Time synchronization method and device in passive optical network and passive optical network

An apparatus for time synchronization in a passive optical network (PON), comprising:

• a receiving unit configured to receive a timestamp TMtli associated with a first downlink frame from the OLT to an ONU and a frame sequence number of the first downlink frame via an ONU Management and Control Interface (OMCI);
• wherein the frame sequence number is a value derived from a superframe counter;
• wherein the timestamp TMtli and the frame sequence number of the first downlink frame are used for time synchronization between an ONU and the OLT;
• an adjusting unit configured to adjust a local clock according to the timestamp TMtli associated with the first downlink frame from the OLT to an ONU and the frame sequence number of the first downlink frame to achieve the time synchronization of the ONU with the OLT.

A passive optical network (PON), comprising:

• an optical line terminal (OLT);
• and
• a plurality of optical network units (ONUs), wherein:
• the OLT is configured to obtain a timestamp TMtli associated with a first downlink frame from the OLT to an ONU and a frame sequence number of the first downlink frame, wherein the frame sequence number is a value derived from a superframe counter and send the timestamp TMtli and the frame sequence number via an ONU Management and Control Interface (OMCI), wherein the timestamp TMtli and the frame sequence number are used for time synchronization between an ONU and the OLT;
• the ONU is configured to receive the timestamp TMtli associated with the first downlink frame from the OLT to an ONU and the frame sequence number of the first downlink frame via the OMCI and adjust a local clock according to the timestamp TMtli associated with the first downlink frame from the OLT to an ONU and the frame sequence number of the first downlink frame to achieve the time synchronization of the ONU with the OLT.

An apparatus for time synchronization in a passive optical network (PON), comprising:

• at least one processor and a memory coupled to the at least one processor;
• wherein the at least one processor is configured to receive a timestamp TMtli associated with a first downlink frame from the OLT to an ONU and a frame sequence number of the first downlink frame via an ONU Management and Control Interface (OMCI);
• wherein the frame sequence number is a value derived from a superframe counter;
• wherein the timestamp TMtli and the frame sequence number of the first downlink frame are used for time synchronization between an ONU and the OLT.