ROBUST AND RESILIENT TIMING ARCHITECTURE FOR CRITICAL INFRASTRUCTURE

• US 20160306048A1
• Filed: 04/17/2015
• Published: 10/20/2016
• Est. Priority Date: 04/17/2015
• Status: Active Grant

• Current Assignee: Mitre Corporation
• Original Assignee: Mitre Corporation
• Inventors: DUNN, Jeffrey, McKENNA, Sean, MARTIN, Cynthia E., COHEN, Michael L.
• Granted Patent: US 10,775,749 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G04G 7/00 Synchronisation radio-controlled time-pieces G04R
• CPC Class Codes: G04R 20/02 the radio signal being sent by a satellite, e.g. GPS

Abstract

A device for transmitting synchronized timing including a receiver, a transmitter, one or more processors, memory, and one or more programs, wherein the one or more programs are stored in the memory and configured to be executed by the one or more processors, the programs including instructions for receiving through the receiver a timing signal comprising first time information that is synchronized to a time standard, determining second time information based at least partially on the first time information, composing a message formatted in accordance with a global navigation satellite system (GNSS) standard, wherein the message comprises the second time information, and transmitting the message through the transmitter on a radio signal having a frequency in the frequency modulation (FM) radio frequency band.

Claims

1. A device for transmitting synchronized timing comprising:

a receiver;

a transmitter;

one or more processors;

memory; and

one or more programs, wherein the one or more programs are stored in the memory and configured to be executed by the one or more processors, the programs including instructions for;

receiving through the receiver a timing signal comprising first time information that is synchronized to a time standard;

determining second time information based at least partially on the first time information;

composing a message formatted in accordance with a global navigation satellite system (GNSS) standard, wherein the message comprises the second time information; and

transmitting the message through the transmitter on a radio signal having a frequency in a frequency modulation (FM) radio frequency band.

2. The device of claim 1, wherein the time standard is Coordinated Universal Time (UTC).

3. The device of claim 1, wherein the synchronization of the first time information to the time standard is accurate to within 10 nanoseconds [goal is 1 nanosecond].

4. The device of claim 1, wherein the first time information is independent of a GNSS.

5. The device of claim 1, wherein the receiver is configured to receive the timing signal over fiber optic cable from a ground-based time transmitter.

6. The device of claim 1, wherein the second time information is synchronized to the time standard and the synchronization is accurate to within 500 nanoseconds [goal is 100].

7. The device of claim 1, wherein the message further comprises information based on a location of the device.

8. The device of claim 1, wherein the transmitter is configured to simultaneously transmit the message on two radio signals having frequencies in the FM radio frequency band.

9. The device of claim 1, further including instructions for encrypting the message prior to transmitting the message through the transmitter.

10. The device of claim 1, wherein the message comprises at least one of a pseudorandom noise code, time-of-week information, and clock correction information.

11. A method comprising:

at an electronic device with a processor, a receiver, and a transmitter;

receiving through the receiver a timing signal comprising first time information that is synchronized to a time standard;

determining second time information based at least partially on the first time information;

composing a message formatted in accordance with a GNSS standard, wherein the message comprises the second time information; and

transmitting the message through the transmitter on a radio signal having a frequency in an FM radio frequency band.

12. The method of claim 11, wherein the time standard is UTC.

13. The method of claim 11, wherein the synchronization of the first time information to the time standard is accurate to within 10 nanoseconds [goal is 1 nanosecond].

14. The method of claim 11, wherein the first time information is independent of a GNSS.

15. The method of claim 11, wherein the receiver is configured to receive the timing signal over fiber optic cable from a ground-based time transmitter.

16. The method of claim 11, wherein the second time information is synchronized to the time standard and the synchronization is accurate to within 500 nanoseconds [goal is 100].

17. The method of claim 11, wherein the message further comprises information based on a location of the device.

18. The method of claim 11, wherein the transmitter is configured to simultaneously transmit the message on two radio signals having frequencies in the FM radio frequency band.

19. The method of claim 11, further comprising encrypting the message prior to transmitting the message through the transmitter.

20. The method of claim 11, wherein the message comprises at least one of a pseudorandom noise code, time-of-week information, and clock correction information.

37. The system of claim 19, wherein the one or more errors comprises low signal strength or loss of signal.

21. A receiving device comprising:

a receiver;

a transmitter;

one or more processors;

memory; and

one or more programs, wherein the one or more programs are stored in the memory and configured to be executed by the one or more processors, the programs including instructions for;

receiving through the receiver a radio signal having a frequency in an FM radio frequency band, the radio signal comprising a message formatted in accordance with a GNSS standard;

extracting first time information from the message;

determining second time information based at least partially on the first time information, wherein the second time information is synchronized to a time standard;

generating a timing signal based at least partially on the second time information; and

transmitting the timing signal through the transmitter.

