Systems for and methods of determining likelihood of mobility of reference points in a positioning system

• US 8,971,915 B2
• Filed: 06/09/2011
• Issued: 03/03/2015
• Est. Priority Date: 06/11/2010
• Status: Active Grant

• Current Assignee: Skyhook Wireless Incorporated (Liberty Broadband Corp.)
• Original Assignee: Skyhook Wireless Incorporated (Liberty Broadband Corp.)
• Inventors: Alizadeh-Shabdiz, Farshid, Brachet, Nicolas, Cavanaugh, Gerald, Dancus, Andrei, Jones, Russel K., Steger, Christopher
• Primary Examiner(s): ZEWDU, MELESS NMN
• Application Number:
  US13/156,564
• Publication Number:
  US 20110306360A1
• Time in Patent Office: 1,363 Days
• Field of Search: 455/67.11, 455/403, 4554041-4042, 455418-421, 455/422.1, 455446-449, 4554561-4566, 455/517, 455520-526, 455/550.1, 455/556.2, 455/561, 455423-425, 455433-434, 455/500, 370/310, 370/328, 370/338, 370349-350, 34235763-35766, 342/357.71, 342385-386, 342/420, 342457-458
• US Class Current: 455/456.1
• CPC Class Codes: G01S 1/024 of beacon transmitters
• CPC Class Codes: G01S 5/021 Calibration, monitoring or correction G01S5/0252 takes precedence
• CPC Class Codes: G01S 5/0252 Radio frequency fingerprinting
• CPC Class Codes: G01S 5/0278 involving statistical or probabilistic considerations G01S5/0252, G01S5/0294 take precedence
• CPC Class Codes: G01S 5/14 Determining absolute distances from a plurality of spaced points of known location
• CPC Class Codes: H04W 24/00 Supervisory, monitoring or testing arrangements
• CPC Class Codes: H04W 4/02 Services making use of location information
• CPC Class Codes: H04W 64/00 Locating users or terminals or network equipment for network management purposes, e.g. mobility management

Abstract

Systems for and methods of determining likelihood of mobility of reference points in a positioning system are disclosed. A method of determining a measure of likelihood that a designated wireless device is a mobile device includes determining a set of reference points associated with a designated wireless device. The reference points are a geographic position at which signals from the device were detected and/or another wireless device from which signals were also detected by a receiver within a selected period of time during which the signals from the designated device were detected. The method also includes retrieving statistical information about a temporal distribution of detection of signals of reference points, a spatial distribution of the reference points, and/or a cardinality of the reference points. The method includes determining a measure of likelihood that the designated wireless device is a mobile wireless device based on the statistical information.

Claims

1. A method of determining and using a measure of likelihood that a designated wireless device is a mobile device which lacks a fixed geographic position, the method comprising:

determining a set of one or more reference points associated with the designated wireless device, the one or more of the reference points being at least one of (i) a geographic position at which signals from the designated wireless device were detected and (ii) another wireless device from which signals were also detected by a receiver of a third wireless device within a selected period of time during which the signals from the designated wireless device were detected by the receiver;

receiving statistical information about at least one of (i) a temporal distribution of times of detection of the signals of the reference points of the set, (ii) a spatial distribution of the reference points, and (iii) a cardinality of the set or at least one subset of the reference points; and

determining a measure of likelihood that the designated wireless device is a mobile wireless device which lacks a fixed geographic position based on the statistical information; and

in response to the measure of likelihood, excluding the designated wireless device from being used by a positioning system as a reference point for estimating a position of a client device.

2. The method of claim 1, wherein the measure of likelihood is a probability.

3. The method of claim 1, further comprising:

grouping each reference point of the set into clusters of at least one reference point based on location information associated with a corresponding reference point;

the statistical information about the cardinality of the set or the at least one subset of the reference points including a count of the cluster groupings.

