KR101278167B1 - Method and apparatus for measuring position using access point - Google Patents

Abstract

The present invention relates to a location measuring method and a location measuring device for measuring the location of a communication terminal moving in a subway by using an access point for short-range communication, the location measurement device interworking with the subway information system according to the present invention communicates A location measuring method for measuring a location of a terminal includes: storing step of storing installation information of access points in a storage unit; A first receiving step of receiving, from the communication terminal, information of a neighboring access point detected by the communication terminal; Confirming whether the peripheral access point is an access point of a subway line by referring to the installation information of the access points stored in the storage means; A second receiving step of identifying a subway station corresponding to the peripheral access point from the installation information of the access points stored in the storage means and receiving subway information around the subway station from the subway information system; And generating a location measurement result for the communication terminal based on the subway information.

Description

METHOD AND APPARATUS FOR MEASURING POSITION USING ACCESS POINT}

The present invention relates to a position measuring technique of a communication terminal, and more particularly, to a position measuring method and apparatus for measuring a position of a communication terminal moving in a subway using an access point for near field communication.

With the development of mobile communication technology, location measurement technology for measuring the position of a communication terminal in a communication network has been actively studied. Representative examples include a GPS positioning technique using a satellite and a positioning technique using a base station.

GPS positioning technology has a problem that a GPS receiver must be mounted on a communication terminal, and GPS positioning technology was developed for military use by the US Department of Defense, and GPS positioning technology with high precision is not disclosed. In addition, it is impossible to receive GPS signals indoors, so GPS position measurement is impossible. Therefore, GPS location measurement is not possible for a communication terminal moving by subway.

In addition, the position measuring technique using the base station has the advantage that the GPS receiver does not need to be installed in the communication terminal, but compared with the GPS position measuring technique, the error of position measurement reaches tens to hundreds of meters, which causes a problem in that the accuracy of position measurement is inferior. Therefore, it is difficult to accurately measure the position of the communication terminal moving to the subway.

Recently, near-field wireless communication service using a wireless LAN has been activated. The short-range wireless communication service uses a terminal equipped with a wireless LAN such as a notebook, a PDA, and a smart phone to connect to an access point installed at a short distance so as to use the wireless Internet while moving. Recently, as the demand for short-range communication increases, a large number of access points are installed in various places indoors and outdoors.

As many of the above access points are installed in various places indoors and outdoors, the use of such access points enables location measurement of communication terminals even in indoors where GPS positioning technology is not applied, and also many access points are installed. Accordingly, the use of such access points enables more precise location positioning than a location measurement technique using a base station.

Recently, location positioning technology using an access point for short distance communication has been actively researched.

SUMMARY OF THE INVENTION An object of the present invention is to provide a location measuring method and a location measuring device for measuring a location of a communication terminal moving in a subway by using an access point for near field communication in accordance with the above-described communication environment change.

Other objects and advantages of the present invention can be understood by the following description, and will be more clearly understood by the embodiments of the present invention. It will also be readily apparent that the objects and advantages of the invention may be realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims.

According to an aspect of the present invention, there is provided a location measuring method for measuring a location of a communication terminal by a location measuring device interworking with a subway information system, the method comprising: a storing step of storing installation information of access points in a storage unit; A first receiving step of receiving, from the communication terminal, information of a neighboring access point detected by the communication terminal; Confirming whether the peripheral access point is an access point of a subway line by referring to the installation information of the access points stored in the storage means; A second receiving step of identifying a subway station corresponding to the peripheral access point from the installation information of the access points stored in the storage means and receiving subway information around the subway station from the subway information system; And generating a location measurement result for the communication terminal based on the subway information.

The generating may include checking a moving direction of the communication terminal when the number of subways included in the subway information is plural; And selecting the subway moving in the identified movement direction as the subway on which the communication terminal is boarded.

In the checking of the moving direction, it is preferable to check the moving direction by analyzing the position coordinates of the access point having the largest signal strength among the neighboring access points detected by the communication terminal at a time difference.

The location measuring method may further include: selecting a predetermined number of access points among the neighboring access points based on information of the neighboring access points when the neighboring access points are not the access points of the subway line as a result of the checking in the checking step; A calculation step of extracting the position coordinates of each selected access point from the storage means and calculating the center of gravity coordinates using the extracted position coordinates; And determining the calculated center of gravity coordinates as the final position of the communication terminal.

In accordance with another aspect of the present invention for achieving the above object and a position measuring device for measuring the position of the communication terminal using the information of the access point interlocked with the information, the storage means for storing the installation information of the access point; Receiving means for receiving information of a neighboring access point from the communication terminal; And confirming the subway station corresponding to the peripheral access point in the installation information of the access points stored in the storage means, receiving subway information around the subway station from the subway information system, and based on the received subway information. Measuring means for generating a position measuring result for the apparatus.

When the number of subways included in the subway information is plural, the measuring means may check the moving direction of the communication terminal and select the subway moving in the checked moving direction as the subway boarded by the communication terminal.

Preferably, the measuring means checks the moving direction by analyzing the position coordinates of the access point having the largest signal strength among the neighboring access points detected by the communication terminal with time difference.

The location measuring apparatus may further include selecting means for selecting a predetermined number of access points among the neighboring access points based on the information of the neighboring access points, wherein the measuring means further includes: If not, the position coordinates of each of the access points selected by the selection means are extracted from the storage means, the center of gravity coordinates are calculated using the extracted position coordinates, and the calculated center of gravity coordinates are determined as the final position of the communication terminal. .

The present invention can improve the accuracy of position measurement by measuring the position of a communication terminal moving in the subway by using information of an access point having a small service radius installed in the subway station.

In particular, the present invention can measure the location of the communication terminal using the access point information for each location measured for each location in the room, thereby enabling accurate location measurement in the room.

