JP5255958B2 - Database management system, database management method, and database management program - Google Patents

Description

  The present invention relates to a database management system, a database management method, and a database management program for managing a database that holds information indicating the relationship between radio wave reception intensity and position, which is used for positioning of a mobile communication terminal.

Conventionally, techniques for estimating the position of a mobile communication terminal based on the reception intensity (reception level) of radio waves received by the mobile communication terminal have been proposed. In Patent Document 1, information indicating the relationship between the reception intensity of a radio wave received from a predetermined base station and the position where the radio wave is received is stored in a database, and matching with the reception intensity is performed using the database. And a technique for estimating the position of the mobile communication terminal.
JP-A-7-231473

  With the method described in Patent Document 1, if the information indicating the above relationship stored in the database is not appropriate information, the position of the mobile communication terminal cannot be estimated accurately. For example, if the location where the base station, which is the source of radio waves, is installed, or if the propagation environment changes due to the construction of the building, etc. The position of a mobile communication terminal cannot be estimated.

  The present invention has been made in view of the above, and is a database management system capable of appropriately updating a database used for positioning of a mobile communication terminal and holding information indicating the relationship between radio wave reception intensity and position An object of the present invention is to provide a database management method and a database management program.

  In order to achieve the above object, a database management system according to the present invention is a database that holds information indicating the relationship between the reception intensity and position of a radio wave according to a radio wave transmission source, which is used for positioning of a mobile communication terminal. Is a database management system for managing intensity information receiving means for receiving intensity information indicating reception intensity of radio waves corresponding to a transmission source received or transmitted by a mobile communication terminal, and radio waves received by the mobile communication terminal Alternatively, position information receiving means for receiving position information indicating the transmitted position, and update means for updating the database based on the intensity information received by the intensity information receiving means and the position information received by the position information receiving means. And.

  In the database management system according to the present invention, the intensity information indicating the reception intensity of the radio wave corresponding to the transmission source received or transmitted by the mobile communication terminal is received, and the radio wave is received or transmitted by the mobile communication terminal. Position information indicating the position is received. The database is updated based on the intensity information and position information. Therefore, according to the database management system concerning the present invention, since the above-mentioned database is updated based on the information actually measured by the mobile communication terminal, the database can be appropriately updated.

  The position information receiving means preferably receives position information measured by GPS. According to this configuration, accurate position information can be acquired with certainty, so that the database can be updated more appropriately.

Comparing means for comparing the intensity information received by the intensity information receiving means with the information indicating the received intensity held in the database to determine whether the matching between them is successful or not is further provided . According to this configuration, the database can be appropriately updated according to the state of the database.

The updating means includes a transmission source related to the strength information received by the strength information receiving means, and a past update time of information indicating a relation related to the received strength held in the database, which is a comparison target by the comparing means, Update the database by weighting the strength information received by the strength information receiving means according to at least one of the past update count of the information indicating the relationship related to the received strength and the accuracy of the position related to the received strength. It is desirable to do. According to this configuration, the database can be updated more appropriately according to the detailed database state.

In accordance with the result of comparison by the comparison means, the information processing device further comprises position information requesting means for requesting transmission of position information, and the position information receiving means transmits position information transmitted in response to the transmission request made by the position information requesting means. that will receive. According to this configuration, since the position information is received only when the database needs to be updated, the present invention can be implemented efficiently.

The position information requesting unit makes a transmission request for position information when matching fails as a result of comparison by the comparison unit, and the strength received by the strength information receiving unit when matching is successful as a result of comparison by the comparison unit. The source of the information and the past update time of the information indicating the relationship related to the received intensity held in the database, which is the object of comparison by the comparison means, and the number of past updates of the information indicating the relationship related to the received intensity In accordance with at least one of the accuracy of the position related to the received intensity, it is determined whether or not to request transmission of position information, and the transmission request is performed in accordance with the determination . According to this configuration, it is possible to determine when the database needs to be updated more appropriately, and the present invention can be implemented more efficiently.

It is desirable that the updating unit refers to the accuracy of the position information received by the position information receiving unit, determines whether or not to update the database, and performs the update according to the determination . According to this configuration, the database to be updated can have more appropriate contents.

The updating means preferably acquires speed information indicating the moving speed of the mobile communication terminal, determines whether to update the database according to the speed information, and performs the update according to the determination . When the mobile communication terminal is moving, the strength information or the position information is not suitable for updating, so that updating in that case can be prevented.

  By the way, the present invention can be described as an invention of a database management system as described above, and can also be described as an invention of a database management method and a database management program as follows. This is substantially the same invention only in different categories and the like, and has the same operations and effects.

  That is, the database management method according to the present invention is a database management method for managing a database used for positioning of a mobile communication terminal and holding information indicating the relationship between the reception intensity and position of the radio wave according to the radio wave source. An intensity information receiving step for receiving intensity information indicating reception intensity of a radio wave corresponding to a transmission source received or transmitted by a mobile communication terminal, and a position where the radio wave is received or transmitted by the mobile communication terminal. A position information receiving step for receiving position information indicating, an intensity step received in the strength information receiving step, and an updating step for updating the database based on the position information received in the position information receiving step. Features.

  In the position information receiving step, it is desirable to receive position information measured by GPS.

The method further includes a comparison step of comparing the strength information received in the strength information reception step with the information indicating the reception strength held in the database to determine whether or not the matching between the two is successful.

