JP5667356B2 - Mobile communication terminal - Google Patents

Description

  The present invention relates to a mobile communication terminal having a positioning function using a base station.

  2. Description of the Related Art Conventionally, a positioning service using GPS (Global Positioning System) has been provided to acquire current location information of a mobile communication terminal. In this service, a mobile communication terminal receives auxiliary information for capturing radio waves from a GPS satellite from a PDE (Position Determination Entity) via a base station.

  At this time, when the mobile communication terminal is communicating with a remote base station or repeater (relay station), it is difficult to capture the GPS satellite because the accuracy of the auxiliary information received from the PDE is not sufficient. When four or more GPS satellites cannot be captured, the positioning mode is based on the position information of the base station, so the positioning result is calculated as the base station periphery, and the error from the current location often increases. .

  In such a situation, for example, Patent Document 1 discloses an algorithm for improving the positioning accuracy from the next time on by notifying the server (PDE) of the acquisition result of the GPS satellite.

Japanese Patent Laid-Open No. 2003-139841

  However, even with the method of Patent Document 1, since the positioning algorithm is effective for the second and subsequent positioning processes, it has not been expected to reduce the positioning error in the first positioning.

  An object of this invention is to provide the portable communication terminal which can improve positioning accuracy more stably by selecting a suitable base station.

The mobile communication terminal according to the present invention is a mobile communication terminal corresponding to a plurality of frequency bands , and receives from the base station a position information collecting unit that collects position information of the base station transmitted from the base station. a radio wave state collecting unit that collects and measures the radio wave conditions, among the prior SL plurality of frequency bands, the number of base stations is a frequency band not less than the predetermined number, it noted and selects a frequency band suitable for positioning positioning a frequency band selection unit, the identification data of the second condition is satisfied base station among the base stations included in the frequency band selected by the frequency band selection unit for selecting a first condition is satisfied frequency band for A positioning unit that notifies a server and executes GPS positioning processing using auxiliary positioning data received from the positioning server via the base station.

Further, the location information includes information of at least latitude and longitude of each base station, the first condition is satisfied the frequency band, the frequency is not more than a predetermined deviation in latitude and longitude information of each base station A belt is preferred.

The frequency band that satisfies the first condition is preferably a frequency band in which the radio wave condition from each base station is better than a predetermined value.

Furthermore, the positioning unit, when performing the GPS positioning process using a frequency band the non-first condition is satisfied frequency band, it is preferable to change the parameters related to acquisition success probability of GPS satellites.

  In the GPS positioning process, the positioning unit preferably changes a parameter relating to a GPS satellite acquisition success probability when the positioning auxiliary data is received from a relay station.

  In addition, the positioning unit is based on the positioning mode of either the Based mode in which the positioning calculation is performed based on the GPS signal, or the Assisted mode in which the positioning server performs the positioning calculation using the GPS signal or the position information of the base station. It is preferable to execute a GPS positioning process.

  Further, the positioning unit, if the number of GPS satellites captured in the GPS positioning process is less than a predetermined, or the positioning result is outside the range of the area specified by the position information of the base station involved in the positioning calculation, It is preferable to change the positioning mode and execute the GPS positioning process again.

The frequency band is preferably a band class.

  According to the present invention, positioning accuracy can be improved more stably by selecting an appropriate base station.

1 is an external perspective view of a mobile phone according to an embodiment of the present invention. It is a block diagram which shows the function of the mobile telephone which concerns on embodiment of this invention. It is a figure which shows an example of the base station database for positioning which concerns on embodiment of this invention. It is a figure which shows an example of the electric field strength information which concerns on embodiment of this invention. It is a figure which shows an example of arrangement | positioning of the mobile telephone and base station which concern on embodiment of this invention. It is a figure which shows an example of the optimal base station database which concerns on embodiment of this invention. It is a flowchart which shows the process which collects the positional information on the base station which concerns on embodiment of this invention. It is a flowchart which shows the process which collects the electric field strength information of the base station which concerns on embodiment of this invention. It is a flowchart which shows the judgment process of the distribution condition of the base station which concerns on embodiment of this invention. It is a flowchart which shows the GPS positioning process which concerns on embodiment of this invention.

  Hereinafter, an example of an embodiment of the present invention will be described. In the present embodiment, a mobile phone 1 will be described as an example of a mobile communication terminal.

