JP2015109580A - Mobile terminal, method for transmitting position information, and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To optimize timing for transmitting position information.SOLUTION: A mobile terminal measures a migration length of the mobile terminal and elapsed time from a time point at which last transmission of position information is performed. The mobile terminal determines whether or not a measured time length is equal to or longer than a reference period, every time migration by reference length is measured; and transmits position information from a communication unit to a server device, in the case that the measured time length is equal to or longer than the reference period. The mobile terminal also changes the reference length or reference period, depending on migration speed of the mobile terminal.

Description

  The present invention relates to a technique for transmitting position information.

  In recent years, the utility value of moving body position information has increased. Patent Documents 1 to 3 describe techniques for transmitting position information representing the current position of a moving body at a predetermined cycle. Further, Patent Document 1 describes that when the moving speed of the moving body becomes equal to or higher than the set speed, the transmission interval of the position information is shortened. Patent Document 2 describes that position information is not transmitted when the vehicle is in a stopped state. Patent Document 3 describes that when the current vehicle speed is a low speed that is less than the reference vehicle speed, the position information is transmitted once.

JP-A-10-212426 JP 2002-74591 A JP 2004-220262 A

In the techniques described in Patent Documents 1 to 3, since the timing for transmitting the position information is determined regardless of the moving distance of the moving object, for example, when the moving object is moving at high speed, the position information represents The interval between positions becomes large, and the position of the moving body cannot be specified with high accuracy.
In addition, in order to accurately identify the position of the mobile body, it is preferable that the transmission interval of the position information is small, but the moving speed of the mobile terminal, the density of base stations around the mobile terminal, and the proximity of the mobile terminal Depending on the number of other mobile terminals, there may be a problem if the transmission interval of the position information is reduced. For example, when the density of base stations around the mobile terminal is low, if the location information is transmitted frequently, the location information is transmitted to one base station many times, and the load on the line of this base station increases. End up. In addition, when there are many other mobile terminals near the mobile terminals, if these mobile terminals frequently transmit location information, the load on the line of the base station that accommodates these mobile terminals increases. . On the other hand, when a mobile terminal performs communication using a high-speed communication method, it is better to reduce the transmission interval of position information because it does not matter much if position information is transmitted frequently.
An object of the present invention is to optimize the timing for transmitting position information.

  The present invention includes a communication unit that communicates with a server device, a measurement unit that measures a moving distance of the terminal, a first acquisition unit that acquires position information indicating the position of the terminal, and a transmission time point of the position information A time measuring unit for measuring the time elapsed since the time, and each time measuring the measurement unit moved a reference distance, it is determined whether the length of time measured in the time measuring unit is equal to or longer than a reference period, If the length is equal to or longer than the reference period, a transmission control unit that transmits the position information acquired by the first acquisition unit from the communication unit to the server device, a moving speed of the own terminal, and the own terminal are included. The density of base stations installed in the first range, the number of other mobile terminals existing in the second range including its own terminal, and the communication method used by the communication unit in communication with the server device At least one according to said reference distance and previous It provides a mobile terminal and a changing unit that changes at least one of the reference period.

The mobile terminal includes a second acquisition unit that acquires the movement speed, and the change unit includes the reference when the movement speed acquired by the second acquisition unit is smaller than a first threshold value. At least one of the distance and the reference period may be increased.
The mobile terminal includes a second acquisition unit that acquires the density, and the change unit, when the density acquired by the second acquisition unit is smaller than a second threshold, the reference distance or At least one of the reference periods may be increased.
The mobile terminal includes a second acquisition unit that acquires the number of the other mobile terminals, and the change unit is configured such that the number of the other mobile terminals acquired by the second acquisition unit is a third threshold value. If larger, at least one of the reference distance or the reference period may be increased.
The communication unit corresponds to both a first communication method and a second communication method having a higher communication speed than the first communication method, and the changing unit is configured to communicate the server with the server device. However, when the second communication method is used, the third threshold value may be increased.
The communication unit corresponds to both a first communication method and a second communication method having a higher communication speed than the first communication method, and the changing unit is configured to communicate the server with the server device. When using the second communication method, at least one of the reference distance and the reference period may be reduced.

