TIMED FINGERPRINT LOCATING IN WIRELESS NETWORKS

• US 20110207470A1
• Filed: 02/25/2010
• Published: 08/25/2011
• 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: Puthenpura, Sarat, Zhao, Wenjie, Fix, Jeremy, Austin, Mark, Meredith, Sheldon
• Granted Patent: US 8,224,349 B2
• Time in Patent Office: Days
• 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 facilitating locating a User Equipment (UE) in a wireless network, the method comprising:

determining a set of geographical bin grid framework frame locations, the bin grid framework having a predetermined granularity;

determining a set of NodeB Site Pairs (NBSPs), the set of NBSPs comprising a first NodeB site and a second NodeB site, wherein the location of each NodeB site is known;

determine a set of reference frames, wherein there is at least one reference frame for each NBSP, the location of each reference frame being known;

accessing a first time value (OV(1)) for a first frame of the bin grid framework correlated to a first known geographic location;

accessing a location information for the first known geographic location;

determining a first differential value (DV(1)) for the first frame, related, at least in part, to a difference between the location of the first frame and the location of a first NBSP;

accessing a location information for a first reference location correlating to the first NBSP;

determining a second differential value (DV(2)) for the first reference frame, related, at least in part, to a difference between the location of the first reference frame and the location the first NBSP; and

determining a time value (OV(2)) based, at least in part, on OV(1), DV(1), and DV(2).

2. The method of claim 1, wherein determining the value of OV(2) employs the formula:

OV(2)=OV(1)+DV(2)−

DV(1).

3. The method of claim 1, further comprising:

determining a set of values comprising computed differential values for each NBSP and the frames within a predetermined distance from each NBSP, each computed differential value is related, at least in part, to a difference between a location of a frame and the location of a relevant NBSP, wherein a relevant NBSP is a NBSP within the predetermined distance.

4. The method of claim 3 wherein determining the set of values employs the formula:

DV(NBSP_PQ,X_F)=OV(NBSP_QP, X_F)−

OV(NBSP_QP,X_R)+DV(NBSP_PQ,X_R) for a set of P, set of Q, and set of F, and where R is correlated to P, and wherein P, Q, F and R are index values that can be incremented.

5. The method of claim 3, further comprising:

accessing a time value for a second UE in the network as OV(3);

determining a subset of relevant NBSP for the second UE;

determining a lookup value based at least in part on OV(3),

returning a first subset of frames for a search through the frame data value set, searching for frames correlated to the lookup value and a NBSP of the subset of relevant NBSP.

6. The method of claim 5, wherein determining the lookup value employs the formula:

Lookup Value=OV(3)−

OV(2)+DV(2).

7. The method of claim 5, further comprising:

determining a second relevant NBSP of the subset of relevant NBSP for the second UE;

returning a second subset of frames for a search through the frame data value set, searching for frames correlated to the lookup value and the second relevant NBSP; and

indicating intersecting frames between the first returned subset and second returned subset of frames.

8. The method of claim 7 wherein a single intersecting frame is indicated, such that the geographic location of the intersecting frame is the most probable location of the UE.

9. The method of claim 7, wherein a plurality of intersecting frames is indicated, determining additional intersecting frames from additional subsets of frames by searching the data value set for frames correlated to the lookup value and additional NBSP of the subset of relevant NBSP, so as to converge on a single frame being the most probable location for the UE.

11. The method of claim 1, wherein the predetermined granularity of the geographical frame locations is 100 m×

100 m for each frame.

12. The method of claim 1, wherein the predetermined granularity of the geographical frame locations is 1×

1 UMTS chip for each frame.

13. The method of claim 1, wherein the first time value and the correlated known geographic location are accessed at a location aware UE.

14. The method of claim 13, wherein the location aware UE employs AGPS for location awareness.

10. The method of 9, wherein the intersecting frame sets do not converge.

15. A system for determining the location of a UE in a wireless network, the system comprising:

a plurality of NodeBs;

at least one bin grid framework, with a predetermined level of granularity, mapped to a geographic area of the wireless network to facilitate locating UEs within particular frames based at least in part on UE time data;

at least one frame of the bin grid framework designated as a reference frame for each NodeB Site Pair (NBSP) comprising two NodeBs separated by no more than a predetermined number of UMTS chips;

a time fingerprint locating (TFL) platform that is communicatively coupled to a processor and memory storing at least a data set relating to differential frame values for at least one NBSP, the TFL platform accessing timing data related to a UE and comparing the timing data to the stored data set correlated to a relevant NBSP to facilitate determining the location of the UE within the wireless network.

16. The system of claim 15, wherein the stored data represents the differential distance of each frame if the bin grid framework from each NodeB in each relevant NBSP calculated by:

DV(ij,X)=OV(ji,X)−

OV(ji,R)+DV(ij,R),

wherein i is one NodeB of the NBSP, j is the other NodeB of the NBSP, X indicates the target frame, R indicates a reference frame, DV indicates a differential value and OV indicates an observed value. and

the data set is indexed across relevant NBSPs.

17. The system of claim 16, wherein a first lookup comparing a target value with stored values performed by the processor on a subset of the stored data, the subset being determined by an index relating to a first relevant NBSP, returns a first set of frames that represent possible locations of the UE.

18. The system of claim 17, wherein a second lookup comparing the target value with stored values performed by the processor on a subset of the stored data, the subset being determined by an index relating to a second relevant NBSP, returns a second set of frames that represent possible locations of the UE.

19. The system of claim 18, wherein the processor determines the intersection of the first and second set of frames to reduce the number of frames that represent possible locations of the UE.

20. The system of claim 19, wherein a single frame results from the determined intersection, the location of the UE is determined to be within the granular area of the geographic area or the wireless network mapped by the frame.

21. A system for accessing a bin grid framework data set representative of a geographical portion of a wireless network, the system comprising:

a processor communicatively coupled to at least one memory component;

an interface to the wireless network;

the processor being operative to;

access location and timing data related to one or more UEs of the wireless network through the wireless network interface;

determine and store at the at least one memory component, differential values related to reference frames of the bin grid framework and designated NBSP for a plurality of NBSPs;

determine and store the differential values related to non-reference frames of the bin grid framework and designated NBSP for a plurality of NBSP;

index the stored values by NBSP;

search the stored values to return information relating to the bin grid network;

determine a search value for a UE of a plurality of relevant NBSPs such that sets of frames can be returned, said frames having a substantial probability of indicating the location of the UE.