Timed fingerprint locating in wireless networks

• US 8,494,557 B2
• Filed: 06/14/2012
• Issued: 07/23/2013
• Est. Priority Date: 02/25/2010
• Status: Active Grant

• Current Assignee: AT&T Mobility II LLC (AT&T, Inc.)
• Original Assignee: AT&T Mobility II LLC (AT&T, Inc.)
• Inventors: Meredith, Sheldon, Austin, Mark, Fix, Jeremy, Zhao, Wenjie, Puthenpura, Sarat
• Primary Examiner(s): Chang, Joseph
• Application Number:
  US13/523,778
• Publication Number:
  US 20120252489A1
• Time in Patent Office: 404 Days
• Field of Search: 455/456.1, 370/328
• US Class Current: 455/456.1
• CPC Class Codes: G01S 5/0252 Radio frequency fingerprinting
• CPC Class Codes: G01S 5/12 by co-ordinating position lines of different shape, e.g. hyperbolic, circular, elliptical or radial
• CPC Class Codes: H04W 24/00 Supervisory, monitoring or testing arrangements
• CPC Class Codes: H04W 28/04 Error control
• CPC Class Codes: H04W 64/00 Locating users or terminals or network equipment for network management purposes, e.g. mobility management
• CPC Class Codes: H04W 88/08 Access point devices

Abstract

Systems and techniques for determining the location of user equipment (UE) in a wireless network are disclosed. These techniques leverage geometric calculations for an overlaid bin grid framework mapping the wireless network area to store differential values for each frame of the bin grid framework for each pair of relevant NodeBs. A timing offset can be determined, such that when a time value from a target UE is accessed, the location can be quickly determined with minimal real time computation. In an aspect, the target UE time value can be search for in the pre-computed differential value data set indexed by a relevant NodeB site pair to return a set of frames (forming a hyperbola between the site pair) that can be intersected with a second set of frames for a second NodeB site pair for the same UE. The intersecting frames can represent the location of the UE in the wireless network. Further, the data can be leveraged to correct timing in the network.

Claims

1. A method, comprising:

receiving, by a system comprising a processor, a first observed time value associated with first radio links between a first pair of radios of a wireless network and a user equipment in the wireless network;

determining, by the system, a first differential time value based on the first observed time value, a first reference observed time value, and a first reference differential time value; and

determining, by the system, a location for the user equipment based on the first differential time value.

2. The method of claim 1, wherein the determining the first differential time value is determined by subtracting the first reference observed time value from the first observed time value and adding the first reference differential time value.

3. The method of claim 1, wherein the receiving the first observed time value comprises receiving the first observed time value based on a first propagation time for a first radio signal between a first radio of the first pair of radios and the user equipment, a second propagation time for a second radio signal between a second radio of the first pair of radios and the user equipment, a first delay time associated with the first radio of the first pair of radios, and a second delay time associated with the second radio of the first pair of radios.

4. The method of claim 1, wherein the first reference observed time value and the first reference differential time value are predetermined, and a wireless network base station comprises a first radio of the first pair of radios.

5. The method of claim 1, wherein the first observed time value is based on a first propagation time for a first radio signal between a first radio of the first pair of radios and the user equipment, a second propagation time for a second radio signal between a second radio of the first pair of radios and the user equipment, a first delay time associated with the first radio of the first pair of radios, and a second delay time associated with the second radio of the first pair of radios.

6. The method of claim 1, wherein the determining the location comprises comparing the first differential time value to a set of predetermined differential values associated with the first pair of radios of the wireless network.

7. The method of claim 1, wherein the determining the location comprises receiving a set of potential locations determined by comparing the first differential time value to a set of predetermined differential values associated with the first pair of radios of the wireless network.

8. The method of claim 1, further comprising:

receiving, by the system, a second observed time value associated with second radio links between a second pair of radios of the wireless network and the user equipment, wherein the second pair of radios is different from the first pair of radios; and

determining, by the system, a second differential time value based on the second observed time value, a second reference observed time value, and a second reference differential time value.

9. The method of claim 8, wherein the receiving the first observed time value comprises receiving the first observed time value associated with the first radio links between the first pair of radios and the user equipment, wherein the first pair of radios comprises a first radio and a second radio, and the receiving the second observed time value comprises receiving the second observed time value associated with the second radio links between the second pair of radios and the user equipment, wherein the second pair of radios comprises the second radio and a third radio.

10. The method of claim 8, wherein the receiving the first observed time value comprises receiving the first observed time value associated with the first radio links between the first pair of radios and the user equipment, wherein the first pair of radios comprises a first radio and a second radio, and the receiving the second observed time value comprises receiving the second observed time value associated with the second radio links between the second pair of radios and the user equipment, wherein the second pair of radios comprises a third radio and a fourth radio.

11. The method of claim 8, further comprising:

determining, by the system, a location for the user equipment based on the first differential time value and the second differential time value.

12. The method of claim 11, wherein the determining the location comprises comparing the first differential time value to a first set of predetermined differential values associated with the first pair of radios of the wireless network and comparing the second differential time value to a second set of predetermined differential values associated with the second pair of radios of the wireless network.

13. The method of claim 11, wherein the determining the location comprises receiving a subset of potential locations determined by analyzing a first set of locations determined by comparing the first differential time value to a first set of predetermined differential values associated with the first pair of radios of the wireless network and a second set of locations determined by comparing the second differential time value to a second set of predetermined differential values associated with the second pair of radios of the wireless network.

14. The method of claim 13, wherein the receiving the subset of potential locations comprises receiving a union of the first set of locations and the second set of locations.

15. A system, comprising:

memory to store instructions; and

processor, coupled to the memory, that facilitates execution of the instructions to perform operations, comprising;

receiving a first observed time value associated with radio links between a first pair of radios of a wireless network and a user equipment of a wireless network;

determining a first differential time value based on the first observed time value, a first reference observed time value, and a first reference differential time value, wherein the first reference observed time value and first reference differential time value are predetermined; and

determining a location for the user equipment based on the first differential time value.

16. The system of claim 15, wherein the determining the first differential time value comprises subtracting the first reference observed time value from the first observed time value and adding the first reference differential time value.

17. The system of claim 15, wherein the first observed time value is based on a first propagation time for a first radio signal between a first radio of the first pair of radios and the user equipment, a second propagation time for a second radio signal between a second radio of the first pair of radios and the user equipment, a first delay time associated with the first radio of the first pair of radios, and a second delay time associated with the second radio of the first pair of radios.

18. A computer-readable storage medium storing instructions that, in response to execution, cause a system comprising a processor to perform operations, comprising:

receiving a first observed time value associated with wireless cellular radio links between a first pair of radios of a wireless network and a user equipment of the wireless network;

determining a first differential time value based on the first observed time value, a first reference observed time value, and a first reference differential time value; and

determining a location for the user equipment based on the first differential time value.

19. The computer-readable storage medium of claim 18, wherein the determining the first differential time value comprises subtracting the first reference observed time value from the first observed time value and adding the first reference differential time value.