JP2007228018A - Emergency call terminal - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the matter of an emergency call terminal that the positional information cannot be obtained by utilizing the global positioning system, and to obtain the current outline position precisely even if the installation position of a wireless base station is unknown. <P>SOLUTION: A terminal 1 comprises a terminal control section 2 having a CPU 2a and an RAM 2b, a GPS positioning device 3 for determining the terminal position by GPS, and a wireless communication section 4 for communicating with a wireless base station. When the terminal 1 is operated by a holder and the positioning device 3 obtains the positional information, the terminal control section 2 associates the ID code of a base station communicating with the wireless communication section 4 with the GPS positioning data obtained, and makes a database which is stored in the RAM 2b. If the positioning device 3 cannot obtain the positional information when the terminal 1 is operated, the terminal control section 2 can substitute the GPS positioning data stored in that database for the GPS positioning data of the present terminal 1. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an emergency call terminal having a function of transmitting position information of a terminal measured using a satellite positioning system using a wireless communication system such as GSM (Global system for Mobile Communication).

  2. Description of the Related Art In recent years, mobile terminals equipped with positioning devices that position themselves by performing positioning calculation processing using a satellite positioning system such as GPS (Global Positioning System) have been put into practical use (for example, Patent Document 1). reference). As such a portable terminal, for example, an emergency call terminal used in an emergency call system is known. The emergency call terminal is, for example, held by a child or an elderly person. When operated in an emergency or the like, the position of the emergency call terminal at the time of operation is obtained by GPS positioning calculation processing. Then, the emergency call terminal reports the obtained position to the call center via the wireless communication network by connecting to a wireless base station capable of transmitting and receiving wireless signals. In the call center, the location of the holder holding the emergency call terminal can be grasped by reporting the location from the emergency call terminal.

  By the way, as described above, in order to perform positioning calculation processing using, for example, GPS, it is necessary for the positioning device to receive a satellite signal transmitted from a GPS satellite. However, when the emergency call terminal is located indoors, or when the holder of the emergency information terminal is in an attitude that blocks the transmitted satellite signal, the satellite signal is received from the GPS satellite. Cannot be performed, and positioning calculation processing cannot be performed. That is, since the area where satellite signals can be received is narrower than the area where wireless communication with the radio base station can be performed, the emergency call terminal can perform satellite communication with the radio base station. May not be able to be received and may not be able to position itself.

  Conventionally, in order to enable the call center to grasp the approximate position of the emergency call terminal even when positioning by GPS is not possible, when the position information cannot be acquired, the previously determined position information is There is known an emergency call terminal that is configured to be transmitted to. However, in the case that the emergency call terminal holder has moved a long distance from the position where the previous positioning was made, such as when GPS positioning could not be performed for a long time since the last positioning, the position where the previous positioning was performed There is a problem that it is no longer suitable for use as an approximate position.

  On the other hand, a telecommunications carrier that provides a wireless communication network uses a database or the like in which the installation position of the wireless base station is recorded to determine the installation location of the wireless base station with which the mobile phone terminal is currently communicating. There is known a location information service provided as an approximate location. The radio base station with which the emergency call terminal is currently communicating can be identified by the base station ID code included in the radio wave transmitted from the radio base station. That is, as in this location information service, it is possible to obtain the approximate location of the emergency call terminal by using a database in which information for identifying a radio base station and a location where the radio base station is installed are used. . However, in order to acquire location information using this database, it is necessary to make a contract with a communication carrier. Therefore, for example, when using a wireless communication network provided by a plurality of carriers and providing a wide range of services using an emergency call system, it is necessary to contract with these carriers. Becomes complicated. In addition, since the database of the installation positions of the wireless base stations of a plurality of communication carriers is used, the data processing system of the call center becomes complicated and costs increase. Furthermore, some communication carriers may not provide location information services, and the installation location of the wireless base station may remain unknown as described above, and the approximate location of the emergency information terminal may not be obtained.

In Patent Document 1, position information by GPS is acquired when positioning by GPS is possible and wireless communication with a radio base station is not possible, and the position information is indicated as out-of-service position when communication with the radio base station is possible. A mobile phone having a function of transmitting as information is described. However, Patent Document 1 does not disclose an effective solution for the above-described problem.
Japanese Patent Laid-Open No. 2004-235827

  The present invention has been made in view of the above problems, and even if the position information cannot be obtained using a satellite positioning system and the installation position of the radio base station is unknown, the present approximate position It is an object of the present invention to provide an emergency information terminal that can accurately obtain the information.

  In order to achieve the above object, the invention of claim 1 is directed to a positioning device that receives a signal of a satellite positioning system and measures a terminal position, and a radio base station that transmits and receives radio signals and constitutes a radio communication network. Terminal control having a function of communicating with the wireless communication network by communicating with the wireless communication network, communicating with the positioning device and the wireless communication unit, and transmitting position information obtained by the positioning device from the wireless communication unit An emergency call terminal comprising: a base station ID code of a radio base station with which the radio communication unit is communicating when the positioning device obtains location information; And the obtained position information are made into a database in association with each other and stored.