  The present invention includes a step of measuring a moving distance of the own terminal, a step of acquiring position information representing the position of the own terminal, a step of measuring a time elapsed from a transmission time of the position information, and a reference distance moved Each time is measured, it is determined whether or not the length of the measured time is equal to or longer than a reference period, and when the length is equal to or longer than the reference period, the acquired position information is transmitted from the communication unit to the server device. Transmitting to the mobile terminal, the moving speed of the own terminal, the density of base stations installed in the first range including the own terminal, the number of other mobile terminals existing in the second range including the own terminal, and A method of transmitting position information, comprising: changing at least one of the reference distance and the reference period according to at least one of communication methods used by the communication unit in communication with the server device. .

  The present invention includes a step of measuring a moving distance of the terminal itself, a step of acquiring position information representing the position of the terminal, a step of measuring a time elapsed since the transmission of the position information, and a reference distance. Each time it is measured that it has moved, it is determined whether or not the length of the measured time is equal to or longer than a reference period. If the length is equal to or longer than the reference period, the acquired position information is transmitted to the communication unit. To the server device, the moving speed of the own terminal, the density of the base stations installed in the first range including the own terminal, and the other mobile terminals existing in the second range including the own terminal Changing at least one of the reference distance and the reference period according to the number and at least one of communication methods used by the communication unit in communication with the server device. To provide a program.

  According to the present invention, the timing for transmitting position information can be optimized.

It is a figure which shows the structure of a communication system. It is a figure which shows the hardware constitutions of a mobile terminal. It is a figure which shows the function structure of a mobile terminal. It is a flowchart which shows the transmission process of a positional information. It is a figure which shows the specific example of the transmission process of a positional information. It is a flowchart which shows a change process. It is a figure which shows an example of the change of a reference | standard period. It is a figure which shows the specific example of the transmission process of the positional information using the reference | standard period after a change. It is a figure which shows an example of map information. It is a figure which shows the function structure of the mobile terminal which concerns on 2nd Embodiment. It is a flowchart which shows the change process which concerns on 2nd Embodiment. It is a figure which shows an example of the change of the reference period which concerns on 2nd Embodiment. It is a figure explaining the function of the server apparatus which concerns on 3rd Embodiment. It is a flowchart which shows the change process which concerns on 3rd Embodiment. It is a figure which shows an example of the change of the reference period which concerns on 3rd Embodiment. It is a flowchart which shows the change process which concerns on 4th Embodiment. It is a figure which shows an example of the change of the reference period which concerns on 4th Embodiment.

1. First Embodiment Hereinafter, a first embodiment of the present invention will be described with reference to the drawings.

1-1. Configuration (1) Configuration of Communication System 1 FIG. 1 is a diagram illustrating a configuration of the communication system 1. The communication system 1 includes a server device 10, a base station 20, and a mobile terminal 30. Server device 10 and base station 20 are connected via network 2. The mobile terminal 30 is connected to the base station 20 by radio.

  The mobile terminal 30 is, for example, a mobile phone or a smartphone. The mobile terminal 30 moves as the user who has the mobile terminal 30 moves. For example, when the user gets on the vehicle 3 with the mobile terminal 30, the mobile terminal 30 moves as the vehicle 3 moves. The mobile terminal 30 transmits location information indicating the current location to the server device 10. The base station 20 communicates with the mobile terminal 30 in the cell. The location information transmitted from the mobile terminal 30 is transmitted to the server device 10 via the base station 20. The server device 10 specifies the position of the mobile terminal 30 based on the position information received from the mobile terminal 30. The position specified in this way is used for providing various services by the server device 10, for example.

(2) Configuration of Mobile Terminal 30 FIG. 2 is a diagram illustrating a hardware configuration of the mobile terminal 30. The mobile terminal 30 includes a processor 31, a main memory 32, a communication unit 33, an input unit 34, a display unit 35, a storage unit 36, a positioning unit 37, and an acceleration sensor 38. The mobile terminal 30 may include a configuration for performing a voice call in addition to these configurations.

  The processor 31 is, for example, a CPU (Central Processing Unit). The processor 31 controls each unit of the mobile terminal 30 by executing a program stored in the storage unit 36. The main memory 32 is, for example, a RAM (Random Access Memory). The main memory 32 temporarily stores programs and data. The main memory 32 is used as a work area when the processor 31 executes a program.

