Publikation
Sub-Microsecond Time Synchronization in Industrial 5G and Beyond: Design and Experimental Evaluation
Michael Gundall; Leonard Kleinberger; Devanshu Anand; Hans Dieter Schotten
In: GLOBECOM 2026 - 2026 IEEE Global Communications Conference. IEEE Global Communications Conference (Globecom-2026), December 7-11, Macau, China, IEEE, 12/2026.
Zusammenfassung
Time synchronization is a fundamental requirement for industrial IoT applications, including smart grids, factory automation, and closed-loop control, where sub-microsecond accuracy is often mandatory. While wired solutions such as the Precision Time Protocol (PTP) achieve nanosecond-level accuracy, their performance cannot be directly transferred to wireless systems. Tunneling PTP over 5G user plane traffic results in only millisecond-level accuracy, which makes it insufficient for industrial use cases. In this paper, we build upon the principle of Reference Broadcast Infrastructure Synchronization (RBIS) and propose an efficient and precise time synchronization scheme for 5G and Beyond (B5G) networks that operates independently of GNSS availability and synchronization guarantees at the modem level. The proposed approach is implemented and evaluated on a mostly Commercial Off-The-Shelf (COTS) testbed comprising a COTS gNB, UEs, and 5GC. Only the RX ports of Software Defined Radios are used to timestamp the synchronization signal. A comprehensive comparison of different estimation algorithms, including Moving Average Filter, Kalman Filter, and Recursive Least Squares (RLS) variants, is conducted. Experimental results demonstrate that the proposed RLS-based estimator achieves two-digit nanosecond-level accuracy and precision, outperforming all evaluated baselines and confirming the suitability of 5G-RBIS for demanding industrial IoT environments.