JP2012160988A - Method and system for displaying target area based on location information from mobile terminal - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and the like in which a database server acquires location information satisfying a predetermined condition from one and more mobile terminals to output a map on which a scale of a target area is displayed in an overlapping manner.SOLUTION: A mobile terminal acquires current location information by serving a state where a predetermined condition is satisfied as a trigger and transmits the location information and a terminal identifier to a database server. The database server accumulates the location information with respect to each terminal identifier. Further, the database server extracts a confidence ellipse area based on a predetermined confidence level value from a plurality of pieces of location information with respect to each terminal identifier. Accordingly, a map image on which the confidence ellipse area is overlapped is output.

Description

  The present invention relates to a technique for displaying an area map based on position information of a mobile terminal.

  The radio quality of a mobile terminal in a radio communication system is greatly affected by a surrounding communication environment such as a shield with a base station. Conventionally, a telecom operator's investigator had to visit each region in order to measure the radio quality with the base station. At this time, in order for the communication carrier to manage the radio quality and the location information in association with each other, the accuracy of the location information is extremely important.

  Conventionally, there are various techniques for calculating position information and determining the accuracy of position information.

  There is a technique for accurately determining the current position of a vehicle for a system for calculating the current position (see, for example, Patent Documents 1 and 2). According to this technique, a highly reliable candidate point such as a branch point is calculated using the traveling direction of the vehicle, the travel distance, and road data. There is also a technique for calculating candidate points by further using relative displacement (see, for example, Patent Documents 3 and 4). Furthermore, there is a technique for calculating a candidate point with high reliability based on the map matching based on the determination result of whether or not the vehicle has turned a predetermined angle or more (see, for example, Patent Document 5).

  Further, there is a map matching technique for estimating the current position by measuring the electric field strength from the base station of the mobile phone system a plurality of times and identifying the moving direction of the mobile phone from the smoothed measured electric field strength (for example, patents) Reference 6). According to this technique, the current position is estimated based on electric field intensity data using electric field-coordinate conversion and a moving trace based on the moving direction.

  Furthermore, there is a technique for determining the reliability in GPS (Global Positioning System) positioning and correcting the vehicle position (see, for example, Patent Document 7). According to this technology, the travel distance of a predetermined section obtained by self-contained navigation is compared with the distance of a section corresponding to the predetermined section obtained by GPS, and the reliability of GPS positioning is calculated according to the difference value. .

  Furthermore, there is a technique for determining the reliability of positioning data for a map display device (see, for example, Patent Document 8). According to this technique, the fact that the position at the same reference voltage changes with time due to crustal movement or the like is used. The reliability of a plurality of past positioning data is determined depending on whether or not it is moving in a certain direction along with the change in the acquisition time. Further, the reliability of the newly acquired positioning data is determined depending on whether or not the measured data values in the past match a certain direction.

  Furthermore, there is a technique for displaying the current position of the vehicle on the ring road with certainty even while traveling on the ring road (see, for example, Patent Document 9). According to this technique, the current position is calculated using the link data of the link formed on the ring road and the measured values of the travel distance and traveling direction of the vehicle.

  Further, regarding the position information detection system, there is a technique for displaying the size of a point to be displayed as a size corresponding to the accuracy of the position information when displaying the position information of the mobile terminal on the map screen (for example, patents). Reference 10). According to this technology, position information obtained from a plurality of types of mobile radio communication systems such as a mobile phone network, a wireless LAN, and GPS is used. Then, a correction frequency distribution is created from the weight based on the estimation accuracy of various position information and the frequency distribution of the position information. The average position of this correction frequency distribution is determined as position information of the mobile terminal. Then, the accuracy of the position information is determined based on the correction frequency distribution.

  Furthermore, there is a technique for determining the walking behavior of a pedestrian and estimating the position of the pedestrian using a distance sensor, an orientation sensor, an altitude sensor, or the like (for example, see Patent Document 11).

  According to the techniques described in Patent Documents 1 to 11 described above, it is possible to detect a degradation point of radio quality by managing the positional information obtained by positioning and the radio quality in association with each other. As another technique, there is a technique for estimating a significant position of a user who has a mobile terminal (see, for example, Non-Patent Documents 2 to 4). The “significant position” refers to a position range that is meaningful to the user, such as “the neighborhood of the home and the nearest station”. According to this technology, continuous / discontinuous position information in a mobile terminal is acquired, and clustering is performed based on the proximity of the acquisition times. As a result, the behavior of the user is modeled and traced, and an area range (significant position) with a relatively long stay time is extracted.

  In contrast to the technique described above, there is a technique in which a mobile terminal transmits location information to a server to measure a wireless quality degradation point (dead zone) (see, for example, Patent Documents 12 and 14). According to this technique, when the mobile terminal detects that the mobile terminal is out of the service area of the base station, the mobile terminal performs positioning by the GPS function and stores the position information. Thereafter, when the mobile terminal detects again that it has entered the service area of the base station, it transmits the already stored location information to the server via the network. As a result, the telecommunications carrier that operates the server can collect the location information of the location where the wireless quality is degraded.