FIG. 1 is an external perspective view of a mobile phone 1 (mobile communication terminal) according to the present embodiment.
The mobile phone 1 includes an operation unit side body 2 and a display unit side body 3. The operation unit side body 2 includes an operation unit 11 on the front surface unit 10 and a microphone 12 to which a voice uttered by a user of the mobile phone 1 during a call or when using a voice recognition application is input. The The operation unit 11 includes a function setting operation button 13 for activating various functions such as various setting functions, a telephone book function, and a mail function, and an input operation button 14 for inputting numbers of telephone numbers, mail characters, , And a determination operation button 15 for performing determination and scrolling in various operations.

  The display unit side body 3 includes a display unit 21 for displaying various types of information on the surface unit 20 and a receiver 22 for outputting the voice of the other party of the call.

  Further, the upper end portion of the operation unit side body 2 and the lower end portion of the display unit side body 3 are connected via a hinge mechanism 4. In addition, the mobile phone 1 relatively rotates the operation unit side body 2 and the display unit side body 3 which are connected via the hinge mechanism 4, so that the operation unit side body 2 and the display unit side body 3 are rotated. The body 3 can be in an open state (open state), or the operation unit side body 2 and the display unit side body 3 can be folded (folded state).

FIG. 2 is a block diagram showing functions of the mobile phone 1 according to the present embodiment.
The mobile phone 1 includes an operation unit 11, a display unit 21, a control unit 30, a communication unit 40, a main antenna 41, a GPS communication unit 50, a GPS antenna 51, a voice control unit 60, and a storage unit 70. And comprising.

  The control unit 30 controls the entire mobile phone 1, and performs predetermined control on the display unit 21, the communication unit 40, the GPS communication unit 50, the voice control unit 60, and the like, for example. In addition, the control unit 30 receives input from the operation unit 11 or the like and executes various processes. Then, the control unit 30 controls the storage unit 70 to read various programs and data, and write data when executing processing.

  Further, the control unit 30 includes a position information collection unit 31, a radio wave status collection unit 32, a base station selection unit 33, and a positioning unit 34. And control part 30 will output the acquired position information based on the predetermined processing accompanied by communication with a base station, if the positioning request of the present position is received from the user of cellular phone 1. In addition, the function of each part with which the control part 30 is provided is mentioned later.

  The communication unit 40 communicates with an external device (base station) in a predetermined frequency band (for example, 2 GHz band or 800 MHz band). Then, the communication unit 40 demodulates the signal received from the main antenna 41, supplies the processed signal to the control unit 30, modulates the signal supplied from the control unit 30, and outputs the signal from the main antenna 41. Send to external device.

  In particular, in this embodiment, the communication unit 40 is connected to a positioning server (PDE) via a network from a base station in addition to transmission / reception of signals related to voice calls, mails, etc., and receives satellite acquisition auxiliary information (positioning assistance). Data) and positioning results. Note that the positioning method executed by the control unit 30 differs depending on the satellite acquisition status, and the contents of the transmitted and received data also differ.

  The GPS communication unit 50 demodulates a radio signal of a predetermined frequency band from a GPS satellite received by the GPS antenna 51 and supplies the processed signal to the control unit 30. The functions of the GPS communication unit 50 and the GPS antenna 51 may be performed by the communication unit 40 and the main antenna 41, respectively.

  The sound control unit 60 performs predetermined sound processing on the signal supplied from the communication unit 40 under the control of the control unit 30, and outputs the processed signal to the receiver 22. The receiver 22 outputs the signal supplied from the audio control unit 60 to the outside. This signal may be output from a speaker (not shown) instead of the receiver 22 or together with the receiver 22.

  In addition, the voice control unit 60 processes the signal input from the microphone 12 according to the control of the control unit 30, and outputs the processed signal to the communication unit 40. The communication unit 40 performs predetermined processing on the signal supplied from the voice control unit 60 and outputs the processed signal from the main antenna 41.

  The storage unit 70 includes, for example, a working memory and is used for arithmetic processing by the control unit 30. In the present embodiment, a program for executing processing described later, various databases, and the like are stored. Note that the storage unit 70 may also serve as a removable external memory.

  Here, the types of GPS positioning in the mobile phone 1 will be described. There are an Assisted mode and a Based mode for positioning.

  In the Assisted mode, the mobile phone 1 receives satellite acquisition assistance information (Acquisition Assistance data) from the positioning server and searches for satellites. The search result is returned to the positioning server, and position calculation is performed by the positioning server. The mobile phone 1 receives the position calculation result and outputs it as a positioning result.