  According to a second aspect of the present invention, there is provided a positioning device for receiving a satellite positioning system signal and positioning a terminal position, and transmitting / receiving a radio signal and communicating with any one of a plurality of radio base stations constituting a radio communication network. An emergency provided with a wireless communication unit connected to a wireless communication network, and a terminal control unit having a function of communicating with the positioning device and the wireless communication unit and transmitting position information obtained by the positioning device from the wireless communication unit When the positioning device obtains location information, the terminal control unit is a reporting terminal, and at that time, the cell ID included in the radio signal transmitted from the radio base station with which the radio communication unit is communicating The code or location area code and the obtained position information are associated with each other to form a database, and are stored and held.

  According to a third aspect of the present invention, there is provided a positioning device that receives a signal of a satellite positioning system and measures a terminal position, and transmits / receives a radio signal to communicate with any one of a plurality of radio base stations constituting a radio communication network. An emergency provided with a wireless communication unit connected to a wireless communication network, and a terminal control unit having a function of communicating with the positioning device and the wireless communication unit and transmitting position information obtained by the positioning device from the wireless communication unit When the positioning device obtains location information, the terminal control unit is a reporting terminal, and at that time, the base station ID code of the radio base station with which the radio communication unit is communicating, and the obtained location The information and the electric field intensity of the radio wave transmitted from the wireless base station are associated with each other to be stored in a database and stored.

  According to a fourth aspect of the present invention, in the first or second aspect of the invention, the terminal control unit is a database that stores one or more pieces of position information for one base station ID code, cell ID code, or location area code. Based on the location information, the location of the radio base station corresponding to the base station ID code, cell ID code, or location area code and the radio communication unit can be connected to the radio base station. It has the function which estimates the area which is.

  According to a fifth aspect of the present invention, in the third aspect of the present invention, the terminal control unit obtains one or more pieces of position information for one base station ID code and an electric field strength of a radio wave transmitted from the radio base station. When the database is stored and held, the position of the radio base station corresponding to the base station ID code and the area where the radio communication unit can be connected to the radio base station are estimated based on the position information and the electric field strength. It has a function.

  According to a sixth aspect of the present invention, in the invention according to any one of the first to third aspects, the positioning device automatically detects when the wireless communication unit communicates with a wireless base station that has not communicated before. The terminal position measurement is started.

  The invention of claim 7 is the invention according to any one of claims 1 to 6, wherein the terminal control unit uses a base station ID code, cell ID code, or location area code already stored in a database. When new position information to be associated is obtained, if the distance between the position information and the stored position information is within a predetermined distance, the stored position information is deleted and newly stored. The obtained position information is stored and held.

  The invention of claim 8 is the invention according to any one of claims 1 to 7, wherein the terminal control unit uses a base station ID code, cell ID code, or location area code already stored in a database. When new position information to be associated is obtained, if the distance between the position information and the position information stored and held is equal to or greater than a predetermined distance, the position information already stored and deleted is deleted and newly stored. The position information obtained is stored and held.

  According to the first aspect of the present invention, when the terminal control unit obtains location information, the base station ID code of the radio base station with which the radio communication unit is communicating at that time and the obtained location information Are stored in a database and stored, so even if the position information cannot be obtained using the satellite positioning system, the position information stored in the database is used as the current terminal position information. It becomes possible. Therefore, even if the installation position of the radio base station is unknown, the current approximate position can be obtained with high accuracy.

  According to the invention of claim 2, when the terminal control unit obtains the position information, the cell ID included in the radio signal transmitted from the radio base station with which the radio communication unit is communicating at that time Since the code or location area code and the obtained position information are associated with each other in a database and stored, the position stored in this database is stored even if the position information cannot be obtained using the satellite positioning system. The information can be used as the current terminal position information. Therefore, even if the installation position of the radio base station is unknown, the current approximate position can be obtained with high accuracy. In addition, since the cell ID code or the location area code is stored in the database, one record corresponds to a wide range as compared with the case of storing the base station ID code, and even if there are few records stored in the database. It is possible to obtain the current approximate position over a wide range.

  According to the invention of claim 3, when the terminal control unit obtains the position information, the base station ID code of the radio base station with which the radio communication unit is communicating at that time, and the obtained position A database is created by associating information and the electric field intensity of the radio wave transmitted from the radio base station, and stored. Therefore, when GPS positioning data to be substituted for the current GPS positioning data of the terminal 1 is acquired from the database, GPS positioning data that is considered to correspond to the current terminal position is acquired and transmitted to the call center D. Thus, the accuracy of the current approximate position can be further improved.

  According to the invention of claim 4, since the terminal control unit estimates the position of the corresponding radio base station and the area where the radio communication unit can be connected to the radio base station, based on the location information database. It becomes possible to obtain the current approximate position of the emergency call terminal more accurately.

  According to the invention of claim 5, the terminal control unit determines the location of the radio base station based on the database of the base station ID, the location information, and the electric field strength and the area where the radio communication unit can connect to the radio base station. Since the estimation is performed, the current approximate position of the emergency call terminal can be obtained with high accuracy even when the installation position of the radio base station is unknown as described above. In addition, since the position of the radio base station is estimated with higher accuracy along with the electric field strength of the radio wave, the accuracy of the current approximate position can be further improved.

