KR20110112094A - Location measuring method and apparatus using access point for local area communication - Google Patents

Abstract

The present invention relates to a position measuring method and a position measuring apparatus for measuring the position of a mobile terminal using an access point for short-range communication, the position measurement for measuring the position of the communication terminal using the access point according to the present invention The method includes storing the location-specific access point information measured for each location; An extraction step of extracting information of a reference access point from the access point information for each location; A classification step of classifying measurement position coordinates among the extracted reference access point information into a plurality of categories; A calculation step of calculating the center of gravity coordinates using the measurement position coordinates selected in each category; And determining the calculated center of gravity coordinates as the final position of the communication terminal.

Description

METHOD AND APPARATUS FOR MEASURING LACATION USING ACCESS POINT}

The present invention relates to a position measurement technology of a communication terminal, and more particularly, to a position measurement method and apparatus using an access point for near field communication.

With the development of mobile communication technology, location measurement technology for measuring the position of a mobile 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.

Among these, GPS positioning technology has a problem in that a GPS receiver should be installed in a mobile 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, the position measuring technique using the base station has the advantage that the GPS receiver does not need to be installed in the mobile terminal, but compared to the GPS position measuring technique, the error of the position measurement reaches tens to hundreds of meters, and thus the accuracy of the position measurement is deteriorated.

On the other hand, in recent years, a short range 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 access points are installed indoors and outdoors, the use of such access points enables location measurement for a mobile terminal even in a room where GPS positioning technology is not applied, and also many access points are installed. Accordingly, by using the access points as described above, it is possible to increase the accuracy of location positioning rather than the location measurement technology using the base station.

Accordingly, in recent years, location positioning technology using an access point for near field communication has been actively studied.

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 mobile terminal using an access point for short-range 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. Also, it will be readily appreciated that the objects and advantages of the present invention may be realized by the means and combinations thereof indicated in the claims.

According to an aspect of the present invention for achieving the above object, a location measurement method for measuring the location of the communication terminal using the access point, the storing step of storing the access point information for each location measured by location; An extraction step of extracting information of a reference access point from the access point information for each location; A classification step of classifying measurement position coordinates among the extracted reference access point information into a plurality of categories; A calculation step of calculating the center of gravity coordinates using the measurement position coordinates selected in each category; And determining the calculated center of gravity coordinates as the final position of the communication terminal.

The calculating step of the position measuring method may include: a first calculating step of selecting a measurement position coordinate for each category to form a plurality of groups and calculating the center of gravity coordinates of each group; A second calculation step of grouping the calculated center of gravity coordinates of each group again to form a plurality of groups and calculating the center of gravity coordinates of each group; And a third calculation step of repeating the second calculation step to calculate the final one center of gravity coordinate.

The classifying step of the location measuring method may classify the measurement position coordinates into a plurality of categories based on signal strength information among extracted information of the reference access point.

The extracting of the location measuring method may include: extracting measurement location coordinates of a reference access point from the location-specific access point information; Calculating center of gravity coordinates using the extracted measurement position coordinates; Confirming measurement position coordinates separated by a predetermined distance or more based on the calculated center of gravity coordinates; And removing information of the measured reference access point from the identified measurement position coordinates.

Alternatively, the extracting of the location measuring method may include: a first step of extracting measurement position coordinates of a reference access point from location-specific access point information; Selecting a predetermined number of measurement position coordinates from the extracted measurement position coordinates; A third step of calculating the center of gravity coordinates using the selected measurement position coordinates and confirming the measurement position coordinates separated from the center of gravity coordinates by a predetermined distance or more; A fourth step of sequentially repeating the second step and the third step with respect to all the measurement position coordinates extracted in the first step; And a fifth step of removing information of the reference access point measured from the measurement position coordinates identified in the third step.

In this case, in the fourth step, in selecting the measurement position coordinates in the second step, some of the previously selected measurement position coordinates may be selected as they are, and others may select other measurement position coordinates.

At this time, the second step, it is preferable to select sequentially from the measurement position coordinates of the large signal strength.

According to another aspect of the present invention for achieving the above object, a position measuring device for measuring the position of the communication terminal using the access point, the storage means for storing the access point information for each location measured by location; Extraction means for extracting information of a reference access point from location-specific access point information stored in the storage means; Classification means for classifying measurement position coordinates among the extracted reference access point information into a plurality of categories; And calculating means for calculating the center of gravity coordinates using the measurement position coordinates selected in each category, and determining the calculated center of gravity coordinates as the final position of the communication terminal.

The calculation means forms a plurality of groups by selecting the measurement position coordinates for each category, calculates the center coordinates of each group, and divides the calculated center coordinates of each group into a plurality of groups. By repeating the process of calculating the center of gravity coordinates of the final one can be calculated the center of gravity coordinates.

In addition, the classification unit may classify the measurement position coordinates into a plurality of categories based on the signal strength information among the extracted reference access points.

Meanwhile, the position measuring device extracts the measurement position coordinates of the reference access point from the access point information for each position, calculates the center of gravity coordinates, and measures at the measurement position coordinates separated by a predetermined distance or more based on the center of gravity coordinates. And removing means for removing information of the neighboring access point.

