Estimating the location of a wireless terminal based on the lighting and acoustics in the vicinity of the wireless terminal

• US 9,285,455 B2
• Filed: 09/19/2012
• Issued: 03/15/2016
• Est. Priority Date: 09/19/2012
• Status: Active Grant

• Current Assignee: Polaris Wireless Incorporated
• Original Assignee: Polaris Wireless Incorporated
• Inventors: Vannucci, Giovanni, DeMont, Jason Paul
• Primary Examiner(s): PHAM, TIMOTHY X
• Application Number:
  US13/622,410
• Publication Number:
  US 20140080505A1
• Time in Patent Office: 1,273 Days
• Field of Search: 455/456.1
• US Class Current: 1/1
• CPC Class Codes: G01S 5/012 Identifying whether indoors or outdoors
• CPC Class Codes: G01S 5/02524 Creating or updating the radio-map
• CPC Class Codes: G01S 5/0278 involving statistical or probabilistic considerations G01S5/0252, G01S5/0294 take precedence

Abstract

A technique is disclosed for estimating the location of a wireless terminal at an unknown location in a geographic region. The technique is based on a two-part recognition, the first part being that there are certain optical and acoustic characteristics that are present in some environments while not being present in others, such as lighting flicker and sound reverberation. The second part of the recognition is that a correlation exists between the presence of flicker and reverberation in the vicinity of a wireless terminal and whether the wireless terminal is indoors or not. Under certain environmental conditions, flicker and reverberation are often present indoors but not outdoors. By accounting for flicker and reverberation being detected or not being detected in the vicinity of the wireless terminal, the disclosed technique is able to estimate whether the wireless terminal is indoors, which the technique also uses to improve the location estimate.

Claims

1. A method of estimating the probability that a wireless terminal is indoors, the method comprising:

generating, by the wireless terminal and as a consequence of the wireless terminal'"'"'s normal operation, sound;

measuring, by the wireless terminal, a sample of sound in the vicinity of the wireless terminal, wherein at least a portion of the generated sound is the sound that is measured by the wireless terminal;

generating, by the wireless terminal, a characterization of reverberation in the vicinity of the wireless terminal based on the sample of sound in the vicinity of the wireless terminal;

measuring, by the wireless terminal, a sample of light in the vicinity of the wireless terminal;

generating, by the wireless terminal, a characterization of flicker in the vicinity of the wireless terminal based on the sample of light in the vicinity of the wireless terminal; and

generating, by the wireless terminal, an estimate of the probability that the wireless terminal is indoors based on;

(i) the characterization of reverberation in the vicinity of the wireless terminal; and

(ii) the characterization of flicker in the vicinity of the wireless terminal.

2. The method of claim 1 wherein generating a characterization of reverberation further comprises indicating a number and strength of reflections in the sample of sound.

3. The method of claim 1 wherein the generated sound is a ringtone that is generated when the wireless terminal receives a call.

4. A wireless terminal comprising:

a sound detector for measuring a sample of sound in the vicinity of the wireless terminal, wherein the sample of sound is at least a portion of sound generated by the wireless terminal as a consequence of the wireless terminal'"'"'s normal operation;

a light detector for measuring a sample of light in the vicinity of the wireless terminal;

a processor for generating;

(1) a characterization of reverberation in the vicinity of the wireless terminal based on the sample of sound;

(2) a characterization of flicker in the vicinity of the wireless terminal based on the sample of light; and

(2) an estimate of the probability that the wireless terminal is indoors based on;

(i) the characterization of reverberation and the characterization of flicker in the vicinity of the wireless terminal.

5. The wireless terminal of claim 4 wherein sound generated by the wireless terminal is generated when the wireless terminal receives a call.

