Time synchronization over ethernet passive optical networks

Time synchronization is critical when using Ethernet passive optical networks as a mobile backhaul to support time-sensitive services. This article presents an overview of time synchronization methods over EPON. It outlines the requirements and challenges particular to the EPON link delay asymmetry, and presents the technical solution recently approved by IEEE. Performance analysis and prototype results demonstrate that this technical solution meets various time synchronization requirements. The article then reviews the major standard efforts on EPON time synchronization that employ this solution, IEEE Std 802.1ASTM-2011 Clause 13. With this standard in place, EPON can play its part in time distribution networks.