Signal comparison-based location determining method

• US 8,170,583 B2
• Filed: 03/09/2010
• Issued: 05/01/2012
• Est. Priority Date: 09/19/2006
• Status: Active Grant

• Current Assignee: Broadphone, LLC
• Original Assignee: Broadphone, LLC
• Inventors: Shkedi, Roy
• Primary Examiner(s): PHUONG, DAI
• Application Number:
  US12/720,362
• Publication Number:
  US 20100159951A1
• Time in Patent Office: 784 Days
• Field of Search: 4554321-442, 4554561-4563
• US Class Current: 455/456.1
• CPC Class Codes: G01S 5/02521 using a radio-map
• CPC Class Codes: H04W 4/023 using mutual or relative location information between multiple location based services [LBS] targets or of distance thresholds

Abstract

At least one portable RF communications device in conjunction with at least two fixed-location service-area antenna stations respectively capable of RF communication with the at least one device performs the steps of: (I) using a portable device at a selected location to measure RF communications signals from the plurality of local fixed-location service-area antenna stations and electronically storing at least two of the respective reception signal strength measurements; and (II) monitoring a portable device location by causing the device to measure reception signal strength associated with local fixed-location service-area antenna stations signals, and to electronically compare these measurements with the stored at least two measurements.

Claims

1. A signal-comparison based location-determining method, operable by a first portable RF communications device in conjunction with a plurality of fixed-location service-area antenna stations capable of RF communication with the first portable RF communications device wherein the antenna stations are substantially continuously operating, the method comprising:

(a) the first portable RF communications device monitoring its location by (i) receiving communications signals from a first plurality of the antenna stations, (ii) identifying at least one ID within at least one of the received communications signals, and (iii) measuring the signal strengths associated with a received communications signal from the first plurality of antenna stations; and

(b) the first portable RF communication device determining if a monitored location is within proximity of a location chosen by a user of the first portable RF communication device, as a result of (i) electronically comparing the at least one ID and at least one figure based on the signal strengths of the first plurality of antenna stations at the monitored location with the at least one ID and the at least one figure based on signal strengths of the first plurality of antenna stations at the location chosen by the user, and (ii) determining if the difference between the signal strengths measured at the monitored location and the signal strengths at the location chosen by the user is less than a predetermined threshold.

2. The method of claim 1 wherein the chosen location signal strengths were measured by the first portable RF communication device.

3. The method of claim 1 wherein the chosen location signal strengths were measured by a second portable RF communication device, different from the first portable RF communication device.

4. The method of claim 1 wherein the chosen location signal strengths and at least one ID originated from a database of geographic locations and corresponding signal strengths and IDs.

5. The method of claim 4 wherein the database is stored remotely, and not on the first portable RF communication device.

6. The method of claim 5 wherein the database is built by a service provider.

7. The method of claim 4 wherein the database is built based on multiple locations, where for each location, GPS measurements and signal strength measurements are performed and the IDs of nearby antenna stations of the plurality of antenna stations are recognized.

8. The method of claim 7 wherein at least for some of the locations, signal strength measurements are taken at different times.

9. The method of claim 7 wherein the signal strength measurements are taken using a portable RF communication device.

10. The method of claim 9 wherein the signal strength measurements or calculation results made using the signal strength measurements, along with the antenna station IDs, are sent by the portable RF communication device to a server responsible for building the database of geographic locations and corresponding signal strengths and antenna stations IDs.

11. The method of claim 4 wherein the chosen location signal strengths and at least one ID is taken from the database of geographic locations and corresponding signal strengths and IDs using a geographic location entered by the first portable RF communication device user as the location chosen by the user.

12. The method of claim 4 wherein the chosen location signal strengths and at least one ID, which corresponds with a geographical location chosen by the first portable RF communication device user, is the result of extrapolating the signal strengths of locations in the database of geographic locations and corresponding signal strengths and IDs.

13. The method of claim 4 wherein the chosen location signal strengths and at least one ID, which corresponds with a geographical location chosen by the first portable RF communication device user, is taken from the database of geographic locations and corresponding signal strengths and IDs, said database being built using computational closure.

14. The method of claim 1 wherein the at least one ID is a cell ID.

15. The method of claim 1 wherein the first portable RF communication device is a mobile phone.

16. The method of claim 1 wherein the first portable RF communication device is a ubiquitous computer.

17. The method of claim 1 wherein the monitoring step comprises ‘

low accuracy monitoring’ and

‘

high accuracy monitoring’

.

18. The method of claim 17 wherein ‘

low accuracy monitoring’

includes comparing the chosen location IDs with the current location IDs.

19. The method of claim 18 wherein ‘

high accuracy monitoring’

takes place only if the current location IDs are determined to match the chosen location IDs in the ‘

low accuracy monitoring’

step.

20. The method of claim 19 wherein ‘

high accuracy monitoring’

includes measuring a signal strength at the current location.

21. The method of claim 1 wherein the monitoring step is performed iteratively, with a predetermined time delay between successive iterations such that data from the monitoring step is used only if a substantial portion of the successive measurements are alike within a predetermined threshold.

22. The method of claim 1 wherein the ‘

at least one figure based on the signal strengths’

is the signal strengths, for both the monitored location and the chosen location.

23. The method of claim 1 wherein the ‘

at least one figure based on the signal strengths of the first plurality of antenna stations’

is a figure based on a calculation using the signal strengths of the first plurality of antenna stations.

24. The method of claim 1 wherein determining if the monitored location is within proximity of a location chosen by the user of the first portable RF communication device further includes informing a location-based software program application running on the portable device that the device is at the location chosen by the user or is no longer at the location chosen by the user.

25. The method of claim 1 wherein determining if the monitored location is within proximity of a location chosen by the user of the first portable RF communication device further includes launching a location-based software program application on the portable device when the device is at the location chosen by the user.

26. The method of claim 1 wherein the determining of part (b) starts taking place or stops taking place at one or more of the following:

(i) at specific time intervals, or (ii) at specific times, or (iii) depending on the rate the user'"'"'s location changes, or (iv) at the occurrence of an event, or (v) upon a request from the network, or (vi) upon a request from a software application on the device, or (vii) upon a request from the user.

27. The method of claim 26 wherein the determining of part (b) starts taking place or stops taking place at the occurrence of an event, and wherein the event is the device switching from one to another of the antenna stations with which it is registered.

28. The method of claim 27 wherein the antenna station with which the device is registered is a cell base station.

29. The method of claim 27 wherein the antenna station with which the device is registered is a WiFi base station.

30. The method of claim 1 wherein the at least one ID is a WiFi network ID.

31. A signal-comparison based location-determining system, comprising:

(a) a first portable RF communications device communicating with a plurality of fixed-location service-area antenna stations capable of RF communication with the first portable RF communications device, wherein the antenna stations are substantially continuously operating;

(b) software residing on the first portable RF communications device, said software causing the first portable RF communications device to monitor its location by (i) receiving communications signals from a first plurality of the antenna stations, (ii) identifying at least one ID within at least one of the received communications signals, and (iii) measuring signal strengths associated with a received communications signal from the first plurality of antenna stations; and

(c) software residing on the first portable RF communication device, said software causing the first portable RF communication device to determine if the monitored location is within proximity of a location chosen by a user of the first portable RF communication device, as a result of (i) electronically comparing the at least one ID and at least one figure based on the signal strengths of the first plurality of antenna stations at the monitored location with the at least one ID and at least one figure based on signal strengths of the first plurality of antenna stations at the location chosen by the user, and (ii) determining if the difference between the signal strengths measured at the monitored location and the signal strengths at the location chosen by the user is less than a predetermined threshold.