In addition, the present invention, by measuring the position of the communication terminal moving to the subway in conjunction with the subway information system enables a more accurate position measurement.

In addition, the present invention solves the trouble of manually confirming the actual installation coordinates of the access point by estimating the installation position coordinates of the access point that is installed at random.

1 is a diagram illustrating a communication environment according to an embodiment of the present invention.
2 is a diagram illustrating a network configuration of a position measurement system according to an embodiment of the present invention.
3 is a view for explaining a method of collecting access point information by location according to an embodiment of the present invention.
4 is a table of access point information for each location according to an embodiment of the present invention.
5 is a flowchart illustrating a method for determining virtual position coordinates of an access point in a position measurement server according to an exemplary embodiment of the present invention.
6 is a diagram illustrating an example of extracting a rising inflection point based on a signal strength distribution over time of an access point.
7 is a flowchart illustrating a method of measuring the location of a communication terminal in a location measurement server according to an embodiment of the present invention.
8 is a flowchart illustrating a method of measuring a location of a communication terminal in a location measurement server according to another embodiment of the present invention.
9 is a flowchart illustrating a method of calculating a position coordinate using a gravity center method according to an embodiment of the present invention.
10 is a view for explaining a process of calculating the center of gravity coordinates according to an embodiment of the present invention.
11 is a block diagram illustrating a configuration of a location measurement server according to an embodiment of the present invention.

The foregoing and other objects, features and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings, in which: There will be. In the following description, well-known functions or constructions are not described in detail since they would obscure the invention in unnecessary detail. Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

1 is a diagram illustrating a communication environment according to an embodiment of the present invention.

Referring to FIG. 1, a communication environment according to the present invention includes access points (APs) 160 and 170 that provide Internet services using short-range wireless communication (eg, WiFi) for each subway station 110 and 130. This is installed. In addition, although not shown in the figure, a base station providing a mobile communication service is installed to overlap with access points (APs). The communication terminal may use a voice call or wireless Internet while moving through the base station, and access the wired Internet network through the access points 160 and 170 to use an Internet service.

The base station generally has a service radius of several kilometers to several tens of kilometers. In contrast, access points 160 and 170 that provide Internet services through short-range wireless communication have a service radius of only a few m. In addition, since the access point 160 and 170 is low in purchase cost and installation cost, a large number of access points 160 and 170 are installed and used in various places such as a home, a company, or a shopping mall.

Thus, a number of access points 160, 170 are located within the service radius of the base station, in particular for each subway station. Users using a communication terminal use the Internet service where the signals of the access points 160 and 170 are picked up, and use the base station where the signals of the access points 160 and 170 are not picked up. Use the Internet service through.

Rather than location measurement using a base station with a wide service radius, the accuracy of the communication terminal is further improved by using the access points 160 and 170 having a narrow service radius.

2 is a diagram illustrating a network configuration of a position measurement system according to an embodiment of the present invention.

Referring to FIG. 2, an access point (AP) 290-1,..., 290-N for providing Internet service using near field wireless communication and base stations 200-1,. , 200-N are installed in various places. A large number of access points (AP) 290-1, ..., 290-N are installed in each subway station. As described with reference to FIG. 1, the access points (APs) 290-1,..., 290 -N and the base stations 200-1,..., 200 -N have overlapping service radiuses. Is installed. Since the service radius of the base stations 200-1 to 200-N is larger, a plurality of access points (APs) 290-1 to 290-N are provided in the base stations 200-1 to 200- ., 290-N.

The access points (APs) 290-1 through 290-N are connected to the wired Internet network 210 to provide Internet services, and the access points (APs) 290-1 through 290- Is connected to the mobile communication network 230 to provide a mobile communication service. The wired Internet 210 and the mobile communication network 230 interoperate with each other. 2, a location measurement server 250 connected to the wired Internet network 210 and the mobile communication network 230 and an access point information DB 270 managed by the location measurement server 250 are included.

The access point information DB 270 stores identification information (e.g., MAC address, SSID, etc.) of the access points installed inside / outside and coordinate information of an actual installation location. In addition, the access point information DB 270 stores access point information for each location, which is moved by the access point information collecting terminal and measured for each location. The access point information for each position collected by the position is collected position information collected by the access point information collecting terminal and collected at a predetermined period, identification information of the access points detected at the collecting position, signal strength, and base station identification information. This will be described later in detail.

When the location measurement server 250 receives a location measurement request for a specific mobile terminal, the location measurement server 250 uses identification information of an access point 290-1,..., 290 -N to which the positioning target mobile terminal can access. In conjunction with the subway information system 280 to measure the location of the mobile terminal to be positioned. A method of measuring the position of the position measurement server 250 will be described later in detail.

The subway information system 280 is a system for managing subway lines, subway dispatch information, subway location information, transfer information, station information, and the like. Provided at 250.

3 is a view for explaining a method of collecting access point information by location according to an embodiment of the present invention.

As illustrated in FIG. 3, the access point information collecting device 310 collects information by measuring signals of neighboring access points at regular time periods while traveling outdoors and subway stations. The information collected by the apparatus for collecting access point information may include subway station information, collection time, collection location information (eg, latitude / longitude), and identification information of access points that transmit signals in the vicinity measured at the collection location (eg, MAC). Address), signal strength (e.g., RSSI), and identification information (cell ID, or PN code) of the base station covering the corresponding acquisition location. In the case of the outdoor, the latitude and longitude coordinates can be immediately checked, but an indoor room such as a subway station may be collected by setting virtual latitude and longitude coordinates or by giving actual latitude and longitude coordinates to an indoor surface.

Referring to FIG. 3, at an A point point, the access point information collecting device 310 detects an access point for which a signal is caught at the A point point. The AP 310 collects the MAC address and signal strength (RSSI) and the A point of the A point, the latitude / longitude information, and the time of the time, and the APs whose signals are detected at the A point. Detect the identification information of the base station covering the and stores it. In addition, the access point information collection device 310 stores the information of the subway station when the A point point is a subway station. As described above, the apparatus for collecting access point information collects and stores information of access points at each point at a predetermined time period (for example, 1 minute unit) while moving around.