  There is also a technique for creating an area map based on wireless quality (see, for example, Patent Document 13). According to this technique, the number / amount of information transmission from the mobile terminal and the network load can be reduced by changing the range of the wireless quality transmitted from the mobile terminal to the server according to the type of the communication system. For example, for a wide area system such as a cellular system, a mobile terminal acquires radio quality and position information when radio quality deteriorates below a predetermined quality. For a narrow area system such as a wireless LAN, when the wireless quality exceeds a predetermined quality, the wireless quality and position information are acquired. The mobile terminal transmits the acquired wireless quality and location information to the server, and the server creates area maps in different communication systems.

JP 08-292050 A Japanese Patent Laid-Open No. 08-334336 Japanese Patent Laid-Open No. 08-334367 Japanese Patent Laid-Open No. 08-334370 JP 08-334372 A Japanese Patent Laid-Open No. 2000-213948 JP 2003-279362 A JP 2004-144711 A JP 2006-292928 A JP 2009-272742 A JP 2009-229204 A Japanese Patent Laying-Open No. 2005-210530 JP 2008-306240 A JP 2010-088074 A

“Hybrid Positioning In CDMA Networks, Invitational Workshop on Opportunistic RF Localization for Next Generation Wireless Devices”, [online], [Search January 6, 2011], Internet <URL: http://www.cwins.wpi.edu/ workshop08 / pres / tech_3.pdf> "A User-Centered Location Model, Personal and Ubiquitous Computing 2002" Toyama Midori, Hattori Takashi, Kanno Tatsuya, "Learning Significant Positions Using Mobile Phone Positioning Functions", [online], [January 7, 2011], Internet <URL: http: //www.tom .sfc.keio.ac.jp / ~ next / papers / 2005-ipsj.pdf> Shigeki Kurokawa, Hiroyuki Yokoyama, Kazuyoshi Yoshii, Hideki Aso, “Examination of Significant Location Extraction Method from Sparse Location Information History”, 13th Information Theory Learning Theory Workshop (IBIS 2010), [online], [ January 7, 2011], Internet <http://ibisml.org/ibis2010/preview/P4-6.pdf> Introduction to statistics, "9.4 In case of multivariate", [online], [Search January 7, 2011], Internet <URL: http://www.snap-tck.com/room04/c01/stat/stat09 /stat0904.html>

  According to the techniques described in Patent Documents 12 to 14 described above, it is possible to identify an area where radio degradation of a predetermined threshold or more has occurred in a wide area radio communication system or an area where radio communication is possible in a narrow area radio communication system. .

  However, any positioning method that can be realized by the mobile terminal, such as the GPS positioning method, the multiple base station positioning method, and the hybrid positioning method, causes a positioning error. For this reason, even if wireless quality degradation or the like is detected, it is necessary to allow the position information to include an error, and it is relatively difficult to acquire an accurate position. For example, the positioning error based on these positioning methods may range from several tens of meters to several hundreds of meters (see, for example, Non-Patent Document 1).

  The main reason for this is that for wide-area wireless communication systems such as mobile phone networks, wireless quality degradation occurs indoors or behind buildings, and for narrow-area systems such as wireless LAN, the available locations are indoors. This is because there are many cases. In any positioning method such as GPS positioning, multiple base station positioning, and hybrid positioning, when positioning is performed indoors, the positioning error is larger than usual.

  In particular, according to the techniques described in Patent Documents 12 to 14, the purpose is to acquire the position information of the wireless quality degradation location, and how much error is included in the position information. It is extremely difficult to estimate.

  According to the technique described in Patent Document 10, the size of the point displayed on the map screen is changed according to the accuracy of the position information based on the distribution of the correction frequency so that the user can understand the relative accuracy. ing. However, it is impossible to make the user understand the scale of the target area.

  In addition, the techniques described in Patent Documents 1 to 11 and Non-Patent Documents 2 to 3 described above are based on the premise of obtaining a plurality of continuous position information, and have wireless quality (for example, an error exceeding a predetermined threshold). It is impossible to let the network operator's supervisor understand the size of the target area that triggers that the above condition is satisfied.

  Note that any of the conventional techniques requires a plurality of continuous location information in one mobile terminal, and does not assume location information based on low-frequency positioning about once or twice. That is, it is impossible to grasp the scale of the target area by collecting and aggregating position information of a large number of mobile terminals.

  Therefore, according to the present invention, the database server can acquire position information satisfying a predetermined condition from at least one or more mobile terminals, and can output a map in which the scale of the target area is displayed in a superimposed manner. An object of the present invention is to provide an area display method and system.

According to the present invention, in a target area display method for displaying a target area using a system having a mobile terminal capable of acquiring location information and a database database server that collects location information from the mobile terminal,
A first step of acquiring current location information triggered by a mobile terminal reaching a predetermined condition;
A second step in which the mobile terminal transmits the location information and the terminal identifier to the database server;
A third step in which the database server accumulates location information for each terminal identifier;
A fourth step in which the database server extracts a trust ellipse area based on a predetermined confidence level value (100 · (1-β)%) from a plurality of pieces of position information within a predetermined range for each terminal identifier;
The database server includes a fifth step of outputting a map image on which the confidence ellipse area is superimposed.

