GEO-LOCATION USING DISTRIBUTED COMPOSITE GPS SIGNALS

• US 20080117101A1
• Filed: 06/29/2007
• Published: 05/22/2008
• Est. Priority Date: 11/17/2006
• Status: Active Grant

• Current Assignee: Alcatel-Lucent USA, Inc. (Nokia Corporation)
• Original Assignee: Alcatel-Lucent USA, Inc. (Nokia Corporation)
• Inventors: Pan, Vic
• Granted Patent: US 7,602,335 B2
• Time in Patent Office: Days
• US Class Current: 342/357.09
• CPC Class Codes: G01C 21/206 specially adapted for indoor navigation
• CPC Class Codes: G01S 19/11 wherein the cooperating elements are pseudolites or satellite radio beacon positioning system signal repeaters
• CPC Class Codes: G01S 19/17 Emergency applications
• CPC Class Codes: G01S 19/40 Correcting position, velocity or attitude
• CPC Class Codes: G01S 19/46 the supplementary measurement being of a radio-wave signal type

Abstract

A wireless communication arrangement provides GPS coverage in areas where GPS satellites or macrocells are not directly detectable by a mobile station that is used for placing an emergency call. A detector detects a plurality of GPS satellites and provides a composite GPS signal that is re-radiated through a distributed antenna system to provide GPS signal coverage within a selected area such as inside of a building. The signal reach at each re-radiator assembly is individually controlled to keep the composite GPS signal coverage area within a selected limit. A mobile station used to place an emergency call reports the composite GPS signal information in a data call or SMS message that is associated with the emergency voice call. That information is then used for GEO-location to determine the location of the mobile station. A disclosed example includes a technique for addressing a scenario where a mobile station directly detects a satellite and detects the composite GPS signal.

Claims

1. A method of facilitating an emergency call from a mobile station, comprising

detecting global positioning system (GPS) satellites with a detector;

generating a composite GPS signal based on detected satellites;

distributing the composite GPS signal at a plurality of locations within a selected area; and

individually controlling an amount of power of the distributed GPS signal at each of the plurality of locations.

2. The method of claim 1, comprising

increasing an amount of amplification of the distributed GPS signal in at least one of the plurality of locations;

and

decreasing an amount of amplification of the distributed GPS signal in at least one other of the plurality of locations.

3. The method of claim 2, wherein the selected area comprises a building and comprising

decreasing the amount of amplification to prevent the distributed GPS signal from being detectable outside of the building;

and

increasing the amount of amplification to allow the distributed GPS signal to be detected outside of the building.

4. The method of claim 1, wherein the selected area comprises a building and comprising

controlling the amount of power to distribute the distributed GPS signal outside of the building at least near a selected level of the building.

5. The method of claim 1, wherein the selected area comprises a building and comprising

controlling the amount of power to prevent the distributed GPS signal from being detectable outside of the building.

6. The method of claim 1, comprising

receiving an emergency call from a mobile station that detected the composite GPS signal;

receiving at least one signal from the mobile station indicative of the detected composite GPS signal in association with the emergency call; and

determining a location of the mobile station from the received signal.

7. The method of claim 6, comprising

receiving at least one of a short message service message or a data call that is indicative of the detected composite GPS signal from the mobile station.

8. The method of claim 6, comprising

forwarding the determined location to an entity that can provide a response to the emergency call.

9. A method of handling an emergency call from a mobile station, comprising:

receiving an emergency call from a mobile station in a location where the mobile station does not directly detect enough global positioning system (GPS) satellites or enough macrocells to provide location information;

receiving an indication of at least a composite GPS signal that was detected by the mobile station at the location, the composite GPS signal being based on information regarding GPS satellites; and

determining the location of the mobile station from the received indication.

10. The method of claim 9, comprising

forwarding information regarding the emergency call and the determined location to an entity that can respond to the emergency call.

11. The method of claim 9, wherein the composite GPS signal is obtained from a detector comprising an antenna supported on a building having a known address and comprising determining the mobile station location as the address.

12. The method of claim 9, wherein the received indication is based on a number of satellites and comprising

determining whether the received indication provides sufficient information for locating the mobile station;

determining possible mobile station locations from information regarding each of a plurality of subcombinations of the number of satellites; and

selecting one of the possible mobile station locations that corresponds to a known location as the location of the mobile station.

13. The method of claim 12, comprising

removing one of the number of satellites from consideration to establish a first subset of the satellites during one attempt at determining the possible mobile station locations;

and

subsequently removing a different one of the number of satellites from consideration to establish a next subset of satellites during another attempt at determining the possible mobile station locations.

14. The method of claim 13, comprising

performing the subsequently removing until one of the following is achieved

i) each of the number of satellites has been removed from consideration;

or

ii) a possible mobile station location that corresponds to an identifiable location is obtained.

15. The method of claim 14, comprising

using the obtained possible mobile station location as the determined location of the mobile station.

16. The method of claim 14, comprising

sequentially removing an increasing plurality of the number of satellites from consideration to establish additional subsets of satellites for determining the possible mobile station location;

and

continuing the sequentially removing and considering until a possible mobile station location that corresponds to an identifiable location is obtained.

17. A method of communicating, comprising:

placing an emergency call from a location where it is not possible to directly detect a plurality of global positioning system (GPS) satellites;

detecting a composite GPS signal that is based on timing information regarding the plurality of GPS satellites while in the location; and

providing an indication of the detected composite GPS signal in association with the placed emergency call.

18. The method of claim 17, comprising

providing the indication by at least one of placing a data call or sending a short message service message.