In this case, it is preferable that the removing means extracts the measurement position coordinates of the reference access point based on the signal strength information.

Alternatively, the position measuring device may calculate the center of gravity coordinates by selecting a predetermined number of measurement position coordinates of the reference access point from the access point information for each position, and measure the measurement position coordinates that are separated by a predetermined distance or more based on the center of gravity coordinates. And removing means for sequentially repeating the checking process for all the measurement position coordinates of the reference access point, and removing information of the measured reference access point from the checked measurement position coordinates.

At this time, it is preferable that in the repetition, the removing means selects some of the previously selected measurement position coordinates as it is and selects other measurement position coordinates. In addition, it is preferable that the said removal means selects sequentially from the measurement position coordinate with a big signal intensity in selecting another measurement position coordinate.

The present invention can improve the accuracy of the position measurement by measuring the position of the communication terminal using information of an access point having a small service radius installed at various places.

In addition, the present invention can further improve the accuracy of the position measurement by removing the information of the access point which is unnecessary in measuring the position of the communication terminal using the information of the access point.

In addition, 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.

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 location measurement system according to an embodiment of the present invention.
3 is a view for explaining a method of collecting location-specific access point information according to an embodiment of the present invention.
4 is a diagram illustrating a table of access point information for each location according to an embodiment of the present invention.
5 is a flowchart illustrating a location measurement method performed in a location measurement server according to an embodiment of the present invention.
6 is a diagram illustrating a process of extracting and processing data from an access point information DB according to an embodiment of the present invention.
7 is a diagram illustrating a process of calculating position coordinates of a mobile terminal according to one embodiment of the present invention.
8 is a block diagram showing the configuration of a location measurement server according to an embodiment of the present invention.
9 is a flowchart illustrating a method of removing unnecessary access point measurement information according to an embodiment of the present invention.
10 is a diagram illustrating a data processing procedure for removing unnecessary access point measurement information according to an embodiment of the present invention.
11 is a diagram illustrating a position coordinate calculation process for removing unnecessary access point measurement information according to an embodiment of the present invention.
12 is a block diagram showing the configuration of a location measurement server according to another 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 includes a base station for providing a mobile communication service and an access point (AP) for providing an Internet service using short-range wireless communication (eg, WiFi). The mobile terminal can use a voice call, wireless Internet, etc. during the movement through the base station, and can also access the wired Internet network through the access point to use the Internet service.

Base stations typically have a service radius of several km to tens of kilometers. In contrast, an access point that provides Internet service through short-range wireless communication has a service radius of only a few meters to several tens of meters. In addition, since access points have low purchase and installation costs, many access points are installed and used in various places such as homes, companies, or shopping malls.

Thus, as shown in FIG. 1, a plurality of access points 160-1,... 160-5 are located within the service radius 110, 130, 150 of the base station. Users who use a mobile terminal use the access points 160-1, ... 160-5 to access and use the Internet service where the signals of the access points 160-1, ... 160-5 are detected. Where no signal at points 160-1, ...

In addition, in recent years, the functions of smart phones have been improved, and users carrying smart phones are increasing. In addition, access points 160-1, .. 160-5) are being installed. As described above, since a large number of floating populations are provided with a large number of access points (160-1, ... 160-5), the position measurement using the access points (160-1, ... 160-5) Utilization is increasing. Rather than location measurement using a base station having a wide service radius, the accuracy of the mobile terminal is further improved by measuring the location of the mobile terminal using the access points 160-1,...

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

Referring to FIG. 2, an access point (AP) 290-1,..., 290 -N providing an Internet service using near field communication and a base station 200-1..., Providing a mobile communication service are provided. , 200-N) are installed everywhere. As shown in FIG. 1, the access points (AP) 290-1,..., 290 -N and the base stations 200-1,..., 200 -N are installed with their service radii overlap each other. do. Since the service radius of the base stations 200-1,..., 200 -N is larger, multiple access points (APs) 290-1,... Within the base stations 200-1,. , 290-N) is installed.

The access point (AP) 290-1,..., 290 -N is connected to a wired Internet network 210 to provide an Internet service, and the base stations 200-1,. Is connected to the mobile communication network 230 to provide a mobile communication service. The wired internet network 210 and the mobile communication network 230 interoperate with each other. 2, the location measurement server 250 connected to the wired Internet network 210 and the mobile communication network 230 and the access point information DB 270 managed by the location measurement server 250 are included.

The access point information DB 270 stores identification information (eg, MAC address, SSID, etc.) and coordinate information of an actual installation location of access points installed indoors / outside. In addition, the access point information DB 270 stores the access point information for each location measured by the location where the access point information collecting terminal is moved. The location-specific access point information collected for each location may include collection location information collected by the access point information collecting terminal at regular intervals, identification information and signal strength of the access points detected at the collection location, 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 identification information of the base stations 200-1,..., 200 -N where the mobile terminal is located is connected to the mobile terminal. The location of the mobile terminal is measured using identification information of the access points 290-1, ..., 290-N. The method of measuring the position of the position measuring server 250 will be described later in detail.