4. The method of claim 1, further comprising:

for each of the reference points which is the another wireless device, retrieving a count of instances in which the signals from the another wireless device are received within the selected period of time during which signals from a further unique wireless device are received; and

determining a number of the instances of signal reception that corresponds to a selected percentile;

the determining the measure of likelihood that the designated wireless device is the mobile wireless device being based on the cardinality of the set or the at least one subset of the reference points exceeding the number of instances of signal reception that corresponds to the selected percentile.

5. The method of claim 1, further comprising:

the statistical information about the temporal distribution of times of the detection of the signals of the reference points of the set including measures of durations of time during which the signals from the designated wireless device remained detectable at the geographic positions; and

the determining the measure of likelihood that the designated wireless device is the mobile wireless device being further based on the durations of the time.

6. The method of claim 5, further comprising determining the measures of the durations of the time during which the signals from the designated wireless device remained detectable based on a quantity of time passage between a first detection of signals from the designated wireless device at a corresponding reference point and at least one subsequent detection of signals from the designated wireless device at the corresponding reference point.

7. The method of claim 1, further comprising:

the statistical information about the temporal distribution of the times of the detection of the signals of the reference points of the set including measures of durations of time during which the signals from the designated wireless device remained detectable by the receiver within the selected period of time during which the signals from the another wireless device were detectable by the same receiver; and

the determining the measure of likelihood that the designated wireless device is the mobile wireless device being further based on the durations of the time.

8. The method of claim 7, further comprising determining the measures of the durations of the time during which the signals from the designated wireless device remained detectable by the receiver within the selected period of time during which the signals from the another wireless device were detectable by the same receiver based on a quantity of time passage between a first detection of signals and at least one subsequent detection of signals.

9. The method of claim 1, wherein the designated wireless device has an identifier and the method further comprising associating, in a reference database, the identifier with an indication of the measure of likelihood that the designated wireless device is the mobile wireless device which lacks the fixed geographic position.

10. The method of claim 1, wherein the measure of likelihood is a binary decision.

11. The method of claim 10, wherein the designated wireless device has an identifier and the method further comprising associating, in a reference database, the identifier with an indication that the designated wireless device is not suitable for use as the reference point.

12. The method of claim 10, wherein the designated wireless device has a first identifier and the method further comprising inferring that a second designated wireless device is a mobile wireless device which lacks a fixed geographic position based on a comparison of the first identifier and a second identifier associated with the second designated wireless device.

13. The method of claim 10, further comprising inferring that a wireless device other than the designated wireless device is a mobile wireless device which lacks a fixed geographic position based on the other wireless device having a relationship with the designated wireless device, the existence of the relationship being based on the designated wireless device and the other wireless device being within signal reception range of a same position within the selected period of time.

14. The method of claim 1, wherein the designated wireless device is a WiFi-enabled access point.

15. The method of claim 1, wherein the designated wireless device is a mobile telephone transceiver installation.

16. The method of claim 1, wherein the another wireless device of the set is at least one of a WiFi-enabled access point and a mobile telephone transceiver installation, for each reference point of the set that is the another wireless device.

17. A system for determining and using a measure of likelihood that a designated wireless device is a mobile device which lacks a fixed geographic position, the system comprising:

a non-transitory computer readable media including instructions that when executed by a computer system cause the computer system to;

determine a set of one or more reference points associated with the designated wireless device, the one or more of the reference points being at least one of (i) a geographic position at which signals from the designated wireless device were detected and (ii) another wireless device from which signals were also detected by a receiver of a third wireless device within a selected period of time during which the signals from the designated wireless device were detected by the receiver;

retrieve statistical information about at least one of (i) a temporal distribution of times of detection of the signals of the reference points of the set, (ii) a spatial distribution of the reference points, and (iii) a cardinality of the set or at least one subset of the reference points;

determine the measure of likelihood that the designated wireless device is a mobile wireless device which lacks the fixed geographic position based on the statistical information; and

in response to the measure of likelihood, exclude the designated wireless device from being used by the computer system as a reference point for estimating a position of a client device.