According to another embodiment of the target area display method of the present invention,
For the first step, the mobile terminal further acquires the positioning accuracy in the acquired position information,
For the second step, the mobile terminal sends the positioning accuracy along with the location information to the database server,
For the third step, the database server accumulates positioning accuracy along with location information,
About a 5th step, it is also preferable that a database server specifies on a map the reliable ellipse area superimposed on a map image so that it can identify visually based on positioning accuracy and the number of terminal identifiers.

  According to another embodiment of the target area display method of the present invention, it is also preferable to determine a confidence level value for the fourth step based on a dispersion value of position information and positioning accuracy.

  According to another embodiment of the target area display method of the present invention, for the fourth step, the confidence ellipse area estimates a representative value range of a population based on a two-dimensional normal distribution, and has a confidence level. The value is also preferably a probability that a representative value of the population is included inside the ellipse.

According to another embodiment of the target area display method of the present invention,
A fifth step in which the database server determines whether or not a plurality of trusted ellipse areas based on a plurality of terminal identifiers overlap each other;
A database server for a plurality of terminal identifiers whose trust ellipse areas overlap with each other, a sixth step of extracting a trust ellipse area based on a predetermined confidence level value from a plurality of pieces of position information of all the terminal identifiers;
It is also preferable that the database server has a seventh step of outputting a map image on which the confidence ellipse area is superimposed.

According to another embodiment of the target area display method of the present invention, for the first step, the mobile terminal
(1) Triggered by the fact that the wireless quality is below a predetermined threshold,
(2) Triggered by execution of predetermined data communication, or (3) Triggered by execution of predetermined user operation,
It is also preferable to obtain current position information.

According to the present invention, in a target area display system that includes a mobile terminal capable of acquiring location information and a database server that collects location information from the mobile terminal, the database server displays a target area.
The mobile terminal
Triggered by reaching a predetermined condition as a trigger, positioning means for acquiring current position information,
Position information means for transmitting the position information and the terminal identifier to the database server,
The database server
Location information storage means for storing location information for each terminal identifier;
For each terminal identifier, individual area extraction means for extracting a trust ellipse area based on a predetermined confidence level value (100 · (1-β)%) from a plurality of position information,
And a map output means for outputting a map image on which the confidence ellipse area is superimposed.

According to another embodiment of the target area display system of the present invention,
About mobile terminals
The positioning means further acquires the positioning accuracy in the acquired position information,
The position information transmitting means transmits the positioning accuracy together with the position information to the database server,
About the database server
The location information storage means also stores the positioning accuracy along with the location information,
It is also preferable that the map output means clearly shows the confidence ellipse area to be superimposed on the map image on the map so that it can be visually identified based on the positioning accuracy and based on the number of terminal identifiers.

  According to another embodiment of the target area display system of the present invention, it is also preferable that the individual area extraction unit determines the confidence level value based on the dispersion value of the position information and the positioning accuracy.

  According to another embodiment of the target area display system of the present invention, for the individual area extraction means of the database server, the confidence ellipse area estimates the range of the representative value of the population based on the two-dimensional normal distribution. The confidence level value is also preferably a probability that a representative value of the population is included inside the ellipse.

According to another embodiment of the target area display system of the present invention, the database server
Superimposition area determination means for determining whether or not a plurality of trusted ellipse areas based on a plurality of terminal identifiers overlap each other;
For a plurality of terminal identifiers whose trust ellipse areas overlap with each other, the whole area extracting means for extracting a trust ellipse area based on a predetermined confidence level value from a plurality of pieces of position information of all these terminal identifiers,
The map output means preferably outputs a map image in which the entire confidence ellipse area is superimposed.

According to another embodiment of the target area display system of the present invention, for the first step, the mobile terminal
(1) Triggered by the fact that the wireless quality is below a predetermined threshold,
(2) Triggered by execution of predetermined data communication, or (3) Triggered by execution of predetermined user operation,
It is also preferable to obtain current position information.

  According to the target area display method and system of the present invention, the database server acquires position information satisfying a predetermined condition from at least one mobile terminal, and outputs a map in which the scale of the target area is displayed in a superimposed manner. can do.

