System and method for displaying country on mobile stations within satellite systems

• US 6,292,666 B1
• Filed: 05/06/1999
• Issued: 09/18/2001
• Est. Priority Date: 05/06/1999
• Status: Expired due to Term

• Current Assignee: Ericsson, Inc. (Telefonaktiebolaget LM Ericsson)
• Original Assignee: Ericsson, Inc. (Telefonaktiebolaget LM Ericsson)
• Inventors: Alperovich, Vladimir, Siddiqui, Aqeel
• Primary Examiner(s): Maung, Nay
• Assistant Examiner(s): BEAMER, TEMICA M
• Application Number:
  US09/306,701
• Time in Patent Office: 866 Days
• Field of Search: 455/456, 455/457, 455/432, 455/433, 455/566, 455/435, 455/427, 455/428, 455/429, 455/12.1
• US Class Current: 455/456.4
• CPC Class Codes: H04B 7/18547 for geolocalisation of a station position fixing by direction or distance determination G01S5/00

Abstract

A telecommunications system and method is disclosed for providing accurate country information to Mobile Stations (MSs) within a satellite network. At the time of location update, the MS sends Global Positioning System (GPS) coordinates identifying the location of the MS to a serving Mobile Switching Center (MSC) via a satellite. The MSC determines the identity of the current country that the MS is located in, and calculates the distance to the nearest country border. The current country identity and distance information are transmitted back to the MS via the satellite. Thereafter, the MS continues to calculate GPS coordinate information, and if the distance between the current location of the MS and the location of the MS at the time of the previous location update becomes equal to or greater than received distance information, a query is done to the MSC to determine the current country where the MS is located. If the country has changed, then the new country is displayed on the MS.

Claims

1. A satellite telecommunications system for providing the current country that a mobile subscriber is located in to the mobile subscriber, comprising:

a mobile station within said satellite system for determining a location of said mobile station and displaying a country identity associated with said location; and

a ground segment for receiving said location from said mobile station via a satellite, determining said country identity based upon said location, calculating a distance between said mobile station and a border between a country associated with said country identity and an adjacent country and transmitting said country identity and said distance to said mobile station via said satellite;

wherein said mobile station transmits a query to said ground segment to determine a new country identity and a new distance when the difference between said location and a new location determined by said mobile station is greater than said received distance.

2. The satellite system of claim 1, wherein said ground segment comprises:

a mobile switching center in wireless communication with said mobile station via said satellite; and

a satellite-adapted base station system in wireless communication with said mobile station via said satellite and connected to said mobile switching center.

3. The satellite system of claim 1, wherein said mobile station includes a Global Positioning System (GPS) receiver for calculating said location, said location comprising GPS coordinates.

4. The satellite system of claim 3, wherein said ground segment has a coordinate database therein containing a plurality of coordinate information and associated country codes.

5. The satellite system of claim 4, wherein said ground segment accesses said coordinate database to correlate said GPS coordinates with a given one of said coordinate information, said country code associated with said given coordinate information being used to determine said country identity.

6. The satellite system of claim 5, wherein said ground segment further includes a country database containing said country codes and associated country information.

7. The satellite system of claim 6, wherein said ground segment accesses said country database to determine said country information associated with said country code associated with said given coordinate information, said determined country information being said country identity.

8. The satellite system of claim 1, wherein said location is sent from said mobile station to said ground segment in a Location Updating message.

9. The satellite system of claim 8, wherein said country identity is transmitted from said ground segment to said mobile station in a Location Update Acknowledgment message.

10. The satellite system of claim 1, wherein said ground segment accesses a subscriber record associated with said mobile station and compares said subscriber record with said adjacent country, said ground segment transmitting a warning indicator along with said distance and country identity to said mobile station when said subscriber record indicates a problem with said adjacent country.

11. The satellite system of claim 1, wherein said mobile station has a memory therein for storing said location, said country identity and said distance.

12. The satellite system of claim 1, wherein said ground segment transmits a minimum period to said mobile station along with said country identity and said distance, said query being transmitted only when said minimum period has been exceeded.

13. The satellite system of claim 12, wherein said mobile station originates a call using a called party number in international format during said minimum period.