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

As shown in FIG. 3, the vehicle 310 equipped with the access point information collecting terminal collects the information by measuring the signals of the neighboring access points at a predetermined time period while moving around the road at a low speed. The information collected by the access point information collecting terminal includes a collection time, collection position information (eg, latitude / longitude), identification information (eg, MAC address) and signal of access points transmitting a signal in the vicinity measured at the collection position. Strength (e.g., RSSI) and identification information (cell ID, or PN code) of the base station covering the corresponding collection location.

Referring to FIG. 3, at an A point point, the access point information collecting terminal mounted on the vehicle 310 detects an access point at which a signal is caught at the A point point. The access point information collecting terminal covers the latitude / longitude information of the A point point, the time at that time point, and the MAC address and signal strength (RSSI) and the A point point of the access points at which the signal is detected at the A point point. Detect identification information of the base station and store it. As described above, the access point information collecting terminal collects and stores the information of the access points at each point at a predetermined time period (for example, 1 minute unit) while moving around at a low speed.

4 is a diagram illustrating a table of access point information for each location according to an embodiment of the present invention. As described with reference to FIG. 3, the access point information collecting terminal moves and collects neighboring access point information at a predetermined time period, and the collected location-specific access point information is shown in FIG. 4. As shown in FIG. 4, the table includes a time field 410, a location field 430, a MAC address field 450, an RSSI field 470, and a cell ID field 490.

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

5 is a flowchart illustrating a location measurement method performed in a location measurement server according to an embodiment of the present invention, and FIG. 6 is a diagram illustrating processing by extracting data from an access point information DB 270 according to an embodiment of the present invention. A diagram illustrating a process of doing so.

Referring to FIG. 5, first, the access point information collecting terminal collects peripheral access point information at regular time periods while moving around at low speed as described with reference to FIGS. 3 and 4. The access point information for each location collected by the access point information collecting terminal may be transmitted from the access point information collecting terminal 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 collection terminal in the access point information DB 270 (S501). Alternatively, location-specific access point information collected by the access point information collecting terminal may be stored in the access point information DB 270 by an administrator.

After the location-specific access point information is collected in this way, the location measurement server 250 receives a location measurement request for a specific mobile terminal (S503). At this time, the location measurement server 250, from the specific mobile terminal to the identification information (for example, cell ID or PN code) of the base station covering the area where the specific mobile terminal is located and the access point that the signal is picked up in the specific mobile terminal Receive identification information (e.g., MAC address or SSID).

The location measurement server 250 controls the specific mobile terminal to transmit the identification information of the base station and the identification information of the access point by using the identification information of the specific mobile terminal. The specific mobile terminal transmits identification information and signal strengths of a plurality of access points, and the location measurement server 250 may use the identification information of the access point having the largest signal strength, or may use any one of them. . Hereinafter, the received access point is defined as a reference access point.

The location measurement server 250 receiving the location measurement request as described above uses the access point information DB 270 by using the identification information of the base station covering the area where the specific mobile terminal is located when the location measurement request is received. In step S505, the access point information for each location that holds the identification information of the base station is first extracted.

Specifically, the access point information DB 270 stores a table of access point information for each location as shown in FIG. 4, and the location measurement server 250 has access point information for each location having identification information of the base station in the table. Extract For example, when the identification information of the base station is the cell ID '1', only the access point information for each location having the cell ID '1' is extracted from the table of FIG. 4. FIG. 6A illustrates an example of extracting access point information for each location having a cell ID of '1' from the table of FIG. 4.

Next, the location measurement server 250 uses the identification information (here, MAC address) of the reference access point to which the specific mobile terminal received together when receiving the location measurement request, in this case, the first extracted location. In each access point information, only measurement information of the reference access point is secondarily extracted (S507).

Specifically, when the MAC address of the reference access point that the specific mobile terminal can access is' 111.112 ', the location measurement server 250 is the MAC address' 111.112 in the access point information for each location of Figure 6 (a) Only the measurement information of the access point corresponding to 'is extracted. FIG. 6 (b) extracts only the measurement information of the access point corresponding to the MAC address '111.112' from the access point information for each location of FIG. 6 (a).

Subsequently, the location measurement server 250 classifies the measurement information of the reference access point extracted secondarily into M categories based on signal strength (eg, RSSI) (S509). For example, if the RSSI value is more than -40dB and less than -50dB, the first category is classified. If the RSSI value is more than -50dB and less than -80dB, the second category is classified. If the RSSI value is more than -80dB and less than -100dB, it is classified into three categories. . 6C illustrates an example of classifying measurement information of the reference access point extracted secondarily according to the above criteria. As described above, when the measurement information of the reference access point is classified into M categories, the number of measurement information of the reference access point belonging to each category may not be equal to each other.

Here, M is preferably a natural number of 3 or more to form a polygon. When classifying the measurement information of the reference access point into each category, it is preferable to set the minimum number of measurement information included in each category to K ⁿ (K is a natural number of 3 or more, n is a natural number of 0 or more). This is for polygon formation when applying the center of gravity method later.

