ACCESS POINT SELECTION FOR NETWORK-BASED POSITIONING

• US 20150094085A1
• Filed: 02/18/2014
• Published: 04/02/2015
• Est. Priority Date: 09/30/2013
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: DUA, Praveen, AGRAWAL, Meghna
• Granted Patent: US 9,426,770 B2
• Time in Patent Office: Days
• US Class Current: 455/456.1
• CPC Class Codes: A01K 1/01 Removal of dung or urine, e.g. from stablesA01K1/015 takes precedence; from poultry houses A01K31/04
• CPC Class Codes: A01K 1/0114 Litter boxes with screens for separating excrement from litter
• CPC Class Codes: A47L 13/52 Dust pans; Crumb trays
• CPC Class Codes: E01H 1/006 Specially adapted for removing excrements hand implements E01H1/12
• CPC Class Codes: E01H 5/06 dislodging essentially by non-driven elements, e.g. scraper blades , snow-plough blades, scoop blades
• CPC Class Codes: H04W 64/00 Locating users or terminals or network equipment for network management purposes, e.g. mobility management

Abstract

A method for network-based positioning of a mobile device as described herein includes selecting a first set of access points (APs) to take first positioning measurements from the mobile device; obtaining the first positioning measurements from the first set of APs; selecting, based on the first positioning measurements, a second set of APs to take second positioning measurements from the mobile device; obtaining the second positioning measurements from the second set of APs; and determining a location of the mobile device based on the first positioning measurements and the second positioning measurements.

Claims

1. A method for network-based positioning of a mobile device, the method comprising:

selecting a first set of access points (APs) to take first positioning measurements from the mobile device;

obtaining the first positioning measurements from the first set of APs;

selecting, based on the first positioning measurements, a second set of APs to take second positioning measurements from the mobile device;

obtaining the second positioning measurements from the second set of APs; and

determining a location of the mobile device based on the first positioning measurements and the second positioning measurements.

2. The method of claim 1 wherein selecting the first set of APs comprises:

designating a central AP;

radially dividing an area extending from the central AP into a plurality of sectors; and

selecting, as the first set of APs, one or more APs from each of the sectors.

3. The method of claim 2 wherein selecting the first set of APs further comprises selecting the first set of APs based on relative distance between neighboring APs.

4. The method of claim 2 wherein selecting the first set of APs further comprises selecting the first set of APs based on relative signal strengths between neighboring APs.

5. The method of claim 1 wherein at least one of the first positioning measurements or the second positioning measurements comprise round trip time (RTT) measurements.

6. The method of claim 1 wherein at least one of the first positioning measurements or the second positioning measurements comprise received signal strength indication (RSSI) measurements.

7. The method of claim 1 wherein selecting the first set of APs comprises selecting the first set of APs based on a set of APs used for a previous position fix for the mobile device.

8. The method of claim 1, further comprising:

at a second time subsequent to a first time of determining the location of the mobile device, determining whether a difference between the first time and the second time is less than a threshold, wherein the location of the mobile device determined at the first time is a first location of the mobile device; and

if the difference between the first time and the second time is less than the threshold, selecting, based on the first location of the mobile device, a third set of APs to take third positioning measurements from the mobile device, obtaining the third positioning measurements from the third set of APs, and determining a second location of the mobile device based on the first location of the mobile device and the third positioning measurements.

9. The method of claim 1, further comprising:

at a second time subsequent to a first time of determining the location of the mobile device, determining whether an estimated amount of movement of the mobile device between the first time and the second time is less than a threshold, wherein the location of the mobile device determined at the first time is a first location of the mobile device; and

if the estimated amount of movement is less than the threshold, selecting, based on the first location of the mobile device, a third set of APs to take third positioning measurements from the mobile device, obtaining the third positioning measurements from the third set of APs, and determining a second location of the mobile device based on the first location of the mobile device and the third positioning measurements.

10. The method of claim 1 wherein selecting the second set of APs comprises:

designating an initial estimated location of the mobile device based on the first positioning measurements or a previously determined location of the mobile device;

radially dividing an area extending from the initial estimated location into a plurality of sectors; and

selecting, as the second set of APs, one or more APs from each of the sectors.

11. The method of claim 1 wherein selecting the second set of APs comprises:

identifying an AP of the first set of APs having a strongest mean received signal strength indication (RSSI); and

selecting the second set of APs based on a neighboring AP list for the AP of the first set of APs having the strongest mean RSSI.

12. The method of claim 1 wherein:

the method further comprises determining an estimated coarse position of the mobile device based on the first positioning measurements; and

selecting the second set of APs comprises selecting the second set of APs based at least in part on the estimated coarse position of the mobile device.