4 is a table of access point information for each location according to an embodiment of the present invention. The apparatus for collecting access point information moves and collects peripheral access point information at regular time periods, and the collected location-specific access point information is shown in FIG. 4. As shown in FIG. 4, the table includes a subway station information field 420, a time field 410, a location field 430, a MAC address field 450, an RSSI field 470, and a cell ID field 490. Include.

The time field 410 records the time when the access point information collecting device collects the neighboring access point information, the location field 430 records the collecting location information (latitude / longitude information), and the MAC address field 450 MAC addresses of peripheral access points detected at the collection location are recorded, RSSI field 470 records the signal strength of the peripheral access points detected at the collection location, and cell ID field 490 covers the collection location. The cell ID of the base station is recorded. Here, although only one cell ID of the base station is shown as being recorded, a plurality of cell IDs may be detected and recorded in the cell boundary region. The subway station information field 420 records information of the subway station when the collecting position is the subway station.

According to the position measuring method according to the present invention, in order to position the mobile terminal using the access point, it is necessary to know the installation position coordinates of the access points (hereinafter, referred to as facility coordinates). The access points 160, which are installed in the local areas by the communication companies themselves, have the installation location coordinates in the communication company. However, in the case of a private access point, it is installed irrespective of a communication company, and coordinates of the installation position of the private access point can not be known without confirming to the installer who installed the corresponding private access point. Therefore, as described with reference to FIG. 3, there is a need for a method capable of estimating installation location coordinates of access points whose access point information collecting device is moved and whose installation location coordinates are not checked among collected access points. Hereinafter, a method of estimating installation location coordinates of access points for which installation location coordinates of the access points collected by the apparatus for collecting access point information are not confirmed will be described with reference to FIG. 5. That is, the installation position coordinates of the access points estimated below are virtual position coordinates as estimated values, not the actual installation position coordinates of the corresponding access point.

5 is a flowchart illustrating a method for determining virtual position coordinates of an access point in a position measurement server according to an exemplary embodiment of the present invention.

Referring to FIG. 5, first, the apparatus for collecting access point information, as described with reference to FIGS. 3 and 4, moves around at low speed and collects information by measuring signals of neighboring access points at a predetermined time period. Location-specific access point information collected by the access point information collecting device may be transmitted from the access point information collecting device and received by the location measurement server 250 through the internet network 210 or the mobile communication network 230. The location measurement server 250 stores the access point information for each location received from the access point information collecting device in the access point information DB 270. Alternatively, location-specific access point information collected by the access point information collecting device may be stored in the access point information DB 270 by an administrator.

After the access point information for each location is collected, the location measurement server 250 stores measurement information for each location of the specific access point whose installation location coordinates are not identified in the collected access point information, 270) (S501). That is, it extracts measurement information by position in which the information of the specific access point is measured. For example, in FIG. 4, the information of the access point having the MAC address of 111.112 is contained in the group 1, group 2, group 3, group 4, and group N-1 and extracts the information.

After extracting the measurement information for each location of the specific access point, the location measurement server 250 extracts the signal strength (for example, RSSI) from the measurement information for each location and lays out the information in the time order (S503). For example, referring to FIG. 4, when the signal strengths of the access points having the MAC address of 111.112 are listed in time order, they are -40 dB, -50 dB, -80 dB, -80 dB, and -40 dB.

In operation S505, the location measurement server 250 extracts a rising inflection point by analyzing a change in the signal strength with time, after arranging the signal strengths of the specific access points in chronological order. Herein, the upward inflection point is a point when the signal intensity reaches the highest point. Specifically, FIG. 6 shows an example of extracting a rising inflection point based on a signal intensity distribution over time of an access point. When signal strengths of access points are listed in chronological order, as shown in FIG. 6, The point at which the peak reaches the elevation is extracted to the point A and C, and the point A and the point C are extracted as the rising inflection point.

When the upward inflection point is extracted, the position measurement server 250 calculates the center coordinates of the polygon (or straight line) having the measurement position coordinates of the upward inflection point, that is, the measurement position coordinates at which the signal intensity of the upward inflection point has been measured, Determines the calculated center coordinates as virtual position coordinates of the specific access point, and stores the virtual position coordinates in the access point information DB 270 (S507). Here, the center coordinate may be a center of gravity, or may be one of an inner core and an outer core. Also, the center coordinates may be obtained according to the weight according to the signal intensity, reflecting the signal strength.

The reason for utilizing the ascending inflection point in the above-described embodiment is that the ascending inflection point is closest to the actual installation position of the access point, where the signal strength of the access point is the highest.

As described above, the method for determining the virtual position coordinates of the access point with reference to FIG. 5 is performed for all the access points to which the access point information collecting device moves and whose installation position coordinates are not checked.

7 is a flowchart illustrating a method of measuring the location of a communication terminal in a location measurement server according to an embodiment of the present invention.

Referring to FIG. 7, the location measurement server 250 receives a location measurement request for a specific communication terminal (S701). The location measurement server 250 may receive a location measurement request directly from the specific communication terminal, that is, the location target terminal, or may receive a location measurement request from another communication terminal, or as a device for providing a location-based service. A location measurement request may also be received.

The location measurement server 250 receiving the location measurement request as described above receives identification information (eg, MAC address or SSID) of neighboring access points and signal strength information of the corresponding neighboring access points from the positioning target terminal (S703). The location measurement server 250 controls the location target terminal to transmit information of the neighboring access point by using the identification information of the location target terminal. The positioning target terminal transmits information (eg, identification information and signal strength) of a plurality of access points.

