Seamless Link-level Redundancy to Improve Reliability of Industrial Wi-Fi Networks

TL;DR

This paper introduces a link-level redundancy architecture for Wi-Fi in industrial settings, enhancing reliability and reducing latency through optimized diversity techniques, supported by simulation results.

Contribution

It proposes a general framework for seamless link-level redundancy in Wi-Fi, including optimizations to improve communication quality and reliability in industrial environments.

Findings

Packet losses are significantly reduced.

Network latency improves noticeably.

Redundancy enhances Wi-Fi reliability in industrial scenarios.

Abstract

The adoption of wireless communications and, in particular, Wi-Fi, at the lowest level of the factory automation hierarchy has not increased as fast as expected so far, mainly because of serious issues concerning determinism. Actually, besides the random access scheme, disturbance and interference prevent reliable communication over the air and, as a matter of fact, make wireless networks unable to support distributed real-time control applications properly. Several papers recently appeared in the literature suggest that diversity could be leveraged to overcome this limitation effectively. In this paper a reference architecture is introduced, which describes how seamless link-level redundancy can be applied to Wi-Fi. The framework is general enough to serve as a basis for future protocol enhancements, and also includes two optimizations aimed at improving the quality of wireless communication by avoiding unnecessary replicated transmissions. Some relevant solutions have been analyzed by means of a thorough simulation campaign, in order to highlight their benefits when compared to conventional Wi-Fi. Results show that both packet losses and network latencies improve noticeably.