In the update step, the transmission source related to the strength information received in the strength information receiving step, and the past update time of the information indicating the relationship related to the received strength held in the database, which is the comparison target in the comparison step, The database is updated by weighting the strength information received in the strength information reception step according to at least one of the past number of updates of the information indicating the relationship related to the received strength and the accuracy of the position related to the received strength. It is desirable to do.

In accordance with the comparison result in the comparison step, the information processing method further includes a position information request step for requesting transmission of position information, and in the position information reception step, the position information transmitted in response to the transmission request made in the position information request step that will receive.

In the position information request step, if the matching fails as a result of the comparison in the comparison step, a request for transmitting position information is made, and if the matching is successful as a result of the comparison in the comparison step, the strength received in the strength information receiving step The transmission source of the information, the past update time of the information indicating the relationship related to the reception strength held in the database, which is the object of comparison in the comparison step, and the number of past updates of the information indicating the relationship related to the reception strength In accordance with at least one of the accuracy of the position related to the received intensity, it is determined whether or not to request transmission of position information, and the transmission request is performed in accordance with the determination .

In the update step, it is desirable to determine whether or not to update the database with reference to the accuracy of the position information received in the position information reception step, and to perform the update according to the determination .

In the update step, it is desirable to acquire speed information indicating the moving speed of the mobile communication terminal, determine whether to update the database according to the speed information, and perform the update according to the determination .

In addition, the database management program according to the present invention causes a computer to manage a database that holds information indicating the relationship between the reception intensity and position of the radio wave according to the radio wave transmission source, which is used for positioning of the mobile communication terminal. Strength information receiving function for receiving strength information indicating the received strength of radio waves corresponding to a transmission source received or transmitted by a mobile communication terminal, and strength information received by the strength information receiving function. Is compared with the information indicating the received strength stored in the database, and if the matching fails as a result of the comparison by the comparison function for determining the success or failure of the matching between the two, the position information transmission request is made. In addition, if the matching is successful as a result of the comparison by the comparison function, the strength information received by the strength information reception function The transmission source, the past update time of the information indicating the relationship related to the received strength held in the database, the comparison target by the comparison function, the number of past updates of the information indicating the relationship related to the received strength, and A position information request function for determining whether or not to make a transmission request for position information according to at least one of the position accuracy related to the received intensity, and for making a transmission request according to the determination; Location information reception function for receiving location information indicating the location where radio waves are received or transmitted by the mobile communication terminal, and intensity information received by the strength information reception function, transmitted in response to a transmission request made by the request function And an update function for updating the database based on the position information received by the position information receiving function.

  According to the present invention, the database used for positioning of the mobile communication terminal and holding information indicating the relationship between the reception intensity and position of the radio wave according to the radio wave transmission source is based on the information measured by the mobile communication terminal. Since the information is updated by the information, the database can be updated appropriately.

  Hereinafter, preferred embodiments of a database management system and a database management method according to the present invention will be described in detail with reference to the drawings. In the description of the drawings, the same elements are denoted by the same reference numerals, and redundant description is omitted.

  FIG. 1 shows a positioning server 10 which is a database management system according to this embodiment. The positioning server 10 is a device that estimates the position of the cellular terminal (mobile communication terminal) 20. The positioning of the cellular terminal 20 by the positioning server 10 is performed using a framework of a cellular communication system (mobile communication system). Specifically, it is performed based on the reception intensity (reception level) of the radio wave transmitted from the cellular base station 30 and received by the cellular terminal 20. From the information indicating the reception intensity, a positioning database 11 that holds information indicating the relationship between the reception level and position of the radio wave corresponding to the cellular base station 30 is referred to, and matching processing is performed to determine the position of the cellular terminal 20. Presumed. The positioning server 10 can transmit / receive information to / from the cellular terminal 20 via the cellular base station 30 or the like. Note that the positioning server 10 may be included in the mobile communication network.

  The cellular terminal 20 is a mobile communication terminal that can perform mobile communication. The cellular communication 20 performs wireless communication with the cellular base station 30. That is, the cellular communication 20 transmits and receives radio waves to and from the cellular base station 30. The cellular terminal 20 measures the reception intensity of the radio wave received from the cellular base station 30 and transmits the information (intensity information) to the positioning server 10 for the positioning of the terminal 20 itself. The intensity information transmitted from the cellular terminal 20 to the positioning server 10 is associated with information (for example, a base station ID) specifying the cellular base station 30 that has transmitted the radio wave, and the information is also transmitted. Is done. Further, the cellular terminal 20 may measure the RTT (Round Trip Time) of the radio wave and transmit it together with the intensity information.

  The intensity information transmitted from the cellular terminal 20 to the positioning server 10 is also used for updating the positioning database 11. Further, the strength information may be transmitted from the cellular terminal 20 to the positioning server 10 only for updating the positioning database 11. The cellular terminal 20 also has a GPS positioning function for receiving radio waves from a GPS (Global Positioning System) satellite 40 and positioning the terminal 20 based on the radio waves. When the GPS positioning is successful, the cellular terminal 20 acquires position information (for example, latitude and longitude information) indicating the position of the terminal 20 as a positioning result, and information (for example, error radius) indicating the accuracy of positioning. To do. When the cellular terminal 20 transmits intensity information to the positioning server 10 for updating the positioning database 11, the cellular terminal 20 also transmits information obtained by GPS positioning at the position where the intensity information is acquired to the positioning server 10. In addition, when GPS positioning fails, the information to that effect is transmitted. In addition, when the altitude (altitude) can be acquired by GPS positioning, the information may also be included in the position information. Transmission of information obtained by GPS positioning may be transmitted together with intensity information, or may be performed in response to a request from the positioning server 10 as will be described later (in this case, not only transmission but GPS The positioning itself may also be performed in response to a request from the positioning server 10).