Next, the location measurement server 250 randomly selects one reference access point from each category to form a predetermined number of groups, and among the measurement information of the reference access points belonging to each of the formed groups, the location information (here The location information is calculated using the location coordinates of the point where the corresponding access point is measured, that is, the measurement location coordinates recorded in the access point information for each location, not the actual location coordinates of the access point (S511). ). Instead of randomly selecting one reference access point in each category, one group may be formed by selecting one RSSI value in a large order. There is no limit to the method of choice.

Specifically, it demonstrates using FIG. FIG. 7 is a diagram illustrating a process of calculating a position coordinate of a mobile terminal according to an embodiment of the present invention. In the above-described embodiment, three categories are classified into three categories, and measurement information of three reference access points is included in each category. This is an example of a case. The concentric circles 710, 730, and 750 indicated by three dotted lines in FIG. 7 are service radii divided according to signal strength around a central reference access point, and each concentric circle corresponds to the three categories. When the measurement information of one reference access point in each category is selected to form a group, three groups are formed, and when the center of gravity coordinates are obtained using the measurement position coordinates among the measurement information of the access points belonging to each group, FIG. As shown in (a), three center of gravity coordinates such as 'A', 'B' and 'C' are calculated.

At this time, as described above, the number of measurement information of the reference access point belonging to each category may not be the same in each category. Therefore, when the location measurement server 250 selects the measurement information of the reference access point by one in each category to form a group, the smallest number of groups is formed among the number of the measurement information included in each category. For example, when the first category includes five measurement information, the second category includes three measurement information, and the third category includes five measurement information, one access point is included in each category. The number of groups formed by selection becomes three.

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 N again from the obtained center of gravity coordinates to form a predetermined number of groups, and Find the center of gravity coordinates for each group of center of gravity coordinates. This process is repeated until one center of gravity coordinate is obtained (S513).

Specifically, the center of gravity coordinates obtained in FIG. 7A are 'A', 'B', and 'C'. Since the center of gravity coordinates are three, no further group configuration is meaningless, and when the center of gravity coordinates of a triangle having the three center of gravity coordinates as the vertices are obtained, one center of gravity coordinate 770 as shown in FIG. Is obtained.

Here, N is preferably a natural number of 3 or more, but may be two coordinates of the center of gravity obtained in step S512. At this time, the center of a straight line connecting two center of gravity coordinates is the center of gravity coordinates.

And more preferably, N may be equal to K. This is because when N and K are the same, all polygons (for example, triangles) of the same pattern are used when obtaining the center of gravity coordinates in step S513. However, N does not necessarily need to be K, and in step S513, groups of N pieces are obtained to obtain the center of gravity coordinates, and finally, the center of gravity of the number greater than N and less than 2 × N (X, N <X <2 × N) If the coordinates remain, you can create a polygon with a vertex of the number (X) of centers greater than N and less than 2 × N to obtain the final single center of gravity coordinates.

In addition, when determining the center of gravity coordinates in step S513, N is selected and used in every process. However, it is not necessary to select N in every process, and the center of gravity coordinates may be variably selected.

Finally, the location measurement server 250 determines the final one center of gravity coordinates 770 obtained by the center of gravity method as the final position of the specific mobile terminal (515). The location measurement server 250 transmits the coordinate information of the determined maximum position to a place where the location information is requested (eg, a mobile terminal or a web server). The determined coordinate position information of the final position may be provided in a map form or may be provided in an address corresponding to the coordinate. The form of providing the location information can be used without limitation.

In the above-described embodiment, in step S505, access point information for each location is first extracted using identification information (ie, cell ID) of the base station covering the area where the mobile terminal of the location measurement target is located. It does not have to be done. Step S507 may be performed without performing step S505 to extract measurement information of the reference access point using identification information (eg, MAC address) of the reference access point to which the mobile terminal of the location measurement target can access. If step S507 is performed without performing step S505, the location measurement speed may be reduced because all the access point information for each location needs to be retrieved. However, if the step S505 is performed, the location measurement does not need to be performed. You can speed it up.

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

Referring to FIG. 8, the location measurement server 250 according to the present embodiment may include an access point information collector 810, a location information request receiver 820, a first data extractor 830, and a second data extractor ( 840, a category classifier 850, and a position calculator 860.

The access point information collecting unit 810 receives the access point information for each location measured by the access point information collecting terminal at a predetermined time period and stores the access point information in the access point information DB 270. The access point information collecting unit 810 may receive the access point information for each location from the access point information collecting terminal directly through the internet network 210 or the mobile communication network 230. Location-specific access point information is the same as the example of FIG. 4.

The location information request receiver 820 receives a location measurement request for a specific mobile terminal. The location measurement request may be received from the specific mobile terminal, or may be received from other communication network equipment at the request of another mobile terminal. The location information request receiving unit 830 may identify identification information (eg, cell ID or PN code) of a base station covering an area where the specific mobile terminal is located and identification information (eg, for example) of a reference access point to which the specific mobile terminal may access. MAC address or SSID) is received from the specific mobile terminal.