  Here, when the mobile phone 1 searches for satellites, if four or more satellites can be captured, GPS Fix mode positioning that can be expected to provide the highest accuracy is performed. Then, positioning is performed in the Hybrid Fix mode using the delay time of the radio wave from the base station, the AFLT Fix mode, and the Sector Fix mode using the position information of the base station.

  In addition, since the search for the satellite is terminated at a predetermined time by the timer, the acquisition may fail depending on the accuracy of the satellite acquisition auxiliary information. That is, when communicating with a distant base station, since the error of the satellite capture auxiliary information is large, the capture sensitivity of the satellite is deteriorated, and there is a case where the positioning by the high-accuracy GPS Fix mode cannot be performed.

  In the Based mode, the mobile phone 1 receives satellite information (Ephemeris data and Almanac data) from the base station. The mobile phone 1 searches for satellites after creating satellite capture auxiliary information based on the received satellite information. Furthermore, the mobile phone 1 performs its own position calculation without transmitting the search result to the positioning server. Therefore, in the Based mode, positioning cannot be performed when the mobile phone 1 cannot capture the satellite.

Next, each part of the control unit 30 will be described in detail.
The location information collection unit 31 receives a predetermined message (System Parameter Message or Mobile Station Registered Message) transmitted from this base station while searching for a communicable base station. Then, the location information collection unit 31 collects the location information of the base station included in the received message and records it in the positioning base station database.

FIG. 3 is a diagram showing an example of a positioning base station database according to the present embodiment.
In the positioning base station database, for base stations with which the mobile phone 1 can communicate, identifiers (BSID) of these base stations, a band class (BC) indicating a frequency band, a code (PN) for signal synchronization, a frequency ( FREQ), latitude (Lat), and longitude (Lon) are stored. In addition, the time when the message is received may be stored in the positioning base station database.

  The radio wave status collection unit 32 periodically receives neighboring base station information (Active Set and Neighbor Set) from the communicating base station, and receives an electric field as a received radio wave status of radio waves transmitted from these neighboring base stations. Measure strength. The radio wave status collection unit 32 collects the measured electric field strength and records it in a database (electric field strength information).

FIG. 4 is a diagram illustrating an example of the electric field strength information according to the present embodiment.
The field strength information stores, for each band class (BC), an Active Set or Neighbor Set classification, a PN, and an electric field strength (Strength).

  The base station selection unit 33 refers to the location information (positioning base station database) collected by the location information collection unit 31 and the radio wave situation (field strength information) collected by the radio wave situation collection unit 32, and the mobile phone 1 It is determined whether or not the distribution of base stations around is suitable for the positioning process. That is, the base station selection unit 33 determines that the base station arrangement is suitable for the positioning process when the first condition described later is satisfied, and the base station satisfying the second condition described later is included in this arrangement. Select a station. Then, the base station selection unit 33 records information on the selected base station (position information, radio wave status) in the optimum base station database.

  Here, one of the first conditions is that a predetermined number or more of base stations are arranged. That is, when the number of base stations is less than a predetermined number and sparsely arranged, the positioning auxiliary data received from the base station is low in reliability, so that the number of base stations is large. The number of base stations is preferably determined for each band class, and the base station selection unit 33 selects a band class in which a predetermined number or more of base stations are arranged.

  Also, one of the first conditions is that the distribution of the number of base stations among a plurality of communication systems is a preset distribution. Here, the communication system indicates, for example, a band class, and when the location information and the radio wave status are collected with a distribution different from the installation status of base stations (installation ratio for each band class), the communication environment Is not normal, and the positioning accuracy may be lowered, so that the distribution is normal.

  Furthermore, one of the first conditions is that the latitude and longitude information included in the position information is not biased beyond a predetermined value. If base stations are arranged in a specific direction, such as when they are distributed unevenly, if positioning is performed in Assisted mode using these base stations, the positioning results are likely to shift in a specific direction. There is concern about a decrease in accuracy. Therefore, it is a condition that the base stations are distributed evenly. Note that bias determination is also preferably performed for each band class, and the base station selection unit 33 selects a band class in which the base stations are arranged without bias.

  Also, one of the first conditions is that the radio wave condition is better than a predetermined value. That is, when the radio wave from the base station is a weak electric field, the reliability of the positioning auxiliary data is low because the base station is far away, and there is a concern that a communication error may occur. Therefore, it is a condition that the radio wave condition (electric field strength) is not less than a predetermined value. Note that the determination of the radio wave condition is also preferably performed for each band class, and the base station selection unit 33 selects a band class in which a strong electric field base station is arranged.

