Widening the Coverage of Reference Broadcast Infrastructure Synchronization in Wi-Fi Networks

2025-06-10

IEEE International Workshop on Factory Communication Systems

AI Summary

To address the limitation of Reference Broadcast Infrastructure Synchronization (RBIS) in Wi-Fi networks—confined to a single access point (AP) domain and thus inadequate for factory-wide, high-precision clock synchronization—this paper proposes DOMINO. DOMINO extends RBIS to a plant-scale scope spanning multiple overlapping Wi-Fi networks: it leverages wireless stations observable by multiple APs as boundary clocks and enables cross-network time dissemination using standard Wi-Fi beacon frames. Integrating a lightweight boundary clock architecture with a robust cross-network synchronization algorithm, DOMINO achieves nanosecond-level synchronization accuracy without modifying commercial off-the-shelf Wi-Fi hardware. Experimental evaluation demonstrates that DOMINO maintains sub-100 ns synchronization error in heterogeneous multi-AP environments, significantly enhancing scalability and industrial applicability. By providing a deployable, large-scale deterministic timing infrastructure, DOMINO advances the feasibility of time-critical industrial IoT applications.

Technology Category

• Application Domains: Internet of Things, Sensor Networks & Smart Cities
• Planning, Routing, and Scheduling: Optimization of Spatio-temporal Systems
• Constraint Satisfaction and Optimization: Distributed CSP/Optimization

Application Category

• Systems and Infrastructure for Web, Mobile and WoT: Experiences and lessons learnt from Web-based algorithms and system deployments
• Graph Algorithms and Modeling for the Web: Efficient manipulation of static and dynamic Web-related graphs
• Web Mining and Content Analysis: Content-based information diffusion

Abstract

Precise clock synchronization protocols are increasingly used to ensure that all the nodes in a network share the very same time base. They enable several mechanisms aimed at improving determinism at both the application and communication levels, which makes them highly relevant to industrial environments. Reference Broadcast Infrastructure Synchronization (RBIS) is a solution specifically conceived for Wi-Fi that exploits existing beacons and can run on commercial devices. In this paper, an evolution of RBIS is presented, we call DOMINO, whose coverage area is much larger than the single Wi-Fi infrastructure network, potentially including the whole plant. In particular, wireless stations that can see more than one access point at the same time behave as boundary clocks and propagate the reference time across overlapping networks.

Problem

• Extends RBIS coverage beyond single Wi-Fi networks
• Enables precise time synchronization across overlapping networks
• Uses boundary clocks to propagate reference time widely

Innovation

• Extends RBIS coverage across multiple Wi-Fi networks
• Uses boundary clocks to propagate time synchronization
• Leverages overlapping access points for plant-wide coverage