AraSync: Precision Time Synchronization in Rural Wireless Living Lab

TL;DR

AraSync is a system designed to achieve nanosecond-level time synchronization in rural wireless labs, enabling precise experiments for next-generation wireless systems like 5G and 6G.

Contribution

This paper presents the design and implementation of AraSync, a novel end-to-end synchronization system utilizing PTP over fiber and wireless links with detailed performance characterization.

Findings

Achieves nanosecond synchronization accuracy.

Wireless channel and weather significantly affect synchronization.

Effective across fiber and mmWave/microwave links.

Abstract

Time synchronization is a critical component in network operation and management, and it is also required by Ultra-Reliable, Low-Latency Communications (URLLC) in next-generation wireless systems such as those of 5G, 6G, and Open RAN. In this context, we design and implement AraSync as an end-to-end time synchronization system in the ARA wireless living lab to enable advanced wireless experiments and applications involving stringent time constraints. We make use of Precision Time Protocol (PTP) at different levels to achieve synchronization accuracy in the order of nanoseconds. Along with fiber networks, AraSync enables time synchronization across the AraHaul wireless x-haul network consisting of long-range, high-capacity mmWave and microwave links. In this paper, we present the detailed design and implementation of AraSync, including its hardware and software components and the PTP network topology. Further, we experimentally characterize the performance of AraSync from spatial and temporal dimensions. Our measurement and analysis of the clock offset and mean path delay show the impact of the wireless channel and weather conditions on the PTP synchronization accuracy.