  The second condition is a case where, among the combinations of base stations that can be selected from the arrangement satisfying the first condition, the positional information is less biased than other combinations. That is, when the base station selection unit 33 determines that the arrangement of base stations satisfies the first condition and is an environment suitable for positioning, the base station selection unit 33 selects a predetermined number of base stations with less bias from these base stations. Select and record as the optimal base station to receive positioning auxiliary data.

FIG. 5 is a diagram showing an example of the arrangement of the mobile phone 1 and base stations according to the present embodiment.
In this example, a base station of band class (BC) “3” exists in a strong electric field without bias. On the other hand, the base station of band class “6” has only one weak electric field. Therefore, the base station selection unit 33 selects a base station of band class “3” as the optimum base station.

FIG. 6 is a diagram showing an example of the optimum base station database according to the present embodiment.
The optimum base station database includes a classification of the selected band class (BC), an identifier (BSID) of the optimum base station, a signal synchronization code (PN), a frequency (FREQ), a latitude (Lat), and a longitude (Lon ) And electric field strength (Strength) are stored.

  The positioning unit 34 notifies the PN (identification data) of the optimum base station selected by the base station selection unit 33 to the positioning server, and uses the positioning auxiliary data received from the positioning server via the optimum base station. The GPS positioning process is executed.

  In addition, when the location of the base station does not satisfy the first condition, the positioning unit 34 changes a parameter (search window size) relating to a GPS satellite acquisition success probability in the GPS positioning process. Thereby, even if it is positioning auxiliary data with a low precision, since it becomes easy to succeed in acquisition of a GPS satellite, an improvement in positioning precision can be expected.

  Further, the positioning unit 34 also changes a parameter (search window size) related to a GPS satellite acquisition success probability even when positioning auxiliary data is received from a relay station (repeater) in the GPS positioning process. The same applies to a femto base station as well as a relay station (repeater).

  In the GPS positioning process, the positioning unit 34 determines whether the number of captured GPS satellites is less than a predetermined value (for example, less than 4), or an area in which the positioning result is specified by the position information of the base station (MAR: Maximum). If it is outside the range of (Antenna Range), it is determined that the positioning accuracy is low, the positioning mode is changed, and the GPS positioning process is executed again. That is, the positioning unit 34 changes to the Assisted mode when positioning is performed in the Based mode, and changes to the Based mode and performs positioning again when positioning is performed in the Assisted mode. Thereby, the positioning part 34 can improve the reliability of positioning accuracy.

  FIG. 7 is a flowchart showing a process of collecting location information of the base station according to this embodiment. This process is periodically repeated until the power of the mobile phone 1 is turned off or the radio wave off mode (communication function stop) is set.

  In step S1, the location information collection unit 31 determines whether a predetermined message transmitted from the base station has been received. When this determination is YES, the control unit 30 moves the predetermined to step S2, and when the determination is NO, the control unit 30 moves the process to step S5.

  In step S2, the position information collection unit 31 records the position information acquired from the message received in step S1 in the positioning base station database.

  In step S3, the position information collection unit 31 starts measuring a database update timer that defines the longest update interval of the positioning base station database. This timer value is preferably set according to the communication environment. For example, if the radio wave is stable, the timer value may be set large.

  In step S <b> 4, the location information collection unit 31 sets the intermittent reception process to be turned on, for example, to receive messages at intervals of 5.12 seconds in order to reduce power consumption of the mobile phone 1.

  In step S5, the position information collection unit 31 determines whether or not the database update timer started in step S3 has expired. If this determination is YES, control unit 30 moves the process to step S2. In this case, the position information collection unit 31 considers that there is no change in the position information, and updates only the time information in the positioning base station database. On the other hand, if the determination is NO, the control unit 30 moves the process to step S6.

  In step S6, the location information collection unit 31 changes the received band class in order to search for base stations in other frequency bands.

  In step S7, the position information collecting unit 31 turns off the intermittent reception process. As a result, the location information collection unit 31 immediately tries to receive a message in step S1, and thus it is easy to acquire location information of a new base station.

  This process may be executed only during standby in order to avoid a call or data communication stop associated with a change in band class.

  FIG. 8 is a flowchart showing a process of collecting the electric field strength information of the base station according to this embodiment. This process is repeated periodically until the power of the mobile phone 1 is turned off or the radio wave off mode is set.