  Further, the cellular terminal 20 may be provided with a function of acquiring speed information indicating the moving speed of the terminal 20 and transmitting it to the positioning server 10. The speed information can be acquired, for example, by measuring the time change of the GPS positioning result. Alternatively, the speed of the terminal 20 may be detected by another speed sensor provided in the cellular terminal 20.

  Note that it is not necessary for all the cellular terminals 20 that are positioning targets of the positioning server 10 to have a GPS positioning function, and only the cellular terminals 20 that transmit information for updating the positioning database 11 have a GPS positioning function. What is necessary is just to be provided. There may be a cellular terminal 21 for updating the positioning database 11 that is not a positioning target of the positioning server 10. The cellular terminal 21 for updating the positioning database 11 is, for example, an in-vehicle communication terminal as shown in FIG. 1, and corrects the position information measured by the GPS positioning function using a car navigation technology or the like and has high accuracy. The position information (calibration data) of the terminal 21 can be acquired. The cellular terminal 21 for updating the positioning database 11 also transmits the strength information and the position information to the positioning server 10 in the same manner as the cellular terminal 20 described above. The cellular terminals 20 and 21 include hardware such as a CPU (Central Processing Unit), a memory, and a wireless communication module.

  Each cellular base station 30 is a component in the mobile communication network, but is a radio wave source that transmits radio waves for performing the above-described positioning, and is installed with its position determined in advance. Each cellular base station 30 is set with information for uniquely identifying the cellular base station 30 such as a base station ID, and the positioning server 10 and the cellular terminal 20 are based on the information. Can be specified. The cellular base station 30 includes hardware such as a CPU, a memory, and a wireless communication module.

  Subsequently, the functional configuration of the positioning server 10 will be described. As shown in FIG. 1, the positioning server 10 includes a positioning database 11, an intensity information receiving unit 12, a position information receiving unit 13, a comparing unit 14, a position information requesting unit 15, and an updating unit 16. Configured. The above constituent elements are constituent elements as a database management system according to the present invention. In addition to the above constituent elements, means for performing positioning processing using the positioning database 11 and positioning the cellular terminal 20 are also provided. ing.

  As described above, the positioning database 11 is used for positioning of the cellular terminal 20 and indicates information indicating the relationship between the radio wave reception intensity at the cellular terminal 20 corresponding to the cellular base station 30 and the position of the cellular terminal 20. It is a database to keep. Specifically, the positioning database 11 holds the above information by storing data in the table shown in FIG.

  As shown in FIG. 2, the positioning database 11 stores data for each pattern of radio wave reception intensity received by the cellular terminal 20 at a predetermined position. For one pattern, data of reception intensity for each of up to n cellular base stations 30 is stored as information of reception intensity ("base station-1" to "base station-n" data in the figure). . The data of each cellular base station 30 includes base station ID (data such as “ID-1-1” in the figure), data indicating reception intensity (data such as “LV-1-1” in the figure), and RTT. Is composed of three pieces of data (data such as “RTT-1-1” in the figure). That is, the cellular base station 30 (data) for each pattern (the combination of the cellular base stations 30 can be different for each pattern).

  The stored data such as signal strength may be data of a predetermined number of digits, for example. For example, if the number of digits after the decimal point is rounded down, 200.367 dBm is set to 20.3 dBm (the number of digits to be truncated can be set to an arbitrary number). Moreover, it is good also as data with a fixed width | variety. For example, when the reception strength is 50 to 60 dBm, the data stored in the table is “1”, when the reception strength is 40 to 50 dBm, the data stored in the table is “2”, and the reception strength is 30 to 40 dBm. The data stored in the table may be “3”. The above patterning may be similarly performed on data other than signal strength. Further, when the number of the cellular base stations 30 in one pattern is less than n, nothing may be stored in the data in that portion (empty).

  The data of each pattern includes position coordinate data (data such as “Pos-1” in the figure), accuracy data (data such as “Acc-1” in the figure), and time stamp as position information. Data (data such as “T-1” in the figure), update count data (data such as “N-1” in the figure), and height data (data such as “H-1” in the figure) ) Are stored in association with each other. The position coordinate data is position data that is estimated as the location of the cellular terminal 20 when the signal intensity of the radio wave received by the cellular terminal 20 is the reception intensity of the corresponding pattern. Specifically, the position coordinate data is the same data as the position information (for example, latitude and longitude information) acquired by the GPS positioning function of the cellular terminal 20.

  The accuracy data is data indicating the accuracy of the position of the cellular terminal 20 estimated from the position coordinates. Specifically, the accuracy data (for example, error information acquired by the GPS positioning function of the cellular terminal 20). Radius) is the same data. The time stamp data is data indicating the (latest) past time when the corresponding pattern data (position coordinates, accuracy, etc.) is updated. The update count data is data indicating the number of times the corresponding pattern data (position coordinates, accuracy, etc.) has been updated. The height data is altitude (elevation) data corresponding to the position coordinates, and is similar to the information acquired by the GPS positioning function of the cellular terminal 20.

  The positioning server 10 receives from the cellular terminal 20 intensity information (radiation intensity pattern) indicating the reception intensity of the radio wave corresponding to the cellular base station 30, and the information and the radio wave stored in the positioning database 11. The position of the cellular terminal 20 is estimated by matching with the intensity pattern. The above matching is performed in the same manner as a conventional positioning technique using a database such as the positioning database 11.