The first data extracting unit 830 uses the identification information of the base station covering the area where the specific mobile terminal is located, received by the location information request receiving unit 830, to access the base station from the access point information DB 270. Extract access point information for each location that holds identification information. For example, when the access point information DB 270 stores a table of access point information for each location as shown in FIG. 4, and the identification information of the base station is the cell ID '1', the first data extracting unit 830 Only the access point information for each location having the cell ID '1' is extracted from the table of FIG. 4. FIG. 6A illustrates an example of extracting access point information for each location having a cell ID of '1' from the table of FIG. 4.

The second data extracting unit 840 is extracted by the first data extracting unit 850 using identification information of a reference access point to which the specific mobile terminal received by the location information request receiving unit 830 can access. Only the measurement information corresponding to the identification information of the reference access point is extracted from the access point information for each location. For example, when the MAC address of the reference access point is '111.112', the second data extracting unit 840 may access an access corresponding to the MAC address '111.112' in the access point information for each location of FIG. Only the measurement information of the point is extracted. FIG. 6 (b) extracts only the measurement information of the access point corresponding to the MAC address '111.112' from the access point information for each location of FIG. 6 (a).

The category classifier 850 classifies measurement information of the reference access point extracted by the second data extractor 840 into M categories based on signal strength (eg, RSSI). For example, if the RSSI value is more than -40dB and less than -50dB, the first category is classified. If the RSSI value is more than -50dB and less than -80dB, the second category is classified. If the RSSI value is more than -80dB and less than -100dB, it is classified into three categories. . 6C illustrates an example of classifying measurement information of the reference access point extracted secondarily according to the above criteria.

As such, when the category classification unit 850 classifies measurement information of the reference access point into M categories, the number of measurement information belonging to each category may not be the same for each category. Here, it is preferable that said M is three or more natural numbers. When classifying measurement information into each category, it is preferable to set the minimum number of measurement information included in each category to K ⁿ (K is a natural number of 3 or more, n is a natural number of 0 or more). This is to facilitate the construction of polygons when applying the center of gravity method.

The position calculation unit 860 forms a predetermined number of groups of measurement information one by one in each category classified by the category classification unit 850, and among the measurement information of the reference access point belonging to each of the formed groups. The center coordinates of each group are calculated using the position information (where the position information here is not the actual position coordinate of the access point but the measurement position coordinate of the point where the access point is measured). At this time, instead of selecting the measurement information one by one in each category, one group may be formed by selecting one RSSI value in the order of increasing order. There is no limit to the method of choice.

For example, it demonstrates using FIG. This is the case when there are three categories classified by the category classification unit 850. The concentric circles 710, 730, and 750 indicated by three dotted lines in FIG. 7 are service radii divided according to signal strength around a central reference access point, and each concentric circle corresponds to the three categories. When one group of measurement information is selected from each category to form a group, three groups are formed, and when the center of gravity coordinates are obtained using the measurement position information among the measurement information of the access points belonging to each group, FIG. ), Three center of gravity coordinates are calculated: 'A', 'B', and 'C'.

At this time, as described above, the number of measurement information belonging to each category may not be the same for each category. Accordingly, when the position calculation unit 860 selects one piece of measurement information from each category to form a predetermined number of groups, the position calculator 860 forms the smallest number of groups among the number of measurement information included in each category. For example, when five measurement information is included in the first category, three measurement information is included in the second category, and five measurement information is included in the third category, one measurement information is included in each category. The number of groups formed by selection becomes three.

In addition, the position calculation unit 860 obtains the center of gravity coordinates as described above, and then randomly selects the center of gravity coordinates by N again from the obtained center of gravity coordinates to form a predetermined number of groups, and the weight of the N units Find the center of gravity coordinates for each group of center coordinates. The position calculation unit 860 repeats this process until one center of gravity coordinate is obtained, and determines the one center of gravity coordinate as the final position of the position measurement target terminal.

For example, the center of gravity coordinates obtained in FIG. 7A are 'A', 'B', and 'C'. Since the center of gravity coordinates are three, no further group configuration is meaningless, and when the center of gravity coordinates of a triangle having the three center of gravity coordinates as the vertices are obtained, one center of gravity coordinate 770 as shown in FIG. Is obtained.

In the positioning server 250 illustrated in FIG. 8, the first data extracting unit 830 may not be included. The second data extracting unit 840 may extract the measurement information of the access point directly by using the identification information (eg, MAC address) of the reference access point to which the mobile terminal of the position measurement target can access. Since the first data extractor 830 first extracts the access point information for each location, the second data extractor 840 may not search all the access point information for each location, thereby increasing the location measurement speed.

On the other hand, in general, the identification information of the access point is unique to each access point, but in recent years, there is an increasing number of cases of illegally copying and using the identification information of the access point. Therefore, when measuring the location of the mobile terminal, errors in location measurement may increase due to a plurality of access points having the same identification information. In addition to fixed access points, mobile access points are increasing. The mobile access point is a device mounted on a moving vehicle or a train to provide a wireless Internet service. If information by the mobile access point is used when measuring the location of the mobile terminal, an error in location measurement may increase.