It is a system configuration diagram in the present invention. It is a sequence diagram in the present invention. It is explanatory drawing showing a 2-dimensional normal distribution and the 95% confidence ellipse area of the representative (average) value of a population. It is explanatory drawing of a reliable ellipse area in case the number of mobile terminals is comparatively small, positioning accuracy is comparatively low, and a dispersion value is equivalent to the reference | standard in case positioning accuracy is low. It is a graph showing (beta) value derived | led-out based on positioning accuracy and a dispersion value. It is explanatory drawing of a reliability ellipse area in the case where the number of mobile terminals is relatively small, the positioning accuracy is relatively high, and the variance value is equivalent to the standard when the positioning accuracy is high. It is explanatory drawing of a reliability ellipse area in case there are comparatively few mobile terminals, a positioning accuracy is comparatively high, and a dispersion value is comparatively large compared with the reference | standard when a positioning accuracy is high. It is explanatory drawing of a trust ellipse area in case the number of mobile terminals is comparatively large, a positioning accuracy is comparatively low, and a dispersion | distribution value is equivalent to the reference | standard when positioning accuracy is low. It is explanatory drawing at the time of accumulating each confidence ellipse area in the case where the number of mobile terminals is relatively large, the positioning accuracy is relatively high, and the variance value is relatively large compared to the reference when the positioning accuracy is high. is there. FIG. 10 is a map in which a confidence ellipse area is superimposed based on FIG. 4 and FIGS. It is a functional block diagram of the mobile terminal and database server in this invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a system configuration diagram according to the present invention.

  According to FIG. 1, a plurality of base stations 3 are arranged, and each base station 3 communicates with a mobile terminal 1 located in the service area. All the base stations 3 are connected to the mobile communication network of the communication carrier. The mobile communication network may be a mobile phone network that covers a wide area, for example, and the mobile terminal 1 may be a mobile phone, for example.

  The service areas of the plurality of base stations 3 are arranged in a superimposed manner so that a dead zone does not occur. However, when a building such as a building is interposed between the mobile terminal and the base station, radio waves are cut off, resulting in a dead zone. As a carrier, we want to detect such dead zones as much as possible.

  According to FIG. 1, the wireless quality is represented on a two-dimensional map (area map). The z-axis representing the radio quality represents a better radio quality as the value becomes higher. According to FIG. 1, the radio quality is represented hierarchically in a pyramid shape with the base station 3 as the center. This indicates that the closer the position of the mobile terminal 1 is to the base station 3, the better the radio quality.

  Further, according to FIG. 1, a database server (LAS-DB (Location Information and Available System Information Data Base)) 2 that collects location information of mobile terminals is connected to the mobile communication network. The database server 2 can create an area map based on radio quality by receiving location information and radio quality from the mobile terminal 1.

The mobile terminal 1 such as a mobile phone is equipped with a positioning unit and can measure the current position. Examples of the positioning unit include the following.
"GPS positioning system": Positioning by positioning radio waves from GPS satellites "Multiple base station positioning system": Positioning by communication radio waves with multiple neighboring base stations "Hybrid positioning system": GPS positioning system + multiple base station positioning system

  Further, the mobile terminal 1 measures the radio quality by the radio communication interface unit for the base station 3. Examples of radio quality include reception quality, number of retransmissions, and data error rate. The reception quality includes, for example, RSS (Received Signal Strength), C / I (carrier to interference wave ratio), and Ec / Io (average energy per PN chip versus total received power spectral density).

  Radio quality in good condition is when the received signal strength is high, the signal-to-interference and noise ratio is large, the number of retransmissions is small, or the data error rate is low. On the other hand, the bad radio quality is when the received signal strength is low, the signal-to-interference / noise ratio is small, the number of retransmissions is large, or the data error rate is high.

  According to FIG. 1, when the radio quality deteriorates below a predetermined threshold value, the mobile terminal 1 measures and stores the position at that time. Then, when the mobile terminal 1 returns to a state in which the radio quality is good, the mobile terminal 1 transmits the position information when the radio quality is deteriorated to the database server 2 together with the radio quality.

  As a telecommunications carrier, by creating an area map as shown in FIG. 1, the wireless quality corresponding to the position of the mobile terminal can be grasped, which can be used for facility design and service quality improvement.

  FIG. 2 is a sequence diagram in the present invention.

  According to FIG. 2, it is assumed that the mobile terminal 1 has moved from the service area of the base station 3 to the dead zone.

(S11) The mobile terminal 1 acquires the current position information using a trigger as reaching a predetermined condition. Here, the predetermined conditions include, for example, the following depending on the use of the target area to be extracted.
(Trigger 1) The wireless quality is below a predetermined threshold (Trigger 2) A predetermined data communication is executed (Trigger 3) A predetermined user operation is executed. According to FIG. Since the location is to be extracted, (Trigger 1) is applied. When the mobile terminal 1 enters the dead zone and the wireless quality falls below a predetermined threshold, the mobile terminal 1 activates the positioning unit and measures the current position.

  As another use of the target area to be extracted, (trigger 2) is applied when trying to extract a place where a lot of “passing communication” is performed by the mobile game terminal. “Passing communication” refers to a function in which a portable game machine automatically and instantaneously communicates with a game machine of another player that affects the progress of the game using a wireless LAN. When the passing communication is executed, the mobile terminal 1 activates the positioning unit and measures the current position.

  Further, as another application of the target area to be extracted, (trigger 3) is applied when trying to extract a place where a lot of specific photographs are taken. The mobile terminal 1 activates the positioning unit and measures the current position when a specific photograph is taken by the camera using the application.

