Locating Method

• US 20100285815A1
• Filed: 07/31/2008
• Published: 11/11/2010
• Est. Priority Date: 07/31/2007
• Status: Active Grant

• Current Assignee: Google Technology Holdings LLC (Alphabet Inc.)
• Original Assignee: Ludwig-Maximilians-Universitat Munchen
• Inventors: Neukum, Oliver, Linnhoff-Popien, Claudia, Treu, Georg, Küpper, Axel
• Granted Patent: US 9,002,368 B2
• Time in Patent Office: Days
• US Class Current: 455/456.1
• CPC Class Codes: G01S 19/34 Power consumption
• CPC Class Codes: G01S 5/0263 by combining or switching between positions derived from two or more separate positioning systems
• CPC Class Codes: G01S 5/0289 of multiple transceivers, e.g. in ad hoc networks

Abstract

The invention relates to a method for locating a first mobile terminal within a radio network. Said method comprises the following steps: a first locating process is carried out to determine an initial position of the first terminal; the first locating process is deactivated; a second locating process is carried out to at least approximately determine the current position of the first terminal relative to the initial position; and the first locating process is activated and carried out again to determine a new initial position of the first terminal when the current position reaches a minimum distance from the initial position. The invention also relates to a method for determining cliques of mobile terminals in a radio network encompassing a plurality of mobile terminals. Said method comprises the following steps: one or more independent numbers of terminals is determined, each couple of terminals of each of the independent numbers being located at a distance from each other that is greater than a predetermined threshold value; and at least one clique of terminals is determined, the couples of which are located at a shorter distance from each other than a predetermined threshold value, each independent number containing a maximum of one terminal of the clique.

Claims

1. A method for locating a first mobile terminal within a radio network, comprising the following steps:

a first locating process is carried out to determine an initial position of the first terminal;

the first locating process is deactivated;

a second locating process is carried out to at least approximately determine the current position of the first terminal relative to the initial position; and

the first locating process is activated and carried out again to determine a new initial position of the first terminal when the current position reaches a minimum distance from the initial position.

2. The method according to claim 1, wherein the first locating process exhibits greater accuracy than the second locating process and the second locating process consumes less energy from the first terminal than the first locating process.

3. The method according to claim 1, wherein reaching the minimum distance indicates the proximity of the first terminal to the boundary of a predefined zone, wherein the zone is assigned a-location-based service of the first terminal.

4. The method according to claim 1, wherein the second locating process determines the current position with the help of the speed of the first terminal, wherein the speed of the first terminal is given or determined.

5. The method according to claim 1, wherein the second locating process determines the current position with the aid of the speed, acceleration, phases and/or frequency drift of a radio signal, which is received by the first terminal from a base station.

6. The method according to claim 1, wherein the second locating process determines the current position with the aid of quality features of radio signals, which the first terminal receives from at least one base station, particularly with the help of the signal strength (RSS), the signal quality (SNR) and/or the bit rate of the signal.

7. The method according to claim 6, comprising a repetition of the monitoring of the quality features, wherein the constancy of the quality features is taken into account in determining the current position.

8. The method according to claim 6, wherein the second locating process determines the current position by comparing the quality features of several signals, which are received from the respective base stations by the terminal.

9. The method according to claim 1, wherein the second locating process determines the current position by monitoring identifiers, which are received from several base stations by the terminal.

10. The method according to claim 1, wherein the second locating process determines the current position by determining an indicator (eCBS), which depends on the number of joint base stations from which the first terminal receives signals in consecutive passes and/or on quality features of the radio signals, which are received from base stations by the terminal.

11. The method according to claim 10, wherein the indicator represents the quality features of the radio signals at the distance of the first terminal from the initial position.

12. The method according to claim 10, wherein the indicator (eCBS) is determined using the following formula:

13. The method according to claim 10, wherein the current position and/or the distance from the initial position are derived from the indicator (eCBS) by means of information on the topology of the radio network.

14. The method according to claim 10, wherein the current position and/or the distance from the initial position are derived from the indicator (eCBS) by means of a learning algorithm, particularly a Bayessian decision system or a local regression analysis.

15. The method according to claim 10, wherein the current position and/or the distance from the initial position are derived from the indicator (eCBS) by means of a linear map.

16. The method according to claim 10, wherein the current position and/or the distance from the initial position are derived from the indicator (eCBS) by means of a hyperbolic tangent.

17. The method according to claim 15, comprising:

the provision of values outside the first terminal for carrying out mapping; and

the storage of values on the first terminal.

18. The method according to claim 17, wherein the first terminal retrieves the mapping values to carry out the mapping.

19. The method according to claim 10, wherein the first locating process is activated and carried out again if the indicator (eCBS) reaches a predetermined threshold.

20. The method according to claim 1, comprising the following steps:

determining the probability with which the current position has actually reached the minimum distance from the initial position; and

activating and repeating the first locating process, if the probability is greater than a predefined value.

21. The method according to claim 1, wherein the first locating process is a GPS-based process.

22. The method according to claim 1, wherein the second locating process is a GSM-based process.

23. The method according to claim 1 comprising:

determining the current position of the first terminal relative to the position of a second terminal, wherein the minimum distance between the first and second terminals is illustrated.

24. The method of locating mobile terminals in a radio network comprising:

using the process according to claim 1 to determine the current position of a plurality of mobile terminals relative to one another.

25. The method according to claim 24 comprising the following steps:

determining the distance between pairs of the plurality of terminals;

determining one or more independent numbers of terminals from the plurality of terminals, wherein the pairs of terminals of each of the independent numbers are located at a distance from each other that is greater than the minimum distance; and

determining at least one clique of terminals, pairs of which are located at a shorter distance from each other than the minimum distance, each independent number containing a maximum of one terminal of the clique.

27. The method according to claim 25comprising:

monitoring of the particular cliques by checking whether the relative distance of terminals in the cliques can exceed a threshold value.

28. The method according to claim 25 comprising:

determining the formation of new cliques by monitoring whether the relative distance of terminals from the independent numbers can fall below a threshold value.

29. The method according to claim 25, wherein cliques are determined by a central server, which is connected to the terminals.

30. A device, particularly a radio-based terminal such as a mobile phone, designed to carry out the process according to claim 1.

31. A radio network for mobile terminals, designed to carry out the process according to claim 24.

32. A data-processing program with machine-readable instructions for carrying out the steps in the processes according to claim 1 on a data-processing device.

33. The data carrier on which a data-processing program is stored according to claim 32.

26. A method for determining cliques of mobile terminals within a radio network with a plurality of mobile terminals comprising the following steps:

determining one or more independent numbers of terminals, wherein the pairs of terminals of each of the independent numbers are located at a distance from each other that is greater than a predetermined threshold value; and

determining at least one clique of terminals, pairs of which are located at a shorter distance from each other than a predetermined threshold value, each independent number containing a maximum of one terminal of the clique.