When the information of the neighboring access point is received, the location measurement server 250 checks whether the received information of the neighboring access point is the information of the access point of the subway line (S705). Since the table of access point information stored in the access point information DB 270 includes the subway station information, the location measurement server 250 determines that the neighboring access points access the subway line based on the subway station information included in the table. You can check whether it is a point.

As a result of the checking, when the information of the neighboring access points is not the information of the access point of the subway line, the location measurement server 250 performs general location positioning instead of subway location positioning (A). This will be described later with reference to FIG. 8.

On the other hand, when the information of the neighboring access point is the information of the access point of the subway line, the location measurement server 250 checks the corresponding subway station based on the information of the neighboring access point (S707). Specifically, the location measurement server 250 checks the subway station recorded in the subway station information field corresponding to the information of the neighboring access point in the table of access point information stored in the access point information DB 270.

Subsequently, the location measurement server 250 transmits the information of the identified subway station to the subway information system 280 and receives subway information around the corresponding subway station from the subway information system 280 (S709). Preferably, the subway information system 280 transmits the information of the subway entering or entering the subway station, that is, the subway identification number and the direction information, the location information on the line, etc. to the location measurement server 250. If the subway station is entering or there is no subway, the subway information system 280 transmits information about this.

The location measurement server 250 receiving the subway information analyzes the corresponding subway information and analyzes whether there is a subway in the vicinity of the identified subway station (S711). If there is no subway in the vicinity of the corresponding subway station, and transmits the current subway station to the place requesting the location measurement, for example, the positioning target terminal (S713). Preferably, the location measurement server 250 may display the identified subway station as the location of the positioning target terminal on the map on which the subway line is displayed and transmit the same.

On the other hand, if there is a subway in the vicinity of the identified subway station, the location measurement server 250 checks whether there are a plurality of subway (S715). For example, in the case of the subway line 2, the lines of the outer circulation and the internal circulation exist, and therefore, the subway of the line circulation and the subway of the internal circulation may exist simultaneously in the subway station. In this way, it is to check whether there are a plurality of subways in the subway station.

When there are a plurality of subways in the subway station, the location measurement server 250 checks the moving direction of the positioning target terminal in order to determine which subway among the plurality of subways the positioning target terminal is moving in (S717).

Specifically, the location measurement server 250 selects an access point having the largest signal strength among the neighboring access points received from the positioning target terminal, and determines the location coordinates (first location coordinates) of the selected access point. ). After the predetermined time (for example, 5 seconds) elapses, the location measurement server 250 controls to transmit the information of the neighboring access point to the positioning target terminal to receive the information of the neighboring access point, and receives the received neighboring access. The access point information DB 270 checks the position coordinate (second position coordinate) of the access point having the largest signal strength among the points.

Then, the location measurement server 250 compares the first location coordinates with the second location coordinates to determine which direction the positioning target terminal is moving in. The location coordinates are coordinates based on latitude and longitude coordinates, and may determine east, west, north and south directions based on the coordinates. For example, when the subway station is a line 2 and the positioning target terminal moves from the west to the east, it may be determined that the subway station is in the subway of the internal circulation. Alternatively, the location measurement server 250 may check the moving direction by measuring the location of the positioning target terminal twice at regular time intervals by using the center of gravity method described below with reference to FIG. 8.

The location measurement server 250 confirming the movement direction of the positioning target terminal as described above selects the subway moving in the movement direction (S719), and the information (for example, the subway identification number, the position on the line, etc.) of the selected subway. The subway line is displayed on the map where it is displayed, and then transmitted to a location requesting location measurement, for example, a positioning target terminal (S721).

On the other hand, as a result of checking in the above-described step S715, when there are not a plurality of subways, that is, when only one subway is around the subway station, the location measurement server 250 determines the information of the subway (for example, the subway identification number and the line). Location, etc.) is displayed on a map displaying the subway line, and is transmitted to a location requesting for measurement, for example, a positioning target terminal (S721).

Thereafter, the location measurement server 250 checks whether the location measurement is completed (S723), and if the location measurement is not finished, the location measurement server 250 repeats the above-described step S703 to perform the above-described location measurement process. The end of the location measurement may be determined by determining whether a termination signal for terminating the location-based service is received from the location requesting location measurement, for example, the positioning target terminal.

When performing the initial position measurement, the terminal to be located is located in the subway station, but may have entered or entered the subway station. Therefore, there may be some error in the initial position measurement result, the error can be corrected in steps S709 and S711 while repeating the process with reference to FIG. That is, if the positioning target terminal is located at the subway station but has not entered or entered the subway station, the subsequent positioning measurement process, that is, the positioning target terminal is located at the subway station in steps S709 and S711. The surrounding subway disappears, and thus, the positioning target terminal is determined to be located at the subway station without boarding the subway, so that an error may be corrected.

FIG. 8 is a flowchart illustrating a method of measuring a location of a communication terminal in a location measurement server according to another embodiment of the present invention, and specifically illustrates step A of FIG. 7.

Referring to FIG. 8, when the positioning target terminal is not at the subway station, the location measurement server 250 first selects an access point having facility coordinates among neighboring access points received from the positioning target terminal (S801). That is, the location measurement server 250 checks access points having facility coordinates, that is, actual installation coordinates, in the access point information DB 270 using identification information (eg, MAC address) of neighboring access points. Hereinafter, assume that the number of primary selected access points is n.

At this time, if there is no access point in which facility coordinates exist, the access point is not selected in this step. In selecting an access point having facility coordinates, only an access point having a signal strength equal to or greater than a predetermined signal strength may be selected. In the case of an access point having a small signal strength, since the access point is located at a long distance from the positioning target terminal, the facility coordinates of the corresponding access point are excluded even if they exist.

