Multiprotocol Wireless Timer Synchronization for IoT Systems

TL;DR

This paper introduces a high-precision, protocol-independent wireless timer synchronization method for IoT systems that achieves nanosecond accuracy by exploiting radio timeslots and hardware-timed events.

Contribution

It presents a novel synchronization protocol that decouples from upper-layer retransmissions, enabling nanosecond-level accuracy in resource-constrained IoT devices.

Findings

Optimal synchronization frequency of 1000 Hz yields ~20 ns delay without traffic.

Sub-500 ns accuracy maintained under typical BLE traffic conditions.

Larger connection intervals and lower throughput improve synchronization quality.

Abstract

Accurate time synchronization is essential for Internet of Things (IoT) systems, where multiple distributed nodes must share a common time base for coordinated sensing and data fusion. However, conventional synchronization approaches suffer from nondeterministic transmission latency, limited precision, or restricted bidirectional functionality. This paper presents a protocol-independent wireless timer synchronization method that exploits radio timeslots to transmit precisely timestamped beacons in a proprietary radio mode. By decoupling synchronization from upper-layer packet retransmissions and leveraging hardware-timed radio events, the proposed approach significantly reduces scheduling uncertainty and achieves nanosecond-level synchronization accuracy. Comprehensive experiments evaluate the impacts of synchronization frequency, RSSI, BLE connection interval, and throughput on synchronization performance. The results demonstrate that an optimal synchronization frequency of 1000 Hz yields an approximately 20 ns delay in the absence of communication stack activity while maintaining sub-500 ns accuracy under most realistic BLE traffic conditions. Furthermore, larger connection intervals, lower application throughput, and higher RSSI consistently improve synchronization quality by reducing radio resource contention and packet loss. The proposed scheme provides a general and high-precision synchronization solution suitable for resource-constrained IoT systems.