System and method for positioning a mobile station using two base stations

• US 6,477,379 B2
• Filed: 10/28/1998
• Issued: 11/05/2002
• Est. Priority Date: 10/28/1998
• Status: Expired due to Term

• Current Assignee: Unwired Planet LLC (JP Morgan Chase & Co)
• Original Assignee: Ericsson, Inc. (Telefonaktiebolaget LM Ericsson)
• Inventors: Kingdon, Christopher Hugh
• Primary Examiner(s): Cumming, William
• Assistant Examiner(s): LE, LANA N
• Application Number:
  US09/181,592
• Publication Number:
  US 20020132623A1
• Time in Patent Office: 1,469 Days
• Field of Search: 455/456, 455/457, 455/439, 455/524, 455/422, 455/436, 455/502, 342/357.01, 342/450
• US Class Current: 455/456.1
• CPC Class Codes: G01S 5/14 Determining absolute distances from a plurality of spaced points of known location
• CPC Class Codes: H04W 64/00 Locating users or terminals or network equipment for network management purposes, e.g. mobility management

Abstract

A system and method are provided for determining the location or position of a mobile station (MS) within a digital wireless network when only two base stations are available for time of arrival or other triangulation measurements. A call setup is initiated concurrently with the gathering of timing advance or other such location data on the targeted MS, thereby allowing cell sector information to be collected. This data, along with the locating data, is then reported to a Master Positioning Center where distance calculations are made from the locating data. Positional ambiguities are then resolved with a comparison to the serving cell identity recovered during the call placement to the mobile when the locating data was being taken.

Claims

1. A telecommunications system for determining the location of a mobile station therein, said telecommunications system comprising:

a serving base transceiver station in radio communication with said mobile station, said mobile station having a call connection through said serving base transceiver station;

a second base transceiver station in radio communication with said mobile station; and

positioning means for positioning said mobile station within said telecommunications system using location data and resolving positional ambiguities using cell-related area information associated with said call connection, said location data comprising serving location data from said serving base transceiver station and other location data from said second base transceiver station.

2. A telecommunications system according to claim 1, wherein said location data from said serving and second base transceiver stations comprise timing advance data.

3. A telecommunications system according to claim 1, wherein said positioning means comprises a master positioning center, said serving and second base transceiver stations forwarding said serving and other location data, respectively, to said master positioning center, said serving base transceiver station further forwarding the cell-related area information to said master positioning center, the cell-related area information determined by the call connection to said serving base transceiver station.

4. A telecommunications system according to claim 3, wherein said master positioning center, said serving and second base transceiver stations and said mobile station are within a home mobile network of said telecommunications system.

5. A telecommunications system according to claim 3, wherein said master positioning center is within said home mobile network, and said serving and second base transceiver stations are within a visitor mobile network.

6. A telecommunications system according to claim 1, further comprising:

a base station controller for controlling said serving and second base transceiver stations, said base station controller forwarding said location data from said serving and second base transceiver stations to said positioning means.

7. A telecommunications system according to claim 1, further comprising:

a first and second base station controller for respectively controlling said serving and second base transceiver stations, said respective base station controller forwarding said serving and other location data to said positioning means.

8. The telecommunications system according to claim 1, wherein the cell-related area information identifies a cell served by said serving base transceiver station serving said mobile station.

9. The telecommunications system according to claim 1, wherein the cell-related area information identifies a sector within a cell served by said serving base transceiver station serving said mobile station.

10. The telecommunications system according to claim 1, wherein the cell-related area information identifies a predefined portion of a cell known to the telecommunications system served by said serving base transceiver station serving said mobile station.

11. In a telecommunications system, a method for determining the location of a mobile station therein, said method comprising the steps of:

requesting a location update on said mobile station;

retrieving, from a serving base transceiver station in communication with said mobile station, serving location data and cell-related area information on the location of said mobile station, said mobile station having a call connection through said serving base transceiver station;

retrieving, from a second base transceiver station in communication with said mobile station, other location data on the location of said mobile station; and

determining, from location data on said mobile station, the location of said mobile station within said telecommunications system, said location data including said serving location data from said serving base transceiver station and said other location data from said second base transceiver station, said retrieved cell-related area information being used to resolve positional ambiguities during said step of determining.

12. The method according to claim 11, wherein said step of requesting comprises:

requesting, by a requesting entity within a Public Switched Telephone Network, said location update through a gateway mobile switching center within said telecommunications system.

13. The method according to claim 12, wherein said gateway mobile switching center, said serving and second base transceiver station and second mobile station are within a home mobile network of said telecommunications system, said location update request remaining within said home mobile network.

14. The method according to claim 12, wherein said gateway mobile switching center is within a home mobile network, and said serving and second base transceiver station and said mobile station are within a visitor mobile network, said location update request being forwarded from said home mobile network to said visitor mobile network.