  According to the invention of claim 6, since the positioning device automatically starts positioning of the terminal position when the wireless communication unit communicates with a wireless base station that has not communicated before, the wireless base station that communicates for the first time Information about stations can be quickly registered in the database, and the database can be enriched to accommodate more radio base stations. Therefore, by using this database, it is possible to obtain the current approximate position in a wider range and with higher accuracy.

  According to the invention of claim 7, when new position information associated with a base station ID code or the like already stored in the database is obtained, the distance between the position information and the stored position information Is within the predetermined distance, the stored position information is deleted and the newly obtained position information is stored and held, so that the data registered in the database becomes the latest information. Therefore, it is possible to improve the accuracy of the data in the database, and it is possible to more reliably obtain the current approximate position of the emergency information terminal.

  According to the invention of claim 8, when new position information associated with a base station ID code or the like already stored in a database is obtained, the distance between the position information and the stored position information If it is equal to or greater than a predetermined distance, the stored location information is deleted and the newly obtained location information is stored, so even when the base station ID code of the radio base station is changed, for example, It is possible to update the data registered in the database with the changed data. Therefore, it is possible to improve the accuracy of the data in the database, and it is possible to more reliably obtain the current approximate position of the emergency information terminal.

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows an example of an emergency call terminal (hereinafter referred to as a terminal) according to the first embodiment of the present invention. FIG. 2 shows an example of an emergency call system using the terminal 1. The terminal 1 is configured to be capable of transmitting information obtained by positioning its own position using a satellite positioning system such as GPS (Global Positioning System) using a wireless communication system such as GSM (Global system for Mobile Communication). It is what has been. As illustrated in FIG. 1, the terminal 1 includes a terminal control unit 2, a GPS positioning device (positioning device) 3, and a wireless communication unit 4.

  The terminal control unit 2 includes a CPU 2a and a RAM 2b. The CPU 2 a is configured to be able to communicate with the RAM 2 b, the positioning device 3, and the wireless communication unit 4, and controls the operation of the terminal 1. The RAM 2b stores, for example, position information obtained by the positioning device 3 as will be described later.

  The positioning device 3 has a GPS antenna 3c and, for example, receives a satellite signal transmitted from a GPS satellite E and performs a positioning calculation process to determine a terminal position and obtain position information. The positioning device 3 has positioning information necessary for obtaining position information. This positioning information is used to obtain a satellite signal from the GPS satellite E. As the positioning information, the current time, the approximate position of the terminal 1, and the orbit information of the GPS satellite E are used. Among the positioning information, the current time and orbit information are acquired by receiving a satellite signal transmitted from the GPS satellite E. Further, the approximate position of the terminal 1 is acquired from, for example, the position previously stored by the positioning device 3 stored in the RAM 2b. Using this positioning information, the positioning device 3 selects a GPS satellite E that is in a position where a satellite signal can be obtained, and performs positioning calculation based on the satellite signal received from the selected GPS satellite E. It is configured such that the current position information of the terminal 1 can be obtained by executing the process.

  The wireless communication unit 4 includes a wireless circuit control unit 4a and a wireless circuit unit 4b. In the wireless communication unit 4, the wireless circuit control unit 4 a controls access to the wireless circuit unit 4 b by time division multiplexing, and the wireless circuit unit 4 b wirelessly transmits via the antenna 4 c connected to the wireless circuit unit 4 b according to the control. Signals are transmitted and received.

  An example of an emergency call system to which the terminal 1 is applied will be described with reference to FIG. The terminal 1 is capable of receiving a radio signal among a plurality of radio base stations (hereinafter referred to as base stations) A1, A2, A3, ..., An by radio communication by the radio communication unit 4. By communicating, it is connected to a radio communication network B of a radio communication system constituted by these base stations A1, A2, A3,. When the position of the terminal 1 changes and communication with the base station An that has been communicating until then becomes impossible, the connection to the wireless communication network B is started by starting communication with another base station An capable of communication at that position. Is configured to be maintained. A call center D that receives a report from the terminal 1 is connected to the wireless communication network B. FIG. 2 shows only the base station A1 among the plurality of base stations A1, A2, A3,.

  FIG. 3 shows a part of a wireless communication network B of a wireless communication system by a communication carrier used by this emergency call system. As shown in the figure, among the base stations A1, A2, A3,..., An constituting the wireless communication network B, for example, base stations A1, A2, A3 and base stations A4, A5, A6 are gathered, respectively. Cells C1 and C2 are configured. The cells C1 and C2 are collected to constitute one location area L. That is, the wireless communication network B includes a plurality of location areas L1, L2,..., Ln each including a plurality of cells Cn each including a plurality of base stations An. Each unit of the base station An, the cell Cn, and the location area Ln is uniquely assigned with a base station ID code, a cell ID code, and a location area code in the wireless communication network B. Each of these codes is included in a radio signal transmitted from each base station An. Thereby, when the radio communication unit 4 of the terminal 1 receives a radio signal, the base station An that has transmitted the radio signal can be identified to which cell Cn and the location area Ln. ing.

