Method and arrangement for locating a mobile terminal in a multicell radio arrangement

• US 20090149191A1
• Filed: 08/17/2006
• Published: 06/11/2009
• Est. Priority Date: 08/31/2005
• Status: Active Grant

• Current Assignee: Unify Patente GmbH & Co. KG (Atos Se)
• Original Assignee: Siemens AG
• Inventors: Luers, Jurgen
• Granted Patent: US 8,086,252 B2
• Time in Patent Office: Days
• US Class Current: 455/456.100
• CPC Class Codes: H04W 64/00 Locating users or terminals or network equipment for network management purposes, e.g. mobility management

Abstract

A method and system for locating a mobile terminal in a multicell radio system are provided. A plurality of radio base stations detect the field strength of a data transmission of the mobile terminal and the location of the mobile terminal is determined the values are provided. The mobile terminal is switched into an active state, then a plurality of the radio base stations are set to the radio channel used by the mobile terminal to be located, and the mobile terminal is prompted to emit a response message as a result of the communication of a test data transmission. The received field strength of the received response message is measured by the radio base stations and communicated to a central device, after which the location of the mobile terminal is determined by the central device on the basis of the measured values.

Claims

1-8. -8. (canceled)

9. A method for locating a mobile terminal in a multicell radio system having a plurality of radio base stations, comprising:

switching the mobile terminal to an active state;

setting a radio channel for at least a portion of the radio base stations to be the same as a the radio channel used by the mobile terminal to be located;

transmitting a response message from the mobile terminal in response to the mobile terminal receiving a test data message;

by at least a portion of the radio base stations;

measuring a received field strength of the response message which is received by the respective base station, and

transmitting the field strength to a central device; and

determining the location of the mobile terminal by the central device via the measured values.

10. The method as claimed in patent claim 9, further comprises switching the radio base stations back to an original radio channel of the respective station, the switching back occurring after the determining the location.

11. The method as claimed in patent claim 9, wherein the mobile terminal is switched to the active state by sending a data transmission to the mobile terminal from the radio base station associated with the mobile terminal.

12. The method as claimed in patent claim 11, wherein the mobile terminal is kept in the active state by further data transmissions, the mobile terminal kept active until after the transmitting the response message.

13. The method as claimed in patent claim 9, wherein a normal operation of the radio base stations that are set to the radio channel of the mobile terminal is interrupted.

14. The method as claimed in patent claim 9,

wherein a plurality of mobile terminals are to be located,

wherein the mobile terminals associated with the respective radio channel are activated on one radio channel or successively on a plurality of radio channels,

wherein the activated mobile terminals transmit a response message in response to having received a message excited in order to transmit a data transmission, and

wherein the received field strengths of this response message are recorded by measurement.

15. The method as claimed in patent claim 9, wherein the radio base stations carrying out time-critical and/or high-priority data transmissions are excluded from switching of their radio channel.

16. A multi-cell radio system for locating a mobile terminal, comprising:

a central device for determining the location of the mobile terminal;

a plurality of radio base stations; and

a plurality of radio channels, with the radio base stations each being associated with one of the radio channels,

wherein at least one of the radio base stations transmits a data transmission to the mobile terminal,

wherein the radio base stations switch to a radio channel associated with the mobile terminal during a time associated with locating the mobile terminal,

wherein the mobile terminal transmits a response to the data transmission,

wherein the radio base stations transmits a received field strength of the response received from the mobile terminal, the strength transmitted to the central device,

wherein the central device uses the field strengths to determine the location of the mobile terminal.

17. The system for locating a mobile terminal as claimed in claim 16,

wherein the mobile terminal includes a receiver, an active operating mode, and a power-save operating mode,

wherein during the power-save operating mode the mobile terminal periodically switches the receiver on for a short duration after a time duration, and

wherein during the active operating mode the receiver is on.

18. The system for locating a mobile terminal as claimed in claim 17, wherein the data transmission is transmitted to the mobile terminal, which is in the power-save operating mode, in order to switch the mobile terminal to an active operating mode.

19. The system for locating a mobile terminal as claimed in claim 18, wherein the data transmission is transmitted to the mobile terminal, which is in the power-save operating mode, in order to switch the mobile terminal to the active operating mode.

20. The system for locating a mobile terminal as claimed in claim 18, wherein the data transmission is repeated in order to keep the mobile terminal to the active operating mode.

21. A method for locating a mobile terminal in a multicell radio system having a plurality of radio base stations, comprising:

determining by a central device to switch the mobile terminal from a power-save operating mode to an active operating mode;

determining which of the plurality of radio base stations the mobile terminal is registered, the mobile terminal and the radio base station to which the mobile terminal is registered using a first radio channel,

setting a flag in a beacon provided by the radio base station to which the mobile terminal is registered, the flag for the mobile terminal in order to switch the mobile terminal to the active operating mode;

periodically switching a receiver of the mobile terminal on for a short duration during the power-save operating mode, while the transmitter turned off the mobile terminal does not send or receive information;

detecting the flag by the mobile terminal, the detection during the short duration of the transmitter being turned on;

setting a radio channel for at least a portion of the radio base stations to be the same as a the first radio channel;

transmitting a response message from the mobile terminal in response to the mobile terminal receiving a test data message;

measuring by at least a portion of the radio base stations a received field strength of the response message which is received by the respective base station and transmitting the field strength to a central device; and

determining the location of the mobile terminal by the central device via the measured values.

22. The method as claimed in patent claim 21, wherein when the mobile terminal does not detect the flag, the receiver is turned off for a time duration.

23. The method as claimed in patent claim 21, further comprises switching the radio base stations back to an original radio channel of the respective station, the switching back after the determining the location.