Using GPS signals to synchronize stationary multiple master networks

• US 20030214936A1
• Filed: 05/16/2002
• Published: 11/20/2003
• Est. Priority Date: 05/16/2002
• Status: Abandoned Application

• Current Assignee: Sun Microsystems Incorporated (Oracle Corporation)
• Original Assignee: Sun Microsystems Incorporated (Oracle Corporation)
• Inventors: Goff, Max K.
• Application Number:
  US10/147,201
• Publication Number:
  US 20030214936A1
• Time in Patent Office: Days
• US Class Current: 370/350
• CPC Class Codes: H04B 7/2693 Centralised synchronisation, i.e. using external universal time reference, e.g. by using a global positioning system [GPS] or by distributing time reference over the wireline network

Abstract

One embodiment of the present invention provides a system that uses Global Positioning System (GPS) signals to synchronize multiple masters on a stationary network. During operation, the system receives the GPS signals at the multiple masters. Next, the system extracts a time value from the GPS signals at each master, and uses the extracted time value to synchronize a local clock at each master. The system subsequently uses the local clock at each master to synchronize interactions between masters.

Claims

1. A method for using Global Positioning System (GPS) signals to synchronize multiple masters on a stationary network, comprising:

receiving the GPS signals at the multiple masters on the stationary network;

extracting a time value from the GPS signals at each master;

using the extracted time value to synchronize a local clock at each master; and

using the local clock at each master to synchronize interactions between masters.

2. The method of claim 1, further comprising sending a synchronization signal from a master on the stationary network to a slave, which does not possess a GPS receiver, in order to synchronize a local clock on the slave with the local clock on the master.

3. The method of claim 1, wherein extracting the time value from the GPS signals involves using Universal Coordinated Time (UTC) correction parameters in the GPS signals to convert a GPS time value into a UTC time value.

4. The method of claim 1, wherein extracting the time value from the GPS signals involves using Standard Positioning Service (SPS) signals within the GPS signals to obtain a time value that is accurate to within 340 nanoseconds.

5. The method of claim 1, wherein extracting the time value from the GPS signals involves using Precise Positioning Service (PPS) signals within the GPS signals to obtain a time value that is accurate to within 200 nanoseconds.

6. The method of claim 1, wherein receiving the GPS signals involves receiving differential GPS signals in addition to GPS signals.

7. The method of claim 1, wherein receiving the GPS signals involves receiving Wide Area Augmentation System (WAAS) signals in addition to GPS signals.

8. The method of claim 1, wherein receiving the GPS signals involves receiving Local Area Augmentation System (LAAS) signals in addition to GPS signals.

9. The method of claim 1, wherein each master includes a computer system coupled to the stationary network.

10. The method of claim 1, wherein the multiple masters are geographically distributed.

11. A computer-readable storage medium storing instructions that when executed by a computer cause the computer to perform a method for using Global Positioning System (GPS) signals to synchronize multiple masters on a stationary network, the method comprising:

receiving the GPS signals at the multiple masters on the stationary network;

extracting a time value from the GPS signals at each master;

using the extracted time value to synchronize a local clock at each master; and

using the local clock at each master to synchronize interactions between masters.

12. The computer-readable storage medium of claim 11, wherein the method further comprises sending a synchronization signal from a master on the stationary network to a slave, which does not possess a GPS receiver, in order to synchronize a local clock on the slave with the local clock on the master.

13. The computer-readable storage medium of claim 11, wherein extracting the time value from the GPS signals involves using Universal Coordinated Time (UTC) correction parameters in the GPS signals to convert a GPS time value into a UTC time value.

14. The computer-readable storage medium of claim 11, wherein extracting the time value from the GPS signals involves using Standard Positioning Service (SPS) signals within the GPS signals to obtain a time value that is accurate to within 340 nanoseconds.

15. The computer-readable storage medium of claim 11, wherein extracting the time value from the GPS signals involves using Precise Positioning Service (PPS) signals within the GPS signals to obtain a time value that is accurate to within 200 nanoseconds.

16. The computer-readable storage medium of claim 11, wherein receiving the GPS signals involves receiving differential GPS signals in addition to GPS signals.

17. The computer-readable storage medium of claim 11, wherein receiving the GPS signals involves receiving Wide Area Augmentation System (WAAS) signals in addition to GPS signals.

18. The computer-readable storage medium of claim 11, wherein receiving the GPS signals involves receiving Local Area Augmentation System (LAAS) signals in addition to GPS signals.

19. The computer-readable storage medium of claim 11, wherein each master includes a computer system coupled to the stationary network.

20. The computer-readable storage medium of claim 11, wherein the multiple masters are geographically distributed.

21. An apparatus that uses Global Positioning System (GPS) signals to synchronize multiple masters on a stationary network, comprising:

multiple masters on the stationary network;

a receiver within each master that is configured to receive the GPS signals;

a local clock within each master;

an extraction mechanism within each master that is configured to extract a time value from the GPS signals;

a synchronization mechanism within each master that is configured to use the extracted time value to synchronize the local clock at the master; and

an interaction mechanism within each master that is configured to use the local clock at the master to synchronize interactions with other masters on the stationary network.

22. The apparatus of claim 21, further comprising a sending mechanism within a master that is configured to send a synchronization signal from the master to a slave, which does not possess a GPS receiver, in order to synchronize a local clock on the slave with the local clock on the master.

23. The apparatus of claim 21, wherein the extraction mechanism is configured to use Universal Coordinated Time (UTC) correction parameters in the GPS signals to convert a GPS time value into a UTC time value.

24. The apparatus of claim 21, wherein the extraction mechanism is configured to use Standard Positioning Service (SPS) signals within the GPS signals to obtain a time value that is accurate to within 340 nanoseconds.

25. The apparatus of claim 21, wherein the extraction mechanism is configured to use Precise Positioning Service (PPS) signals within the GPS signals to obtain a time value that is accurate to within 200 nanoseconds.

26. The apparatus of claim 21, wherein the receiver within each master is configured to receive differential GPS signals in addition to GPS signals.

27. The apparatus of claim 21, wherein the receiver within each master is configured to receive Wide Area Augmentation System (WAAS) signals in addition to GPS signals.

28. The apparatus of claim 21, wherein the receiver within each master is configured to receive Local Area Augmentation System (LAAS) signals in addition to GPS signals.

29. The apparatus of claim 21, wherein each master includes a computer system coupled to the stationary network.

30. The apparatus of claim 21, wherein the multiple masters are geographically distributed.