Method and Apparatus for Using Ranging Measurements in a Multimedia Home Network

• US 20100098110A1
• Filed: 10/15/2009
• Published: 04/22/2010
• Est. Priority Date: 10/16/2008
• Status: Active Grant

• Current Assignee: Entropic Communications, LLC (FIG LLC (d/b/a Fortress Investment Group LLC))
• Original Assignee: Entropic Communications Incorporated (Maxlinear Incorporated)
• Inventors: MUELLER, Arndt
• Granted Patent: US 8,363,681 B2
• Time in Patent Office: Days
• US Class Current: 370/503
• CPC Class Codes: H04J 3/0664 unidirectional timestamps
• CPC Class Codes: H04J 3/0682 by delay compensation, e.g. by compensation of propagation delay or variations thereof, by ranging
• CPC Class Codes: H04L 41/147 for predicting network behaviour
• CPC Class Codes: H04L 41/149 for prediction of maintenance
• CPC Class Codes: H04L 43/0852 Delays

Abstract

According to various embodiments of the disclosure, systems, methods and apparatuses are provided for using ranging to improve network efficiency. In particular, various embodiments of the disclosure provide ranging to improve local clock time synchronization. According to one embodiment, a method for synchronizing a plurality of nodes on a communication network is provided, comprising: exchanging local clock times between a first node and a second node over the communication network; performing a ranging method between the first and second nodes based on the local clock times exchanged between the first and second nodes, wherein the ranging method results in an estimated propagation delay between the first and second nodes; and adjusting the local clock times of the first and second nodes based on the estimated propagation delay, thereby resulting in a synchronized local clock time at the first and second nodes.

Claims

1. A method for synchronizing a plurality of nodes on a communication network, comprising:

exchanging a local clock time between a first node and a second node over the communication network;

performing a ranging method between the first and second nodes based on the local clock time exchanged, wherein the ranging method results in an estimated propagation delay between the first and second node; and

adjusting the local clock time either the first or second node based on the estimated propagation delay, thereby resulting in a synchronized local clock time between the first and second node.

2. The method of claim 1, further comprising using the synchronized local clock time in subsequent packet transmissions between the first and second nodes.

3. The method of claim 1, wherein exchanging local clock times, performing the ranging method, and adjusting the local clock times comprises:

transmitting from the first node and receiving at the second node a first packet, wherein the first packet comprises a first packet clock time comprising the local clock time of the first node at transmission time, and a scheduled arrival clock time;

setting the local clock time of the second node to the first packet clock time;

transmitting from the second node and receiving at the first node a second packet at the first scheduled arrival clock time, wherein the second packet is received by the first node at an actual arrival clock time;

calculating and storing the estimated propagation delay at the first node, wherein calculating the estimated propagation delay is based on the first scheduled arrival clock time and the first actual time;

transmitting from the first node and receiving at the second node a third packet, wherein the third packet comprises the estimated propagation delay; and

storing the estimated propagation delay at the second node.

4. The method of claim 3, wherein a transmission time of a transmitted packet is measured at 90% of peak amplitude of a transmission signal, 90% of peak power of a transmission signal, 90% of total power of a transmission signal, or a mean delay of a transmission signal.

5. The method of claim 3, wherein an arrival time of a received packet is measured at 90% of peak amplitude of a received signal, 90% of peak power of a received signal, 90% of total power of a received signal, or a mean delay of a received signal.

6. The method of claim 1, wherein the first node is a network coordinator.

7. The method of claim 1, wherein the second node is a new node and the method is performed as part of admission of the second node to the communication network.

8. The method of claim 1, wherein the method is performed periodically to maintain synchronization between the first and second nodes.

9. The method of claim 1, wherein the communication network is a mesh network.

10. The method of claim 1, wherein the communication network operates in accordance with a Multimedia over Coax Alliance (MoCA) standard.

11. A network device, comprising:

a controller;

a device module;

memory coupled to the controller;

computer executable program code on a computer readable medium configured to cause the controller to perform the functions of;

exchanging local clock times between a first node and a second node over a communication network;

performing a ranging method between the first and second nodes based on the local clock times exchanged between the first and second nodes, wherein the ranging method results in an estimated propagation delay between the first and second nodes; and

adjusting the local clock times of the first and second nodes based on the estimated propagation delay, thereby resulting in a synchronized local clock time at the first and second nodes.

12. The network device of claim 11, wherein the computer executable program code is further configured to cause the controller to use the synchronized local clock time in subsequent packet transmissions between the first and second nodes.

13. The network device of claim 11, wherein the functions of exchanging local clock times, performing the ranging method, and adjusting the local clock times comprises:

transmitting from the first node and receiving at the second node a first packet, wherein the first packet comprises a first packet clock time comprising the local clock time of the first node at transmission time, and a scheduled arrival clock time;

setting the local clock time of the second node to the first packet clock time;

transmitting from the second node and receiving at the first node a second packet at the first scheduled arrival clock time, wherein the second packet is received by the first node at an actual arrival clock time;

calculating and storing the estimated propagation delay at the first node, wherein calculating the estimated propagation delay is based on the first scheduled arrival clock time and the first actual time;

transmitting from the first node and receiving at the second node a third packet, wherein the third packet comprises the estimated propagation delay; and

storing the estimated propagation delay at the second node.

14. The network device of claim 13, wherein a transmission time of a transmitted packet is measured at 90% of peak amplitude of a transmission signal, 90% of peak power of a transmission signal, 90% of total power of a transmission signal, or a mean delay of a transmission signal.