  In step S11, the radio wave condition collection unit 32 receives the Active Set and Neighbor Set information from the communicating base station.

  In step S12, the radio wave condition collection unit 32 measures the electric field strength of the radio wave received from the base station included in the Active Set and the Neighbor Set received in step S11, and records the electric field strength information.

  In step S13, the radio wave condition collection unit 32 starts measuring the database update timer that defines the update interval of the electric field strength information. This timer value is preferably set according to the communication environment. For example, if the radio wave is stable, the timer value may be set large.

  In step S14, the radio wave status collection unit 32 determines whether or not the database update timer has expired. The control unit 30 waits until this determination becomes YES, and when it becomes YES, the loop is continued.

  FIG. 9 is a flowchart showing a base station distribution status determination process according to the present embodiment. This process is periodically executed when a request for GPS positioning is received or at a predetermined timing.

  In step S21, the base station selection unit 33 reads the positioning base station database and acquires the position information of the base station.

  In step S22, the base station selection unit 33 reads the electric field strength information and acquires the radio wave condition of the base station.

  In step S23, the base station selection unit 33 determines whether or not the number of base stations of Active Set and Neighbor Set acquired in step S22 is equal to or greater than a predetermined value. If this determination is YES, control unit 30 moves the process to step S24, and if the determination is NO, the control unit 30 moves the process to step S29.

  In step S24, the base station selection unit 33 determines whether or not the distribution of the number of base stations between the band classes is appropriate. If this determination is YES, control unit 30 moves the process to step S25, and if the determination is NO, the control unit 30 moves the process to step S29.

  In step S25, the base station selection unit 33 determines whether there is no bias in the latitude and longitude of the base station based on the position information acquired in step S21. If this determination is YES, control unit 30 moves the process to step S26, and if the determination is NO, the control unit 30 moves the process to step S29.

  In step S26, the base station selection unit 33 determines whether the electric field strength is not a weak electric field based on the radio wave situation acquired in step S22. When this determination is YES, the control unit 30 moves the process to step S27, and when the determination is NO, the control unit 30 moves the process to step S29.

  In step S27, the base station selection unit 33 determines that the base station distribution around the mobile phone 1 is suitable for the positioning process, and turns on the optimum base station arrangement flag.

  In step S28, the base station selection unit 33 selects the optimum base station that satisfies the second condition from the base stations that are determined to satisfy the first condition by the determinations in steps S23 to S26, and enters the optimum base station database Write.

  In step S29, the base station selection unit 33 determines that the base station distribution around the mobile phone 1 is not suitable for the positioning process, and turns off the optimum base station arrangement flag.

  FIG. 10 is a flowchart showing the GPS positioning process according to this embodiment. This process is executed following the above-described process for determining the distribution status of base stations when a request for GPS positioning is received. In addition, when the base station distribution status determination process is periodically executed, this process may be executed immediately.

  In step S31, the positioning unit 34 determines whether the communicating base station is not a repeater. If this determination is YES, control unit 30 moves the process to step S32, and if the determination is NO, the control unit 30 moves the process to step S35.

  In step S <b> 32, the positioning unit 34 determines whether or not the optimal base station arrangement flag is turned on in the base station distribution state determination process. If this determination is YES, the control unit 30 moves the process to step S33, and if the determination is NO, the control unit 30 moves the process to step S35.

  In step S33, the positioning unit 34 reads the optimum base station database and acquires information on the optimum base station suitable for positioning.

  In step S34, the positioning unit 34 notifies the PN of the optimum base station acquired in step S33 to the positioning server, and then performs GPS positioning based on the auxiliary data.

  In step S35, the positioning unit 34 performs GPS positioning after changing the positioning parameters (increasing the search window size) because the reliability of the auxiliary data received from the base station is low.

  In step S36, the positioning unit 34 determines whether the number of captured GPS satellites is a predetermined number (four) or more and the positioning result is within the coverage (MAR) of the base station. If this determination is YES, control unit 30 ends the process, and if the determination is NO, the control unit 30 moves the process to step S37.

  In step S37, the positioning unit 34 changes the positioning mode from the Based mode to the Assisted mode or from the Assisted mode to the Based mode for re-positioning because the reliability of the positioning result is low.

  In step S38, the positioning unit 34 performs GPS positioning again using the positioning mode changed in step S37.