13. A positioning server comprising:

an access point (AP) coordination module configured to select a first set of APs to take first positioning measurements from a mobile device, to obtain the first positioning measurements from the first set of APs, to select, based on the first positioning measurements, a second set of APs to take second positioning measurements from the mobile device, and to obtain the second positioning measurements from the second set of APs; and

a positioning engine communicatively coupled to the AP coordination module and configured to determine a location of the mobile device based on the first positioning measurements and the second positioning measurements.

14. The positioning server of claim 13 wherein the AP coordination module is further configured to select the first set of APs by designating a central AP, radially dividing an area extending from the central AP into a plurality of sectors, and selecting, as the first set of APs, one or more APs from each of the sectors.

15. The positioning server of claim 14 wherein the AP coordination module is further configured to select the first set of APs based on relative distance between neighboring APs.

16. The positioning server of claim 14 wherein the AP coordination module is further configured to select the first set of APs based on relative signal strengths between neighboring APs.

17. The positioning server of claim 13 wherein at least one of the first positioning measurements or the second positioning measurements comprise round trip time (RTT) measurements or received signal strength indication (RSSI) measurements.

18. The positioning server of claim 13 wherein the AP coordination module is further configured to select the first set of APs based on a set of APs used for a previous position fix for the mobile device.

19. The positioning server of claim 13 wherein the AP coordination module is further configured to select the second set of APs by identifying an AP of the first set of APs having a strongest mean received signal strength indication (RSSI) and selecting the second set of APs based on a neighboring AP list for the AP of the first set of APs having the strongest mean RSSI.

20. The positioning server of claim 13 wherein:

the positioning engine is further configured to determine an estimated coarse position of the mobile device based on the first positioning measurements; and

the AP coordination module is further configured to select the second set of APs based at least in part on the estimated coarse position of the mobile device.

21. An apparatus that facilitates network-based positioning of a mobile device, the apparatus comprising:

means for selecting a first set of access points (APs) to take first positioning measurements from the mobile device;

means for obtaining the first positioning measurements from the first set of APs;

means for selecting, based on the first positioning measurements, a second set of APs to take second positioning measurements from the mobile device;

means for obtaining the second positioning measurements from the second set of APs; and

means for determining a location of the mobile device based on the first positioning measurements and the second positioning measurements.

22. The apparatus of claim 21 wherein the means for selecting the first set of APs comprises:

means for designating a central AP;

means for radially dividing an area extending from the central AP into a plurality of sectors; and

means for selecting, as the first set of APs, one or more APs from each of the sectors.

23. The apparatus of claim 22 wherein the means for selecting the first set of APs further comprises selecting the first set of APs based on at least one of relative distance between neighboring APs or relative signal strengths between neighboring APs.

24. The apparatus of claim 21 wherein the means for selecting the first set of APs comprises means for selecting the first set of APs based on a set of APs used for a previous position fix for the mobile device.

25. The apparatus of claim 21 wherein the means for selecting the second set of APs comprises:

means for identifying an AP of the first set of APs having a strongest mean received signal strength indication (RSSI); and

means for selecting the second set of APs based on a neighboring AP list for the AP of the first set of APs having the strongest mean RSSI.

26. The apparatus of claim 21 wherein:

the apparatus further comprises means for determining an estimated coarse position of the mobile device based on the first positioning measurements; and

the means for selecting the second set of APs comprises means for selecting the second set of APs based at least in part on the estimated coarse position of the mobile device.

27. A positioning server comprising:

a memory storing instructions; and

at least one processor communicatively coupled to the memory and configured to execute the instructions, wherein the instructions, when executed by the at least one processor, cause the at least one processor to;

select a first set of access points (APs) to take first positioning measurements from a mobile device;

obtain the first positioning measurements from the first set of APs;

select, based on the first positioning measurements, a second set of APs to take second positioning measurements from the mobile device;

obtain the second positioning measurements from the second set of APs; and

determine a location of the mobile device based on the first positioning measurements and the second positioning measurements.

28. The positioning server of claim 27 wherein the instructions, when executed by the at least one processor, further cause the at least one processor to:

designate a central AP;

radially divide an area extending from the central AP into a plurality of sectors; and

select, as the first set of APs, one or more APs from each of the sectors.

29. The positioning server of claim 27 wherein the instructions, when executed by the at least one processor, further cause the at least one processor to:

identify an AP of the first set of APs having a strongest mean received signal strength indication (RSSI); and

select the second set of APs based on a neighboring AP list for the AP of the first set of APs having the strongest mean RSSI.

30. The positioning server of claim 27 wherein the instructions, when executed by the at least one processor, further cause the at least one processor to:

determine an estimated coarse position of the mobile device based on the first positioning measurements; and

select the second set of APs based at least in part on the estimated coarse position of the mobile device.