Granted Patent B2

US 8,630,546 · App. 12/916,880 · Granted Jan 14, 2014

Abstract

Claims (87)

1. A method comprising:

monitoring, with a network interface device, one or more instances when the network interface device transmits information to an optical line terminal (OLT) within a current frame;

determining, with the network interface device, a time when a next frame should be received by the network interface device based on the monitored one or more instances when the network interface device transmits information to the OLT;

receiving time of day (TOD) information associated with a frame;

modifying the TOD information to account for delays in the network interface device for receiving the TOD information;

determining a time when the frame associated with the TOD information should be received by the network interface device based at least on the determined time when the next frame should be received by the network interface device; and

loading the modified TOD information, within a TOD clock on the network interface device, based on the time when the frame associated with the TOD information should be received by the network interface device to synchronize the TOD clock on the network interface device with a TOD clock on the OLT.

2. The method of claim 1 , wherein the next frame comprises the frame associated with the TOD information.

3. The method of claim 1 , further comprising:

determining an identifier for the next frame.

4. The method of claim 3 , further comprising:

receiving an identifier for the frame associated with the TOD information,

wherein determining the time when the frame associated with the TOD information should be received by the network interface device comprises determining the time when the frame associated with the TOD information should be received by the network interface device based at least on the identifier for the frame associated with the TOD information, the identifier for the next frame, and the determined time when the next frame should be received by the network interface device.

5. The method of claim 3 , further comprising:

receiving an identifier for the current frame;

determining a response time of the network interface device; and

receiving an equalization delay of the network interface device,

wherein determining an identifier for the next frame comprises determining the identifier for the next frame based at least on the identifier for the current frame, the equalization delay of the network interface device, the response time of the network interface device, and a temporal length of each frame.

6. The method of claim 1 , wherein monitoring one or more instances when the network interface device transmits information to the OLT comprises at least one of monitoring a burst-enable signal, monitoring a current through a laser within a laser housing coupled to the network interface device, and monitoring a current through a photo-diode within the laser housing coupled to the network interface device.

7. The method of claim 1 , further comprising:

receiving an equalization delay and a byte range, within the current frame, that define when the network interface device should transmit information to the OLT;

determining a start time based on the byte range; and

determining a response time of the network interface device,

wherein determining the time when the next frame should be received by the network interface device comprises determining the time when the next frame should be received by the network interface device based on the monitored one or more instances when the network interface device transmits information to the OLT, the equalization delay, the start time, the response time, and a temporal length of each frame.

8. The method of claim 7 , wherein receiving the equalization delay and the byte range comprises receiving the equalization delay and the byte range in at least one of a physical layer operations and maintenance (PLOAM) message and an optical network unit (ONU) management control interface (OMCI) message.

9. The method of claim 1 , wherein the network interface device and the OLT are part of an optical network, and wherein the optical network comprises at least one of a passive optical network and an active optical network.

10. An optical network comprising:

a network interface device that includes a processor configured to transmit information to an optical line terminal (OLT) and receive time of day (TOD) information associated with a frame; and

a synchronization module configured to:

monitor one or more instances when the network interface device transmits information to the OLT within a current frame; and

determine a time when a next frame should be received by the network interface device based on the monitored one or more instances when the network interface device transmits information to the OLT,

wherein at least one of the processor and synchronization module is configured to modify the TOD information to account for delays in the network interface device for receiving the TOD information, and

wherein the synchronization module is configured to:

determine a time when the frame associated with the TOD information should be received by the network interface device based at least on the determined time when the next frame should be received by the network interface device; and

load the modified TOD information, within a TOD clock on the network interface device, based on the determined time when the frame associated with the TOD information should be received by the network interface device to synchronize the TOD clock on the network interface device with a TOD clock on the OLT.

11. The optical network of claim 10 , wherein the next frame comprises the frame associated with the TOD information.

12. The optical network of claim 10 , wherein at least one of the processor and synchronization module includes the TOD clock.

13. The optical network of claim 10 , wherein the synchronization module is further configured to determine an identifier for the next frame.

14. The optical network of claim 13 ,

wherein the network interface device is configured to receive an identifier for the frame associated with the TOD information,

wherein the synchronization module is configured to determine the time when the frame associated with the TOD information should be received by the network interface device based at least on the identifier for the frame associated with the TOD information, the identifier for the next frame, and the determined time when the next frame should be received by the network interface device.

15. The optical network of claim 13 ,

wherein the synchronization module receives an identifier for the current frame and receives an equalization delay of the network interface device,

wherein the synchronization module determines the identifier for the next frame based at least on the identifier for the current frame, the equalization delay of the network interface device, a response time of the network interface device, and a temporal length of each frame.