  The strength information receiving unit 12 is strength information receiving means for receiving, from the cellular terminal 20, strength information (radio wave strength pattern) received by the cellular terminal 20 and indicating the received strength of the radio wave according to the cellular base station 30. . The radio field intensity pattern is, for example, information in which one or more base station IDs and reception intensity are associated with each other. The intensity information receiving unit 12 outputs the received intensity information to the updating unit 16. Further, the strength information receiving unit 12 also outputs the received strength information to the comparing unit 14 as necessary.

  The position information receiving unit 13 is position information receiving means for receiving, from the cellular terminal 20, position information indicating the position where the cellular terminal 20 has received the radio wave related to the intensity information. The position information is obtained by positioning by the GPS positioning function of the cellular terminal 20 as described above. Further, the position information corresponds to the intensity information as described above. When the location information and the strength information are separately transmitted from the cellular terminal 20 to the positioning server 10, the positioning server 10 determines that each information is associated with each other by including the same ID. Keep it available. The position information receiving unit 13 outputs the received position information to the updating unit 16.

  The comparison unit 14 is a comparison unit that compares the intensity information received by the intensity information reception unit 12 with information indicating the reception intensity held in the positioning database 11. The comparison unit 14 matches the radio wave intensity pattern received by the intensity information receiving unit 12 with the radio wave intensity pattern stored in the positioning database 11. Specifically, the comparison unit 14 calculates a correlation coefficient between the pattern of the radio wave intensity received by the strength information receiving unit 12 and each pattern of the radio wave intensity stored in the positioning database 11 and stores the correlation coefficient in advance. It is determined whether there is a correlation coefficient equal to or greater than the threshold value. The comparison unit 14 determines that the matching is successful when there is a correlation coefficient equal to or greater than a threshold value stored in advance. On the other hand, the comparison unit 14 determines that the matching has failed when there is no correlation coefficient equal to or greater than the threshold stored in advance. Note that the matching process can be performed using a method similar to that used when performing matching by using the positioning database 11.

  The comparison performed by the comparison unit 14 is performed for determining whether to update the positioning database 11 as described later. For example, when the matching fails, the radio wave intensity pattern (or a similar pattern) received by the intensity information receiving unit 12 is not included in the positioning database 11, and the positioning database 11 is updated. And For example, even if matching is successful, in order to make the contents of the positioning database 11 more appropriate, the positioning database 11 is updated when a specific condition is satisfied.

  The comparison unit 14 outputs information on the success / failure of the matching, and the strength information received by the strength information receiving unit 12 to the position information requesting unit 15 and the updating unit 16 when the matching is successful. In addition, when the matching is successful, the comparison unit 14 determines the radio field intensity pattern stored in the positioning database 11 that matches the radio field intensity pattern received by the intensity information reception unit 12 (for example, the above-described correlation). The pattern information related to the pattern having the highest number (information corresponding to the row in FIG. 2) is also output to the position information requesting unit 15 and the updating unit 16 as information to be compared. That is, the comparison unit 14 outputs the information of the pattern of the matching source and the matching destination to the position information request unit 15 and the update unit 16.

  The location information requesting unit 15 is location information requesting means for requesting the cellular terminal 20 to transmit location information. For example, the location information request unit 15 transmits a signal related to a location information transmission request to the cellular terminal 20. Based on the information input from the comparison unit 14, the position information request unit 15 determines whether or not to send a position information transmission request as follows. The determination based on the information input from the comparison unit 14 depends on whether or not the positioning database 11 should be updated. That is, when the positioning database 11 is to be updated, it is determined that a position information transmission request is made. This is because the location information of the cellular terminal 20 is necessary for updating the positioning database 11. Hereinafter, updating the positioning database 11 by making a transmission request for position information is also referred to as sample extraction.

  When the matching by the comparison unit 14 fails, the position information request unit 15 determines to make a position information transmission request. Further, when the matching by the comparing unit 14 is successful, the position information requesting unit 15 sets a sample extraction probability based on the information input from the comparing unit 14 and sends a request for transmitting position information from the sample extraction probability. Determine whether to do it. Specifically, the cellular base station 30 (the base station ID) related to the strength information received by the strength information receiving unit 12 (from which cellular base station 30 the radio wave received by the cellular terminal 20 is transmitted), In addition, the sampling probability is set based on at least one of the time stamp, the update count, and the accuracy of the pattern stored in the positioning database 11 matched by the comparison unit 14.

  For example, in the cellular base station 30 (its base station ID) related to the strength information received by the strength information receiving unit 12, the cellular base station 30 (its base station ID) to which the positioning database 11 should be updated with priority. Is included, the sampling probability is set high. The cellular base station 30 (its base station ID) to which the positioning database 11 should be updated with priority is set in advance by the administrator of the positioning server 10 and stored in the position information requesting unit 15. The cellular base station 30 to which the positioning database 11 should be updated with priority includes, for example, information on the pattern of the positioning database 11 such as a newly installed cellular base station 30 or a cellular base station 30 whose installation position has been changed. In particular, it is a necessary cellular base station 30.

  Alternatively, the sample extraction probability P may be set from the increasing function of the elapsed time Δt from the time stamp of the pattern stored in the positioning database 11 to the present. It is desirable to set the extraction probability P higher as the elapsed time Δt increases. For example, the position information requesting unit 15 may set P by calculating P using an equation P = 1−exp (−Δt). This takes into account the fact that when the time has passed since the past update, the pattern of the received intensity has changed due to environmental changes or the like.

