Radio telecommunication network with fraud-circumventing registration

• US 5,790,073 A
• Filed: 03/13/1996
• Issued: 08/04/1998
• Est. Priority Date: 03/13/1996
• Status: Expired due to Term

• Current Assignee: CDC Propriete Intellectuelle
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Tayloe, Daniel Richard, Vanden Heuvel, Dean Paul, Lester, Joseph Olk, Blanchard, Scott David, Wild, Johanna Alexandra
• Primary Examiner(s): Tarcza, Thomas H.
• Assistant Examiner(s): PHAN, DAO LINDA
• Application Number:
  US08/627,218
• Time in Patent Office: 874 Days
• Field of Search: 342/357, 342/457, 342/450, 455/13.2, 455/12.1, 701/213
• US Class Current: 342/357.2
• CPC Class Codes: G01S 1/026 of associated receivers
• CPC Class Codes: G01S 5/12 by co-ordinating position lines of different shape, e.g. hyperbolic, circular, elliptical or radial
• CPC Class Codes: H04B 7/1855 using a telephonic control signal, e.g. propagation delay variation, Doppler frequency variation, power variation, beam identification

Abstract

A system (28) provides communication services to mobile units (24). Mobile units (24) perform a unit-based location process (46, 48) to determine their locations. The system (28) performs a system-based location process (64, 66) to independently determine mobile unit locations. The system-based process may determine location less precisely than the unit-based process. A location selection process (104) evaluates the unit-determined location in view of a system-determined location error region to decide whether the unit-determined location is reliable. If the unit-determined location is reliable, it is used (120) to qualify communication services to be provided to the mobile unit (24). If the unit-determined location is unreliable, the system-based process is repeated (116) to improve the system-determined location precision, and the resulting system-determined location is used (118) to qualify communication services to be provided to the mobile unit (24).

Claims

1. In connection with a radio telecommunication system that has a satellite node and which provides communication services to mobile units, a method of qualifying a mobile unit to utilize said communication services, said method comprising the steps of:

performing, by said mobile unit, a first location process to determine a first location for said mobile unit;

said mobile unit communicating said first location to said system;

said radio telecommunication system performing a second location process in response to communications conducted between said mobile unit and said satellite node, said second location process determining a second location for said mobile unit, said second location having a second location error region; and

said radio telecommunication system deciding whether said first location is reliable in response to said second location error region by determining whether said first location resides within said second location error region, and

when the first location is not reliable, the method additionally includes the steps of;

repeating the step of said system performing the second location process until said second location is within a predetermined geolocation tolerance for said second location; and

granting system access to said mobile unit based on said second location, and when said first location is reliable, the method additionally includes the step of granting system access to said mobile unit based on said first location.

2. A method as claimed in claim 1 additionally comprising the step of configuring said first and second location processes so that said first location has a first location error region associated therewith, and said first location error region is smaller than said second location error region.

3. A method as claimed in claim 1 wherein:

prior to providing communication services to said mobile unit, said system associates mobile unit geolocation information with user identity information; and

said method additionally comprises the step of using said first location for said mobile unit geolocation information when said deciding step decides that said first location is reliable.

4. A method as claimed in claim 1 wherein:

prior to granting access to said mobile unit, said system associates mobile unit geolocation information with user identity information; and

said method additionally comprises the step of determining, when said deciding step decides that said first location is unreliable, whether said second location error region betters said predetermined geolocation tolerance.

5. A method as claimed in claim 4 wherein:

said second location process additionally determines a second location for said mobile unit; and

said method additionally comprises the step of using said second location for said mobile unit geolocation information when said determining step determines that said first location is unreliable and that said second location error region betters said predetermined geolocation tolerance.

6. A method as claimed in claim 4 additionally comprising the step of conducting additional location-determination communications between said satellite node and said mobile unit when said determining step determines that said first location is unreliable and that said second location error region does not better said predetermined geolocation tolerance.

7. A method as claimed in claim 1 wherein:

said system projects a plurality of communication cells over diverse predetermined areas of the earth and each communication cell has a unique identity;

said mobile unit is located in one of said communication cells;

said second location process identifies a time of arrival curve in response to signal propagation delay between said mobile unit and said satellite node and identifies said one communication cell; and

said second location process defines said second location error region to reside along an area defined as the intersection between said one communication cell and said time of arrival curve.

8. A method as claimed in claim 1 wherein said satellite node moves in an orbit around the earth, and said second location process comprises the steps of:

identifying a time of arrival curve relative to a position for said satellite node in response to signal propagation delay between said mobile unit and said satellite node;

identifying a frequency of arrival curve relative to said position for said satellite node in response to Doppler between said mobile unit and said satellite node; and

defining said second location error region to reside in an area located at the intersection of said time of arrival and frequency of arrival curves.

9. A method as claimed in claim 1 wherein:

said method additionally comprises the step of determining, outside said system, speed data for said mobile unit;

said method additionally comprises the step of sending said speed data to said system;

said satellite node moves in an orbit around the earth; and

said second location process determines said second location error region in response to Doppler detected in said communications conducted between said mobile unit and said satellite node and adjusted in response to said speed data.