15. The network device of claim 13, wherein an arrival time of a received packet is measured at 90% of peak amplitude of a received signal, 90% of peak power of a received signal, 90% of total power of a received signal, or a mean delay of a received signal.

16. The network device of claim 11, wherein the first node is a network coordinator.

17. The network device of claim 11, wherein the second node is a new node and the functions are performed as part of admission of the second node to the communication network.

18. The network device of claim 11, wherein the functions of exchanging local clock times, performing the ranging method, and adjusting the local clock times are performed periodically to maintain synchronization between the first and second nodes.

19. The network device of claim 11, wherein the communication network is a mesh network.

20. The network device of claim 11, wherein the communication network operates in accordance with a Multimedia over Coax Alliance (MoCA) standard.

21. A computer program product comprising a computer usable medium having computer readable program code embodied therein for synchronizing a plurality of nodes on a communication network, the computer program product comprising computer readable program code configured to cause a device to:

exchange local clock times between a first node and a second node over a communication network;

perform a ranging method between the first and second nodes based on the local clock times exchanged between the first and second nodes, wherein the ranging method results in an estimated propagation delay between the first and second nodes; and

adjust the local clock times of the first and second nodes based on the estimated propagation delay, thereby resulting in a synchronized local clock time at the first and second nodes.

22. The computer program product of claim 21, wherein the computer executable program code is further configured to cause the device to use the synchronized local clock time in subsequent packet transmissions between the first and second nodes.

23. The computer program product of claim 21, wherein the functions of exchanging local clock times, performing the ranging method, and adjusting the local clock times comprises:

transmitting from the first node and receiving at the second node a first packet, wherein the first packet comprises a first packet clock time comprising the local clock time of the first node at transmission time, and a scheduled arrival clock time;

setting the local clock time of the second node to the first packet clock time;

transmitting from the second node and receiving at the first node a second packet at the first scheduled arrival clock time, wherein the second packet is received by the first node at an actual arrival clock time;

calculating and storing the estimated propagation delay at the first node, wherein calculating the estimated propagation delay is based on the first scheduled arrival clock time and the first actual time;

transmitting from the first node and receiving at the second node a third packet, wherein the third packet comprises the estimated propagation delay; and

storing the estimated propagation delay at the second node.

24. The computer program product of claim 23, wherein a transmission time of a transmitted packet is measured at 90% of peak amplitude of a transmission signal, 90% of peak power of a transmission signal, 90% of total power of a transmission signal, or a mean delay of a transmission signal.

25. The computer program product of claim 23, wherein an arrival time of a received packet is measured at 90% of peak amplitude of a received signal, 90% of peak power of a received signal, 90% of total power of a received signal, or a mean delay of a received signal.

26. The computer program product of claim 21, wherein the first node is a network coordinator.

27. The computer program product of claim 21, wherein the second node is a new node and the functions are performed as part of admission of the second node to the communication network.

28. The computer program product of claim 21, wherein the functions of exchanging local clock times, performing the ranging method, and adjusting the local clock times are performed periodically to maintain synchronization between the first and second nodes.

29. The computer program product of claim 21, wherein the communication network is a mesh network.

30. The computer program product of claim 21, wherein the communication network operates in accordance with a Multimedia over Coax Alliance (MoCA) standard.

31. A network interface module, comprising:

a controller;

memory coupled to the controller;

computer executable program code on a computer readable medium configured to cause the controller to perform the functions of;

exchanging local clock times between a first node and a second node over a network;

performing a ranging method between the first and second nodes based on the local clock times exchanged between the first and second nodes, wherein the ranging method results in an estimated propagation delay between the first and second nodes; and

adjusting the local clock times of the first and second nodes based on the estimated propagation delay, thereby resulting in a synchronized local clock time at the first and second nodes.

32. The network interface module of claim 31, wherein the computer executable program code is further configured to cause the controller to use the synchronized local clock time in subsequent packet transmissions between the first and second nodes.

33. The network interface module of claim 31, wherein the functions of exchanging local clock times, performing the ranging method, and adjusting the local clock times comprises:

transmitting from the first node and receiving at the second node a first packet, wherein the first packet comprises a first packet clock time comprising the local clock time of the first node at transmission time, and a scheduled arrival clock time;

setting the local clock time of the second node to the first packet clock time;

transmitting from the second node and receiving at the first node a second packet at the first scheduled arrival clock time, wherein the second packet is received by the first node at an actual arrival clock time;

calculating and storing the estimated propagation delay at the first node, wherein calculating the estimated propagation delay is based on the first scheduled arrival clock time and the first actual time;

transmitting from the first node and receiving at the second node a third packet, wherein the third packet comprises the estimated propagation delay; and

storing the estimated propagation delay at the second node.

34. The network interface module of claim 33, wherein a transmission time of a transmitted packet is measured at 90% of peak amplitude of a transmission signal, 90% of peak power of a transmission signal, 90% of total power of a transmission signal, or a mean delay of a transmission signal.

35. The network interface module of claim 33, wherein an arrival time of a received packet is measured at 90% of peak amplitude of a received signal, 90% of peak power of a received signal, 90% of total power of a received signal, or a mean delay of a received signal.

36. The network interface module of claim 31, wherein the first node is a network coordinator.

37. The network interface module of claim 31, wherein the second node is a new node and the functions are performed as part of admission of the second node to the communication network.

38. The network interface module of claim 31, wherein the functions of exchanging local clock times, performing the ranging method, and adjusting the local clock times are performed periodically to maintain synchronization between the first and second nodes.

39. The network interface module of claim 31, wherein the communication network is a mesh network.

40. The network interface module of claim 31, wherein the communication network operates in accordance with a Multimedia over Coax Alliance (MoCA) standard.