  Alternatively, the sample extraction probability P may be set from the pattern update count j stored in the positioning database 11. It is desirable to set the extraction probability P higher as the number of updates j is smaller. For example, the location information requesting unit 15 may calculate P using the formula P = 1 / (j + 1) and set the sample extraction probability. This is because the possibility that the information in the positioning database 11 is not appropriate is high when the number of updates is small.

  Further, the sample extraction probability P may be set from the accuracy of the pattern stored in the positioning database 11. It is desirable to set the extraction probability P higher as the accuracy is lower (for example, the error radius a is larger). For example, the location information requesting unit 15 may calculate P using the equation P = a / (a + A) and set the sample extraction probability. Here, A is the maximum error radius, and is stored in the position information request unit 15 in advance. This is because the information in the positioning database 11 is not appropriate when the accuracy is low.

  The sample extraction probability may be set by comprehensively judging from each of the above elements. For example, the sample extraction probability may be set by taking the average of the sample extraction probabilities set using each data.

  When the sample extraction probability P set as described above is equal to or greater than a prestored threshold value, the position information request unit 15 determines to make a position information transmission request. Further, the location information request unit 15 generates a uniform distribution of random numbers from 0 to 1 each time. If the random number is smaller than the sample extraction probability P, the location information request unit 15 determines to make a location information transmission request. The position information request unit 15 makes a position information transmission request in accordance with the above determination. Note that the information input from the comparison unit 14 includes information for specifying the cellular terminal 20, and the location information requesting unit 15 specifies the cellular terminal 20 to which a transmission request is to be made from the information.

  The updating unit 16 is an updating unit that updates the positioning database 11 based on the strength information received by the strength information receiving unit 12 and the position information received by the position information receiving unit 13. In addition, the update unit 16 specifies the pattern data to be updated in the positioning database 11 based on the information input from the comparison unit 14. When the matching by the comparison unit 14 fails, the updating unit 16 stores the intensity information received by the intensity information receiving unit 12 and the position information received by the position information receiving unit 13 in the positioning database 11 as new patterns. to add.

  When the matching by the comparing unit 14 is successful, the updating unit 16 updates the pattern information related to the radio wave intensity pattern stored in the positioning database 11 that matches the radio wave intensity pattern received by the strength information receiving unit 12. Identify as a target. In this case, the update is performed as follows, for example. The updating unit 16 compares the accuracy related to the radio wave intensity pattern received by the strength information receiving unit 12 with the accuracy related to the radio wave intensity pattern stored in the positioning-target positioning database 11. When the accuracy related to the radio wave intensity pattern received by the intensity information receiving unit 12 is higher, the position coordinate, accuracy, and height data are the data related to the radio wave intensity pattern received by the intensity information receiving unit 12. Update (replace data). The radio field intensity data corresponding to each cellular base station 30 includes the radio field intensity pattern received by the intensity information receiving unit 12 and the radio field intensity pattern stored in the positioning target database 11 to be updated. If they are different (when the radio field intensity patterns are not the same), the radio field intensity data corresponding to each cellular base station 30 is also related to the radio field intensity pattern received by the intensity information receiving unit 12 May be replaced.

In addition to the above, new data is used by using both data relating to the radio wave intensity pattern received by the intensity information receiving unit 12 and data relating to the radio wave intensity pattern stored in the positioning target database 11 to be updated. Update data (position coordinate, accuracy and height data) may be generated and updated using the data. Specifically, each piece of data may be weighted based on the accuracy, time stamp, cellular base station 30, number of updates, and the like, and new update data may be generated based on the weight. For example, the accuracy (a1) of the position information (Pos_RENEW) related to the radio wave intensity pattern received by the intensity information receiving unit 12 and the position information (Pos_DB) related to the radio wave intensity pattern stored in the positioning target database 11 to be updated. ), When determining the respective weights w1, w2 (w1 + w2 = 1), w1 and w2 are calculated from the following equations, and then the new position information (Pos ′) for updating is obtained. calculate.
w1 = a2 / (a1 + a2), w2 = a1 / (a1 + a2)
Pos ′ = w1 × Pos_RENEW + w2 × Pos_DB
Similarly, the updating accuracy and height are calculated using the generated weights, and the positioning database 11 is updated with the calculated data.

  The radio field intensity data corresponding to each cellular base station 30 includes the radio field intensity pattern received by the intensity information receiving unit 12 and the radio field intensity pattern stored in the positioning target database 11 to be updated. If they are different (when the radio field intensity patterns are not the same), the radio field intensity data corresponding to each cellular base station 30 is also calculated for updating using the weights generated as described above. And may be replaced.

  In addition, about said weight, it is good also as using the fixed value preset and memorize | stored by the update part 16. FIG. For example, the weight (w1) of the data related to the pattern of the radio wave intensity received by the strength information receiving unit 12 is 0.2, and the weight of the data related to the pattern of the radio wave intensity stored in the positioning database 11 to be updated (w2). ) Is set to a fixed value in advance such as 0.8.

  When updating the positioning database 11, the update unit 16 updates the time stamp and the update count of the updated pattern data. The time stamp stores information on the time of update. The number of updates is incremented by one. However, when new pattern data is added, the number of updates is set to zero.

  In addition, when there is a change in the configuration of the mobile communication network or the reception environment of radio waves, it is considered that the information stored in the positioning database 11 changes, for example, the position information corresponding to the same intensity information pattern changes significantly. It is done. When updating the positioning database 11, it is desirable to detect such a situation and reset the number of updates corresponding to the pattern to zero. For example, if the threshold value is set in advance and the accuracy of the data before and after the update is the same, but the fluctuation of the position coordinates (distance between the positions before and after the update) is equal to or greater than the threshold value, the number of updates is set to 0. There is a method of resetting.