  The communication unit 33 is an interface that is wirelessly connected to the base station 20. The communication unit 33 performs communication via the base station 20. The communication unit 33 corresponds to both the first communication method and the second communication method having a higher communication speed than the first communication method. The first communication method is, for example, 3G (3rd Generation). The second communication method is, for example, LTE (Long Term Evolution).

  The input unit 34 is, for example, a touch panel and a key. The input unit 34 inputs information corresponding to a user operation to the processor 31. The display unit 35 is, for example, a liquid crystal display. The display unit 35 displays various information. The storage unit 36 is, for example, a flash memory. The storage unit 36 stores various programs and data. The positioning unit 37 is, for example, a GPS (Global Positioning System) receiver. The positioning unit 37 measures the current position of the mobile terminal 30. The acceleration sensor 38 detects the acceleration of the mobile terminal 30.

  FIG. 3 is a diagram illustrating a functional configuration of the mobile terminal 30. The mobile terminal 30 includes a first acquisition unit 310, a measurement unit 311, a timing unit 312, a transmission control unit 313, a second acquisition unit 314, and a change unit 315 by the processor 31 executing one or more programs. Function as.

  The first acquisition unit 310 acquires position information indicating the position of the mobile terminal 30. The measuring unit 311 measures the moving distance of the mobile terminal 30. The timer unit 312 measures the time that has elapsed since the position information was transmitted. Each time the transmission control unit 313 measures that the measurement unit 311 has moved the reference distance, the transmission control unit 313 determines whether the length of time measured by the time measuring unit 312 is equal to or longer than the reference period. In the case described above, the position information acquired by the first acquisition unit 310 is transmitted from the communication unit 33 to the server device 10. The second acquisition unit 314 acquires the moving speed of the mobile terminal 30. The changing unit 315 changes the reference distance or the reference period according to the moving speed acquired by the second acquiring unit 314.

1-2. Operation The mobile terminal 30 performs a transmission process of transmitting position information representing the current position to the server device 10 based on the moving distance of the mobile terminal 30 and the time elapsed since the previous transmission of the position information. Further, the mobile terminal 30 performs a change process for changing the reference distance or the reference period according to the moving speed of the mobile terminal 30. Thus, by changing the reference distance or the reference period, the transmission interval of the position information is changed. Each process will be described below.

(1) Position Information Transmission Processing FIG. 4 is a flowchart showing position information transmission processing. This transmission process is started when the mobile terminal 30 is powered on, for example. When the mobile terminal 30 is powered on, the positioning unit 37 measures the current position at predetermined time intervals. The first acquisition unit 310 acquires position information representing the current position measured by the positioning unit 37.

  In step S <b> 101, the measurement unit 311 starts measuring the movement distance of the mobile terminal 30 based on the position measured by the positioning unit 37. In addition, the timer unit 312 starts measuring time.

  In step S102, the transmission control unit 313 determines whether or not the moving distance measured by the measuring unit 311 has reached the reference distance. When the movement distance has not reached the reference distance (step S102: NO), the transmission control unit 313 repeats the determination in step S102 until the movement distance reaches the reference distance. When the moving distance reaches the reference distance (step S102: YES), the transmission process proceeds to step S103.

  In step S103, the transmission control unit 313 determines whether or not the length of time measured by the time measuring unit 312 is equal to or longer than the reference period. If the measured time length is equal to or longer than the reference period (step S103: YES), the transmission process proceeds to step S104.

  In step S <b> 104, the transmission control unit 313 transmits the position information last acquired by the first acquisition unit 310 from the communication unit 33 to the server device 10.

  In step S <b> 105, the transmission control unit 313 resets the movement distance measured by the measurement unit 311 and the time measured by the time measuring unit 312. As a result, the travel distance measured by the measurement unit 311 and the time measured by the time measuring unit 312 both return to zero. After the movement distance and time are reset, the transmission process returns to step S101 again.

  On the other hand, in step S103, when the measured length of time is smaller than the reference period (step S103: NO), the transmission process proceeds to step S106.

