Position measuring method and mobile communication terminal

• US 7,590,424 B2
• Filed: 03/26/2002
• Issued: 09/15/2009
• Est. Priority Date: 03/29/2001
• Status: Expired due to Fees

• Current Assignee: NTT Docomo Incorporated (Nippon Telegraph and Telephone Corporation)
• Original Assignee: NTT Docomo Incorporated (Nippon Telegraph and Telephone Corporation)
• Inventors: Yamamoto, Hiroyuki, Murata, Katsutoshi
• Primary Examiner(s): Harper; Vincent P
• Assistant Examiner(s): Santiago-Cordero; Marivelisse
• Application Number:
  US10/343,075
• Publication Number:
  US 20040029583A1
• Time in Patent Office: 2,730 Days
• Field of Search: 455456-4566, 455/404.2, 455/456.1, 455/457, 701/207, 701213-216, 342/358, 342/357.15, 342/357.09, 342/357.02, 342/357.03, 342/357.06, 342/357.1, 342/357.14, 342/357.01, 342/357.05, 340/426
• US Class Current: 455/456.1
• CPC Class Codes: G01S 19/06 employing an initial estimate of the location of the receiver as aiding data or in generating aiding data

Abstract

Each time mobile communication terminal 10 moves a distance of 150 kilometers, it computes its approximate position by performing a stand-alone position measurement, and stores the approximate position. When mobile communication terminal 10 needs to precisely measure its location it notifies position measurement assist server 30 of the stored approximate position, to thereby perform a GPS position measurement operation by using satellite capturing data transmitted, accordingly, from position measurement assist server 30.

Claims

1. A method of measuring a position of a mobile communication terminal within an area accommodated by a mobile communication network, comprising:

obtaining, from the mobile communication network, a position registration area identifier, wherein the position registration area identifier depends upon a location of the mobile communication terminal within the area accommodated by the mobile communication network;

storing the position registration area identifier in a memory of the mobile communication terminal;

monitoring a number of changes in the position registration area identifier;

detecting that the number of changes in the position registration area identifier since a precise position of the mobile communication terminal was calculated exceeds a threshold;

in response to each detection that the number of changes in the position registration area identifier since the precise position of the mobile communication terminal was calculated exceeds the threshold, determining the precise position of the mobile communication terminal, wherein determination of the precise position of the mobile communication terminal comprises;

retrieving, from the memory, the position registration area identifier;

sending, through the mobile communication network, a request for position measurement assist data to a position assistance server, wherein the request for position measurement assist data includes the position registration area identifier;

in response to receipt of the position measurement assist data, obtaining, at the mobile communication terminal, location data from a satellite; and

in response to obtaining the location data, sending a request for calculation of the precise position of the mobile communication terminal to the position assistance server, wherein the request includes the location data; and

receiving the precise position of the mobile communication terminal at the mobile communication terminal from the position assistance server.

2. The method of claim 1, further comprising:

enabling a user interface to receive selected geographic location information; and

receiving the selected geographic location information.

3. The method of claim 2, wherein the user interface includes a display, and wherein enabling the user interface to receive the selected geographic location information comprises:

displaying a list of names or codes associated with a plurality of municipal divisions.

4. The method of claim 2, wherein said receiving the selected geographic location information comprises:

receiving a selection of a municipal location from a list of names or codes, wherein each of the names or codes is associated with one of a plurality of municipal divisions.

5. The method of claim 2, wherein said obtaining the position registration area identifier further comprises:

retrieving, from the memory, an initial position registration area identifier, wherein the initial position registration area identifier is the position registration identifier stored in the memory before the mobile communication terminal powers down;

determining whether the initial position registration area identifier matches the position registration area identifier; and

in response to determination that the initial position registration area identifier mismatches the obtained position registration area identifier, displaying on the user interface a request for input of a municipal division as the selected geographic location information.

6. The method of claim 2, further comprising:

in response to receipt of the selected geographic location information, determining the precise position of the mobile communication terminal based upon the selected geographic location information.

7. The method of claim 2, further comprising:

sending, through the mobile communication network, an initial request for the position measurement assist data to the position assistance server, wherein the initial request for position measurement assist data includes the selected geographic location information; and

in response to receipt of the position measurement assist data from the position assistance server, obtaining, at the mobile communication terminal, the location data from the satellite.

8. The method of claim 7, further comprising:

sending the location data to the position assistance server; and

receiving, from the position assistance server, the precise location of the mobile communication terminal.

9. The method of claim 1, wherein the mobile communication network includes a plurality of residency areas;

wherein each of the residency areas includes at least one radio cell, and a base station corresponding to each radio cell operates to execute radio communication with the mobile communication terminal, the method further comprising;

the base station transmitting residency area identification information that corresponds to a respective residency area of the plurality of residency areas in which the mobile communication terminal is located to the mobile communication terminal.

10. The method of claim 9, wherein the residency area identification information includes the position registration area identifier that corresponds to the respective residency area.

11. The method of claim 1, wherein the satellite is one of a plurality of satellites, and wherein the position measurement assist data includes satellite identification data indicative of a plurality of satellites, data expressive of delay conditions of radio signals from the plurality of satellites, and data to enable correction of errors in a stand-alone position measurement;

wherein obtaining, at the mobile communication terminal, location data comprises;

receiving, at the mobile communication terminal, radio signals from the satellites indicated by the satellite identification data; and

wherein determination of the precise position of the mobile communication terminal is based upon data obtained from the radio signals, the data expressive of delay conditions, and the data to enable correction of errors.

