DISTRIBUTED LATENCY MEASUREMENT SYSTEM FOR COMMUNICATION SYSTEM ANALYSIS

• US 20110019558A1
• Filed: 07/27/2009
• Published: 01/27/2011
• Est. Priority Date: 07/27/2009
• Status: Abandoned Application

• Current Assignee: Honeywell International Inc.
• Original Assignee: Honeywell International Inc.
• Inventors: Griffin, Brian, Rowe, Eric
• Application Number:
  US12/509,525
• Publication Number:
  US 20110019558A1
• Time in Patent Office: Days
• US Class Current: 370/252
• CPC Class Codes: H04L 43/0858 One way delays
• CPC Class Codes: H04L 43/106 using time related information in packets, e.g. by adding timestamps
• CPC Class Codes: H04L 67/12 specially adapted for proprietary or special-purpose networking environments, e.g. medical networks, sensor networks, networks in vehicles or remote metering networks
• CPC Class Codes: H04L 69/28 Timers or timing mechanisms used in protocols

Abstract

Apparatus and methods are provided for generating real-time measured latency data. A message is generated with a time stamp. The time stamp indicates a time the message was sent. The time the message was sent is determined based on a reference-clock source, such as a Global Positioning System (GPS) satellite. A time that the message was received is determined using the reference-clock source. The real-time measured latency data is determined based on the time stamp and the time the message was received. If user data is present in the message, the user data is determined by removing the time stamp from the message. The time stamp and the time the message was received may be generated using a latency-measuring device that is configured to communicate with the reference-clock source. The latency-measuring device may be aboard an unmanned aerial vehicle (UAV) or an unmanned ground vehicle (UGV).

Claims

1. A method, comprising:

receiving a message via a network at a receiving device, the message comprising a time stamp, wherein the time stamp indicates a time the message was sent based on a first signal from a reference-clock source;

wirelessly receiving a second signal from the reference-clock source;

at the receiving device, determining a message-reception time for reception of the message based a time indicated in the second signal;

determining real-time measured latency data based on the time stamp and the message-reception time; and

outputting the real-time measured latency data.

2. The method of claim 1, wherein receiving the second signal comprises receiving the second signal at a latency-measurement device, wherein the latency-measurement device comprises a data receiver, a data transmitter, a reference clock, and a time-stamp processor.

3. The method of claim 2, wherein the latency-measurement device is configured to be utilized aboard an unmanned aerial vehicle (UAV).

4. The method of claim 2, wherein determining the message-reception time comprises determining the message-reception time at the reference clock.

5. The method of claim 2, wherein determining real-time measured latency data comprises determining real-time measured latency data at the latency-measurement device.

6. The method of claim 1, wherein the reference-clock source is a Global Positioning System (GPS) reference-clock source.

7. The method of claim 6, wherein the reference-clock source is one GPS satellite.

8. The method of claim 7, wherein the message further comprises transmitted data, and wherein the method further comprises:

determining the transmitted data from the message, based on removing the time stamp from the message; and

after removing the time stamp, outputting the transmitted data.

9. A device, comprising:

a processing unit;

a network-communication device;

data storage; and

machine-language instructions, stored in the data storage and configured to instruct the processor to perform functions, the functions comprising;

receiving a message via the network-communication interface, the message comprising a time stamp, wherein the time stamp indicates a time the message was sent based on a first signal from a reference-clock source,

wirelessly receiving a second signal from the reference-clock source,

determining a message-reception time for reception of the message based a time indicated in the second signal,

determining real-time measured latency data based on the time stamp and the message-reception time, and

outputting the real-time measured latency data.

10. The device of claim 9, further comprising a latency-measurement device configured to receive at least the second signal wirelessly from the reference-clock source.

11. The device of claim 10, wherein the device is configured to be utilized aboard an unmanned aerial vehicle (UAV).

12. The device of claim 10, wherein the device is configured to be utilized aboard an unmanned ground vehicle (UGV).

13. The device of claim 10, wherein the reference-clock source is a Global Positioning System (GPS) reference-clock source.

14. The device of claim 13, wherein the functions further comprise:

negotiating a GPS satellite to be used as the reference-clock source.

15. The device of claim 9, wherein the message further comprises transmitted data.

16. The device of claim 15, wherein the functions further comprise:

determining the transmitted data from the message, based on removing the time stamp from the message; and

after removing the time stamp, transmitting the transmitted data.

17. A method, comprising:

generating a message comprising a time-stamp, wherein the time stamp indicates a time for sending the message, and wherein the time for sending the message is based on a wireless signal received from a reference-clock source;

determining that user data is present;

responsive to determining that the user data is present, updating the message to include the user data; and

sending the message over a network via a network interface.

18. The method of claim 17, wherein the reference-clock source is a Global Positioning System (GPS) reference-clock source.

19. The method of claim 17, wherein generating the message comprises generating the message at a latency-measurement device, and wherein the latency-measurement device is configured to:

receive the wireless signal at a reference clock;

generate the time-stamp based on the wireless signal; and

generate the message based on the time-stamp.

20. The method of claim 19, wherein the latency-measurement device is configured to be utilized aboard an unmanned aerial vehicle (UAV).