Thereafter, the location measurement server 250 secondly selects the top k large signal strengths based on the signal strengths of the remaining neighboring access points except the access point having the facility coordinates among the neighboring access points (S803). For example, when it is assumed that there are six access points having facility coordinates among the information of 30 access points received from the positioning target terminal, the location measurement server 250 determines the signal strength based on the signal strength of the remaining 24 access points. Is to choose a large top k.

Here, R = (k + n) is preferably L ⁱ (L is a natural number of 3 or more, i is a natural number of 2 or more). If the number n of access points in which the facility coordinates exist in step S801 exists, as described above, step S803 described above may be omitted.

After selecting the access points as described above, the location measurement server 250 extracts the location coordinates of the selected R access points from the access point information DB 270 (S805).

Specifically, the location measurement server 250 extracts facility coordinates of the access point from the access point information DB 270 for the access point having the facility coordinates.

In addition, the location measurement server 250 checks whether the virtual location coordinates are stored in the access point information DB 270 for the access point for which the facility coordinates do not exist, and for the access point for which the virtual location coordinates are stored. Virtual location coordinates are extracted from the access point information DB 270.

In addition, the location measurement server 250 is based on the signal strength measured and collected for each location of the access points in the access point information DB 270 with respect to the location coordinates of the access points where the facility coordinates and the virtual location coordinates do not exist. As a result, the top i (i is the number of access points) measurement position coordinates having a large signal strength are extracted as position coordinates of the corresponding access points.

For example, if there are three access points in which there are no facility coordinates and virtual location coordinates, and the signal strengths measured for each access point position are -40 dB and -50 dB for the A access point, -50dB, -60dB, -70dB in case of C access point, -60dB and -100dB in case of C access point, and the upper three signals with high signal strength are -40dB and -50dB of A access point, 50 dB. The location measurement server 250 extracts the measurement location coordinates of which -40dB, -50dB of the A access point and -50dB of the B access point are measured as the location coordinates of the access points where the facility coordinates and the virtual location coordinates do not exist. .

As such, after extracting the position coordinates of the access points selected in steps S801 and S803, the position measurement server 250 calculates the final position coordinates using the center of gravity method using the extracted position coordinates (S807). . The location measurement server 250 transmits the final location coordinates to a place (eg, a positioning target terminal) that has requested location measurement (S809). The determined final position coordinates may be provided in the form of a map, or may be changed to an address corresponding to the coordinates. The form of providing the position information can be utilized without limitation.

The position coordinate calculation method using the center of gravity method of step S807 will be described in detail with reference to FIG. 9.

9 is a flowchart illustrating a method of calculating a position coordinate using a gravity center method according to an embodiment of the present invention.

As shown in FIG. 9, the positioning server 250 selects M access points extracted in step S805 shown in FIG. 8 by M (M is a natural number of 3 or more, preferably M and L are the same). (S901), and calculates the center of gravity coordinates of each group using the position coordinates of the access points belonging to each group (S903).

This will be described in detail with reference to Fig. FIG. 10 is a view illustrating a process of calculating the center of gravity coordinates according to an embodiment of the present invention. In the embodiment described with reference to FIG. 8, R is 9 and M is 3. When nine access points are selected in step S805, the selected nine access points are randomly selected three by three to form three groups of three access points. Then, as shown in Fig. 10A, the coordinates of the center of gravity of the triangle having the position coordinates (facility coordinates or virtual position coordinates) of the three access points belonging to each group as vertexes are obtained. In FIG. 10A, 'A', 'B', and 'C' are the center-of-gravity coordinates of each group.

Preferably, access points with facility coordinates are distributed evenly among the groups. For example, when there are three access points in which facility coordinates exist, each group includes one access point in which facility coordinates exist. The reason for doing this is to reduce the position error by including facility coordinates in each group because the facility coordinates are accurate position coordinates.

Next, after the center of gravity coordinates are obtained as described above, the location measurement server 250 randomly selects the center of gravity coordinates by M again from the obtained center of gravity coordinates to form a group, and the center of gravity coordinates of the M pieces Find the coordinates of the center of gravity of each group consisting of. This process is repeated until one center-of-gravity coordinate is obtained (S905).

Specifically, the center of gravity coordinates obtained in FIG. 10A are 'A', 'B', and 'C'. When the coordinates of the center of gravity of the triangle having the vertexes of the three center-of-gravity coordinates are obtained, the center-of-gravity coordinates 1010 are obtained as shown in FIG. 10 (b) Is obtained.

Finally, the position measurement server 250 determines the last one center of gravity 1010 obtained by the gravity center method as the final position of the mobile terminal to be positioned (S907).

In the above embodiment, R has been described as being L ⁱ , but need not necessarily be L ⁱ . The reason why R is described as L ⁱ is that when M is set equal to L, both polygons (for example, triangles) of the same pattern are used when obtaining the center of gravity coordinates in steps S903 and S905. However, R does not necessarily need to be L ⁱ . In step S903 and step S905, group M is used to find the center of gravity coordinates, and if the center of gravity coordinates of the number greater than M and less than 2 × M (X, M <X <2 × M) remain, the value is greater than M. It is also possible to create a polygon with a vertex of the number X center of gravity smaller than xM to obtain a final center of gravity coordinate. Alternatively, when grouping the center of gravity coordinates by a predetermined number to form a group, the number of center of gravity coordinates belonging to the group may not be the same.

8 and 9 have described the case where there are nine or more neighboring access points of the positioning target terminal. If there are 2 or 3 neighboring access points of the positioning target terminal, the center of gravity coordinates of the position coordinates of the 2 or 3 neighboring access points may be determined as the final position coordinates, or if there are 4 neighboring access points, the 3 pieces are bundled and weighed. The center coordinates may be obtained and the center of gravity of the center of gravity coordinates and the position coordinates of the other access point may be determined as the final position coordinates. As described above, in the case of 9 or less, a group of the centers can be appropriately divided to obtain a final position coordinate.

11 is a block diagram illustrating a configuration of a location measurement server according to an embodiment of the present invention.