  Next, an example of the operation when the terminal 1 is operated by the holder in this emergency call system will be described. In this emergency call system, the terminal 1 is held by a holder such as a child or an elderly person. When the operation of the terminal 1 is performed by the holder, the position of the terminal is measured by the positioning device 3 and the wireless communication unit 4 is capable of wireless communication among the base stations An constituting the wireless communication network B at that time. Communicate wirelessly with things that are in good condition. Thus, when the connection between the terminal 1 and the wireless communication network B is established, the location information obtained at the terminal 1 is notified to the call center D via the wireless communication network B, and the location of the terminal 1 is grasped at the call center D. It becomes possible.

  Here, when the terminal 1 is operated by the holder and the positioning device 3 obtains the position information, the terminal control unit 2 of the terminal 1 is connected to the base station An with which the wireless communication unit 4 is communicating. The base station ID code and the obtained GPS positioning data (position information) are associated with each other to form a database and stored in the RAM 2b. FIG. 4 shows an example of a database created in this way and stored in the RAM 2b. A record is added to the database of the base station ID code and the GPS positioning data every time the positioning device 3 obtains position information, and the number of records is gradually increased. Note that the positioning of the position of the terminal 1 by the positioning device 3 is not limited to only when the terminal 1 is operated by the holder. For example, the positioning device 3 is periodically activated at predetermined time intervals under the control of the terminal control unit 2 to measure the terminal position, and at this time, the base station ID code of the base station An with which the wireless communication unit 4 can communicate is obtained. The configuration may be such that the acquired location information and base station ID code are stored in the RAM 2b as a database. For example, by adopting such a configuration, it is possible to reliably increase the number of database records stored in the RAM 2b.

  In this embodiment, when the terminal 1 is operated by the holder, the terminal control unit 2 cannot receive, for example, a satellite signal from the GPS satellite E, and the positioning device 3 is in the position of the terminal. When positioning fails, the database held in the RAM 2b is referred. Then, in the database, the wireless communication unit 4 searches for a record for the same base station ID code as the base station ID code of the base station An that is communicating at that time. When there is a record for the base station ID code in the database, the GPS positioning data stored corresponding to the base station ID code is acquired from the database, and the data is sent to the call center D as the approximate position of the terminal 1 Send.

  Thus, in this embodiment, since the terminal 1 holds the database in which the base station ID code of the base station An and the position information are associated with each other, even if the positioning device 3 cannot obtain the position information. The GPS positioning data stored and held in this database can be used as the GPS positioning data of the current terminal 1. Therefore, even if the position where the base station An is installed is unknown, the current approximate position of the terminal 1 can be obtained with high accuracy and transmitted to the call center D.

  As shown in FIG. 5, the above-described cell ID code or location area code may be recorded in the database in association with the GPS positioning data instead of the base station ID code. At this time, when the terminal 1 is operated and the positioning device 3 fails in positioning and cannot obtain GPS positioning data, the terminal control unit 2 performs the cell ID code of the base station An that is communicating at that time or Search the database for records that contain the same location area code. If there is a record identical to the code, the GPS positioning data in the record is transmitted to the call center D as the approximate position of the terminal 1. Therefore, as described above, even if the position where the base station An is installed is unknown, the current approximate position of the terminal 1 can be accurately obtained and transmitted to the call center D. Further, since the GPS positioning data created in this way in the database is recorded as a cell Cn composed of a plurality of base stations An or within the range of the location area Ln, the base station ID code is set to GPS as described above. Compared with the case of creating a database together with positioning data, one record corresponds to a wide range. Therefore, the current approximate position of the terminal 1 can be obtained over a wide range even if the number of records held in the database is small.

  Next, a second embodiment of the present invention will be described. In each embodiment described below, the same components as those in the first embodiment are denoted by the same reference numerals, and only portions different from the first embodiment will be described. In the second embodiment, when the terminal control unit 2 of the terminal 1 obtains GPS positioning data, the positioning device 3 receives the base station ID code of the base station An with which the wireless communication unit 4 is communicating. The obtained GPS positioning data and the electric field intensity of the radio wave transmitted from the base station An are associated with each other and stored in the RAM 2b.

  FIG. 6 shows an example of a database created in this way and stored in the RAM 2b. The terminal control unit 2 refers to the database held in the RAM 2b when the positioning device 3 fails in positioning the terminal position when the terminal 1 is operated by the holder. Then, in the database, the wireless communication unit 4 searches for a record for the same base station ID code as the base station ID code of the base station An that is communicating at that time. When there is one record for the base station ID code in the database, the GPS positioning data stored corresponding to the base station ID code is transmitted to the call center D as the approximate position of the terminal 1 as described above. To do. On the other hand, when there are a plurality of records for the same base station ID code in the database, the electric field strength close to the electric field strength of the radio wave from the base station An received by the wireless communication unit 4 is selected from those records. A certain record is selected, and the GPS positioning data in the record is transmitted to the call center D as the approximate position of the terminal 1.