For example, when two access points having the same identification information exist, the access point information for each location stored in the access point information DB 270 may include measurement information of the two access points. In this case, when the location measurement target mobile terminal is connected to the first access point, according to the present invention, only the measurement information of the first access point connected to the location measurement target mobile terminal should be used, but the identification information is the same. Because of the two access points, even the measurement information of the second access point is used for position measurement.

Therefore, when the first access point and the second access point are separated by a considerable distance, the positioning information of the mobile terminal is closer to the second access point side rather than the first access point side due to the measurement information of the second access point. do. Therefore, the accuracy of the location measurement information of the mobile terminal is reduced. Therefore, the measurement information of access points installed at different locations with the same identification information needs to be removed during the location measurement process. The same is true of the measurement information of the mobile access point. When the information of the mobile access point is collected at different places far away, the accuracy of the location measurement of the mobile terminal is reduced due to the information measured at the different locations.

9 is a flowchart illustrating a method of removing unnecessary access point measurement information according to an embodiment of the present invention, and FIG. 10 is a view illustrating a process of removing unnecessary access point measurement information according to an embodiment of the present invention.

A method of removing unnecessary access point measurement information described with reference to FIG. 9 is performed between steps S507 and S509 in the position measurement method described with reference to FIG. 5. Referring to FIG. 9, the location measurement server 250 extracts only measurement information of a reference access point to which the location measurement target mobile terminal can access in step S507, and then extracts measurement information of the extracted reference access point to signal strength (RSSI). ) Sort in descending order based on (S901). For example, when the access point information for each location including the measurement information of the reference access point is as shown in FIG. 10 (a), only the measurement information of the reference access point to which the location measurement target mobile terminal can access is extracted and the signal strength ( When sorting in descending order based on RSSI), the result is sorted as shown in FIG.

Subsequently, the position measurement server 250 calculates the center of gravity coordinates using the measurement position coordinates of the upper T measurement information having the largest signal strength RSSI among the measurement information of the reference access points arranged in descending order (S903). . Here, it is preferable that T is a natural number of 3 or more. The position measurement server 250 determines the measurement position coordinates to be removed from the measured position coordinates that are separated by a predetermined distance from the calculated center of gravity coordinates, and determines the access point information for each position measured from the measured position coordinates. Remove (S905).

For example, when the center of gravity coordinates are obtained by using the measurement position coordinates of the top three measurement information having the largest signal strength among the measurement information of the reference access points arranged as shown in FIG. 10 (b), FIG. Same as FIG. 11 is a diagram for obtaining a center of gravity using the measurement position coordinates of an access point according to another embodiment of the present invention. Referring to FIG. 11A, three measurement position coordinates are (12, 15), ( 13, 15) and (20, 21), and obtain the coordinates of the center of gravity of the triangle whose corners are the vertices. The measurement position coordinates 100m or more away from the center of gravity coordinates are (20, 21), and the measurement information measured at the measurement position coordinates of the (20, 21) is N out of the measurement information shown in FIG. -1 group measurement information. Therefore, the measurement information of N-1 group is removed from the position measurement data so as not to be utilized.

Then, the location measurement server 250 selects the number of next higher order measurement information and combines the measurement information not removed in step S905 to form a group consisting of T measurement information again (S907). In addition, the position measurement server 250 obtains the center of gravity coordinates again by using the measured position coordinates of the newly configured T measurement information (S909), and removes the measurement position coordinates that are separated by a predetermined distance or more from the center of gravity coordinates. The measurement position coordinate to be determined is determined, and the access point information for each position measured from the measurement position coordinate is removed so as not to be utilized (S911).

For example, when the liquid measurement information of the N-1 group is removed from the measurement information arranged as shown in FIG. 10 (b), the measurement position coordinates of the 4 groups and the measurement positions of the 1 and 2 groups that are the next higher measurement information are removed. Use the coordinates to find the center of gravity coordinates again. FIG. 11B is an example of obtaining the center of gravity coordinates using the measurement position coordinates of groups 1, 2, and 4. FIG.

After removing the access point measurement information including the next higher measurement information as described above, the location measurement server 250 checks whether there is more measurement information to check (S913), and if there is no measurement information to check if there is more The process from step S907 is repeated.

In the above-described embodiment, the center of gravity coordinates are repeatedly obtained using T measurement position coordinates. When the measurement information to be verified is not T × N (N is a natural number), the T measurement position coordinates are not used at the end. You don't have to. For example, when three measurement position coordinates are used to obtain the center of gravity coordinates and identify the measurement information to be removed, if two measurement information of the next higher level is left after removing one measurement information, the last four measurement information is not three. The position coordinates are used to obtain the center of gravity coordinates to identify the access point measurement information to be removed.

In addition, in the above-described embodiment, a group is formed by grouping T pieces of measurement information for each process, but the number of measurement information for forming a group for each process may not be the same.

In addition, after removing the access point measurement information in step S905, if there is no next higher access point measurement information to check, it may end in step S905.