18. The system of claim 17, wherein the measure of likelihood is a probability.

19. The system of claim 17, wherein the non-transitory computer readable media further includes instructions that when executed by the computer system cause the computer system to group each reference point of the set into clusters of at least one reference point based on location information associated with a corresponding reference point, and the statistical information about the cardinality of the set or the at least one subset of the reference points includes a count of the duster groupings.

20. The system of claim 17, wherein the non-transitory computer readable media further includes instructions that when executed by the computer system cause the computer system to:

for each of the reference points which is another wireless device, retrieve a count of the instances in which the signals from the another wireless device are received within a selected period of time during which signals from a further unique wireless device are received; and

determine a number of the instances of signal reception that corresponds to a selected percentile;

the determining the measure of likelihood that the designated wireless device is the mobile wireless device being based on the cardinality of the set or the at least one subset of reference points exceeding the number of instances of the signal reception that corresponds to the selected percentile.

21. The system of claim 17, wherein the statistical information about the temporal distribution of times of the detection of the signals of reference points of the set including measures of durations of time during which the signals from the designated wireless device remained detectable at the geographic positions, and the determining the measure of likelihood that the designated wireless device is the mobile wireless device being further based on the durations of time.

22. The system of claim 21, wherein the non-transitory computer readable media further includes instructions that when executed by the computer system cause the computer system to determine the measures of the durations of time during which the signals from the designated wireless device remained detectable based on a quantity of time passage between a first detection of signals from the designated wireless device at a corresponding reference point and at least one subsequent detection of signals from the designated wireless device at the corresponding reference point.

23. The system of claim 17, wherein the statistical information about the temporal distribution of times of the detection of signals of reference points of the set includes measures of durations of time during which signals from the designated wireless device remained detectable by the receiver within the selected period of time during which the signals from the another wireless device were detectable by the same receiver, and the determining the measure of likelihood that the designated wireless device is the mobile wireless device being further based on the durations of time.

24. The system of claim 23, wherein the non-transitory computer readable media further includes instructions that when executed by the computer system cause the computer system to determine the measures of the durations of time during which the signals from the designated wireless device remained detectable by the receiver within the selected period of time during which the signals from the another wireless device were detectable by the same receiver based on a quantity of time passage between a first detection of signals and at least one subsequent detection of signals.

25. The system of claim 17, wherein the designated wireless device has an identifier and the non-transitory computer readable media further including instructions that when executed by the computer system cause the computer system to associate, in a reference database, the identifier with an indication of the measure of likelihood that the designated wireless device is the mobile wireless device which lacks the fixed geographic position.

26. The system of claim 17, wherein the measure of likelihood is a binary decision.

27. The system of claim 26, wherein the designated wireless device has an identifier and the non-transitory computer readable media further including instructions that when executed by the computer system cause the computer system to associate, in a reference database, the identifier with an indication that the designated wireless device is not suitable for use as the reference point.

28. The system of claim 26, wherein the designated wireless device has a first identifier and the non-transitory computer readable media further including instructions that when executed by a computer system cause the computer system to infer that a second designated wireless device is a mobile wireless device which lacks a fixed geographic position based on a comparison of the first identifier and a second identifier associated with the second designated wireless device.

29. The system of claim 26, wherein the non-transitory computer readable media further includes instructions that when executed by a computer system cause the computer system to infer that a wireless device other than the designated wireless device is a mobile wireless device which lacks a fixed geographic position based on the other wireless device having a relationship with the designated wireless device, the existence of the relationship being based on the designated wireless device and the other wireless device being within signal reception range of a same position within the selected period of time.

30. The system of claim 17, wherein the designated wireless device is a WiFi-enabled access point.

31. The system of claim 17, wherein the designated wireless device is a mobile telephone transceiver installation.

32. The system of claim 17, wherein the another wireless device of the set is at least one of a WiFi-enabled access point and a mobile telephone transceiver installation, for each reference point of the set that is another wireless device.