  The electric field strength of the radio wave transmitted from the base station An received by the wireless communication unit 4 changes according to the distance from the base station An to the terminal 1. That is, in the second embodiment, since the electric field strength of radio waves is made into a database in addition to the database of the first embodiment, it is possible to know how far the measured point is from the base station An. become. Therefore, when acquiring GPS positioning data to be substituted as the GPS positioning data of the current terminal 1 from the database, the GPS positioning data considered to correspond to the current terminal position is acquired and transmitted to the call center D. Thus, the accuracy of the current approximate position can be further improved.

  Next, a third embodiment of the present invention will be described. In the third embodiment, when the terminal control unit 2 stores and holds one or more pieces of position information in a database for one base station ID code as in the first embodiment described above, the position information Based on the above, the position of the base station An corresponding to the base station ID code and the area where the wireless communication unit 4 can be connected to the base station An are estimated. In the third embodiment, consider a case where a database of GPS positioning data and a base station ID code is stored and held, for example, as shown in FIG. In this case, for example, two records with storage numbers 1 and 4 are for the same base station ID code.

  Thus, for example, when a plurality of records are held in the database for the same base station ID code, the terminal control unit 2 has an area within a predetermined range from the point indicated by each GPS positioning data for the base station ID code. It is estimated that a base station An having the base station ID code exists in the overlapping area. FIG. 8 shows an example of the flow of this estimation process. FIGS. 9A, 9B, and 9C show areas estimated by this estimation process. In the figure, an area where a shaded range is estimated is shown.

  Hereinafter, the estimation process will be described with reference to FIG. The terminal control unit 2 stores the GPS positioning data and the base station ID code in association with each other in the database held in the RAM 2b. Here, let R be the distance that radio waves transmitted from this base station An reach. At this time, as shown in FIG. 9A, the inside of a circle c1 drawn with a radius 2R around the point P1 indicated by the GPS positioning data is set as a temporary area (S1). Thereafter, the terminal control unit 2 searches the database, and determines whether the base station ID code registered in the database at this time is already registered in the database (S2). If the base station ID code is not registered in the database and the base station ID code stored at this time is new in the database, the wireless communication unit 4 determines the area estimated as the temporary area at this time. It is set as this area where the wireless communication unit 4 can be connected to the communicating base station An (S3). On the other hand, when the base station ID code has already been registered in the database, as shown in FIG. 9B, the base station ID code is drawn with a radius 2R around the point P2 indicated by the GPS positioning data of the already registered record. An overlapping range between the inside of the circle c2 and the inside of the circle c1 which is the temporary area set as described above is set as the main area (S4). That is, when this area has already been set for the base station An, the ty round-trip range between the main area and the temporary area set this time is set as a new main area.

  After this area is set as shown in FIG. 9B, when GPS positioning data is obtained when the same base station An and the wireless communication unit 4 are connected, the database is created as described above. And the inside of the circle c3 centered on the point P3 indicated by the GPS positioning data is set as a temporary area. Then, as shown in FIG. 9C, an overlapping range between this temporary area and the main area set as described above based on the records already registered in the database is newly set as the main area. The In this way, the terminal control unit 2 performs estimation processing, estimates an area where the base station An and the wireless communication unit 4 can communicate, and stores area information in the RAM 2b. Then, when the terminal 1 is operated by the holder while the positioning device 3 cannot be positioned by GPS, if the wireless communication unit 4 is communicating with the base station An, the terminal control unit 2 Information on this area stored in the RAM 2b is transmitted from the wireless communication unit 4. In the call center D, by transmitting this information from the terminal 1, it is possible to grasp that the terminal 1 currently exists in this area.

  This area set in this way indicates a range that may be the installation position of the base station An, and includes a range in which the base station An and the wireless communication unit 4 can communicate with each other. It becomes. Therefore, in the third embodiment, even if the installation position of the base station An is unknown, the current approximate position of the terminal 1 can be obtained with higher accuracy.

  Even when a cell ID code or a location area code is recorded in the database instead of a base station ID code, a cell or a location area corresponding to the cell ID code or the location area code is similarly obtained by performing an estimation process. It is possible to estimate the range. Thereby, even when the positioning device 3 cannot perform positioning by GPS, the current approximate position of the terminal 1 can be obtained with high accuracy, and the position of the cell or location area where the terminal 1 exists can be transmitted to the call center D. It becomes possible.

  Next, a fourth embodiment of the present invention will be described. In the fourth embodiment, in the third embodiment, when the database associates the base station ID code with the GPS positioning data and the electric field strength of the radio wave, the wireless communication unit 4 of the terminal 1 The position of the base station An to communicate with and the area where the wireless communication unit 4 can connect to the base station An are estimated.

  FIG. 10 shows an example of a database in the fourth embodiment. In the fourth embodiment, the procedure of the estimation process is substantially the same as that of the third embodiment described above, but according to the electric field strength of the radio wave transmitted from the base station An at that time when setting a temporary area. This is different from the third embodiment in that the size of the temporary area is changed.