(S12) It is also preferable that the mobile terminal 1 further acquires the positioning accuracy in the acquired position information. The positioning accuracy may be set in three stages as follows, for example.
(High accuracy) Positioning by GPS positioning method (Medium) Positioning by hybrid positioning method (Poor accuracy) Positioning by multiple base station positioning method

Further, when only the GPS positioning method is used, “good” or “bad” positioning accuracy may be determined based on an estimated mean square error value (RMSE (Root Mean Square Error)). The mean square error value is obtained by evaluating a difference from the true value X, and is represented by the following expression, for example.
RMSE = √ (Σ [i = 1, n] (X−xi) ^ 2 / n)

(S13) Thereafter, the mobile terminal 1 further moves and transmits [position information, terminal identifier and positioning accuracy] to the database server 2 when communication with the base station 3 is restored.

(S21) The database server 2 receives [position information, terminal identifier, positioning accuracy] from the mobile terminal 1, and accumulates position information and positioning accuracy for each terminal identifier.

(S22) Next, for each terminal identifier, the database server 2 determines a predetermined confidence level value (preferably a plurality of confidence levels) from a representative (average) position and a variance value of a plurality of position information falling within a predetermined range. Value) is extracted. For one terminal identifier possessed by one user, the location information of the location where the wireless quality is degraded is not always the same. One reason is positioning error. Therefore, it is preferable that the position information from the same mobile terminal plotted within a predetermined range is acquired in the same area. People often move according to a certain behavior pattern. For example, if there is a place where wireless quality deteriorates at home, school, work, supermarket, etc., the mobile terminal experiences the same deterioration in wireless quality at the same place. Therefore, assuming that the mother representative (average) position is the area, as described above, a range where the mother representative (average) position exists with a predetermined probability is calculated as an ellipse. The database server 2 (not only for each terminal identifier, but also for each) further adds a reliability ellipse area for each positioning accuracy in the location information (that is, for each terminal identifier and “good”, “medium”, and “bad” accuracy). It is also preferable to calculate.

  Here, a method for calculating the confidence ellipse area will be described.

[Calculation method of trusted ellipse area]
The position information measured by the mobile terminal is represented by two dimensions. Since the collected position information includes a positioning error as described above, the positioning data is based on the observation that it follows a two-dimensional normal distribution (multivariate normal distribution). Here, the confidence ellipse area of the representative (average) value of the population is estimated with the confidence level value β. It is referred to as “100 · (1-β))% confidence ellipse area”. The reliability “100 · (1-β)%” is the probability that the representative (average) value of the population is included in the ellipse. At this time, it is also preferable to determine the β value to be used from the dispersion value of the plurality of pieces of position information falling within a predetermined range and the positioning accuracy in the position information. For example, when the positioning accuracy is “good” (when the ratio of good is large or when only good is collected), the variance value is large, and a relatively small β value is used. On the other hand, when the positioning accuracy is “high” and the variance value is small, a relatively large β value is used. Even when the positioning accuracy is “bad” (when the ratio of bad is large or when only bad is collected), a relatively large β value is used as the variance value is large.

  FIG. 3 is an explanatory diagram showing a two-dimensional normal distribution and a 95% confidence ellipse area of the representative (average) value of the population.

The trust ellipse is calculated by the following equation.
(1 / n) * F (2, φ, β) = (V (ly) * X ^ 2-2 * C (lx, ly) * X * Y + V (lx) * Y ^ 2) /
2 * (V (lx) * V (ly) -C (lx, ly) ^ 2)
lx: Longitude direction representative (average) value of location information measured by mobile terminal
ly: Latitude direction representative () value of location information measured by the mobile terminal
X = x−lx
Y = y-ly
V (lx): variance of lx (longitudinal sample average)
V (ly): Variance of ly (sample average in the latitude direction)
C (lx, ly): covariance of lx and ly
F (2, φ, β): According to the first degree of freedom 2 and the second degree of freedom φ (the degree of freedom of the residual)
Value of 100β% point in F distribution

(S23) The database server 2 determines whether or not a plurality of trusted ellipse areas based on a plurality of terminal identifiers overlap each other. This means that not only one mobile terminal but also a plurality of mobile terminals have experienced the deterioration of the radio quality at the peripheral positions in the same way.

(S24) The database server 2 extracts a trust ellipse area based on a predetermined confidence level value from a plurality of pieces of position information of all the terminal identifiers for a plurality of terminal identifiers whose trust ellipse areas overlap each other. The calculation of the confidence ellipse area here is the same as S22 described above. In this step, the trust ellipse areas that overlap each other may be extracted as a union or product set, or a new trust ellipse area may be extracted, or an ellipse area that includes the trust ellipses that overlap each other may be extracted. Is also preferable.

(S25) Then, the database server 2 outputs a map image on which the confidence ellipse area is superimposed. Here, the database server 2 clearly shows the confidence ellipse area to be superimposed on the map image on the map so that it can be visually identified based on the positioning accuracy and based on the number of terminal identifiers.

