Patent ID: 8768169

Claim:
A time synchronization method for a passive optical network, comprising: implementing time synchronization between an Optical Line Terminal (OLT) and a superior device of the OLT by using an IEEE1588 protocol; implementing time synchronization from the OLT to an Optical Network Unit (ONU) by using a management path, comprising: by the OLT, calculating a transmission delay between the OLT and the ONU, and transferring time information from the OLT to the ONU by using the management path, wherein the time information includes the transmission delay between the ONU and the OLT and sending time identifier information of the time information, wherein the sending time identifier information comprises a secondsfield and a nanosecondsfield; and by the ONU, calculating a time offset between the ONU and the OLT according to the time information so as to implement the time synchronization with the OLT, wherein the management path is an ONU Management and Control Interface (OMCI) message path; and the sending time identifier information of the time information comprises the sending time of a frame triggering the time synchronization and the frame number of the frame.