15. The method according to claim 11, wherein said step of requesting comprises:

requesting, by said mobile station, said location update.

16. The method according to claim 11, wherein the cell-related area information identifies a cell served by said serving base transceiver station serving said mobile station.

17. The method according to claim 11, wherein the cell-related area information identifies a sector within a cell served by said serving base transceiver station serving said mobile station.

18. The method according to claim 11, wherein the cell-related area information identifies a predefined portion of a cell known to the telecommunications system and served by said serving base transceiver station serving said mobile station.

19. A telecommunications system for determining the position of a mobile station, said telecommunications system comprising:

means for requesting a location update on said mobile station;

means for retrieving, from a serving base transceiver station in communication with said mobile station, serving location data and cell-related area information of the location of said mobile station, said mobile station having a call connection through said serving base transceiver station;

means for retrieving, from a second base transceiver station in communication with said mobile station, other location data of the location of said mobile station; and

means for determining, from location data of said mobile station, the location of said mobile station within said telecommunications system, said location data comprising said serving location data from said serving base transceiver station and said other location data from said second base transceiver station, said means for determining the location of said mobile station resolving positional ambiguities using the retrieved cell-related area information.

20. The telecommunications system according to claim 19, wherein said means for requesting comprises:

a requesting entity within a Public Switched Telephone Network for requesting location update through a gateway mobile switching center within said telecommunications system.

21. The telecommunications system according to claim 20, wherein said gateway mobile switching center, said serving and second base transceiver station and second mobile station are within a home mobile network of said telecommunications system, said location update request remaining within said home mobile network.

22. The telecommunications system according to claim 20, wherein said gateway mobile switching center is within a home mobile network, and said serving and second base transceiver station and said mobile station are within a visitor mobile network, said location update request being forwarded from said home mobile network to said visitor mobile network.

23. The telecommunications system according to claim 19, wherein said means for requesting comprises:

a requesting entity within said mobile station that requests said location update.

24. The telecommunications system according to claim 19, wherein the cell-related area information is an identification of a predefined portion of a cell served by said serving base transceiver station, an identification of a sector within a cell served by said serving base transceiver station, or an identification of a cell served by said serving base transceiver station.

25. A method for determining the position of a mobile station within a telecommunications system, said method comprising the steps of:

receiving a positioning request for the mobile station;

identifying a serving base transceiver station and at least one other base transceiver station;

setting up an initial call connection to the serving base transceiver station;

retrieving location data from the serving base transceiver station and the at least one other base transceiver station;

retrieving, from the serving base transceiver station, geographically-related information associated with the initial call connection; and

forwarding the location data and the geographically-related information to a mobile positioning center where distance calculations are determined from the location data and positional ambiguities are resolved using the geographically-related information associated with the initial call connection.

26. The method according to claim 25, wherein said location data comprises time advance (TA) parameters.

27. The method according to claim 25, further comprising prior to said step of identifying, the step of:

determining a base station controller serving the mobile station.

28. The method according to claim 25, wherein the geographically-related information associated with the initial call connection comprises cell-related area information.

29. The method according to claim 28, wherein the cell-related area information is an identification of a predefined portion of a cell served by said serving base transceiver station, an identification of a sector within a cell served by said serving base transceiver station, or an identification of a cell served by said serving base transceiver station.

30. An arrangement for determining the position of a mobile station, said arrangement comprising:

a mobile switching center (MSC);

a mobile positioning center (MPC) in communication with said MSC for forwarding a received positioning request to said MSC;

a base station controller (BSC) currently serving the mobile station, said BSC receives positioning instructions associated with the received positioning request from said MSC; and

at least two base transceiver stations serving the mobile station that are controlled by said BSC, said at least two base transceiver stations taking time advance measurements and one of said at least two base transceiver stations initiating a call to the mobile station and retrieving cell-related area information, said time advance measurements and the cell-related area information

at least two base transceiver stations serving the mobile station that are controlled by said BSC, said at least two base transceiver stations taking time advance measurements and one of said at least two base transceiver stations initiating a call to the mobile station and retrieving cell-related area information, said time advance measurements and the cell-related area information being sent to the MPC where distance calculations are determined from the TA measurements and position ambiguities are resolved from the cell-related area information.

31. The arrangement according to claim 30, further comprising:

a home location register (HLR) and a visitor location register (VLR) both operable to keep track of the area in which the mobile station currently resides and inform said MSC of the area in which the mobile station currently resides.

32. The arrangement according to claim 31, wherein said MSC, said HLR and said MPC are within a home network of said mobile station, said BSC and said at least two base transceiver stations are within a visitor network.

33. The arrangement according to claim 30, wherein said MSC, said MPC, said BSC and said at least two base transceiver stations are within a home network of the mobile station.