  FIG. 4 is an explanatory diagram of the confidence ellipse area when the number of mobile terminals is relatively small, the positioning accuracy is relatively low, and the variance value is equivalent to the reference when the positioning accuracy is low.

  Here, even if the confidence ellipse area as shown in FIG. 4 is obtained, the positioning result varies due to poor positioning accuracy, and is the confidence ellipse area widened? Or is the positioning accuracy good and is the area of the degradation range of the radio quality wide? It is difficult for the observer to understand. For this reason, for S22, the β value to be used is determined from the variance value of the plurality of pieces of position information falling within the predetermined range and the positioning accuracy in the position information. Knowing the magnitude of radio quality degradation is important for the observer.

  According to FIG. 4, since the positioning accuracy is low, the confidence ellipse area is relatively wide. In addition, the number of mobile terminals experiencing wireless quality degradation in the dead zone is relatively small (less than a predetermined threshold). Accordingly, the supervisor can determine that “there is a high possibility that the wireless quality is degraded in a narrow range such as a personal residence or the like that is relatively narrower than the trust ellipse area”.

  FIG. 5 is a graph showing the β value derived based on the positioning accuracy and the variance value.

  Conventionally, only data variation has been used for position estimation. On the other hand, according to the present invention, the estimation accuracy is improved by changing the β value according to the obtained position accuracy in addition to the data variation. In other words, according to the present invention, it is possible to estimate even the same ellipse with the same variation (plot dispersion degree) and apparently the scale included therein.

  FIG. 6 is an explanatory diagram of the confidence ellipse area when the number of mobile terminals is relatively small, the positioning accuracy is relatively high, and the variance value is equivalent to the reference when the positioning accuracy is high.

  According to FIG. 6, since the positioning accuracy is relatively high, the confidence ellipse area is relatively narrow. In addition, the number of mobile terminals experiencing wireless quality degradation in the dead zone is relatively small (less than a predetermined threshold). Therefore, the supervisor can determine that “there is a high possibility that the wireless quality is deteriorated in a range as in the trust ellipse area and in a relatively narrow range such as a private house”.

  FIG. 7 is an explanatory diagram of the confidence ellipse area when the number of mobile terminals is relatively small, the positioning accuracy is relatively high, and the variance value is relatively large compared to the reference when the positioning accuracy is high.

  The number of mobile terminals in FIG. 7 is relatively small as in FIG. However, the dispersion value of the position information in FIG. 4 is equivalent to the reference when the positioning accuracy is low, whereas the dispersion value of the position information in FIG. 7 is relatively larger than the reference when the positioning accuracy is high. . This means that the area where the wireless quality is degraded is relatively wide. Therefore, the β value in FIG. 7 is preferably a value smaller than the β value in FIG. Accordingly, the supervisor can determine that “there is a high possibility that the wireless quality is deteriorated in a relatively wide range such as a private land within the trust ellipse area where only a specific person visits”.

  FIG. 8 is an explanatory diagram of the confidence ellipse area when the number of mobile terminals is relatively large, the positioning accuracy is relatively low, and the variance value is equivalent to the reference when the positioning accuracy is low.

  According to FIG. 8, since the positioning accuracy is low, the individual confidence ellipse area is relatively wide, but the area is narrowed down by taking the product set. In addition, the number of mobile terminals that have experienced degradation of wireless quality in the dead zone is relatively large (greater than a predetermined threshold). Therefore, the supervisor can determine that “there is a high possibility that the wireless quality is deteriorated in the vicinity of this trust elliptic product set area and in a relatively narrow range such as a set, commercial, public facility, etc.”.

  FIG. 9 shows a case where each confidence ellipse area is intersectioned when the number of mobile terminals is relatively large, the positioning accuracy is relatively high, and the variance value is relatively large compared to the reference when the positioning accuracy is high. It is explanatory drawing of.

  According to FIG. 9, the positioning accuracy is high, but the variance of the position information is large. To that end, referring to FIG. 5, the β value is small and each confidence ellipse area is relatively wide. In addition, the number of mobile terminals that have experienced degradation of wireless quality in the dead zone is relatively large (greater than a predetermined threshold). Therefore, the supervisor can determine that “there is a high possibility that the wireless quality is deteriorated in the range as in the trust ellipse area and in a relatively wide range such as a collection, a commercial, or a public facility”.

Note that other cases can also be determined.
(Other 1) Comparison of the number of mobile terminals with low positioning accuracy, wide confidence ellipse area (that is, a large variance value (larger than in the case of FIG. 4)), and experiencing wireless quality degradation in the dead zone If the target is less (less than the predetermined threshold), the supervisor determines that “there is a possibility that the wireless quality is degraded in an area relatively narrower than the trust ellipse area, but the number of users is small” it can.

(Others 2) Positioning accuracy is high, the confidence ellipse area is relatively narrow (that is, the variance value is small), and the number of mobile terminals that experience radio quality degradation in the dead zone is relatively large (below a predetermined threshold) If there are many), the monitor can determine that “there is a high possibility that the wireless quality is deteriorated in a relatively narrow area such as the trust ellipse area and the number of users is large”.