12. A computer readable storage medium for storing a computer program for a mobile communication terminal within an area accommodated by a mobile communication network comprising:

a computer readable medium comprising computer program code, the computer program code executable on a processor of the mobile communication terminal, the computer program code comprising;

computer program code to obtain, from the mobile communication network, a position registration area identifier, wherein the position registration area identifier depends upon a location of the mobile communication terminal within the area accommodated by the mobile communication network;

computer program code to store the position registration area identifier in a memory of the mobile communication terminal;

computer program code to monitor a number of changes in the position registration area identifier;

computer program code to detect that the number of changes in the position registration area identifier since a precise position of the mobile communication terminal was calculated exceeds a threshold;

computer program code to, in response to each detection that the number of changes in the position registration area identifier exceeds the threshold, determine the precise position of the mobile communication terminal, wherein the computer program code to determine the precise position of the mobile communication terminal comprises;

computer program code to retrieve, from the memory, the position registration area identifier;

computer program code to send, through the mobile communication network, a request for position measurement assist data to a position assistance server, wherein the request for position measurement assist data includes the position registration area identifier;

computer program code to, in response to receipt of the position measurement assist data, obtain, at the mobile communication terminal, location data from a satellite; and

computer program code to send a request for calculation of the precise position of the mobile communication terminal to the position assistance server, wherein the request includes the location data; and

computer program code to receive the precise position of the mobile communication terminal at the mobile communication terminal from the position assistance server.

13. The computer readable storage medium of claim 12, further comprising:

computer program code to enable a user interface to receive selected geographic location information; and

computer program code to receive the selected geographic location information.

14. The computer readable storage medium of claim 13, further comprising:

computer program code to display a list of names or codes associated with a plurality of municipal divisions on the user interface.

15. The computer readable storage medium of claim 13, wherein said computer program code to receive the selected geographic location information comprises:

computer program code to receive a selection of a municipal location from a list of names or codes, wherein each of the names or codes is associated with one of a plurality of municipal divisions.

16. The computer readable storage medium of claim 13, further comprising:

Computer program code to, in response to receipt of the selected geographic location information, determine the precise position of the mobile communication terminal based upon the selected geographic location information.

17. The computer readable storage medium of claim 13, further comprising:

computer program code to send, through the mobile communication network, an initial request for the position measurement assist data to the position assistance server, wherein the initial request for position measurement assist data includes the selected geographic location information; and

computer program code to, in response to receipt of the position measurement assist data from the position assistance server, obtain, at the mobile communication terminal, the location data from the satellite.

18. The computer readable storage medium of claim 17 further comprising:

computer program code to send the location data to the position assistance server; and

computer program code to receive, from the position assistance server, the precise location of the mobile communication terminal.

19. A mobile communication terminal for providing navigation information within an area accommodated by a mobile communication network, comprising:

a memory;

a communication interface configured to communicate with the mobile communication network;

a processor in communication with the communication interface and the memory, wherein the processor is configured to obtain, through the communication interface, a position registration area identifier from the mobile communication network, wherein the position registration area identifier depends upon a location of the mobile communication terminal within the area accommodated by the mobile communication network;

the mobile terminal configured to store the position registration area identifier in the memory;

the processor is further configured to monitor a number of changes in the position registration area identifier;

the processor is further configured to detect that the number of changes in the position registration area identifier since a precise position of the mobile communication terminal was last calculated exceeds a threshold;

in response to each detection that the number of changes in the position registration area identifier since the precise position of the mobile communication terminal was last calculated exceeds the threshold, the mobile terminal configured to determine the precise position of the mobile communication terminal, wherein;

the processor is further configured to retrieve the position registration area identifier from the memory;

the processor is further configured to send, with the communication interface, a request for position measurement assist data to a position assistance server, wherein the request for position measurement assist data includes the position registration area identifier;

in response to receipt of the position measurement assist data from the position assistance server, the mobile terminal is further configured to obtain location data from a satellite;

in response to receipt of the location data from the satellite, the processor is further configured to send a request for calculation of the precise position of the mobile communication terminal to the position assistance server, wherein the request for calculation of the precise position includes the location data obtained from the satellite; and

the communication interface is further configured to receive the precise position of the mobile communication terminal from the position assistance server.

20. The mobile communication terminal of claim 19, further comprising a user interface, wherein, the user interface is configured to receive selected geographic location information.

21. The mobile communication terminal of claim 20, wherein in response to receipt of the selected geographic location information, the processor is further configured to determine an initial precise position of the mobile communication terminal based upon the selected geographic location information.

22. The mobile communication terminal of claim 21, wherein:

the processor is further configured to send, through the mobile communication network, an initial request for the position measurement assist data to the position assistance server, wherein the request for position measurement assist data includes the selected geographic location information;

in response to receipt of the position measurement assist data from the position assistance server, the mobile communication terminal is further configured to obtain the location data from the satellite;

in response to receipt of the location data from the satellite, the processor is further configured to send the location data obtained from the satellite to the position assistance server;

the processor is further configured to receive, via the communication interface, the initial precise location of the mobile communication terminal from the position assistance server; and

the processor is further configured to store the initial precise location as the precise location of the mobile communication terminal.

23. The mobile communication terminal of claim 20, wherein the user interface includes a display, and the user interface is configured to display a plurality of geographic divisions on the display;

and

wherein user interface is further configured to receive a selection of one of the displayed geographic divisions as the selected geographic location information.

24. The mobile communication terminal of claim 20, wherein the user interface includes a display, and the user interface is configured to display a list of geographic identifiers, wherein each of the geographic identifiers is associated with a respective one of a plurality of municipal divisions;

and

wherein the user interface is further configured to receive a selection of one of the geographic identifiers as the selected geographic location information.

25. The mobile communication terminal of claim 24, wherein the geographic identifiers include at least one of a plurality of codes associated with municipal divisions and a plurality of names of municipal divisions.