SYSTEM AND METHOD FOR SYNCHRONIZING TELECOM-RELATED CLOCKS IN ETHERNET-BASED PASSIVE OPTICAL ACCESS NETWORK

摘要

A system and method for synchronizing clocks related to telecommunications throughout a point-to-multipoint optical network utilizes downstream data timed using a high frequency transmission clock received from a central office CO (102) to distribute timing information of a central telecom-based clock (316) to remote terminals (ONU). In an exemplary embodiment, the point-to-multipoint optical network system is an Ethernet-based passive optical network PON system that operates in accordance with a Gigabit Ethernet standard. The timing information of the central telecom-based clock (316) is extracted from the downstream data (220) at each remote terminal (ONU) by recovering the high frequency transmission clock (322) and then, deriving a reference clock, which is synchronized with the central telecom-based clock (316), from the recovered transmission clock. The reference clock is then used to generate one or more telecom-related clocks (318) that are needed by the remote terminal (ONU). The system and method allows telecom-related clocks throughout the system to be synchronized in an efficient and cost-effective manner.