6. A method of estimating the location of a wireless terminal, the method comprising:

processing, through an antenna of the wireless terminal, an electromagnetic signal;

generating, by at least one of the wireless terminal and a location server, a value of a location-dependent trait of the electromagnetic signal, wherein the value of the location-dependent trait is dependent on the location of the wireless terminal;

measuring, by the wireless terminal, a sample of sound in the vicinity of the wireless terminal;

measuring, by the wireless terminal, a sample of light in the vicinity of the wireless terminal;

generating, by at least one of the wireless terminal and the location server, a characterization of reverberation in the vicinity of the wireless terminal based on the sample of sound in the vicinity of the wireless terminal and a characterization of flicker in the vicinity of the wireless terminal based on the sample of light in the vicinity of the wireless terminal;

generating, by at least one of the wireless terminal and the location server, an estimate of the probability that the wireless terminal is indoors based on;

(1) the characterization of reverberation in the vicinity of the wireless terminal; and

(2) the characterization of flicker in the vicinity of the wireless terminal; and

generating, by at least one of the wireless terminal and the location server, an estimate of the location of the wireless terminal based on;

(1) the value of the location-dependent trait, and

(2) the estimate of the probability that the wireless terminal is indoors, wherein the estimate of the probability affects a manner in which the value of the location-dependent trait is processed to generate an estimate of the location of the wireless terminal.

7. A method of estimating the location of a wireless terminal, the method comprising:

receiving, by a location server, a value of a location-dependent trait of an electromagnetic signal, wherein the value of the location-dependent trait is dependent on the location of the wireless terminal;

receiving, by the location server, an estimate of the probability that the wireless terminal is indoors, wherein the estimate is based on a characterization of reverberation in the vicinity of the wireless terminal based on a sample of sound obtained in the vicinity of the wireless terminal and a characterization of flicker in the vicinity of the wireless terminal based on a sample of light obtained in the vicinity of the wireless terminal; and

generating, by the location server, an estimate of the location of the wireless terminal based on;

(1) the value of the location-dependent trait, and

(2) the estimate of the probability that the wireless terminal is indoors, wherein the estimate of the probability affects a manner in which the value of the location-dependent trait is processed to generate an estimate of the location of the wireless terminal.

8. The method of claim 7 wherein the sample of sound is at least a portion of sound generated by the wireless terminal as a consequence of the wireless terminal'"'"'s normal operation.

9. The method of claim 8 wherein the sound generated by the wireless terminal is generated when the wireless terminal receives a call.

10. A method comprising:

receiving, by a location server, a value of a location-dependent trait of an electromagnetic signal, wherein the value of the location-dependent trait is dependent on the location of the wireless terminal;

receiving, by a location server, a characterization of reverberation and a characterization of flicker in the vicinity of the wireless terminal;

generating, by the location server, an estimate of the probability that the wireless terminal is indoors based on the characterization of reverberation and the characterization of flicker in the vicinity of the wireless terminal; and

generating, by the location server, an estimate of the location of the wireless terminal based on;

(1) the value of the location-dependent trait, and

(2) the estimate of the probability that the wireless terminal is indoors, wherein the estimate of the probability affects a manner in which the value of the location-dependent trait is processed to generate an estimate of the location of the wireless terminal.

11. The method of claim 10 wherein generating an estimate of the location of the wireless terminal further comprises:

generating an RF map that correlates each of a plurality of locations to the value of the predicted location-dependent trait associated with the wireless terminal at each such location; and

adjusting the RF map based on the estimate of the probability that the wireless terminal is indoors at least some of the locations.

12. A method comprising:

receiving, by a location server, a value of a location-dependent trait of an electromagnetic signal, wherein the value of the location-dependent trait is dependent on the location of the wireless terminal;

receiving, by the location server, a sample of sound in the vicinity of the wireless terminal, wherein the sample of sound is at least a portion of sound generated by the wireless terminal as a consequence of the wireless terminal'"'"'s normal operation;

receiving, by the location server, a sample of light in the vicinity of the wireless terminal;

generating, by the location server, a characterization of reverberation in the vicinity of the wireless terminal based on the sample of sound in the vicinity of the wireless terminal;

generating, by the location server, a characterization of flicker in the vicinity of the wireless terminal based on the sample of light in the vicinity of the wireless terminal;

generating, by the location server, an estimate of the probability that the wireless terminal is indoors based on;

(1) the characterization of reverberation in the vicinity of the wireless terminal;

(2) the characterization of flicker in the vicinity of the wireless terminal, and

generating, by the location server, an estimate of the location of the wireless terminal based on;

(1) the value of the location-dependent trait, and

(2) the estimate of the probability that the wireless terminal is indoors.

13. The method of claim 12 wherein the estimate of the probability affects a manner in which the value of the location-dependent trait is processed to generate an estimate of the location of the wireless terminal.