16. The optical network of claim 10 , wherein the synchronization module monitors at least one of a burst-enable signal from the processor, a current through a laser within a laser housing coupled to the network interface device, and a current through a photo-diode within the laser housing coupled to the network interface device to monitor the one or more instances when the network interface device transmits information to the OLT.

17. The optical network of claim 10 ,

wherein the processor is configured to receive an equalization delay and a byte range, within the current frame, that define when the network interface device should transmit information to the OLT,

wherein the synchronization module is configured to determine a start time based on the byte range,

wherein the processor is configured to determine a response time of the network interface device, and

wherein the synchronization module determines the time when the next frame should be received by the network interface device based on the monitored one or more instances when the network interface device transmits information to the OLT, the equalization delay, the start time, the response time, and a temporal length of each frame.

18. The optical network of claim 17 , wherein the processor receives the equalization delay and the byte range in at least one of a physical layer operations and maintenance (PLOAM) message and an optical network unit (ONU) management control interface (OMCI) message.

19. The optical network of claim 10 , wherein the optical network includes the OLT.

20. The optical network of claim 10 , wherein the network interface device includes the synchronization module, and wherein the synchronization module is external to the processor.

21. The optical network of claim 10 , wherein the optical network comprises at least one of a passive optical network and an active optical network.

22. An optical network comprising:

means for monitoring one or more instances when a network interface device transmits information to an optical line terminal (OLT) within a current frame; and

means for determining a time when a next frame should be received by the network interface device based on the monitored one or more instances when the network interface device transmits information to the OLT;

means for receiving time of day (TOD) information associated with a frame;

means for modifying the TOD information to account for delays in the network interface device for receiving the TOD information;

means for determining a time when a frame associated with the TOD information should be received by the network interface device based at least on the determined time when the next frame should be received; and

means for loading the modified TOD information, within a TOD clock on the network interface device, based on the time when the frame associated with the TOD information should be received by the network interface device to synchronize the TOD clock on the network interface device with a TOD clock on the OLT.

23. The optical network of claim 22 , wherein the next frame comprises the frame associated with the TOD information.

24. The optical network of claim 22 , further comprising:

means for determining an identifier for the next frame.

25. The optical network of claim 24 , further comprising:

means for receiving an identifier for the frame associated with the TOD information;

wherein the means for determining when the frame associated with the TOD information should be received by the network interface device comprises means for determining when the frame associated with the TOD information should be received by the network interface device based at least on the identifier for the frame associated with the TOD information, the identifier for the next frame, and the determined time when the next frame should be received by the network interface device.

26. The optical network of claim 24 , further comprising:

means for receiving an identifier for the current frame;

means for determining a response time of the network interface device; and

means for receiving an equalization delay of the network interface device,

wherein the means for determining an identifier for the next frame comprise means for determining the identifier for the next frame based at least on the identifier for the current frame, the equalization delay of the network interface device, the response time of the network interface device, and a temporal length of each frame.

27. The optical network of claim 22 , wherein the means for monitoring one or more instances when the network interface device transmits information to the OLT comprise at least one of means for monitoring a burst-enable signal, monitoring a current through a laser within a laser housing coupled to the network interface device, and monitoring a current through a photo-diode within the laser housing coupled to the network interface device.

28. The optical network of claim 22 , further comprising:

means for receiving an equalization delay and a byte range, within the current frame, that define when the network interface device should transmit information to the OLT;

means determining a start time based on the byte range; and

means for determining a response time of the network interface device,

wherein the means for determining the time when the next frame should be received by the network interface device comprise means for determining when the next frame should be received by the network interface device based on the monitored one or more instances when the network interface device transmits information to the OLT, the equalization delay, the start time, the response time, and a temporal length of each frame.

29. The optical network of claim 28 , wherein the means for receiving the equalization delay and the byte range comprise means for receiving the equalization delay and the byte range in at least one of a physical layer operations and maintenance (PLOAM) message and an optical network unit (OLT) management control interface (OMCI) message.

30. The optical network of claim 22 , wherein the network interface device and the OLT are part of an optical network, and wherein the optical network comprises at least one of a passive optical network and an active optical network.

31. A computer-readable storage medium comprising instructions that cause one or more processors to:

monitor one or more instances when a network interface device transmits information to an optical line terminal (OLT) within a current frame; and

determine a time when a next frame should be received by the network interface device based on the monitored one or more instances when the network interface device transmits information to the OLT;

receiving time of day (TOD) information associated with a frame;

modifying the TOD information to account for delays in the network interface device for receiving the TOD information;

determining a time when the frame associated with the TOD information should be received by the network interface device based at least on the determined time when the next frame should be received by the network interface device; and

loading the modified TOD information, within a TOD clock on the network interface device, based on the time when the frame associated with the TOD information should be received by the network interface device to synchronize the TOD clock on the network interface device with a TOD clock on the OLT.

Assignments (7)