  In the fourth embodiment, the size of the temporary area is changed by changing the radius of a circle centered on the point indicated by the obtained GPS positioning data according to the electric field strength of the radio wave. The radius of the circle is set in advance so as to be divided into, for example, four levels according to the electric field strength of the radio wave. FIG. 11 shows an example of the relationship between the electric field strength of radio waves and the radius of a circle, that is, the range of a temporary area. Here, let R be the distance that the radio wave transmitted from the base station An reaches. As shown in the figure, when the electric field strength is weak, for example, less than 30 dBμV, the radius of the circle serving as the temporary area is set to be 2R as in the third embodiment. As the electric field strength increases, the temporary area gradually decreases. For example, when the electric field strength is in the range of 30 to 40 dBμV, 40 to 50 dBμV, and 50 dBμV or more, the radius of the circle is 7 / 4R, 6 / 4R, and 5 / 4R are set. The radius of this circle is not limited to this. That is, the radius of the circle may be set to be a distance equal to or slightly larger than the distance from the base station An to the terminal 1 at a certain predetermined electric field strength. Further, the radius of this circle may be divided into more stages according to the electric field strength of the radio wave, or may be set so as to change steplessly.

  With reference to FIGS. 12A, 12B, and 12C, estimation processing in the fourth embodiment will be described. In the figure, the shaded range indicates the range set in this area. As shown in FIG. 12A, when the positioning device 3 measures the terminal position when the wireless communication unit 4 of the terminal 1 is communicating with the base station An, the terminal control unit 2 obtains the obtained GPS positioning data. And the base station ID code and the electric field intensity of the radio wave transmitted from the base station An are made into a database. At this time, it is assumed that the database does not include data on the base station ID code and the electric field strength is 45 dBμV, for example. The terminal control unit 2 sets the temporary area inside the circle c4 having a radius of 6 / 4R corresponding to the electric field intensity of 45 dBμV drawn around the point P4 indicated by the obtained GPS positioning data. And since there is no data about the base station ID code of the base station An communicating at this time in the database, this temporary area is set as the main area.

  Thereafter, GPS positioning data is obtained again during communication with the base station An, and the electric field strength at that time is assumed to be 32 dBμV, for example. At this time, as shown in FIG. 12B, the radius of the temporary area indicated by the circle c5 centered on the point P5 indicated by the GPS positioning data is 7 / 4R because the electric field strength is 32 dBμV. Then, as shown in FIG. 12B, an overlapping range between the main area indicated by the circle c4 set as described above and the temporary area is set as a new main area. Further, when GPS positioning data is obtained during communication with the base station An and the electric field strength at that time is, for example, 28 dBμV, as shown in FIG. 12C, the point P6 indicated by the GPS positioning data is the center. A temporary area indicated by a circle c6 having a radius 2R is set. An overlapping range between this temporary area and the main area set as shown in FIG. 12B is set as a new main area.

  If the wireless communication unit 4 is communicating with the base station An when the terminal 1 is operated, the terminal control unit 2 may, for example, store information on the main area stored in the RAM 2b and the radio wave at that time. The area where the terminal 1 will be currently located is estimated from the electric field strength of. Then, information about the estimated area is transmitted from the wireless communication unit 4. As a result, the call center D can grasp that the terminal 1 currently exists in this area.

  In the fourth embodiment, since the main area set in this way is a narrower range than the main area of the third embodiment, the range where the base station An is installed is more limited. It will be shown. In addition, since this area includes a range in which the base station An and the wireless communication unit 4 can communicate with each other, it is possible to estimate the area where the terminal 1 is considered to be located more limited. Accordingly, it is possible to further improve the accuracy of the current approximate position transmitted from the terminal 1 and to make the approximate position highly reliable.

  Next, a fifth embodiment of the present invention will be described. In the fifth embodiment, when the terminal 1 moves or the like, when the wireless communication unit 4 communicates with the base station An that has not communicated before, the positioning device 3 automatically performs positioning of the terminal position. Is what you do.

  FIG. 13 shows the operation of the terminal 1 in the fifth embodiment. First, when the wireless communication unit 4 starts communication with the base station An, the terminal control unit 2 acquires a base station ID code included in the radio wave from the base station An received by the wireless communication unit 4. Thereafter, the database stored in the RAM 2b is referred to, and it is checked whether or not a record relating to the base station ID code exists in the database (S31). If the record does not exist in the database, the positioning device 3 starts positioning of the terminal position and tries to acquire GPS positioning data (S32). When the GPS positioning data is obtained, the GPS positioning data and the base station ID code are associated with each other and made into a database, as described above. On the other hand, if a record related to the base station ID code already exists in the database, the terminal control unit 2 does not cause the positioning device 3 to start positioning of the terminal position (S33).

  As described above, in the fifth embodiment, when the wireless communication unit 4 starts communication with the base station An that communicates for the first time, the GPS positioning data corresponding to the base station An can be quickly stored in the database. This makes it possible to enrich the database corresponding to more base stations An. Therefore, the terminal 1 can obtain the current approximate position in a wider range and with higher accuracy by using this database. Further, when the record is already held in the database, positioning of the terminal position is not executed, so that the power of the terminal 1 can be saved.