Referring to FIG. 11, the location measurement server 250 according to the present embodiment may include an access point information collector 1110, a virtual access point (AP) coordinate determiner 1130, a location information request receiver 1150, and an access point. The selector 1170 and the position measuring unit 1190 are included.

The access point information collecting unit 1110 receives the access point information for each location collected by the access point information collecting device at a predetermined time period and stores it in the access point information DB 270. The access point information collecting unit 1110 may receive access point information for each location from the access point information collecting device directly through the internet network 210 or the mobile communication network 230. The access point information by location is the same as the example of FIG.

The virtual AP coordinate determination unit 1130 estimates and determines the installation position coordinates of the access point in which facility coordinates do not exist, based on the access point information collected for each position by the access point information collection unit 1110. Position coordinates estimated and determined by the virtual AP coordinate determination unit 1130 are defined as virtual position coordinates.

In detail, the virtual AP coordinate determiner 1130 extracts, from the access point information DB 270, measurement information for each location of a specific access point whose installation location coordinates are not identified among the collected access points. The virtual AP coordinate determiner 1130 extracts measurement information for each location of a specific access point, extracts signal strength (for example, RSSI) from the location-specific measurement information, and lists them in chronological order and at the time of the signal strength. Ascending inflection point is extracted by analyzing the change trend. Herein, the upward inflection point is a point when the signal intensity reaches the highest point.

Specifically, FIG. 6 shows an example of extracting a rising inflection point based on a signal intensity distribution over time of an access point. When signal strengths of access points are listed in chronological order, as shown in FIG. 6, The point at which the peak reaches the elevation is extracted to the point A and C, and the point A and the point C are extracted as the rising inflection point.

When the rising point of inflection is extracted, the virtual AP coordinate determining unit 1130 calculates the measurement position coordinates of the rising inflection point, that is, the center coordinates of the measurement position coordinates at which the signal strength of the rising inflection point is measured, and accesses the calculated center coordinates to the specific access point. The virtual position coordinate of the point is determined, and the virtual position coordinate is stored in the access point information DB 270. Here, the center coordinate may be the center of gravity of the measurement position coordinates, or may be either the inner or outer center.

Therefore, the access point information DB 270 stores facility coordinates or virtual position coordinates for each access point.

The location information request receiver 1150 receives a location measurement request for a specific communication terminal. The location measurement request may be received from other communication network equipment at the request of another communication terminal. When receiving the location information request, the location information request receiver 1150 controls the location target terminal to receive identification information (eg, MAC address or SSID) and signal strength of the neighboring access point of the location target terminal from the location target terminal. do.

The access point selector 1170 selects an access point to be used for location measurement when the location calculation unit 1090 performs general location measurement such as outdoor location measurement instead of subway location measurement. )

The access point selector 1170 selects R pieces from the neighboring access points of the positioning target terminal received by the location information request receiver 1150. R is preferably L ⁱ (L is a natural number of 3 or more, i is a natural number of 2 or more).

In selecting R access points, the access point selector 1170 first selects an access point having facility coordinates from among the neighboring access points with reference to the access point information DB 270, and the rest of the neighboring access points. Select an access point with a large signal strength.

Therefore, when there are R access points with facility coordinates, only an access point with facility coordinates is selected, and when there is a shortage, an access point having a large signal strength is selected (the signal strength is a value measured and reported by the specific mobile terminal. ). In this case, in selecting an access point having facility coordinates, only an access point having a predetermined signal strength or more may be selected. The signal strength is the signal strength of the neighboring access point received by the location information request receiver 1150 from the positioning target terminal.

When the location measurement unit 1190 receives the information of the neighboring access point from the positioning target terminal in the location information request receiving unit 1150, the location measurement unit 1190 confirms whether the received neighbor access point information is the information of the access point of the subway line. Since the table of the access point information stored in the access point information DB 270 includes subway station information, the position measuring unit 1190 determines that the neighboring access points access the subway line based on the subway station information included in the table. You can check whether it is a point.

When the information of the neighboring access point is not the information of the access point of the subway line, the location measuring unit 1190 performs general location positioning instead of the subway location positioning, and when the information of the neighboring access point is the access point of the subway line Perform positioning.

General positioning

The position measuring unit 1190 extracts the position coordinates of the access points selected by the access point selecting unit 1170 from the access point information DB 270, and uses the extracted position coordinates to determine the final one. Calculate the position coordinates. Specifically, the location measuring unit 1190 extracts facility coordinates of the access point from the access point information DB 270 for the access point having the facility coordinates.

In addition, the position measuring unit 1190 checks whether the virtual position coordinates are stored in the access point information DB 270 for the access point where the facility coordinates do not exist, and for the access point where the virtual position coordinates are stored, Virtual location coordinates are extracted from the access point information DB 270.

In addition, the location measuring unit 1190 is based on the signal strength measured and collected for each location of the access points in the access point information DB 270 with respect to the location coordinates of the access points where the facility coordinates and the virtual location coordinates do not exist. As a result, the top i (i is the number of access points) measurement position coordinates having a large signal strength are extracted as the position coordinates of the corresponding access points.

For example, if there are three access points in which there are no facility coordinates and virtual location coordinates, and the signal strengths measured for each access point position are -40 dB and -50 dB for the A access point, -50dB, -60dB, -70dB in case of C access point, -60dB and -100dB in case of C access point, and the upper three signals with high signal strength are -40dB and -50dB of A access point, 50 dB. The location measuring unit 1190 extracts the measured location coordinates of which -40dB, -50dB of the A access point and -50dB of the B access point are measured as the location coordinates of the access points where the facility coordinates and the virtual location coordinates do not exist. .