  In step S <b> 106, the transmission control unit 313 resets only the movement distance measured by the measurement unit 311. After the movement distance is reset, the transmission process returns to step S101 again. In step S106, since the time measured by the time measuring unit 312 is not reset, the time measured by the time measuring unit 312 does not return to 0 and the time measurement is continued.

  FIG. 5 is a diagram illustrating a specific example of position information transmission processing. In this example, the reference distance is set to 100 m in advance, and the reference period is set to 10 seconds in advance. For example, when position information is transmitted at time t0, measurement of movement distance and measurement of time are started at time t0. When the moving distance reaches 100 m at time t1, it is determined whether or not the length of time T1 from time t0 to time t1 is 10 seconds or more. This time T1 is an example of time that has elapsed since the transmission of position information. When the length of time T1 is 10 seconds or more, the position information is transmitted at time t1.

  On the other hand, when the time T1 is smaller than 10 seconds, the position information is not transmitted at the time t1. In this case, after only the movement distance is reset, the measurement of the movement distance and the measurement of time are started again at time t1. When the moving distance reaches 100 m at time t2, it is determined whether or not the length of time T2 from time t0 to time t2 is 10 seconds or more. This time T2 is an example of time that has elapsed since the transmission of the position information. When the length of time T2 is 10 seconds or more, the position information is transmitted at time t2.

(2) Change Process FIG. 6 is a flowchart showing the change process. This change process may be performed before the position information transmission process shown in FIG. 4 or may be performed in parallel with this transmission process. Alternatively, the change process may be performed at a predetermined timing regardless of the position information transmission process.

  In step S <b> 201, the measurement unit 311 measures the moving speed of the mobile terminal 30 based on the acceleration detected by the acceleration sensor 38. The second acquisition unit 314 acquires the moving speed measured by the measurement unit 311.

  In step S202, the changing unit 315 determines whether or not the moving speed acquired by the second acquiring unit 314 is smaller than the first threshold value. When the moving speed is equal to or higher than the first threshold (step S202: NO), the changing process is terminated by skipping the process of step S203. On the other hand, when the moving speed is smaller than the first threshold (step S202: YES), the change process proceeds to step S203.

  In step S203, the changing unit 315 changes the reference distance or the reference period so that the reference distance or the reference period increases. FIG. 7 is a diagram illustrating an example of changing the reference period. In this example, the reference period is set to 10 seconds in advance. For example, when the moving speed of the mobile terminal 30 is smaller than S2, the reference period is changed from 10 seconds to 30 seconds.

  FIG. 8 is a diagram illustrating a specific example of transmission processing using the changed reference period. For example, when the reference period is changed to 30 seconds, when the moving distance reaches 100 m at time t11, it is determined whether or not the length of time T11 from time t0 to time t11 is 30 seconds or more. The If the length of time T11 is less than 30 seconds, the position information is not transmitted at time t11. In this case, after only the movement distance is reset, the measurement of the movement distance and the measurement of time are started again. When the movement distance reaches 100 m again at time t12 and the length of time T12 from time t0 to time t12 is less than 30 seconds, the same processing as described above is performed. When the moving distance reaches 100 m again at time t13 and the length of time T13 from time t0 to time t3 is 30 seconds or more, the position information is transmitted at time t13. In this case, the position information transmission interval is larger than that in the case where the reference period is 10 seconds.

  In the first embodiment, every time it is measured that the mobile terminal 30 has moved the reference distance, it is determined whether or not the length of time that has elapsed since the previous transmission of the position information is greater than or equal to the reference period. When the length is equal to or longer than the reference period, the location information is transmitted from the mobile terminal 30. As described above, by determining the timing for transmitting the position information based on both the moving distance of the mobile terminal 30 and the time elapsed since the previous transmission of the position information, the interval between the positions represented by the position information is increased. It can be suppressed. Thereby, the position of the mobile terminal 30 can be specified with high accuracy.

  In the first embodiment, when the moving speed of the mobile terminal 30 is low, the reference distance or the reference period is increased, and the transmission interval of the position information is increased. If the position information is frequently transmitted when the moving speed of the mobile terminal 30 is low, the same position information is transmitted from the mobile terminal 30 to one base station 20 many times. The load will increase. Moreover, the battery of the mobile terminal 30 will be consumed wastefully by transmission of such positional information. According to the first embodiment, since the timing for transmitting the position information is optimized according to the moving speed of the mobile terminal 30, such a problem can be suppressed.