  Further, when the matching by the comparison unit 14 is successful, the update unit 16 sets the sample extraction probability based on the information input from the comparison unit 14 and updates the positioning database 11 from the sample extraction probability. Determine whether or not. Specifically, the cellular base station 30 (its base station ID) related to the strength information received by the strength information receiving unit 12, and the time stamp of the pattern stored in the positioning database 11 matched by the comparison unit 14, A sample extraction probability is set based on at least one of the number of updates and the accuracy. A specific method for setting the sample extraction probability is the same as the method by the position information requesting unit 15 described above. Note that when the position information requesting unit 15 sets the sample extraction probability and determines the position information transmission request, the setting of the sample extraction probability in the update unit 16 and the determination based thereon are not necessarily required.

  When the speed information of the terminal 20 (when the radio field intensity pattern is acquired) is transmitted from the cellular terminal 20, the update unit 16 receives the information and, based on the information, updates the positioning database. It may be determined whether or not 11 updates are performed. For example, the updating unit 16 may compare the moving speed related to the received speed information with a threshold value that is set and stored in advance, and may not update the positioning database 11 if the moving speed is larger than the threshold value. Good. This is because the data acquired by the cellular terminal 20 at a certain speed or higher is not suitable for updating the positioning database 11. The above is the functional configuration of the positioning server 10 according to the present embodiment.

  FIG. 3 shows a hardware configuration of the positioning server 10. As shown in FIG. 3, the positioning server 10 includes a CPU 101, a RAM (Random Access Memory) 102 and a ROM (Read Only Memory) 103, which are main storage devices, a communication module 104 for performing communication, and an auxiliary storage device such as a hard disk. The computer is configured to include a computer having hardware such as 105. The functions of the positioning server 10 described above are exhibited when these components are operated by a program or the like.

  Subsequently, a process (database management method) executed by the positioning server 10 according to the present embodiment will be described using the flowchart of FIG. This process is started, for example, when information is transmitted from the cellular terminal 20 to the positioning server 10 as a trigger. Note that the processing may be started with a trigger other than the above.

  First, in the positioning server 10, the strength information receiving unit 12 receives the strength information (the pattern of the radio wave intensity) indicating the radio wave reception intensity according to the cellular base station 30 transmitted from the cellular terminal 20 (S01, Strength information receiving step). The information is output to the comparison unit 14 and the update unit 16. In this process, at this time, the positioning server 10 does not receive the position information of the cellular terminal 20 (the cellular terminal 20 does not perform GPS positioning).

  Subsequently, the comparing unit 14 matches the intensity information received by the intensity information receiving unit 12 with the information indicating the received intensity held in the positioning database 11 (S02, comparison step). Subsequently, information on the success or failure of the matching, and information on the pattern of the matching source and the matching destination when the matching is successful are output from the comparison unit 14 to the position information requesting unit 15.

  Subsequently, the success or failure of the matching is determined by the position information request unit 15 based on the information input from the comparison unit 14 (S03, position information request step). When it is determined that the matching is successful, the position information request unit 15 sets the sample extraction probability based on the information input from the comparison unit 14 (S04, position information request step). Subsequently, based on the set sample extraction probability, the position information request unit 15 determines whether or not to send a position information transmission request (S05, position information request step).

  If it is determined in S03 that the matching has failed, or if it is determined in S05 that a location information transmission request is to be made, the location information request unit 15 sends a location information transmission request to the cellular terminal 20. (S06, position information request step). Subsequently, in the cellular terminal 20 that has received the transmission request, GPS positioning is performed (or GPS positioning is performed in advance), and the position information of the terminal 20 is transmitted to the positioning server 10. This position information is information related to the position where the radio wave related to the intensity information is received.

  In the positioning server 10, the position information receiving unit 13 receives the position information transmitted from the cellular terminal 20 (S07, position information receiving step). The received position information is output from the position information receiving unit 13 to the updating unit 16. Subsequently, the updating unit 16 updates the positioning database 11 based on the intensity information received by the intensity information receiving unit 12 and the position information received by the position information receiving unit 13 (S08, update step). . Further, as described above, the update unit 16 may determine whether or not to update the positioning database 11 based on the information input from the comparison unit 14 or the like. The positioning database 11 updated as described above is used for positioning of the cellular terminal 20.

  On the other hand, if it is determined in S05 that a transmission request for position information is not performed, the positioning database 11 is not updated and the process ends. The above is the positioning process executed by the positioning server 10 according to the present embodiment.

  Subsequently, another example of processing (database management method) executed by the positioning server 10 according to the present embodiment will be described using the flowchart of FIG. This process is started, for example, when information is transmitted from the cellular terminal 20 to the positioning server 10 as a trigger. In this process, the information initially transmitted from the cellular terminal 20 to the positioning server 10 includes not only the reception intensity of the radio wave according to the cellular base station 30 but also the location information of the cellular terminal 20 related to the position where the radio wave is received. (However, it is not always necessary to transmit at the same timing, it is only necessary to transmit at almost the same timing).

  First, in the positioning server 10, the strength information receiving unit 12 receives the strength information (the pattern of the radio wave strength) indicating the radio wave reception strength according to the cellular base station 30 transmitted from the cellular terminal 20 (S11, Strength information receiving step). The information is output to the comparison unit 14 and the update unit 16. Further, the position information receiving unit 13 receives the position information transmitted from the cellular terminal 20 (S11, position information receiving step).

