Time Reversal Enabled Fiber-Optic Time Synchronization

TL;DR

This paper introduces a novel fiber-optic time synchronization method using time reversal that simplifies system complexity and enables multiple-access synchronization without a data layer, demonstrated over 230 km.

Contribution

It proposes a time reversal enabled FOTS technique that reduces system complexity and supports multiple-access synchronization, advancing large-scale network applications.

Findings

Successful demonstration over 230 km fiber link

Achieved high-precision synchronization without data layer

Supports multiple-access synchronization along fiber

Abstract

Over the past few decades, fiber-optic time synchronization (FOTS) has provided fundamental support for the efficient operation of modern society. Looking toward the future beyond fifth-generation/sixth-generation (B5G/6G) scenarios and very large radio telescope arrays, developing high-precision, low-complexity and scalable FOTS technology is crucial for building a large-scale time synchronization network. However, the traditional two-way FOTS method needs a data layer to exchange time delay information. This increases the complexity of system and makes it impossible to realize multiple-access time synchronization. In this paper, a time reversal enabled FOTS method is proposed. It measures the clock difference between two locations without involving a data layer, which can reduce the complexity of the system. Moreover, it can also achieve multiple-access time synchronization along the fiber link. Tests over a 230 km fiber link have been carried out to demonstrate the high performance of the proposed method.