  FIG. 10 is a map in which the confidence ellipse area is superimposed based on FIG. 4 and FIGS.

According to FIG. 10, it is displayed so that the supervisor can identify as follows.
[Dashed line] / [Solid line]: [Number of position information: small] / [Number of position information: Many]
[Thin line] / [Thick line]: [Positioning accuracy: Low] / [Positioning accuracy: High]
[White] / [Diagonal]: [Dispersion Value: Equivalent] / [Dispersion Value: Large]
[Dashed lines / thin lines / white] Number of position information: Small Positioning accuracy: Low Variance: Equivalent (corresponding to FIG. 4)
[Dashed line, thick line, white] Number of position information: Small Positioning accuracy: High, Variance: Equivalent (corresponding to Fig. 6)
[Dashed line, thick line, diagonal line] Number of position information: Small Positioning accuracy: High, Dispersion value: Large (corresponding to Fig. 7)
[Solid line / thin line / white] Number of position information: Multiple Positioning accuracy: Low Dispersion value: Equivalent (corresponding to FIG. 8)
[Solid line / thick line / hatched line] Number of position information: Multiple Positioning accuracy: High Variance: Large (equivalent to FIG. 9)
Thereby, the supervisor can make a judgment based on FIGS. 4 and 6 to 9 only by looking at a map as shown in FIG.

  FIG. 11 is a functional configuration diagram of the mobile terminal and the database server in the present invention.

  According to FIG. 11, the mobile terminal 1 includes a wireless communication interface unit 101 that communicates with the base station 3 via air, and a positioning unit 102 that calculates a current position based on positioning radio waves received from the GPS satellite 4 or the base station. Have. In addition, the mobile terminal 1 further includes a positioning activation unit 11, a positioning accuracy acquisition unit 12, and a position information transmission unit 13. These functional components are realized by executing a program that causes a computer mounted on the mobile terminal to function.

  The positioning activation unit 11 activates the positioning unit 102 using the arrival of the predetermined condition as a trigger to acquire the current position information (performs the same processing as S11 in FIG. 2). For example, the trigger may be that the radio quality has deteriorated to a predetermined threshold value or less.

  The positioning accuracy acquisition unit 12 further acquires the positioning accuracy in the acquired position information (executes the same process as S12 in FIG. 2). For example, “good” or “bad” positioning accuracy is determined based on a positioning method or a mean square error value of GPS. The positioning accuracy is output to the position information transmission unit 13.

  The position information transmission unit 13 transmits the position information, the terminal identifier, and the positioning accuracy to the database server 2 (executes the same process as S13 in FIG. 2).

  The database server 2 includes a communication interface unit 201 connected to a network (a mobile communication network according to FIG. 11) and a display unit 202 that displays a map to a supervisor. Further, the database server 2 includes a position information storage unit 21, an individual area extraction unit 22, a superimposition area determination unit 23, an entire area extraction unit 24, and a map output unit 25. These functional components are realized by executing a program that causes a computer mounted on the server to function.

  The location information storage unit 21 stores [location information, positioning accuracy] received from the mobile terminal 1 for each terminal identifier. (The same processing as S21 in FIG. 2 is executed).

  The individual area extraction unit 22 extracts a confidence ellipse area based on a predetermined confidence level value from a plurality of pieces of position information for each terminal identifier (executes processing similar to S22 in FIG. 2). At this time, a β value that is set in advance according to the positioning accuracy and the dispersion value of the position information is used.

  The overlapping area determination unit 23 determines whether or not a plurality of trusted ellipse areas based on a plurality of terminal identifiers overlap each other (execute processing similar to S23 in FIG. 2).

  The whole area extraction unit 24 extracts a trust ellipse area based on a predetermined confidence level value from a plurality of pieces of position information of all the terminal identifiers for a plurality of terminal identifiers whose trust ellipse areas overlap each other (S24 in FIG. 2). The same processing is executed).

  The map output unit 25 outputs a map image on which the confidence ellipse area is superimposed (executes processing similar to S25 in FIG. 2). Here, the database server 2 clearly shows the confidence ellipse area to be superimposed on the map image on the map so that it can be visually identified based on the positioning accuracy and based on the number of terminal identifiers.

  As described above in detail, according to the target area display method and system of the present invention, the database server acquires position information satisfying a predetermined condition from at least one or more mobile terminals, and takes a positioning error into consideration. It is possible to output a map in which the scale of the target area is displayed in a superimposed manner. Thereby, the supervisor can understand the size of the essential target area based on the positioning error.

  According to the present invention, for an event occurring in a specific area, the target area and its scale can be specified. For example, this is not limited to the investigation of the wireless quality degradation area, but can also be used for marketing. For example, a place where a lot of “passing communication” is performed by the mobile game terminal can be extracted. In this case, it is preferable to process each game title. Further, as another application of the target area to be extracted, a place where a lot of specific photographs are taken can be extracted. In this case, it is preferable to process each specific photograph analyzed as “Tokyo Tower” or “Rainbow Bridge” by the image recognition process.