2. Second Embodiment Hereinafter, a second embodiment of the present invention will be described with reference to the drawings. In the first embodiment, the reference distance or the reference period is changed according to the moving speed of the mobile terminal 30, but in the second embodiment, the reference distance is changed according to the density of the base stations 20 around the mobile terminal 30. Or change the base period. In the following description, differences from the first embodiment will be mainly described.

  The configuration of the communication system 1 and the configuration of the mobile terminal 30 are basically the same as those in the first embodiment. However, in the second embodiment, the map information 361 is stored in the storage unit 36.

  FIG. 9 is a diagram illustrating an example of the map information 361. The map information 361 indicates the installation position of the base station 20. In FIG. 9, the installation position of the base station 20 is indicated by dots.

  FIG. 10 is a diagram illustrating a functional configuration of the mobile terminal 30 according to the second embodiment. The mobile terminal 30 has a first acquisition unit 310, a measurement unit 311, a time measuring unit 312, a transmission control unit 313, a second acquisition unit 314, and the like shown in FIG. In addition to the change unit 315, the calculation unit 316 functions.

  The calculation unit 316 calculates the density of the base stations 20 installed in the first range including the terminal itself. The second acquisition unit 314 acquires the density calculated by the calculation unit 316. The changing unit 315 changes the reference distance or the reference period according to the density acquired by the second acquisition unit 314.

  FIG. 11 is a flowchart showing change processing according to the second embodiment. Similar to the first embodiment, this change process may be performed before the position information transmission process shown in FIG. 4 or may be performed in parallel with this transmission process. Alternatively, the change process may be performed at a predetermined timing regardless of the position information transmission process.

  In step S <b> 301, the calculation unit 316 calculates the density of the base stations 20 installed within a predetermined first range including its own terminal, based on the map information 361 stored in the storage unit 36. This first range is a range having a predetermined size centered on the current position measured by the positioning unit 37, for example. The size of the first range is determined in advance so as to include a plurality of base stations 20, for example. Specifically, the calculation unit 316 first calculates the number of base stations 20 installed in the first range based on the installation positions of the base stations 20 indicated by the map information 361. Subsequently, the calculation unit 316 calculates the density of the base stations 20 using the calculated number of base stations 20 and the area of the first range. The second acquisition unit 314 acquires the density calculated by the calculation unit 316.

  In step S302, the changing unit 315 determines whether the density acquired by the second acquiring unit 314 is smaller than the second threshold value. When this density is smaller than the second threshold (step S302: NO), the change process is terminated by skipping the process of step S303. On the other hand, when the density is smaller than the second threshold (step S302: YES), the change process proceeds to step S303.

  In step S303, the changing unit 315 changes the reference distance or the reference period so that the reference distance or the reference period increases. FIG. 12 is a diagram illustrating an example of changing the reference period according to the second embodiment. In this example, the reference period is set to 10 seconds in advance. For example, when the density of the base station 20 is smaller than D2, the reference period is changed from 10 seconds to 30 seconds. In this case, the interval at which the position information is transmitted is larger than when the reference period is 10 seconds.

  In the second embodiment, when the density of the base stations 20 around the mobile terminal 30 is small, the reference distance or the reference period is increased, and the transmission interval of the position information is increased. If the location information is frequently transmitted when the density of the base stations 20 around the mobile terminal 30 is small, the location information is transmitted from the mobile terminal 30 to one base station 20 many times. The load on the line will increase. According to the second embodiment, the timing for transmitting the position information is optimized according to the density of the base stations 20 around the mobile terminal 30, so that such a problem can be suppressed.

3. Third Embodiment Hereinafter, a third embodiment of the present invention will be described with reference to the drawings. In the first embodiment, the reference distance or the reference period is changed according to the moving speed of the mobile terminal 30, but in the third embodiment, according to the number of other mobile terminals 30 existing near the mobile terminal 30. Change the reference distance or reference period. In the following description, differences from the first embodiment will be mainly described.