  Subsequently, the comparison unit 14 performs matching between the intensity information received by the intensity information receiving unit 12 and information indicating the reception intensity held in the positioning database 11 (S12, comparison step). Subsequently, information on the success or failure of the matching, and information on the pattern of the matching source and the matching destination when the matching is successful are output from the comparison unit 14 to the update unit 16.

  Subsequently, the update unit 16 determines the success or failure of matching based on the information input from the comparison unit 14 (S13, update step). When it is determined that the matching is successful, the update unit 16 sets the sample extraction probability based on the information input from the comparison unit 14 (S14, update step). Subsequently, the update unit 16 determines whether or not to update the positioning database 11 based on the set sample extraction probability (S15, update step).

  When it is determined that the matching has failed in S13, or when it is determined to update the positioning database 11 in S15, the strength information received by the strength information receiving unit 12 by the update unit 16 and the position The positioning database 11 is updated based on the position information received by the information receiving unit 13 (S16, update step). Further, as described above, the updating unit 16 may determine whether or not to update the positioning database 11 based on the speed information of the cellular terminal 20 received from the cellular terminal 20. The positioning database 11 updated as described above is used for positioning of the cellular terminal 20.

  On the other hand, if it is determined in S15 that no position information transmission request is made, the positioning database 11 is not updated and the process ends. The above is another example of the positioning process performed by the positioning server 10 according to the present embodiment.

  Note that the determination as to whether or not to make a transmission request for position information and the determination to update the positioning database 11 as described with reference to the flowcharts of FIGS. 4 and 5 do not necessarily have to be performed. For example, when information from the cellular terminal 21 for updating the positioning database 11 is received (for example, information specifying the cellular terminals 20 and 21 is included, thereby determining the transmission source of the information), transmission of position information The position information transmission request and the positioning database 11 may be updated without determining whether to make a request and determining whether to update the positioning database 11.

  As described above, the positioning server 10 according to the present embodiment is updated based on the intensity information and the position information actually measured by the cellular terminal 20, so that the positioning database 11 can be appropriately updated. Further, by using the positioning result by GPS positioning as the position information, accurate position information can be obtained reliably, and therefore the positioning database 11 can be updated more appropriately. However, position information obtained by other positioning methods such as positioning using RTT (Round Trip Time) of radio waves transmitted and received by the cellular terminal 20 may be received.

  In addition, if the location information requesting unit 15 requests the cellular terminal 20 for location information only when the positioning database 11 needs to be updated, the location information can be obtained only when the positioning database 11 needs to be updated. Therefore, the present invention can be implemented efficiently. In addition, it is possible to prevent unnecessary positioning from being performed in the cellular terminal 20.

  Further, as in the present embodiment, the cellular base station 30 related to the radio wave intensity and the update of the pattern to be updated in the positioning database 11, the number of updates, the accuracy of the position information, etc., or the transmission of the position information If the request is made, processing according to the state of the positioning database 11 can be performed, and the positioning database 11 can be updated more appropriately. Further, if the update is determined based on the accuracy of the received position information, the speed information of the cellular terminal 20, or the like, the contents of the positioning database 11 can be made more appropriate.

  In the above-described embodiment, the information stored in the positioning database 11 and used for positioning uses the reception intensity of radio waves received by the cellular terminal 20 (downlink), but is transmitted from the cellular terminal 20. Thus, the reception intensity of radio waves received by the cellular base station 30 may be used (uplink). Even in this case, the configuration and usage of the positioning database 11 can be the same as those described above.

  Further, the positioning database 11 described above may be prepared for each model of the cellular terminal 20, and positioning or database update may be performed using a different positioning database 11 for each model. Even in this case, the configuration and usage of the positioning database 11 can be the same as those described above.

  Subsequently, a database management program for causing a computer (provided in the positioning server 10) to execute the above-described series of database management processing of the positioning server 10 will be described. As shown in FIG. 6, the database management program 51 is stored in a program storage area 50a formed in a recording medium 50 provided in the computer.

  The database management program 51 includes a main module 51a that centrally controls database management processing, an intensity information reception module 51b, a position information reception module 51c, a comparison module 51d, a position information request module 51e, and an update module 51f. It is configured with. The functions realized by executing the intensity information receiving module 51b, the position information receiving module 51c, the comparison module 51d, the position information requesting module 51e, and the update module 51f are the following: the intensity information receiving unit 12 of the positioning server 10 described above, the position information The functions of the receiving unit 13, the comparing unit 14, the position information requesting unit 15, and the updating unit 16 are the same.

  Note that a part or all of the database management program 51 may be transmitted via a transmission medium such as a communication line and received and recorded (including installation) by another device.

It is a figure which shows the function structure of the positioning server which is a database management system which concerns on embodiment of this invention. It is a table which shows the information hold | maintained at the database for positioning. It is a figure which shows the hardware constitutions of the positioning server which concerns on embodiment of this invention. It is a flowchart which shows the process (database management method) performed with the positioning server which concerns on embodiment of this invention. It is a flowchart which shows another example of the process (database management method) performed with the positioning server which concerns on embodiment of this invention. It is a figure which shows the structure of the database management program which concerns on embodiment of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Positioning server, 11 ... Positioning database, 12 ... Strength information receiving part, 13 ... Position information receiving part, 14 ... Comparison part, 15 ... Position information requesting part, 16 ... Update part, 101 ... CPU, 102 ... RAM, DESCRIPTION OF SYMBOLS 103 ... ROM, 104 ... Communication module, 105 ... Auxiliary storage device, 20, 21 ... Cellular terminal, 30 ... Cellular base station, 40 ... GPS satellite, 50 ... Recording medium, 50a ... Program storage area, 51 ... Database management program, 51a ... Main module, 51b ... Strength information receiving module, 51c ... Position information receiving module, 51d ... Comparison module, 51e ... Position information request module, 51f ... Update module.

