Method and apparatus of determinating the position of a mobile station

• US 6,347,227 B1
• Filed: 08/27/1998
• Issued: 02/12/2002
• Est. Priority Date: 08/28/1997
• Status: Expired due to Term

• Current Assignee: Telefonaktiebolaget LM Ericsson
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: Johansson, Jörgen
• Primary Examiner(s): Maung, Nay
• Assistant Examiner(s): BEAMER, TEMICA M
• Application Number:
  US09/141,261
• Time in Patent Office: 1,265 Days
• Field of Search: 455/433, 455/432, 455/456, 455/457, 455/439, 455/440, 455/404, 455/458, 342/357.13, 342/375.09, 342/357.1, 342/457, 701/211, 701/212, 701/213, 701/214, 701/207
• US Class Current: 455/456.1
• CPC Class Codes: H04W 8/04 Registration at HLR or HSS [Home Subscriber Server]
• CPC Class Codes: H04W 8/06 Registration at serving network Location Register, VLR or user mobility server
• CPC Class Codes: H04W 8/10 between location register and external networks

Abstract

The present invention relates generally to the problem of positioning of a mobile station (“MS”) in a Public Land Mobile Network (“PLMN”), and more particularly to the problem of establishing the most accurate estimate of the last known position of the mobile station when the mobile station has switched off or has left the coverage area of the network. An application first sends a request to a Mobile Positioning Center, requesting position information for a particular subscriber. The MPC contacts the preferred Positioning Procedure, e.g. GPS, to obtain the positioning information. If this information is not available then the MPC contacts the HLR to get the last known positioning data. The HLR will try to retrieve the last known positioning data from the VLR and forward it to the MPC. If this is not available then the last known position stored in the HLR is forwarded to the MPC.

Claims

1. A method of determining the position of a mobile station in a mobile radio system for use in an application, said method comprising the steps of:

performing an investigation as to whether a preferred positioning procedure can be obtained;

if said preferred positioning procedure cannot be obtained, then retrieving a first kind of location information stored in a database containing position information about said mobile station;

if said first kind of location information is unavailable, then retrieving a second kind of location information stored in said database and sending said second kind of location information to said application.

2. The method of claim 1 further comprising the step of storing said position information about the mobile station in said database, before said sending and retrieving steps.

3. The method of claim 2, wherein said step of retrieving said first kind of location information further includes the steps of:

a Mobile Positioning Center first contacting a Home Location Register with a Visitor Location Register address for said mobile station;

if said address is invalid then retrieve said last known position data in said Home Location Register; and

if said address is valid then retrieve said last known position data in said Visitor Location Register.

4. The method of claim 3, further comprising the step of storing said first kind of location data in the Visitor Location Register when certain events occur which make said data available in the system.

5. The method of claim 4, wherein:

said event is a Location Update.

6. The method of claim 4, wherein:

said event is a Call Set-Up.

7. The method of claim 4, wherein:

said event is a Handover.

8. The method of claim 4, wherein:

said event is a Call Complete.

9. The method of claim 4, wherein:

said event is an IMSI attach.

10. The method of claim 4, wherein:

said event is an IMSI detach.

11. The method of claim 2, further comprising the step of transferring said first location information in said Visitor Location Register to said Home Location Register for permanent storage when said subscriber record in said Visitor Location Register is to be deleted.

12. The method of claim 1, wherein:

said positioning information is the Cell Global Identity.

13. The method of claim 1, wherein:

said positioning information is the longitude and latitude of said mobile station obtained from a GPS system.

14. The method of claim 1, wherein:

said positioning information is the location of said mobile station obtained from triangulating radio signals from said mobile station to radio base stations in said mobile radio system.

15. The method of claim 1, wherein:

said positioning information includes a time stamp recording the time and date when the information is retrieved.

16. An apparatus for determining the position of a mobile station in a mobile radio system for use in an application, said apparatus comprising:

means for performing an investigation as to whether a positioning procedure can be obtained;

a means for retrieving a first kind of location information stored in a database containing position information about said mobile station;

a means for sending said first kind of location information to said application; and

a means for retrieving a second kind of location information stored in said database and sending said second kind of location information to said application.

17. The apparatus of claim 16, further comprising:

a means for storing said position information about the mobile station in said database.

18. The apparatus of claim 17, wherein:

said mobile radio system is a GSM system having a Visitor Location Register database and a Home Location Register database; and

wherein said first kind of location information is the last known position data of said mobile station stored in the Visitor Location Register and said second kind of Location information is the last known position of said mobile station stored in the Home Location Register.

19. The apparatus of claim 18, further comprising:

a means for retrieving said last known position data in said Home Location Register; and

means for retrieving said last known position data in said Visitor Location Register.

20. The apparatus of claim 19, further comprising:

a means for storing said first kind of location in said Visitor Location Register when certain events occur which make said data available in the system.