission failures and mitigates energy constraints.

Contribution

It introduces a receiver-identified failure detection method and optimizes the IRSA degree distribution for better freshness under energy harvesting constraints.

Findings

IRSA can maintain high information freshness despite energy limitations

Optimized degree distribution improves decoding success rate

Proposed method achieves freshness comparable to unlimited energy systems

Abstract

We investigate an internet-of-things system where energy-harvesting devices send status updates to a common receiver using the irregular repetition slotted ALOHA (IRSA) protocol. Energy shortages in these devices may lead to transmission failures that are unknown to the receiver, disrupting the decoding process. To address this issue, we propose a method for the receiver to perfectly identify such failures. Furthermore, we optimize the degree distribution of the protocol to enhance the freshness of the status updates. Our optimized degree distribution mitigates the adverse effects of potential transmission failures. Numerical results demonstrate that, despite energy-harvesting constraints, IRSA can achieve a level of information freshness comparable to systems with unlimited energy.