22. The receiving device of claim 21, wherein the synchronization of the second time information is accurate to within 10 microseconds relative to the time standard. [goal is 1 microsecond]

23. The receiving device of claim 21, wherein the receiver is configured to simultaneously receive two radio signals having frequencies in an FM radio frequency band.

24. The receiving device of claim 21, including instructions for decrypting the message.

25. The receiving device of claim 21, wherein the message comprises at least one of a pseudorandom noise code, time-of-week information, and clock correction information.

26. The receiving device of claim 21, further comprising a second receiver configured to receive a GNSS signal and determine a GNSS time information from the GNSS signal, and further including instructions for:

detecting one or more errors in the radio signal and the GNSS signal; and

generating the timing signal based at least partially on the second time information when a GNSS signal error is detected and at least partially on the GNSS time information when a radio signal error is detected.

27. A receiving method comprising:

at an electronic device with a processor, a receiver, and a transmitter;

receiving through the receiver a radio signal having a frequency in the FM radio frequency band, the radio signal comprising a message formatted in accordance with a GNSS standard;

extracting first time information from the message;

determining second time information based at least partially on the first time information, wherein the second time information is synchronized to a time standard;

generating a timing signal based at least partially on the second time information; and

transmitting the timing signal through the transmitter.

28. The receiving method of claim 27, wherein the synchronization of the second time information is accurate to within 10 microseconds relative to the time standard. [goal is 1 microsecond]

29. The receiving method of claim 27, wherein the receiver is configured to simultaneously receive two radio signals having frequencies in an FM radio frequency band.

30. The receiving method of claim 27, including decrypting the message.

31. The receiving method of claim 27, wherein the message comprises at least one of a pseudorandom noise code, time-of-week information, and clock correction information.

32. The receiving method of claim 27, further comprising a second receiver configured to receive a GNSS signal and determine a GNSS time information from the GNSS signal, and further including instructions for:

detecting one or more errors in the radio signal and the GNSS signal; and

generating the timing signal based at least partially on the second time information when a GNSS signal error is detected and at least partially on the GNSS time information when a radio signal error is detected.

33. A non-transitory computer readable storage medium storing one or more programs, the one or more programs comprising instructions, which when executed by an electronic device with a receiver and a receiver and a transmitter, cause the device to:

receive through the receiver a radio signal having a frequency in the FM radio frequency band, the radio signal comprising a message formatted in accordance with a GNSS standard;

extract first time information from the message;

determine second time information based at least partially on the first time information, wherein the second time information is synchronized to a time standard;

generate a timing signal based at least partially on the second time information; and

transmit the timing signal through the transmitter.

34. A system comprising:

a transmitting unit comprising;

a first receiver;

a first transmitter;

one or more first processors;

first memory; and

one or more first programs, wherein the one or more first programs are stored in the first memory and configured to be executed by the one or more first processors, the first programs including instructions for;

receiving through the first receiver a first timing signal comprising first time information that is synchronized to a time standard;

determining second time information based at least partially on the first time information;

composing a message formatted in accordance with a GNSS standard, wherein the message comprises the second time information; and

transmitting the message through the first transmitter on a radio signal having a frequency in an FM radio frequency band; and

a receiving unit comprising;

a second receiver;

a second transmitter;

one or more second processors;

second memory; and

one or more second programs, wherein the one or more second programs are stored in the second memory and configured to be executed by the one or more second processors, the second programs including instructions for;

receiving through the second receiver the radio signal;

extracting the second time information from the message transmitted on the radio signal;

determining third time information based at least partially on the second time information, wherein the third time information is synchronized to the time standard;

generating a second timing signal based at least partially on the third time information; and

transmitting the second timing signal through the second transmitter.

35. The system of claim 34, wherein the third time information is synchronized to the time standard with an accuracy of within 10 microseconds. [goal is 1 microsecond].

36. A system comprising:

a receiving module comprising;

a receiver;

a first transmitter;

one or more first processors;

first memory; and

one or more first programs, wherein the one or more first programs are stored in the first memory and configured to be executed by the one or more first processors, the first programs including instructions for;

receiving through the receiver a radio signal having a frequency in the FM radio frequency band, the radio signal comprising a message formatted in accordance with a GNSS standard;

extracting first time information from the message;

determining second time information based at least partially on the first time information, wherein the second time information is synchronized to a time standard;

generating a first timing signal based at least partially on the second time information; and

transmitting the first timing signal through the first transmitter;

a GNSS module configured to receive a GNSS signal and transmit a GNSS timing signal based at least partially on the GNSS signal; and

a management module comprising;

a second transmitter;

one or more second processors;

second memory; and

one or more second programs, wherein the one or more second programs are stored in the second memory and configured to be executed by the one or more second processors, the second programs including instructions for;

detecting one or more errors in the radio signal and the GNSS signal, and

transmitting a second timing signal, wherein the second timing signal is based at least partially on the first timing signal in accordance with detecting an error in the GNSS signal and at least partially on the GNSS timing signal in accordance with detecting an error in the radio signal.