14. The method of claim 12 wherein generating an estimate of the location of the wireless terminal comprises:

generating an RF map that correlates each of a plurality of locations to the value of the predicted location-dependent trait associated with the wireless terminal at each such location; and

adjusting the RF map based on the estimate of the probability that the wireless terminal is indoors at least some of the locations.

15. An apparatus for generating an estimate of the location of a wireless terminal, the apparatus comprising:

a receiver for receiving;

(1) a value of a location-dependent trait of an electromagnetic signal, wherein the value of the location-dependent trait is dependent on the location of the wireless terminal,

(2) a sample of sound in the vicinity of the wireless terminal, and

(3) a sample of light in the vicinity of the wireless terminal;

a processor for generating;

(I) a characterization of reverberation based on the sample of sound in the vicinity of the wireless terminal and a characterization of flicker based on the sample of light in the vicinity of the wireless terminal,

(II) an estimate of the probability that the wireless terminal is indoors based on;

(1) the characterization of reverberation and the characterization of flicker, and

(III) the estimate of the location of the wireless terminal based on;

(1) the value of the location-dependent trait, and

(2) the estimate of the probability that the wireless terminal is indoors, wherein the estimate of the probability affects a manner in which the value of the location-dependent trait is processed to generate an estimate of the location of the wireless terminal; and

a transmitter for transmitting the estimate of the location of the wireless terminal for use in a location-based application.

16. The apparatus of claim 15 wherein the sample of sound is at least a portion of sound generated by the wireless terminal as a consequence of the wireless terminal'"'"'s normal operation.

17. The apparatus of claim 15 wherein the processor for generating the estimate of the location of the wireless terminal further generates the estimate of location based on an adjustment to an RF map, wherein the RF map correlates each of a plurality of locations to the value of the predicted location-dependent trait associated with the wireless terminal at each such location, and wherein the adjustment is based on the estimate of the probability that the wireless terminal is indoors at least some of the locations.

18. A method of estimating the location of a wireless terminal, the method comprising:

receiving, by a location server, a value of a location-dependent trait of an electromagnetic signal, wherein the value of the location-dependent trait is dependent on the location of the wireless terminal;

receiving, by the location server, an estimate of the probability that the wireless terminal is indoors, wherein the estimate is based on a characterization of reverberation in the vicinity of the wireless terminal based on the sample of sound obtained in the vicinity of the wireless terminal; and

generating, by the location server, an estimate of the location of the wireless terminal by;

(1) generating an RF map that correlates each of a plurality of locations to the value of the predicted location-dependent trait associated with the wireless terminal at each such location; and

(2) adjusting the RF map based on the estimate of the probability that the wireless terminal is indoors at least some of the locations.

19. A method comprising:

receiving, by a location server, a value of a location-dependent trait of an electromagnetic signal, wherein the value of the location-dependent trait is dependent on the location of the wireless terminal;

receiving, by a location server, a characterization of reverberation in the vicinity of the wireless terminal;

generating, by the location server, an estimate of the probability that the wireless terminal is indoors based on the characterization of reverberation in the vicinity of the wireless terminal; and

generating, by the location server, an estimate of the location of the wireless terminal by;

(1) generating an RF map that correlates each of a plurality of locations to the value of the predicted location-dependent trait associated with the wireless terminal at each such location; and

(2) adjusting the RF map based on the estimate of the probability that the wireless terminal is indoors at least some of the locations.

20. A method comprising:

receiving, by a location server, a value of a location-dependent trait of an electromagnetic signal, wherein the value of the location-dependent trait is dependent on the location of the wireless terminal;

receiving, by the location server, a sample of sound in the vicinity of the wireless terminal, wherein the sample of sound is at least a portion of sound generated by the wireless terminal as a consequence of the wireless terminal'"'"'s normal operation;

generating, by the location server, a characterization of reverberation in the vicinity of the wireless terminal based on the sample of sound in the vicinity of the wireless terminal;

generating, by the location server, an estimate of the probability that the wireless terminal is indoors based on the characterization of reverberation in the vicinity of the wireless terminal; and

generating, by the location server, an estimate of the location of the wireless terminal based by;

(1) generating an RF map that correlates each of a plurality of locations to the value of the predicted location-dependent trait associated with the wireless terminal at each such location; and

(2) adjusting the RF map based on the estimate of the probability that the wireless terminal is indoors at least some of the locations.