In the above-described embodiment with reference to FIG. 9, step S905 has been described on the assumption that there are measurement position coordinates separated by a predetermined distance or more from the center of gravity coordinates. Can be. At this time, in step S907, except for the measurement information having the smallest signal strength among the M measurement information selected in step S905, a group consisting of M measurement information is further included by including the measurement information of the next higher signal strength to perform the operation. .

That is, if there are measurement position coordinates separated from the center of gravity coordinates by a predetermined distance or more, the next higher measurement information is selected. After excluding them, the operation is performed in a manner of forming M groups by sequentially including next higher order measurement information.

12 is a block diagram showing the configuration of a location measurement server according to another embodiment of the present invention. In FIG. 12, the same reference numerals as used in FIG. 8 are elements that perform the same functions and operations, and description thereof will be omitted. The location measurement server 250 shown in FIG. 12 further includes an access point data removal unit 1201.

If only the measurement information of the reference access point to which the location measurement target mobile terminal can access is extracted by the second data extracting unit 840, the access point data removing unit 1201 may extract the extracted measurement information into the signal strength (RSSI). The center of gravity coordinates are calculated using the measurement position coordinates of the upper T measurement information having the largest signal strength RSSI among the measurement information arranged in the descending order.

For example, when the access point information for each location including the measurement information of the reference access point is as shown in FIG. 10A, the access point data remover 1201 extracts only the measurement information of the reference access point to extract the signal strength. When sorting in descending order based on RSSI), the result is sorted as shown in FIG. And, if the center of gravity coordinates are obtained by using the measurement position coordinates of the top three measurement information having a large signal strength among the measurement information of the access point arranged as shown in FIG. 10 (b), as shown in (a) of FIG. Referring to (a) of FIG. 11, the measurement position coordinates of the three access points are equal to (12, 15), (13, 15), and (20, 21), and the center of gravity of the triangle whose respective coordinates are vertices. Find the coordinates.

The access point data removing unit 1201 determines the measurement position coordinates to be removed from the measured position coordinates that are separated by a predetermined distance or more from the calculated center of gravity coordinates, and access point information for each position measured from the measured position coordinates. Is removed from the measurement information extracted by the second data extractor 840. For example, in FIG. 11A, measurement position coordinates 100 m or more away from the center of gravity coordinates are (20, 21), and the measurement information measured at the measurement position coordinates of (20, 21) is shown in FIG. 10. Measurement information of the N-1 group among the measurement information shown in (b). Therefore, the measurement information of the N-1 group is removed from the position measurement data.

In addition, the access point data removal unit 1201 selects the second number of higher order measurement information and combines the unremoved measurement information to form a group of T measurement information, and newly configures T measurement information. The center of gravity coordinates are again obtained by using the measurement position coordinates of the information, and the above-described operation is repeatedly performed on the measurement information of all reference access points.

For example, when the measurement information of the N-1 group is removed from the measurement information of the reference access points arranged as shown in FIG. Using the measurement position coordinates of the two groups of measurement information, the center of gravity coordinates are obtained again. FIG. 11B is an example of obtaining the center of gravity coordinates using the measurement position coordinates of groups 1, 2, and 4. FIG.

The access point data removing unit 1201 obtains the center of gravity coordinates using the T measurement position coordinates. If the measurement information to be verified is not T × N (N is a natural number), the T measurement position coordinates are last. You do not need to use. In addition, although the access point data removal unit 1201 forms a group by tying T pieces of measurement information for each process, the number of measurement information for forming a group for each process may not be the same.

In the above-described embodiments of the present invention, the measurement position coordinates of the reference access point are sequentially selected and confirmed, but after obtaining the center of gravity coordinates only once using all the measurement position coordinates of the reference access point, the predetermined position is determined from the center of gravity coordinates. Location-specific access point information can also be removed by selecting measurement location coordinates that are more than a distance away.

According to the present invention as described above, when measuring the position of the mobile terminal by using the measurement information of the access point providing the short-range wireless communication, measurement information of the unnecessary access point (measurement information of the mobile access point) to increase the position measurement error By removing and using, etc., the error of position measurement can be reduced and the accuracy of position measurement can be improved. For example, when the first access point and the second access point having the same identification information are separated by a considerable distance, and the mobile terminal is connected to the first access point, the measurement information of the second access point is not removed. Due to the measurement information of the two access points, the positioning information of the mobile terminal is closer to the second access point side than to the first access point side. However, according to the present invention, by removing the measurement information of the second access point to measure the position of the mobile terminal, such a position error can be eliminated, thereby increasing the accuracy of the position measurement information of the mobile terminal.

On the other hand, the access point described in the present invention may be called a micro base station, a pico base station, a ubiquitous base station, or the like according to the policy of a manufacturer or a carrier. Therefore, the access point in the present invention should be understood as a gateway point that can directly communicate with the mobile terminal through short-range communication to provide the Internet service to the mobile terminal through a general-purpose Internet circuit.