10. A method as claimed in claim 9 additionally comprising the step of refraining from communicating said speed data to said system unless said speed data indicates a speed greater than a predetermined speed.

11. A method as claimed in claim 9 wherein:

said determining step additionally determines a heading for said mobile unit;

said sending step additionally sends said heading to said system; and

said second location process additionally adjusts said Doppler in response to said heading.

12. A method as claimed in claim 11 wherein:

said determining step additionally determines an elevation angle for said mobile unit;

said sending step additionally sends said elevation angle to said system; and

said second location process additionally adjusts said Doppler in response to said elevation angle.

13. A method as claimed in claim 1 wherein said first location process comprises the step of monitoring signals broadcast from a plurality of transmitters remotely located from said mobile unit.

14. In connection with a radio telecommunication system that has a satellite node and which provides communication services to mobile units, a method of qualifying a mobile unit to utilize said communication services, said method comprising the steps of:

performing a first location process to determine a first location for said mobile unit;

communicating said first location to said system;

performing a second location process in response to communications conducted between said mobile unit and said satellite node, said second location process determining a second location error region for said mobile unit;

deciding whether said first location is reliable in response to said second location error region;

configuring said first and second location processes so that said first location has a first location error region associated therewith, and said first location error region is smaller than said second location error region;

associating mobile unit geolocation information with user identity information prior to providing communication services to said mobile unit;

using said first location for said mobile unit geolocation information when said deciding step decides that said first location is reliable, said mobile unit geolocation information being better than a predetermined geolocation tolerance; and

determining, when said deciding step decides that said first location is unreliable, whether said second location error region betters said predetermined geolocation tolerance.

15. A method as claimed in claim 14 wherein:

said second location process additionally determines a second location for said mobile unit, and

said method additionally comprises the steps of;

using said second location for said mobile unit geolocation information when said determining step determines that said first location is unreliable and that said second location error region betters said predetermined geolocation tolerance; and

conducting additional location-determination communications between said satellite node and said mobile unit when said determining step determines that said first location is unreliable and that said second location error region does not better said predetermined geolocation tolerance.

16. A method as claimed in claim 15 wherein:

said system projects a plurality of communication cells over diverse predetermined areas of the earth and each communication cell has a unique identity;

said mobile unit is located in one of said communication cells;

said second location process identifies a time of arrival curve in response to signal propagation delay between said mobile unit and said satellite node and identifies said one communication cell; and

said second location process defines said second location error region to reside along an area defined as the intersection between said one communication cell and said time of arrival curve.

17. A telecommunication system which selectively provides communication services to a mobile unit, said system comprising:

a satellite node configured to engage in communications with said mobile unit; and

a system processor in data communication with said satellite node, said system processor being configured to obtain a first location for said mobile unit, said first location being determined by a first location process performed by said mobile unit, to perform a second location process to determine a second location having a second location error region, said second location process being performed by said system processor in response to said communications with said mobile unit, and to decide whether said first location is reliable in response to said second location error region, by determining whether said first location resides within said second location error region, and when the first location is not reliable, the system processor repeats the second location process until said second location is within a predetermined geolocation tolerance for said second location and grants system access to said mobile unit based on said second location, and when said first location is reliable, the system processor grants system access to said mobile unit based on said first location.

18. A system as claimed in claim 17 wherein said system processor is configured to decide whether said first location is reliable by determining whether said first location resides within said second location error region.

19. A system as claimed in claim 18 wherein said system processor is configured to perform said first and second location processes so that said first location has a first location error region associated therewith and said first location error region is smaller than said second location error region.

20. A system as claimed in claim 19 wherein said system processor is configured to:

associate said system associates mobile unit geolocation information with user identity information prior to providing communication services to said mobile unit;

use said first location for said mobile unit geolocation information when said system processor decides that said first location is reliable; and

determine whether said second location error region betters said predetermined geolocation tolerance when said first location is unreliable.

21. A system as claimed in claim 20 wherein said system processor is configured to:

perform said second location process that additionally determines a second location for said mobile unit; and

use said second location for said mobile unit geolocation information when it determines that said first location is unreliable and that said second location error region betters said predetermined geolocation tolerance.

22. A system as claimed in claim 21 wherein said system projects a plurality of communication cells over diverse predetermined areas of the earth and each communication cell has a unique identity, said mobile unit is located in one of said communication cells, and wherein said system processor is configured, as part of said second location process, to:

identify a time of arrival curve in response to signal propagation delay between said mobile unit and said satellite node and identify said one communication cell;

define said second location error region to reside along an area defined as the intersection between said one communication cell and said time of arrival curve;

identify a frequency of arrival curve relative to said position for said satellite node in response to Doppler between said mobile unit and said satellite node; and

define said second location error region to reside in an area located at the intersection of said time of arrival and frequency of arrival curves.