  In addition, the terminal 1 is not limited to the one that holds the record for the base station ID code in the database, and may be configured to hold the record for the cell ID code or the location area code as described above. Further, the base station ID code, the GPS positioning data, and the electric field intensity of the radio wave at that time may be associated with each other to form a database.

Next, a sixth embodiment of the present invention will be described. In the sixth embodiment, when the terminal control unit 2 of the terminal 1 obtains new GPS positioning data associated with the base station ID code already stored in the database held in the RAM 2b. In a predetermined case, the GPS positioning data associated with the base station ID code is deleted from the database. More specifically, when the distance between the point indicated by the GPS positioning data held in the database and the current point is within a predetermined distance or more than a predetermined distance,
A record relating to GPS positioning data stored and held in the database is deleted from the database. Then, the newly obtained GPS positioning data and the base station ID code are associated with each other and formed into a database. For example, as shown in FIG. 14, this processing is performed by associating a base station ID code identical to the base station ID code already stored and stored as storage number 1 in the database and GPS positioning data into a storage number n. It is executed when it is converted into a database.

  FIG. 15 shows an example of processing executed by the terminal control unit 2 in the sixth embodiment. First, based on the latitude and longitude information of the GPS positioning data recorded and held in the database, the terminal control unit 2 stores the previously indicated GPS positioning data and the previously obtained GPS positioning data already stored and held. The distance to the point indicated by is calculated (S51). Then, it is determined whether the distance is within 10 m, for example (S52), and if it is within 10 m, the record of the previous GPS positioning data already stored and retained is deleted from the database (S53). Thereafter, the newly obtained GPS positioning data and the base station ID code are associated with each other and added to the database (S54).

  When the calculated distance is greater than 10 m (S52: NO), it is next determined whether or not the distance is 2R or more (S55). Here, R is the distance that the radio wave transmitted from the base station An reaches. In the sixth embodiment, the terminal control unit 2 has a change counter for determining whether the position of the base station An has changed. If the distance is 2R or more, 1 is added to the value of the change counter (S56). If the value of the change counter after the addition is 3, for example (S57: YES), the terminal control unit 2 clears the change counter to 0 (S58). Then, the record for the previous GPS positioning data already stored in the database is deleted from the database as described above (S53). Thereafter, the newly obtained GPS positioning data and the base station ID code are associated with each other and added to the database (S54).

  When the distance calculated from the GPS positioning data is not within 10 m and is not 2R or more (S55: NO), or when the value of the change counter is not 3 even if the distance is 2R or more (S57: NO), A record of the previous GPS positioning data is maintained in the database (S59). In this state, the newly obtained GPS positioning data and the base station ID code are added to the database in association with each other (S54).

  Thus, in the sixth embodiment, if the point indicated by the newly obtained GPS positioning data is very close to the point indicated by the previous GPS positioning data held in the database, it is newly obtained. Since only the GPS positioning data is held, the GPS positioning data stored in the database becomes new data that seems to be more reliable. In addition, the distance between the point indicated by the newly obtained GPS positioning data and the point indicated by the previous GPS positioning data is far beyond the range in which radio waves from the same base station An can be received. If so, only newly obtained GPS positioning data is retained, so even if, for example, the base station ID code is changed, the GPS positioning data stored in the database reflects the change. It becomes. That is, in the sixth embodiment, it is possible to improve the accuracy of the data in the database, and it is possible to obtain the current approximate position of the terminal 1 more reliably.

  Here, as described above, the terminal control unit 2 is configured to use the change counter and hold only the GPS positioning data newly obtained when the value of the change counter becomes 3, for example, in the database. Therefore, for example, although the base station ID code is not changed, the GPS positioning data newly obtained for some reason indicates a point that is 2R or more away from the point indicated by the previous GPS positioning data. However, the previous GPS positioning data is not immediately deleted. Accordingly, since the previous GPS positioning data is deleted when the base station ID code is changed reliably, it is possible to further improve the accuracy of the data in the database.

  Also in the sixth embodiment, the terminal 1 may be configured to hold a record of the cell ID code or the location area code as described above, and the base station ID code, the GPS positioning data, A configuration in which the electric field intensity of the radio wave at that time is associated with the database may be used. Further, the terminal control unit 2 may not be provided with a change counter, and may be configured to immediately delete the previous GPS positioning data when the calculated distance is, for example, 2R or more. Furthermore, the distance threshold and the value of the change counter when determining whether to delete the previous GPS positioning data are not limited to those described above, and may be set to appropriate values.

  The present invention is not limited to the configuration of each of the embodiments described above, and various modifications can be made as appropriate without departing from the spirit of the invention. For example, the terminal 1 may have a call function like a so-called mobile phone. In addition, the positioning device 3 of the terminal 1 is not limited to the one that supports GPS, but may be one that supports other GNSS (Global Navigation Satellite Systems) such as GALILEO and GRONASS. At this time as well, the terminal 1 can obtain the current approximate position with high precision by configuring the base station ID code and the like and the position information of the terminal 1 in association with each other in the same manner as described above. It becomes possible.