In addition, it is clear that the position measuring method of the present invention can be equally applied not only outdoors but also indoors. At this time, it was described that the latitude / longitude coordinates are used as the measurement position coordinates outdoors, but virtual coordinates may be used as the measurement position coordinates indoors. For example, after the coordinates are divided for each floor of the building, the virtual coordinates are set for each floor, the access point information is collected at each location, and the position of the mobile terminal can be measured using the above-described center of gravity method. .

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. Also, the features described in the individual embodiments herein can be implemented in combination 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. In addition, it should be understood that the division of various system components in the above-described embodiments does not require such division 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.

The present invention described above is capable of various substitutions, modifications, and changes without departing from the technical spirit of the present invention for those skilled in the art to which the present invention pertains. It is not limited by the drawings.

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

Claims (15)

In the position measurement method for measuring the position of the communication terminal using the access point,
A storage step of storing location-specific access point information measured for each location;
An extraction step of extracting information of a reference access point from the access point information for each location;
A classification step of classifying measurement position coordinates among the extracted reference access point information into a plurality of categories;
A calculation step of calculating the center of gravity coordinates using the measurement position coordinates selected in each category; And
And determining the calculated center of gravity coordinates as the final position of the communication terminal. The method of claim 1,
The calculating step,
A first calculation step of forming a plurality of groups by selecting one measurement position coordinate for each category and calculating a center of gravity coordinate of each group;
A second calculation step of grouping the calculated center of gravity coordinates of each group again to form a plurality of groups and calculating the center of gravity coordinates of each group; And
And a third calculation step of repeating the second calculation step to calculate the final one center of gravity coordinate. The method according to claim 1 or 2,
The classification step,
Position measurement method, characterized in that to classify the measurement position coordinates into a plurality of categories based on the signal strength information of the extracted reference access point information The method according to claim 1 or 2,
The extraction step,
Extracting measurement position coordinates of a reference access point from the location-specific access point information;
Calculating center of gravity coordinates using the extracted measurement position coordinates;
Confirming measurement position coordinates separated by a predetermined distance or more based on the calculated center of gravity coordinates; And
And removing information of the measured reference access point from the identified measurement position coordinates. The method according to claim 1 or 2,
The extraction step,
Extracting measured position coordinates of the reference access point from the access point information for each position;
Selecting a predetermined number of measurement position coordinates from the extracted measurement position coordinates;
A third step of calculating the center of gravity coordinates using the selected measurement position coordinates and confirming the measurement position coordinates separated from the center of gravity coordinates by a predetermined distance or more;
A fourth step of sequentially repeating the second step and the third step with respect to all the measurement position coordinates extracted in the first step; And
And a fifth step of removing information of the reference access point measured from the measured position coordinates identified in the third step. The method of claim 5, wherein
The fourth step,
In selecting the measurement position coordinates in the second step, the position measurement method, characterized in that some of the previously selected measurement position coordinates are selected as they are and the other measurement position coordinates. The method according to claim 6,
The second step,
Position measuring method characterized by sequentially selecting from the measurement position coordinates having a large signal strength. In the position measuring device for measuring the position of the communication terminal using the access point,
Storage means for storing location-specific access point information measured for each location;
Extraction means for extracting information of a reference access point from location-specific access point information stored in the storage means;
Classification means for classifying measurement position coordinates among the extracted reference access point information into a plurality of categories; And
Calculating means for calculating the center of gravity coordinates using the measurement position coordinates selected in each category, and determining the calculated center of gravity coordinates as the final position of the communication terminal. The method of claim 8,
The calculation means,
After selecting the measuring position coordinates of each category to form a plurality of groups and calculating the center of gravity coordinates of each group, the center of gravity coordinates of each group are divided into a plurality of groups to determine the center of gravity coordinates of each group. Position measuring apparatus characterized in that for calculating the final one center of gravity coordinates by repeating the calculation process. The method according to claim 8 or 9,
The sorting means,
And measuring position coordinates are classified into a plurality of categories based on signal strength information among the extracted reference access points. The method according to claim 8 or 9,
From the location-specific access point information, the measurement position coordinates of the reference access point are extracted to calculate the center of gravity coordinates, and the information of the neighboring access points measured at the measurement position coordinates separated by a predetermined distance or more from the center of gravity center coordinates is removed. Positioning device further comprising; removing means. The method of claim 11,
The removal means,
And extracting the measurement position coordinates of the reference access point based on the signal strength information. The method according to claim 8 or 9,
In the access point information for each location, a process of calculating a center of gravity coordinate by selecting a predetermined number of measurement position coordinates of the reference access point and confirming the position of the measurement position separated by a predetermined distance or more from the center of gravity reference coordinate And repeating means for sequentially repeating all of the measurement position coordinates, and removing information of the measured reference access point from the identified measurement position coordinates. The method of claim 13,
The removal means,
In the repetition, the position measuring device, characterized in that some of the previously selected measurement position coordinates are selected as they are, and the others are selected. The method of claim 14,
The removal means,
A position measuring apparatus characterized by sequentially selecting from the measuring position coordinates having a large signal strength in selecting other measuring position coordinates.

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