  As described above, according to the present embodiment, in the case of the distribution of base stations capable of performing high-precision GPS positioning (when the first condition is satisfied), the optimum base station used for positioning is selected and the positioning accuracy is determined. Can be improved. If the reliability of the auxiliary data from the base station is low, the positioning accuracy can be improved by changing the positioning parameters to improve the GPS satellite capture probability.

  Further, according to the present embodiment, when the number of GPS satellites captured is less than the predetermined number, or the positioning result is outside the coverage range (MAR) of the base station, the positioning result is changed by changing the positioning mode. Can improve the reliability.

  As mentioned above, although preferred embodiment was described, this invention can be implemented with a various form, without being limited to embodiment mentioned above. In addition, the effects described in the above-described embodiments are merely a list of the most preferable effects resulting from the present invention, and the effects according to the present invention are not limited to those described above.

  In the above-described embodiment, the electric field strength is collected as the radio wave condition, but is not limited thereto. For example, signal intensity, interference wave ratio, and the like may be collected as radio wave conditions.

  In the above-described embodiment, the mobile phone 1 is described as the mobile communication terminal. However, the mobile communication terminal is not limited to this, and the present invention is not limited to the PHS (registered trademark; Personal Handyphone System), PDA (Personal. The present invention can be applied to various portable communication terminals such as a digital assistant, a game machine, a navigation device, and a personal computer.

  Furthermore, in the above-described embodiment, the mobile phone 1 is a type that can be folded by the hinge mechanism 4, but is not limited thereto. The mobile phone 1 is not such a foldable type, but a slide type in which one case is slid in one direction from a state where the operation unit side case 2 and the display unit side case 3 are overlapped, A rotary type (turn type) in which one casing is rotated around the axis line along the overlapping direction of the operation unit side body 2 and the display unit side body 3 or the operation unit side body 2 and the display. The part side housing 3 may be a type (straight type) that is arranged in one housing and does not have a connecting portion. The mobile phone 1 may be a so-called biaxial hinge type that can be opened and closed and rotated.

1 Mobile phone (mobile communication terminal)
DESCRIPTION OF SYMBOLS 11 Operation part 21 Display part 30 Control part 31 Location information collection part 32 Radio wave condition collection part 33 Base station selection part 34 Positioning part 40 Communication part 41 Main antenna 50 GPS communication part 51 GPS antenna 60 Voice control part 70 Storage part

Claims (8)

A mobile communication terminal that supports multiple frequency bands ,
A location information collection unit that collects location information of the base station transmitted from the base station;
A radio wave condition collection unit that measures and collects radio wave conditions received from the base station;
Among previous SL plurality of frequency bands, the number of base stations is a frequency band not less than the predetermined number, Note and frequency to select the first condition is satisfied frequency band for selecting a frequency band suitable for positioning A band selector,
The identification data of the base station satisfying the second condition among the base stations included in the frequency band selected by the frequency band selection unit is notified to the positioning server, and is received from the positioning server via the base station. A mobile communication terminal comprising: a positioning unit that executes GPS positioning processing using auxiliary positioning data. The location information includes at least latitude and longitude information of each base station,
The first condition is satisfied frequency band, the mobile communication terminal according to claim 1 which is a frequency band is not more than a predetermined deviation in latitude and longitude information of each base station. The first condition is satisfied frequency band, the mobile communication terminal according to claim 1 or claim 2 wave condition from each base station is a good frequency band higher than a predetermined. The positioning unit, when performing the GPS positioning process using a frequency band the non-first condition is satisfied frequency band, any one of the preceding claims 1 to change the parameters related to acquisition success probability of GPS satellites The mobile communication terminal described in 1. The positioning unit according to any one of claims 1 to 4 , wherein, in the GPS positioning process, when the positioning auxiliary data is received from a relay station, the positioning unit changes a parameter relating to a GPS satellite acquisition success probability. Mobile communication terminal. The positioning unit is configured to perform the GPS positioning in a positioning mode in which a positioning calculation is performed based on a GPS signal, or an Assisted mode in which a positioning calculation is performed by the positioning server using a GPS signal or position information of a base station. The mobile communication terminal according to any one of claims 1 to 5 , wherein the process is executed. If the number of GPS satellites captured in the GPS positioning process is less than a predetermined value, or the positioning result is outside the range of the area specified by the position information of the base station involved in the positioning calculation, the positioning unit The mobile communication terminal according to claim 6 , wherein the GPS positioning process is executed again after changing the mode. The mobile communication terminal according to any one of claims 1 to 7 , wherein the frequency band is a band class.

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