The position measuring unit 1190 configures a predetermined number of groups by selecting M access points selected by the access point selecting unit 1170 (M is a natural number of 3 or more, preferably M and L are the same), A center of gravity coordinate of each group is calculated using the extracted location coordinates of the access point. In this case, the location measuring unit 1190 evenly distributes the access points having the facility coordinates to each group.

The position measuring unit 1190 selects the center of gravity coordinates at random from the obtained center of gravity coordinates again to form a predetermined number of groups, and obtains the center of gravity coordinates of each group of the M centers of gravity coordinates. . The position measuring unit 1190 repeats this process until one center of gravity coordinate is obtained, and finally, if one center of gravity coordinate is obtained, the position measuring unit 1190 determines the obtained center of gravity as the final position of the positioning target terminal.

When the position measuring unit 1190 calculates the center of gravity coordinates of each group by grouping the center of gravity coordinates by M, the position measuring unit 1190 has a number greater than M and smaller than 2 × M (X, M <X <2 × M). If the center of gravity coordinates remain, a polygon with a vertex of the number of centers of gravity (X) larger than M and smaller than 2 × M can be created to obtain the final center of gravity coordinate.

In addition, when the position measuring unit 1190 makes a group by combining the center of gravity coordinates by a predetermined number, the number of center of gravity coordinates belonging to each group is not the same, and the center of gravity coordinates are obtained to obtain a final center of gravity coordinate. It may be.

As such, the final coordinates calculated by the position measuring unit 1190 are transmitted to the place where the position measurement is requested.

Subway positioning

When the information of the neighboring access point is the information of the access point of the subway line, the position measuring unit 1190 confirms the corresponding subway station based on the information of the neighboring access point. Specifically, the location measuring unit 1190 identifies the subway station recorded in the subway station information field corresponding to the information of the neighboring access point in the table of access point information stored in the access point information DB 270.

In addition, the location measuring unit 1190 transmits the information of the identified subway station to the subway information system 280 and receives subway information around the corresponding subway station from the subway information system 280. The subway information includes a subway identification number, direction information, location information on a line, and the like. If you are entering the subway station, or if no subway is entered, this information is included.

In addition, the location measuring unit 1190 analyzes the subway information to analyze whether there is a subway in the vicinity of the identified subway station. If there is no subway in the vicinity of the corresponding subway station, the current subway station is transmitted to a location requesting location measurement, for example, a positioning target terminal as a location positioning result. Preferably, the location measuring unit 1190 may display the identified subway station as a location of the positioning target terminal on a map on which a subway line is displayed and transmit the same.

In addition, the location measuring unit 1190 checks whether there are a plurality of subways when there are subways in the vicinity of the identified subway station, and if a plurality of subways exist in the subway station, the positioning target terminal is located in any subway of the plurality of subways. Check the moving direction of the positioning target terminal to determine whether the boarding and moving.

In detail, the position measuring unit 1190 selects an access point having the largest signal strength among the neighboring access points received from the positioning target terminal, and sets the position coordinates (first position coordinate) of the selected access point to the access point information DB 270. Check in After the predetermined time (for example, 5 seconds) elapses, the position measuring unit 1190 receives the information of the neighboring access point by controlling to transmit the information of the neighboring access point to the positioning target terminal again, and receives the received neighboring access. The access point information DB 270 checks the position coordinate (second position coordinate) of the access point having the largest signal strength among the points.

Then, the position measuring unit 1190 compares the first position coordinates with the second position coordinates to determine which direction the positioning target terminal is moving in. The location coordinates are coordinates based on latitude and longitude coordinates, and may determine east, west, north and south directions based on the coordinates. For example, when the subway station is a line 2 and the positioning target terminal moves from the west to the east, it may be determined that the subway station is in the subway of the internal circulation.

The location measuring unit 1190 checks the moving direction of the positioning target terminal, selects the subway moving in the moving direction, and displays the selected subway information (for example, the subway identification number, the position on the line, etc.) in the subway line. It is displayed on the map and transmitted to the location requesting location measurement terminal, for example.

If there are not a plurality of subways, that is, only one subway is located near the subway station, the location measuring unit 1190 may display information on the subway lines (for example, a subway identification number, a location on a line, etc.) on which the subway line is displayed. Indicated by the location to send the location measurement request, for example to the positioning target terminal.

The position measuring unit 1190 repeatedly performs the position measurement process by receiving the peripheral access point information from the positioning target terminal repeatedly until the position measurement is completed.

The access point described in the present invention may be referred to as a small base station, a pico base station, a ubiquitous base station, or the like in accordance with a manufacturer or a service provider's policy. Therefore, the access point in the present invention should be understood as a gateway point for directly communicating with the mobile terminal through short-range communication and providing Internet service to the mobile terminal through the general-purpose Internet line.

The method of the present invention as described above may be embodied as a program and stored in a computer-readable recording medium (such as a CD-ROM, a RAM, a ROM, a floppy disk, a hard disk, or a magneto-optical disk).

While the specification contains many features, such features should not be construed as limiting the scope of the invention or the scope of the claims. In addition, the features described in the individual embodiments herein may be combined and implemented in a single embodiment. Conversely, various features described herein in a single embodiment may be implemented in various embodiments individually or in a suitable subcombination.

It is to be understood that, although the operations have been described in a particular order in the figures, it should be understood that such operations are performed in a particular order as shown, or that a series of sequential orders, or all described operations, . In some circumstances, multitasking and parallel processing may be advantageous. It should also be understood that the division of various system components in the above embodiments does not require such distinction in all embodiments. The above-described program components and systems can generally be implemented as a single software product or as a package in multiple software products.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention. The present invention is not limited to the drawings.