The block diagram which shows an example of the emergency call terminal which concerns on the 1st Embodiment of this invention. The figure which shows the structure of the emergency call system using the terminal. The figure which shows a part of radio base station which comprises the radio | wireless communication network used for the emergency call system. The figure which shows an example of the database hold | maintained at a terminal same as the above. The figure which shows the modification of the database. The figure which shows an example of the database hold | maintained at the emergency call terminal which concerns on the 2nd Embodiment of this invention. The figure which shows an example of the database hold | maintained at the emergency call terminal which concerns on the 3rd Embodiment of this invention. The flowchart explaining an example of the estimation process which the terminal performs. (A) is a diagram for explaining the main area estimated by the terminal, (b) is a diagram for explaining the main area that is estimated when a temporary area has already been set for the same base station An, and (c) The figure explaining this area estimated when the positioning of a terminal position is further performed from (b). The figure which shows an example of the database hold | maintained at the emergency call terminal which concerns on the 4th Embodiment of this invention. The figure which shows the relationship between the electrolytic strength applied to the estimation process which the terminal performs, and a temporary area range. (A) is a diagram illustrating the main area estimated by the terminal, (b) is a diagram illustrating the main area estimated when the terminal position is further determined from (a), and (c) is ( The figure explaining this area estimated when the positioning of a terminal position is further performed from b). The flowchart explaining an example of operation | movement of the emergency call terminal which concerns on the 5th Embodiment of this invention. The figure which shows an example of the database hold | maintained at the emergency call terminal which concerns on the 6th Embodiment of this invention. The flowchart which shows an example of the operation | movement which the terminal performs.

Explanation of symbols

1 terminal (emergency call terminal)
2 Terminal control unit 3 GPS positioning device (positioning device)
4 Wireless communication section An base station (wireless base station)
B Wireless communication network

Claims (8)

A positioning device that receives a satellite positioning system signal and positions the terminal;
A wireless communication unit that transmits and receives a wireless signal and connects to the wireless communication network by communicating with any of a plurality of wireless base stations constituting the wireless communication network;
An emergency call terminal comprising a terminal control unit having a function of communicating with the positioning device and the wireless communication unit and transmitting position information obtained by the positioning device from the wireless communication unit,
When the positioning device obtains location information, the terminal control unit associates a base station ID code of a radio base station with which the radio communication unit is communicating at that time with the obtained location information in a database Emergency call terminal, characterized in that it is stored in memory. A positioning device that receives a satellite positioning system signal and positions the terminal;
A wireless communication unit that transmits and receives a wireless signal and connects to the wireless communication network by communicating with any of a plurality of wireless base stations constituting the wireless communication network;
An emergency call terminal comprising a terminal control unit having a function of communicating with the positioning device and the wireless communication unit and transmitting position information obtained by the positioning device from the wireless communication unit,
The terminal control unit, when the positioning device obtains position information, a cell ID code or a location area code included in a radio signal transmitted from a radio base station with which the radio communication unit is communicating An emergency call terminal characterized in that the obtained location information is associated with a database and stored. A positioning device that receives a satellite positioning system signal and positions the terminal;
A wireless communication unit that transmits and receives a wireless signal and connects to the wireless communication network by communicating with any of a plurality of wireless base stations constituting the wireless communication network;
An emergency call terminal comprising a terminal control unit having a function of communicating with the positioning device and the wireless communication unit and transmitting position information obtained by the positioning device from the wireless communication unit,
When the positioning device obtains location information, the terminal control unit obtains the base station ID code of the radio base station with which the radio communication unit is communicating, the obtained location information, and the radio base station An emergency call terminal characterized in that it is stored in a database by associating with the electric field intensity of the radio wave transmitted from the database.   When the terminal control unit stores and holds one or more pieces of position information in a database for one base station ID code, cell ID code, or location area code, the base station ID is based on the position information. The radio base station position corresponding to a code, a cell ID code, or a location area code, and a function for estimating an area where the radio communication unit can be connected to the radio base station. The emergency call terminal according to claim 2.   When the terminal control unit creates a database of one or more pieces of position information for one base station ID code and the electric field intensity of the radio wave transmitted from the radio base station and stores it, the position information and the electric field intensity are stored. 4. The emergency call according to claim 3, further comprising a function of estimating a position of a radio base station corresponding to the base station ID code and an area where the radio communication unit can be connected to the radio base station. Terminal.   4. The positioning device according to claim 1, wherein the positioning device automatically starts positioning of a terminal position when the wireless communication unit communicates with a wireless base station that has not communicated before. The emergency call terminal described in Crab.   The terminal control unit stores and holds the position information when new position information associated with the base station ID code, cell ID code, or location area code already stored in the database is stored. The position information stored and held is deleted and the newly obtained position information is stored and held if the distance to the existing position information is within a predetermined distance. The emergency call terminal described in any of the above.   The terminal control unit stores and holds the position information when new position information associated with the base station ID code, cell ID code, or location area code already stored in the database is stored. The position information already stored and held is deleted and the newly obtained position information is stored and held if the distance to the existing position information is a predetermined distance or more. The emergency call terminal according to any one of 7.

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