14. A method for determining the current country that a mobile station within a satellite telecommunications system is located in, comprising the steps of:

receiving, by a ground segment in wireless communication with said mobile station via a satellite, a location of said mobile station within said satellite system;

determining, by said ground segment, a country identity associated with said location;

calculating, by said ground segment, a distance between said mobile station and a border between a country associated with said country identity and an adjacent country;

transmitting said country identity and said distance from said ground segment to said mobile station via said satellite; and

transmitting a query from said mobile station to said ground segment to determine a new country identity and a new distance when the difference between said location and a new location determined by said mobile station is greater than said received distance.

15. The method of claim 14, wherein said step of determining further comprises the steps of:

accessing a coordinate database within said ground segment, said coordinate database containing a plurality of coordinate information and associated country codes;

correlating said location with a given one of said coordinate information; and

determining said country identity using said country code associated with said given coordinate information.

16. The method of claim 15, wherein said step of determining further comprises the steps of:

accessing a country database within said ground segment, said country database containing said country codes and associated country information; and

determining said country information associated with said country code associated with said given coordinate information, said determined country information being said country identity.

17. The method of claim 16, wherein said step of receiving further comprises the step of:

receiving said location from said mobile station in a Location Updating message.

18. The method of claim 14, wherein said step of transmitting further comprises the step of:

transmitting said country identity from said ground segment to said mobile station in a Location Update Acknowledgment message.

19. The method of claim 14, further comprising the steps of:

accessing, by said ground segment, a subscriber record associated with said mobile station;

comparing said subscriber record with said adjacent country; and

transmitting a warning indicator along with said distance and country identity from said ground segment to said mobile station when said subscriber record indicates a problem with said adjacent country.

20. The method of claim 14, further comprising the step of:

transmitting a minimum period along with said country identity and said distance from said ground segment to said mobile station.

21. A method for displaying the current country that a mobile station within a satellite telecommunications system is located in, comprising the steps of:

determining a location of said mobile station within said satellite system by said mobile station;

transmitting said location from said mobile station to a ground segment in wireless communication with said mobile station via a satellite;

receiving, by said mobile station, a country identity associated with said location and a distance between said mobile station and a border between a country associated with said country identity and an adjacent country from said ground segment via said satellite;

displaying said country identity on a display of said mobile stations;

determining a new location of said mobile station by said mobile station;

comparing said new location with said received location; and

if the difference between said received location and said new location is greater than said received distance, transmitting a query from said mobile station to said ground segment to determine a new country identity and a new distance.

22. The method of claim 21, wherein said step of determining further comprises the step of:

calculating said location using a Global Positioning System (GPS) receiver within said mobile station, said location comprising GPS coordinates.

23. The method of claim 21, wherein said step of transmitting further comprises the step of:

transmitting said location from said mobile station to said ground segment in a Location Updating message.

24. The method of claim 23, wherein said step of receiving further comprises the step of:

receiving said country identity from said ground segment in a Location Update Acknowledgment message.

25. The method of claim 21, wherein said step of receiving further comprises the step of:

receiving a warning indicator along with said distance and country identity from said ground segment when a subscriber record associated with said mobile station indicates a problem with said adjacent country.

26. The method of claim 21, further comprising the step of:

storing said location, said country identity and said distance in a memory within said mobile station.

27. The method of claim 21, further comprising the steps of:

receiving said new country identity and said new distance from said ground segment;

comparing said new country identity with said country identity stored in said memory;

if said new country identity is different than said country identity stored in said memory, displaying said new country identity on said mobile station; and

storing said new location, said new country identity and said new distance in said memory.

28. The method of claim 21, wherein said step of receiving said country identity and said distance further comprises the step of:

receiving a minimum period along with said country identity and said distance from said ground segment.

29. The method of claim 28, wherein said step of transmitting said query further comprises the steps of:

determining whether said minimum period has been exceeded; and

if said minimum period has been exceeded, transmitting said query to said ground segment.

30. The method of claim 28, further comprising the steps of:

determining whether said minimum period has been exceeded; and

if said minimum period has not been exceeded, originating a call using a called party number in international format,

otherwise, originating said call using said called party number in national format.