Using IEEE 1588 and boundary clocks for clock synchronization in telecom networks

TLDR

IEEE 1588 and boundary clocks are employed for phase/time transfer in telecom networks, primarily to satisfy mobile system synchronization needs such as WiMAX and LTE while reducing dependence on GPS in base stations. The study aims to evaluate essential functions for phase/time transfer and report initial field‑trial results using cascaded boundary clocks and synchronous Ethernet across a multi‑kilometer telecom network. The authors implemented cascaded boundary clocks and synchronous Ethernet links over a packet and optical transport network spanning tens of kilometers and network elements, addressing challenges and standardization efforts. The field trials demonstrate that accurate phase/time transfer is achievable over the telecom network, meeting the requirements of mobile systems.

Abstract

This article describes the use of IEEE 1588 and boundary clocks for clock distribution (phase/time transfer) in telecom networks. The technology is primarily used to serve the radio interface synchronization requirements of mobile systems such as WiMAX and LTE, and to reduce the deployment and dependence of GPS systems in base stations. We discuss the most important functions that are necessary for phase/time transfer and present some initial field trial results using a chain of cascaded boundary clocks and synchronous Ethernet links across a packet and optical transport network that spans tens of kilometers and tens of network elements. The results indicate that it is possible to transfer accurate phase/time in a telecom network and meet the requirements of mobile systems. The article also discusses some of the challenges and highlights the ongoing activities in standardization bodies so that IEEE 1588 can be used as a technology in telecom networks.