RF-Zero-Wire: Design and Analysis of Multi-Hop Low-latency Symbol-synchronous RF Communication

2026-03-24

AI Summary

This work addresses the high latency inherent in wireless multihop networks caused by store-and-forward mechanisms and interference avoidance. To overcome these limitations, the authors propose RF-Zero-Wire, a novel protocol that introduces symbol-level concurrent relaying, enabling nodes to forward frame data symbol-by-symbol without requiring strict time synchronization—thereby bypassing traditional hop-by-hop transmission constraints. By modeling the beat-frequency effect induced by carrier frequency offsets and integrating forward error correction coding, the protocol significantly enhances transmission reliability. Experimental results demonstrate that RF-Zero-Wire achieves end-to-end latency below 1 ms for a 5-hop transmission of a 4-byte frame, with only a 0.16% latency increase per hop for a 16-byte frame—substantially outperforming conventional protocols, which typically exhibit over 100% latency growth per hop.

Technology Category

• Planning, Routing, and Scheduling: Optimization of Spatio-temporal Systems
• Cognitive Modeling & Cognitive Systems: Neural Spike Coding
• Multiagent Systems: Agent Communication

Application Category

• Systems and Infrastructure for Web, Mobile and WoT: Web performance, measurement, and characterization
• Graph Algorithms and Modeling for the Web: Algorithms and analysis for heterogeneous, signed, attributed, multi-relational, temporal, higher-order, and annotated Web-related graphs
• Responsible Web: Measurement, analysis, and circumvention of Web censorship

Abstract

The latency gap between wired and wireless networks poses a challenge in the adoption of wireless technologies in latency-sensitive scenarios. The gap is especially notable in multi-hop communication typical for industrial sensor networks and robotic swarms. The main reason behind it is that commonly used wireless protocols rely on store-and-forward routing and costly overhead procedures to avoid interference. This article introduces RF-Zero-Wire, an RF-based symbol-synchronous communication protocol. Instead of relaying the whole frame per hop in a store-and-forward manner, nodes concurrently relay the frame symbol by symbol, without the need for tight time synchronization. Based on data collected in real-world experiments, we reveal that the inevitable carrier frequency offsets (CFOs) introduced by imperfect crystal oscillators cause a beating effect under concurrent symbol transmissions. This is characterized by periodic constructive and destructive interference, which significantly affects reliability. Subsequently, a thorough simulation study shows how the beating problem can be overcome with error correction codes. RF-Zero-Wire allows achieving an end-to-end latency of less than 1ms for a small 4-byte frame transmitted across 5 hops. Moreover, latency is shown to increase only by 0.16% per extra hop for 16-byte frames, which is negligible compared to the over 100% per-hop latency increase observed in store-and-forward protocols. The trade-offs between network reliability and CFO range, communication distance, node density, and achievable data rate are studied in large-scale experiments based on simulation.

Problem

• multi-hop communication
• low-latency
• wireless networks
• store-and-forward
• latency gap

Innovation

• symbol-synchronous communication
• multi-hop low-latency
• carrier frequency offset (CFO)
• concurrent relaying
• error correction codes