Method for disseminating geolocation information for network infrastructure devices

• US 20080101277A1
• Filed: 07/06/2006
• Published: 05/01/2008
• Est. Priority Date: 07/06/2006
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Chen, Liren, Taylor, Kirk S., Steenstra, Jack
• Granted Patent: US 8,340,682 B2
• Time in Patent Office: Days
• US Class Current: 370/328
• CPC Class Codes: G01S 5/0289 of multiple transceivers, e.g. in ad hoc networks
• CPC Class Codes: H04L 67/52 specially adapted for the location of the user terminal
• CPC Class Codes: H04W 4/02 Services making use of location information
• CPC Class Codes: H04W 4/029 Location-based management or tracking services

Abstract

A scheme is provided for distributing reference geographical locations on a network. Geolocation information is integrated or associated with one or more network infrastructure devices to permit them to serve as reference points for the rest of the network. A reference geographical location associated with a network infrastructure device may be broadcast by the network infrastructure device over a network. Alternatively, other network devices may request reference geographical location from a network infrastructure device or obtain it from a network-accessible database that stores such geolocation information. Other network devices can then use the one or more reference geographical locations to determine their own geographical location. By allowing existing network devices to take advantage of the geolocation capability of its “neighboring” network devices, this scheme provides a convenient way to deliver geolocation to many network devices.

Claims

1. A method for disseminating geolocation information between network infrastructure devices, comprising:

obtaining a geographical location of the reference network device;

storing the geographical location as part of the management information base of the reference network device;

providing the geographical location to other network devices on the communication network; and

monitoring for a change in the geographical location of the reference network device.

2. The method of 1 further comprising:

updating the geographical location if the reference network device moves.

3. The method of 1 wherein the geographical location includes a longitude and a latitude.

4. The method of 1 further comprising:

supporting a network time protocol that facilitates distance estimation between the reference network device and other network devices by synchronizing their clocks.

5. The method of 1 wherein the geographical location is automatically propagated to other network devices.

6. The method of 1 wherein the geographical location of the reference network device is obtained from an onboard global positioning device.

7. The method of 1 wherein the geographical location of the reference network device is manually configured into the reference network device.

8. The method of 1 wherein the geographical location of the reference network device is obtained by

acquiring one or more reference geographical locations for other reference network devices;

determining one or more distances from the reference network device to each of the one or more reference geographical locations; and

deriving the geographical location of the reference network device based on the one or more reference geographical locations of the other reference network devices and the one or more distances.

9. The method of 8 wherein the one or more reference geographical locations are obtained from a root reference server on the communication network.

10. The method of 1 further comprising:

associating an accuracy indicator with the geographical location of the reference network device; and

providing the accuracy indicator along with the geographical location of the reference network device.

11. The method of 10 wherein the accuracy indicator is determined based on one or more accuracy indicators associated with one or more reference geographical locations for other reference network devices.

12. The method of 10 further comprising:

updating the geographical location of the reference network device based on one or more new reference geographical locations for other reference network devices having associated accuracy indicators, wherein the reference network device uses a particular reference geographical location only if its associated accuracy indicator is better than the accuracy indicator associated with the reference network device.

13. The method of 1 further comprising:

appending an expiration timestamp to the geographical location provided to other network devices, wherein the expiration timestamp indicates how long the geographical location can be relied on.

14. The method of 1 further comprising:

authorizing the reference network device to provide its geographical location to other network devices on the communication network.

15. The method of 1 wherein the geographical location of the reference network device is obtained by

obtaining a reference geographical location associated with a second reference network device;

synchronizing a first clock in the reference network device with a second clock in the second reference network device, the synchronized first and second clocks facilitating a direct one-way trip time measurement between the reference infrastructure device and the second reference network device;

obtaining a one-way distance between the reference infrastructure device and the second reference network device based on the direct on-way trip time measurement; and

obtaining the geographical location associated with the reference network device based on the reference geographical location and the one-way distance.

16. The method of 15 wherein the direct one-way trip time measurement is performed for both a transmit path from the reference network device and a receive path to the reference network device.

17. The method of 16 wherein the transmit path has a different transmission speed than the receive path.

18. The method of 15 further comprising:

determining the transmission medium between the reference network device and the second reference network device;

determining a propagation speed of the transmission medium;

obtaining a propagation time between the reference network device and the second reference network device based on the transmission medium propagation speed between the reference network device and the second reference network device; and

obtaining the geographical location associated with the reference network device based on the reference geographical location and the propagation time.

19. A network infrastructure device comprising:

an input interface configured to obtain a geographical location associated with the network infrastructure device; and

a processing circuit coupled to the input interface and configured to obtain the geographical location from the interface, and

store the geographical location as part of the management information base of the network infrastructure device;

an output interface coupled to the processing circuit to transmit the geographical location over a communication network to other network devices.

20. The network infrastructure device of 19 wherein the processing circuit is further configured to

automatically propagate the geographical information to other network devices via the output interface.

21. The network infrastructure device of 19 wherein the processing circuit is further configured to

monitor for changes in the geographical location of the network infrastructure device.

