System, method, and computer program product for ethernet passive optical networks

摘要

A system, method, and computer program product for synchronizing time between a centralized controller device and at least one subscriber device on an Ethernet Passive Optical Network (EPON). The MAC control layer of an EPON device is expanded, and additional messaging control is added via the transmission of Ethernet frames. The expansion prevents reliance on a physical layer signal. The time synchronization also allows a time stamp to be incorporated into a message. Thus, bandwidth is not wasted by simply transmitting a time stamp by itself. In an embodiment, the centralized controller device measures the time difference between the time at which a particular ranging request is transmitted and the time at which the particular ranging request is received. The time difference represents the time adjustment value for the particular subscriber device and allows the device to synchronize its time with that of the centralized controller device.