Apparatus and method for locating mobile terminals

• US 20050070306A1
• Filed: 08/06/2004
• Published: 03/31/2005
• Est. Priority Date: 09/29/2003
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Kim, Wuk, Sung, Sang-Kyung, Park, Joon-Goo
• Granted Patent: US 7,526,293 B2
• Time in Patent Office: Days
• US Class Current: 455/456.200
• CPC Class Codes: H04W 64/00 Locating users or terminals or network equipment for network management purposes, e.g. mobility management

Abstract

An apparatus and method for locating mobile terminals is disclosed. A base station transmits a radio signal to mobile terminals located in a specific area, and generates- auxiliary location information for locating mobile terminals from a radio signal received from the terminals. A radio network controller receives the auxiliary location information of the terminals from the base station, and calculates locations of the terminals using the auxiliary location information. A cell broadcaster broadcasts information including assisted GPS information and an auxiliary location information request signal to the terminals located in the area. A core network manages information of mobile terminals connected to a network, and provides an interface with a location service client. This allows location of all of the terminals located in the specific area, irrespective of whether the provision of their location information is permitted, which facilitates rescue when a disaster or calamity occurs in the specific area.

Claims

1. A method for locating a plurality of mobile terminals, comprising the steps of:

a) receiving a location request message for requesting location of the plurality of mobile terminals located in a specific area, from an external client;

b) calculating an identifier of a base station covering the specific area and a list of cells included in the specific area, in response to the location request message;

c) calculating auxiliary location information for calculating locations of the plurality of mobile terminals, based on the calculation result in step (b);

d) transmitting the calculated auxiliary location information to all of the mobile terminals located in the specific area; and

e) receiving location calculation results of all mobile terminals that have received the auxiliary location information.

2. The method according to claim 1, wherein step a) includes the step of receiving a location request message including a service type, a client ID, a ciphering code, geographical area information, the maximum allowable number of UEs, and a maximum response time.

3. The method according to claim 2, wherein the geographical area information is expressed by at least one of an address, a cell list and a polygon.

4. The method according to claim 1, wherein in step (c), the auxiliary location information is calculated according to a one of

a calculation method in which a mobile terminal directly calculates auxiliary location information and

a calculation method in which information for calculating auxiliary location information is received from a mobile terminal and the auxiliary location information is calculated based on the received information.

5. The method according to claim 1, further comprising the step of generating a list of idle mobile terminals among the mobile terminals located in the specific area, using preliminary connection information,

wherein step d) is repeated until responses of all of the idle mobile terminals included in said list of the idle mobile terminals are received.

6. The method according to claim 1, wherein step (d) includes the step of broadcasting the calculated auxiliary location information in the form of an SMS message to idle mobile terminals among the mobile terminals located in the specific area.

7. The method according to claim 1, wherein step (d) includes the step of transmitting an allowed response time interval and a requested-response distribution function, together with the auxiliary location information, to avoid data congestion due to responses from a plurality of unspecified mobile terminals located in the specific area.

8. The method according to claim 1, wherein step (d) includes the step of repeatedly transmitting the auxiliary location information a predetermined number of times to increase reception reliability of a mobile terminal.

9. The method according to claim 1, wherein step (d) includes the step of transmitting the auxiliary location information after adding a control signal for time division to the auxiliary location information.

10. The method according to claim 1, further comprising the step of transmitting assisted GPS information, including GPS satellite orbit information, time information and correction information, to the mobile terminals, and receiving a location calculation result obtained based on the assisted GPS information from the mobile terminals.

11. An apparatus for locating mobile terminals, comprising:

a base station for transmitting a radio signal to mobile terminals located in a specific area, and generating auxiliary location information for location measurement of the mobile terminals from a radio signal received from the mobile terminals;

a radio network controller for receiving auxiliary location information of mobile terminals from the base station, and calculating locations of the mobile terminals using the auxiliary location information;

a cell broadcaster for broadcasting information including assisted GPS information and an auxiliary location information request signal to the mobile terminals located in the specific area; and

a network portion for managing information of mobile terminals connected to a network, and providing an interface with a location service client.

12. The apparatus according to claim 11, wherein the base station receives a location measurement signal, including at least one of a Time of Arrival (TOA) or a Time Difference of Arrival (TDOA), from a mobile terminal.

13. The apparatus according to claim 11, wherein the network portion receives a location request message requesting location of mobile terminals located in a specific area, from a location service client, and transfers data to the cell broadcaster, said data being required to perform cell broadcast for obtaining location information as a response to the location request message.

14. The apparatus according to claim 13, wherein the location request message includes a service type, a client ID, a ciphering code, geographical area information, the maximum allowable number of mobile terminals and a maximum response time.

15. The apparatus according to claim 14, wherein the geographical area information is expressed by at least one of an address, a cell list and a polygon.

16. The apparatus according to claim 14, wherein the network portion includes a processing module for providing a location calculation service, said module converting the geographical area information included in the location request message and performing authentication of the location service client.

17. The apparatus according to claim 11, wherein the cell broadcaster broadcasts a location measurement request signal and assisted GPS information in the form of an SMS message.

18. The apparatus according to claim 17, wherein the cell broadcaster includes information of a list of idle mobile terminals among the mobile terminals located in the specific area, said information of the list being generated based on preliminary connection information, and the cell broadcaster broadcasts the SMS message.

19. The apparatus according to claim 17, wherein the cell broadcaster transmits an allowed response time interval and a requested-response distribution function, together with the auxiliary location information;

to avoid data congestion due to responses from a plurality of unspecified mobile terminals located in the specific area.

20. The apparatus according to claim 17, wherein said broadcaster repeatedly transmits the auxiliary location information a predetermined number of times to increase reception reliability of a mobile terminal.

21. The apparatus according to claim 17, wherein the cell broadcaster transmits the auxiliary location information after adding a control signal for time division to the auxiliary location information.