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

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.