JP3790522B2 - Method for detecting position of mobile communication terminal - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
This invention relates to a position detecting method for detecting a current position of the mobile communication terminal comprising a PHS terminal connected to the public telephone network via the Jo Tokoro of the base station.
[0002]
[Prior art and problems to be solved by the invention]
In communication using a mobile communication terminal composed of a PHS terminal, the mobile communication terminal is connected to an existing public telephone line network via a base station that covers an area where the mobile communication terminal is located, and the public telephone line Communication with other mobile communication terminals or ordinary wired telephones is possible through the network.
[0003]
In this case, the communication between the mobile communication terminal and others is performed via the base station in the area where the mobile communication terminal is located among the base stations installed in many areas, that is, the mobile communication terminal. Through the nearest base station.
[0004]
That is, the base station that performs wireless communication with the mobile communication terminal is specified in advance, and therefore the current position of the mobile communication terminal can be specified by specifying the base station.
[0005]
The position information providing service based on the position detection of the mobile communication terminal composed of the PHS terminal has been rapidly spread in recent years.
This type of position detection method using the relationship between the base station and the mobile communication terminal is inferior in the accuracy of position information compared to the position detection method using the GPS terminal, but the indoor or subway where GPS signals do not reach Etc., and has begun to be used as a useful method for reducing current consumption and narrowing down a rough position.
[0006]
This detection method can also be used for searching for lost children and elderly people, searching for stolen items, or searching for people who lay under a building, etc. It has begun to be widely applied such as searching for facilities used.
[0007]
However, in the position detecting method according to the conventional mobile communication terminal, and it is difficult to increase the accuracy of the position置検unloading, various studies for increasing the detection accuracy than conventional it came performed.
[0008]
For example, in Patent Document 1 described below, a mobile communication terminal exists at a point where an isoelectric field strength curve centered on the base station is drawn from the base station position information and electric field strength information, and the isoelectric field strength curve intersects. A method for obtaining a position with a high probability is disclosed.
Although this method can improve the position detection accuracy, it requires processing by a large server to implement this method, and there is a problem that the cost for position detection becomes enormous.
[0009]
[Patent Document 1]
Japanese Patent Laid-Open No. 11-252622
[Means for Solving the Problems]
The position detection method of the mobile communication terminal of the present invention has been devised to solve such a problem.
Thus to those of claim 1 is a method of detecting the current position of the mobile communication terminal comprising a PHS terminal via a Jo Tokoro of the base station to the public telephone network, said mobile communication terminal Selects three base stations from the plurality of base stations capable of receiving radio waves in the order of the strongest electric field strength, acquires position information and electric field strength information for each base station, and uses the three base stations as vertices After determining the center of gravity by determining a triangle, the three vectors corresponding to the electric field strength from the center of gravity to each vertex are combined, and the direction and position indicated by the combined vector are determined by the current mobile communication terminal. It is defined as a position.
[0011]
[Operation and effect of the invention]
As described above, the present invention does not detect and specify the current position of the mobile communication terminal from the single base station covering the area where the mobile communication terminal is located, but selects the order in the strongest field strength. In order to detect and identify the current position of the mobile communication terminal using the three base stations, moreover, by weighting the relative position with respect to each base station, specifically, between each base station Weighted according to the electric field strength and corrected from the center of gravity of the triangle to detect and identify the current position of the mobile communication terminal, so the current position of the mobile communication terminal is detected with high accuracy. Is possible.
[0012]
Moreover, according to the method of the present invention, the current position of the mobile communication terminal can be easily calculated, the position can be easily detected using a home personal computer, and a low-cost position detection device is provided. It becomes possible.
That is, according to the present invention, it is possible to improve the accuracy of position detection and significantly reduce the cost.
[0013]
【Example】
Next, embodiments of the present invention will be described in detail with reference to the drawings.
1 and 2, reference numeral 10 denotes a mobile communication terminal (here, PHS terminal), which is connected to an existing public telephone line network 18 via a base station 12, a switching center 14, and a relay switching center 16, and such a public telephone line. Communication with other mobile communication terminals or ordinary wired telephones 20 is possible through the network 18.
In FIG. 1, reference numeral 22 denotes a switching center of the public telephone network 18.
[0014]
Here, the communication between the mobile communication terminal 10 and others is performed via the base station 12 in the area where the mobile communication terminal 10 is currently located, among the base stations 12 installed in a number of areas. That is, it is performed via the base station 12 closest to the mobile communication terminal 10.
[0015]
In the case of the mobile communication terminal 10 composed of a PHS terminal, the base station 12 is installed at about 160,000 locations nationwide, for example, and the population coverage is about 93 to 95%.
The mobile communication terminal 10 comprising this PHS terminal holds base station information of 10 to 20 places that can be transmitted and received, and when the radio wave becomes weak, the communication base station 12 is changed to a base station 12 having a stronger radio wave. It uses a handover method that automatically switches to
[0016]
In this case, one mobile communication terminal 10 has position information of a plurality of base stations 12 and electric field strength information thereof.
In this example, the top three base stations 12-1, 12-2 and 12-3 having the strongest electric field strength are extracted from the information, and the history of the extracted base stations 12-1, 12-2 and 12-3 is extracted. Based on position information consisting of information such as degrees or addresses, triangles having the base stations 12-1, 12-2, and 12-3 as vertices are determined, and the center of gravity G is obtained (see FIG. 3).
The center-of-gravity point G is obtained as an intersection of a midline (two-dot chain line in FIG. 3) connecting each vertex of the triangle and the midpoint of the opposite side.
[0017]
In the method of this example, as shown in FIG. 4, vectors B ₁ , B ₂ , and B ₃ corresponding to the electric field strength are drawn from the center of gravity G obtained according to the above toward each vertex. That is, a line segment having a size (length) corresponding to the electric field strength from the center of gravity G is drawn toward the apex of each triangle.
And these three vectors B _1, B _2, B ₃ were vector synthesized and determined the direction indicated by the composite vector B _O and position as the position O of the current mobile communication terminal 10.
[0018]
According to the position detection method of the mobile communication terminal 10 of this example as described above, the current position of the mobile communication terminal 10 can be detected with high accuracy.
Moreover, according to the method of this example, the current position of the mobile communication terminal 10 can be calculated easily, and a simple and low-cost position detection device using a home personal computer 24 can be provided.
[0019]
Although the embodiment of the present invention has been described in detail above, this is merely an example, and the present invention can be implemented in various modifications without departing from the spirit of the present invention.
[Brief description of the drawings]
FIG. 1 is a conceptual diagram of a mobile communication system.
FIG. 2 is an explanatory diagram of a main part of the mobile communication system in FIG. 1;
FIG. 3 is an explanatory diagram of a main part of a processing procedure of the method of the present embodiment.
4 is an explanatory diagram of a processing procedure following FIG. 3. FIG.
[Explanation of symbols]
10 mobile communication terminal 12 the base station 18 a public telephone line network G the center of gravity O detected current position B _{1, B} 2, _{B 3} vector B _O composite vector

Claims (1)

A method of detecting the current position of the mobile communication terminal comprising a PHS terminal connected to the public telephone network via the Jo Tokoro of the base station,
The mobile communication terminal selects three base stations in order of strongest electric field strength from a plurality of base stations capable of receiving radio waves, acquires position information and electric field strength information for each base station, and After determining the triangle with the station as the vertex and determining its center of gravity, the three vectors corresponding to the electric field strength from the center of gravity to each vertex are combined, and the direction and position indicated by the combined vector are determined. A method for detecting a position of a mobile communication terminal, wherein the position is determined as a position of the mobile communication terminal.

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