Claims (11)

A database management system for managing a database used for positioning of a mobile communication terminal and holding information indicating a relationship between a reception intensity and a position of the radio wave according to a radio wave transmission source,
Intensity information receiving means for receiving intensity information indicating reception intensity of radio waves according to the transmission source received or transmitted by the mobile communication terminal;
Comparing means for comparing the strength information received by the strength information receiving means with information indicating the received strength held in the database to determine whether or not the matching between them is successful;
If matching fails as a result of comparison by the comparison means, a request for transmission of position information is made, and if matching is successful as a result of comparison by the comparison means, the intensity information received by the intensity information receiving means is added to the intensity information. The transmission source, the past update time of the information indicating the relationship related to the reception strength held in the database, and the information indicating the relationship related to the reception strength. A position to determine whether to make a transmission request for the position information according to at least one of the past number of updates and the accuracy of the position related to the reception strength, and to perform the transmission request according to the determination Information request means;
Position information receiving means for receiving position information indicating the position where the radio wave is received or transmitted by the mobile communication terminal, transmitted in response to a transmission request made by the position information request means;
Updating means for updating the database based on the intensity information received by the intensity information receiving means and the position information received by the position information receiving means;
A database management system comprising:   The database management system according to claim 1, wherein the position information receiving unit receives the position information measured by GPS. The update means indicates the relationship related to the received intensity held in the database, which is a comparison target by the transmission source related to the intensity information received by the intensity information receiving means, and the comparing means. Received by the strength information receiving means according to at least one of the past update time of the information, the past update count of the information indicating the relationship related to the received strength, and the accuracy of the position related to the received strength The database management system according to claim 1 , wherein the database is updated by weighting the intensity information . The update means refers to the accuracy of the position information received by the position information receiving means, determines whether or not to update the database, and performs the update according to the determination. The database management system according to any one of claims 1 to 3. The updating means acquires speed information indicating a moving speed of the mobile communication terminal, determines whether to update the database according to the speed information, and performs the updating according to the determination. The database management system according to any one of claims 1 to 4, wherein the database management system is characterized. A database management method for managing a database used for positioning of a mobile communication terminal and holding information indicating a relationship between a reception intensity and a position of the radio wave according to a radio wave transmission source,
An intensity information receiving step for receiving intensity information indicating reception intensity of radio waves according to the transmission source received or transmitted by the mobile communication terminal;
A comparison step of comparing the strength information received in the strength information reception step with information indicating the reception strength held in the database to determine whether or not the matching between them is successful;
If matching fails as a result of comparison in the comparison step, a request for transmission of position information is made, and if matching is successful as a result of comparison in the comparison step, the strength information received in the strength information reception step is added. The transmission source, the past update time of the information indicating the relationship related to the reception strength held in the database, and the information indicating the relationship related to the reception strength. A position to determine whether to make a transmission request for the position information according to at least one of the past number of updates and the accuracy of the position related to the reception strength, and to perform the transmission request according to the determination An information request step;
A position information receiving step for receiving position information indicating the position at which the radio wave is received or transmitted by the mobile communication terminal, transmitted in response to the transmission request made in the position information requesting step;
An update step for updating the database based on the strength information received in the strength information receiving step and the location information received in the location information receiving step;
Database management method including.   The database management method according to claim 6, wherein in the position information receiving step, the position information measured by GPS is received. In the updating step, the transmission source related to the strength information received in the strength information receiving step, and the relationship related to the received strength held in the database that is a comparison target in the comparison step are shown. Received in the strength information receiving step according to at least one of the past update time of information, the past update count of the information indicating the relationship related to the received strength, and the accuracy of the position related to the received strength The database management method according to claim 6 , wherein the database is updated by weighting the intensity information . In the updating step, referring to the accuracy of the position information received in the position information receiving step, it is determined whether or not to update the database, and the update is performed according to the determination. The database management method according to any one of claims 6 to 8. In the updating step, speed information indicating the moving speed of the mobile communication terminal is acquired, it is determined whether or not the database is updated according to the speed information, and the updating is performed according to the determination. The database management method according to any one of claims 6 to 9, wherein A database management program for causing a computer to manage a database used for positioning of a mobile communication terminal and holding information indicating a relationship between a reception intensity and a position of the radio wave according to a radio wave transmission source,
An intensity information receiving function for receiving intensity information indicating reception intensity of radio waves according to the transmission source received or transmitted by the mobile communication terminal;
A comparison function for comparing the strength information received by the strength information reception function with information indicating the reception strength held in the database to determine whether or not the matching between the two is successful;
If matching fails as a result of comparison by the comparison function, a request for transmission of position information is made, and if matching is successful as a result of comparison by the comparison function, the strength information received by the strength information reception function is The transmission source, the past update time of the information indicating the relationship related to the reception strength held in the database, which is the object of comparison by the comparison function, and the information indicating the relationship related to the reception strength A position to determine whether to make a transmission request for the position information according to at least one of the past number of updates and the accuracy of the position related to the reception strength, and to perform the transmission request according to the determination An information request function;
A position information receiving function for receiving position information indicating a position at which the radio wave is received or transmitted by the mobile communication terminal, transmitted in response to a transmission request made by the position information request function;
An update function for updating the database based on the strength information received by the strength information receiving function and the position information received by the position information receiving function;
Database management program that causes a computer to execute.

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