  Various changes, modifications, and omissions of the above-described various embodiments of the present invention can be easily made by those skilled in the art. The above description is merely an example, and is not intended to be restrictive. The invention is limited only as defined in the following claims and the equivalents thereto.

DESCRIPTION OF SYMBOLS 1 Mobile terminal 101 Wireless communication interface part 102 Positioning part 11 Positioning start part 12 Positioning accuracy acquisition part 13 Position information transmission part 2 Database server 21 Position information storage part 22 Individual area calculation part 23 Superimposition area determination part 24 Whole area calculation part 25 Map Output unit 3 Base station 4 GPS satellite

Claims (12)

In a target area display method for displaying a target area using a system having a mobile terminal capable of acquiring position information and a database database server that collects position information from the mobile terminal,
A first step of acquiring current location information triggered by the mobile terminal reaching a predetermined condition;
A second step in which the mobile terminal transmits the location information and a terminal identifier to the database server;
A third step in which the database server stores the position information for each terminal identifier;
A fourth step in which the database server extracts, for each terminal identifier, a confidence ellipse area based on a prescribed confidence level value (100 · (1-β)%) from a plurality of pieces of position information within a prescribed range; When,
The database server includes a fifth step of outputting a map image on which the trust ellipse area is superimposed. For the first step, the mobile terminal further acquires positioning accuracy in the acquired location information,
For the second step, the mobile terminal transmits the positioning accuracy together with the location information to the database server,
For the third step, the database server accumulates the positioning accuracy together with the position information,
About a 5th step, the said database server specifies on the map so that the said reliability ellipse area superimposed on the said map image can be visually identified based on the said positioning precision and based on the number of the said terminal identifiers. The target area display method according to claim 1, wherein:   The target area display method according to claim 1, wherein, in the fourth step, the confidence level value is determined based on a variance value of the position information and the positioning accuracy.   Regarding the fourth step, the confidence ellipse area estimates a range of a representative value of a population based on a two-dimensional normal distribution, and the confidence level value includes a representative value of the population within the ellipse. The object area display method according to claim 1, wherein the target area display method is a probability. A fifth step in which the database server determines whether or not a plurality of trusted ellipse areas based on a plurality of terminal identifiers overlap each other;
A sixth step in which the database server extracts a trust ellipse area based on a predetermined confidence level value from a plurality of position information of all the terminal identifiers for a plurality of terminal identifiers in which the trust ellipse areas overlap with each other;
The target area display method according to any one of claims 1 to 4, wherein the database server includes a seventh step of outputting a map image in which the confidence ellipse area is superimposed. For the first step, the mobile terminal
(1) Triggered by the fact that the wireless quality is below a predetermined threshold,
(2) Triggered by execution of predetermined data communication, or (3) Triggered by execution of predetermined user operation,
The target area display method according to claim 1, wherein current position information is acquired. In a target area display system that has a mobile terminal capable of acquiring location information and a database server that collects location information from the mobile terminal, the database server displays a target area.
The mobile terminal
Triggered by reaching a predetermined condition as a trigger, positioning means for acquiring current position information,
A position information means for transmitting the position information and the terminal identifier to the database server;
The database server is
Location information storage means for storing the location information for each terminal identifier;
For each terminal identifier, from a plurality of position information, individual area extraction means for extracting a confidence ellipse area based on a predetermined confidence level value (100 · (1-β)%),
A target area display system comprising map output means for outputting a map image on which the trust ellipse area is superimposed. About the mobile terminal
The positioning means further acquires the positioning accuracy in the acquired position information,
The position information transmitting means transmits the positioning accuracy together with the position information to the database server,
About the database server
The location information storage means also stores the positioning accuracy together with the location information,
The map output means clearly indicates the trust ellipse area to be superimposed on the map image on a map so as to be visually identifiable based on the positioning accuracy and based on the number of terminal identifiers. The target area display system according to claim 7.   The target area display system according to claim 7 or 8, wherein the individual area extraction unit determines the confidence level value based on a variance value of the position information and the positioning accuracy.   With respect to the individual area extraction means of the database server, the confidence ellipse area estimates a representative value range of a population based on a two-dimensional normal distribution, and the confidence level value is within the ellipse. The target area display system according to claim 7, wherein the target area display system is a probability that a representative value is included. The database server is
Superimposition area determination means for determining whether or not a plurality of trusted ellipse areas based on a plurality of terminal identifiers overlap each other;
For a plurality of terminal identifiers in which the trust ellipse areas overlap each other, the whole area extracting means for extracting a trust ellipse area based on a predetermined confidence level value from a plurality of position information of all the terminal identifiers,
The target area display system according to any one of claims 7 to 10, wherein the map output means outputs a map image in which the entire confidence ellipse area is superimposed. For the first step, the mobile terminal
(1) Triggered by the fact that the wireless quality is below a predetermined threshold,
(2) Triggered by execution of predetermined data communication, or (3) Triggered by execution of predetermined user operation,
The current position information is acquired, The target area display system according to any one of claims 7 to 11.

Images