STX-Vote: Improving Reliability with Bit Voting in Synchronous Transmission-based IoT Networks

TL;DR

STX-Vote is an error correction scheme for Synchronous Transmissions in IIoT networks that enhances reliability by leveraging existing redundancy, achieving significant improvements without additional overhead.

Contribution

It introduces STX-Vote, a novel error correction method that mitigates beating effect errors in STX protocols using existing redundancy, without extra on-air costs.

Findings

40% reliability increase in simulations

25-28% reliability improvement on BLE 5 PHYs

8% reliability gain on IEEE 802.15.4

Abstract

Industrial Internet of Things (IIoT) networks must meet strict reliability, latency, and low energy consumption requirements. However, traditional low-power wireless protocols are ineffective in finding a sweet spot for balancing these performance metrics. Recently, network flooding protocols based on Synchronous Transmissions (STX) have been proposed for better performance in reliability-critical IIoT, where simultaneous transmissions are possible without packet collisions. STX-based protocols can offer a competitive edge over routing-based protocols, particularly in dependability. However, they notably suffer from the beating effect, a physical layer phenomenon that results in sinusoidal interference across a packet and, consequently, packet loss. Thus, we introduce STX-Vote, an error correction scheme that can handle errors caused by beating effects. Importantly, we utilize transmission redundancy already inherent within STX protocols so do not incur additional on-air overhead. Through simulation, we demonstrate STX-Vote can provide a 40% increase in reliability. We subsequently implement STX-Vote on nRF52840-DK devices and perform extensive experiments. The results confirm that STX-Vote improves reliability by 25-28% for BLE 5 PHYs and 8% for IEEE 802.15.4; thus, it can complement existing error correction schemes.