290: access point 200: base station
210: Internet network 230: Mobile communication network
270: Access point information DB 250: Position measurement server

Claims (24)

In the position measuring method for measuring the position of the communication terminal by the position measuring device interlocked with the subway information system,
A storage step of storing installation information of the access points in a storage means;
A first receiving step of receiving, from the communication terminal, information of a neighboring access point detected by the communication terminal;
Confirming whether the peripheral access point is an access point of a subway line by referring to the installation information of the access points stored in the storage means;
A second receiving step of identifying a subway station corresponding to the peripheral access point from the installation information of the access points stored in the storage means and receiving subway information around the subway station from the subway information system; And
And generating a location measurement result for the communication terminal based on the subway information. The method of claim 1,
Wherein the generating comprises:
Checking a moving direction of the communication terminal when the number of subways included in the subway information is plural; And
And selecting the subway moving in the identified movement direction as the subway boarded by the communication terminal. 3. The method of claim 2,
Checking the moving direction,
And determining the moving direction by analyzing the position coordinates of the access point having the largest signal strength among the neighboring access points detected by the communication terminal with time difference. The method according to any one of claims 1 to 3,
A selection step of selecting a predetermined number of access points among the neighboring access points based on the information of the neighboring access points when the neighboring access points are not the access points of the subway line as a result of the checking in the confirming step;
A calculation step of extracting the position coordinates of each selected access point from the storage means and calculating the center of gravity coordinates using the extracted position coordinates; And
And determining a calculated center-of-gravity coordinate as a final position of the communication terminal. The method of claim 4, wherein
Wherein,
A first step of grouping the extracted position coordinates and then calculating the center-of-gravity coordinates of each group;
A second step of grouping the calculated center-of-gravity coordinates and calculating the center-of-gravity coordinates of each group; And
And a third step of repeating the second step to calculate a final one of the coordinates of the center of gravity. The method of claim 5, wherein
In the first step,
Wherein the position coordinates are M (M is L ⁱ , where L is a natural number of 3 or more and i is a natural number of 2 or more). The method of claim 4, wherein
The selection step,
Selecting an access point having a signal strength above a threshold. The method of claim 4, wherein
The storing step,
And storing virtual position coordinates for the access point and storing the virtual position coordinates in the storage means. The method of claim 8,
The virtual position coordinate storage step stores,
Collecting signal strengths by location of the access point;
Extracting a rising inflection point by analyzing a change in a signal intensity with respect to time of the access point with respect to time; And
And determining virtual position coordinates of the access point based on the extracted elevation inflection point. The method of claim 9,
Wherein the ascending inflection point is a point at which the peak point is reached while the signal intensity rises. The method of claim 4, wherein
Wherein,
A first extracting step of extracting a corresponding installation position coordinate for an access point that knows installation position coordinates among the selected access points;
A second extracting step of extracting estimated virtual position coordinates for an access point not knowing an installation position coordinate of the selected access point; And
And a third extracting step of extracting the measurement position coordinates measured by the access point for the access point from which the installation position coordinates and virtual position coordinates of the selected access point can not be extracted. The method of claim 11,
The third extraction step may include:
And a measurement position coordinate of which the signal strength is measured to be the largest among the measurement position coordinates of which the access point is measured. In the position measuring device interlocked with the subway information system and measuring the position of the communication terminal using the information of the access point,
Storage means for storing installation information of the access points;
Receiving means for receiving information of a neighboring access point from the communication terminal; And
Check the subway station corresponding to the peripheral access point in the installation information of the access points stored in the storage means, and receive the subway information around the subway station from the subway information system and transmit the information to the communication terminal based on the received subway information. Measuring means for generating a position measuring result for said position measuring device. The method of claim 13,
Wherein the measuring means comprises:
And a plurality of subways included in the subway information, checking a moving direction of the communication terminal and selecting a subway moving in the identified moving direction as a subway boarded by the communication terminal. 15. The method of claim 14,
Wherein the measuring means comprises:
And determining the direction of movement by analyzing the position coordinates of the access point having the largest signal strength among the neighboring access points detected by the communication terminal with time difference. The method according to claim 13 or 14,
Selecting means for selecting a predetermined number of access points of the neighboring access points based on the information of the neighboring access points;
Wherein the measuring means comprises:
If the peripheral access point is not an access point of a subway line, the position coordinates of each of the access points selected by the selecting means are extracted from the storage means, the center of gravity coordinates are calculated using the extracted position coordinates, and the calculated weight And determining a center coordinate as a final position of the communication terminal. 17. The method of claim 16,
Wherein the measuring means comprises:
Computing the center of gravity coordinates of each group by grouping the position coordinates, and then repeats the process of calculating the center of gravity coordinates of each group by grouping the calculated center of gravity coordinates to obtain the final one center of gravity coordinates Position measuring device. The method of claim 17,
Wherein the measuring means comprises:
Wherein the position coordinate is grouped by M (where M is L ⁱ , where L is a natural number of 3 or more and i is a natural number of 2 or more). 17. The method of claim 16,
The selection means,
Selecting an access point having a signal strength of more than a threshold value. 17. The method of claim 16,
And virtual position coordinate determining means for estimating the virtual position coordinate with respect to the access point and storing it in the storage means. 21. The method of claim 20,
Collecting means for collecting the signal strength for each location of the access point;
The virtual position coordinate determination means determines,
And analyzing a change in time with respect to the signal strength for each location of the access point to extract a rising inflection point and estimating a virtual position coordinate of the access point based on the rising inflection point. 22. The method of claim 21,
Wherein the ascending inflection point is a point when a peak is reached while the signal intensity rises. 17. The method of claim 16,
Wherein the measuring means comprises:
Among the access points selected by the selection means, the corresponding installation location coordinates are extracted for the access point that knows the installation location coordinates, and the estimated virtual location coordinates are extracted for the access point that does not know the installation location coordinates. And an access point for which the coordinates have not been extracted, extracting the measured position coordinates of the corresponding access point. 24. The method of claim 23,
Wherein the measuring means comprises:
Wherein the access point extracts the measurement position coordinates at which the signal strength is the largest when extracting the measured measurement position coordinates.

Images