22. The network infrastructure device of 19 wherein the input interface is coupled to one of either an internal geolocation device, an external geolocation device, or a user input device for manual entry of geolocation information.

23. The network infrastructure device of 19 wherein the geographical location of the network infrastructure device is obtained by

acquiring one or more reference geographical locations for other network infrastructure devices;

determining one or more distances from the network infrastructure device to each of the other network infrastructure devices; and

deriving the geographical location of the network infrastructure device based on the one or more reference geographical locations of the other network infrastructure devices and the one or more distances.

24. The network infrastructure device of 19 wherein the input interface is a local interface to couple directly to a reference infrastructure device to obtain a reference geographical location.

25. The network infrastructure device of 24 wherein a transmission medium to the reference infrastructure device and a propagation speed of the transmission medium are known to the network infrastructure device.

26. The network infrastructure device of 25 wherein the transmission medium propagation speed is used to obtain a propagation time to the reference infrastructure device and the geographical location associated with the network infrastructure device is obtained based on the reference geographical location and the propagation time to the reference infrastructure device.

27. The network infrastructure device of 24 further comprising:

a first clock to synchronize with a second clock in the reference infrastructure device, the synchronized first and second clocks facilitating a direct one-way trip time measurement between the network infrastructure device and the reference infrastructure device.

28. The network infrastructure device of 27 wherein the direct one-way trip time measurement is performed for both a transmit path from the network infrastructure device and a receive path to the network infrastructure device.

29. The network infrastructure device of 28 wherein the transmit path has a different transmission speed than the receive path.

30. The network infrastructure device of 19 further comprising:

associating an accuracy indicator with the geographical location of the reference network device; and

transmitting the accuracy indicator along with the geographical location of the network infrastructure device.

31. A network infrastructure device comprising:

means for obtaining the geographical location of the network infrastructure device;

means for storing the geographical location of the network infrastructure device; and

means for providing the geographical location of the network infrastructure device to other network devices.

32. The network infrastructure device of 27 further comprising:

means for monitoring for a change in the geographical location of the network infrastructure device.

33. A machine-readable medium having one or more instructions for enabling a network infrastructure device to facilitate propagation of geolocation information on a communication network, which when executed by a processor causes the processor to:

obtain a reference geographical location associated with a second network infrastructure device;

synchronize a first clock in the network infrastructure device with a second clock in the second network infrastructure device, the synchronized first and second clocks facilitating a direct one-way trip time measurement between the network infrastructure device and the second network infrastructure device;

obtain a one-way distance between the network infrastructure device and the second network infrastructure device based on the direct on-way trip time measurement;

obtain a geographical location associated with the network infrastructure device based on the reference geographical location and the one-way distance; and

provide the geographical location to a third network device on the communication network to enable the third network device to obtain its own geographical location.

34. The machine-readable medium of 33, further comprising one or more instructions to acquire one or more reference geographical locations for other network infrastructure devices;

determine one or more distances from the network infrastructure device to each of the one or more reference geographical locations; and

derive the geographical location of the network infrastructure device based on the one or more reference geographical locations of the other network infrastructure devices and the one or more distances.

35. The machine-readable medium of 33, further comprising one or more instructions to

associate an accuracy indicator with the geographical location of the network infrastructure device;

and

provide the accuracy indicator along with the geographical location of the network infrastructure device.

36. The machine-readable medium of 35 wherein the accuracy indicator is determined based on one or more accuracy indicators associated with one or more reference geographical locations for other network infrastructure devices.

37. The machine-readable medium of 35, further comprising one or more instructions to

update the geographical location of the network infrastructure device based on one or more new reference geographical locations for other network infrastructure devices having associated accuracy indicators, wherein the network infrastructure device uses a particular reference geographical location only if its associated accuracy indicator is better than the accuracy indicator associated with the network infrastructure device.

38. The machine-readable medium of 33, further comprising one or more instructions to

append an expiration timestamp to the geographical location provided to other network devices, wherein the expiration timestamp indicates how long the geographical location can be relied on.

39. A method for disseminating geolocation information across a network, comprising:

providing a reference geographical location from a reference network infrastructure device to other network infrastructure devices on the network;

synchronizing clocks between the reference network device and a first network infrastructure device to facilitate a one-way trip time measurement between the reference network infrastructure device and the first network infrastructure device;

obtaining a distance between the reference network device and the first network infrastructure device based on the one-way trip time measurement; and

obtaining a geographical location for the first network infrastructure device based on the reference geographical location and the distance between the reference network device and the first network infrastructure device.

40. The method of 39 further comprising:

compensating for time delays caused be intervening network devices between the reference network device and the first network infrastructure device to enhance the accuracy of the distance between the reference network infrastructure device and the first network infrastructure device.

41. The method of 39 further comprising:

obtaining a roundtrip time measurement between the reference network infrastructure device and a non-synchronized network infrastructure device;

ascertaining processing delays at the non-synchronized network infrastructure device;

obtaining a distance between the reference network device and the non-synchronized network infrastructure device based on the roundtrip time measurement and compensating for the processing delays; and

obtaining a geographical location for the non-synchronized network infrastructure device based on the reference geographical location and the distance between the reference network device and the non-synchronized network infrastructure device.