  The configuration of the communication system 1 is basically the same as that of the first embodiment. However, the server device 10 has a function of calculating the number of other mobile terminals 30 existing within a predetermined second range including the mobile terminal 30 and transmitting the calculated number to the mobile terminal 30.

  FIG. 13 is a diagram illustrating functions of the server device 10 according to the third embodiment. The server device 10 first receives position information from each mobile terminal 30. Subsequently, the server device 10 calculates the number of other mobile terminals 30 existing within a predetermined second range 4 from the mobile terminal 30 based on the received position information. The second range 4 is a range having a predetermined size centered on the mobile terminal 30, for example. The size of the second range 4 is predetermined based on the size of the cell of one base station 20, for example. Then, the server device 10 transmits the calculated number of other mobile terminals 30 to the mobile terminal 30.

  In the example illustrated in FIG. 13, there are six mobile terminals 30 </ b> B to 30 </ b> G in the second range 4 centering on the mobile terminal 30 </ b> A. Therefore, the server device 10 calculates “6” as the number of other mobile terminals 30 and transmits the calculated number to the mobile terminal 30A.

  The configuration of the mobile terminal 30 is basically the same as in the first embodiment. However, the second acquisition unit 314 acquires the number of other mobile terminals 30 existing in the second range including the own terminal. The changing unit 315 changes the reference distance or the reference period according to the number acquired by the second acquisition unit 314.

  FIG. 14 is a flowchart showing change processing according to the third embodiment. Similar to the first embodiment, this change process may be performed before the position information transmission process shown in FIG. 4 or may be performed in parallel with this transmission process. Alternatively, the change process may be performed at a predetermined timing regardless of the position information transmission process.

  In step S <b> 401, the second acquisition unit 314 acquires the number of other mobile terminals 30 from the server device 10. Specifically, the second acquisition unit 314 sends a request for acquiring the number of other mobile terminals 30 existing in the second range centered on the current position of the mobile terminal 30 from the communication unit 33 to the server. Transmit to the device 10. This request includes position information indicating the current position measured by the positioning unit 37. In response to the request received from the mobile terminal 30, the server device 10 calculates the number of other mobile terminals 30 existing in the second range centered on the current position of the mobile terminal 30, The number of terminals 30 is transmitted to the mobile terminal 30. The second acquisition unit 314 acquires the number of other mobile terminals 30 received from the server device 10 by the communication unit 33.

  In step S402, the changing unit 315 determines whether the number of other mobile terminals 30 acquired by the second acquiring unit 314 is greater than a third threshold value. When the number of the other mobile terminals 30 is equal to or smaller than the third threshold (step S402: NO), the change process is terminated by skipping the process of step S403. On the other hand, when the number of other mobile terminals 30 is larger than the third threshold (step S402: YES), the change process proceeds to step S403.

  In step S403, the changing unit 315 changes the reference distance or the reference period so that the reference distance or the reference period increases. FIG. 15 is a diagram illustrating an example of changing the reference period according to the third embodiment. In this example, the reference period is set to 10 seconds in advance. For example, when the number of other mobile terminals 30 is larger than N2, the reference period is changed from 10 seconds to 30 seconds. In this case, the interval at which the position information is transmitted is larger than when the reference period is 10 seconds.

  In the third embodiment, when the number of other mobile terminals 30 existing near the mobile terminal 30 is large, the reference distance or the reference period is increased, and the transmission interval of the position information is increased. If the location information is frequently transmitted when the number of other mobile terminals 30 existing near the mobile terminal 30 is large, a large amount of location information is transmitted from a large number of mobile terminals 30 to one base station 20, The load on the line of the base station 20 increases. According to the third embodiment, since the timing for transmitting the position information is optimized according to the number of other mobile terminals 30 existing near the mobile terminal 30, such a problem can be suppressed.

4). Fourth Embodiment Hereinafter, a fourth embodiment of the present invention will be described with reference to the drawings. In the first embodiment, the reference distance or the reference period is changed according to the moving speed of the mobile terminal 30, but in the fourth embodiment, according to the communication method used by the communication unit 33 in communication with the server device 10. Change the reference distance or reference period. In the following description, differences from the first embodiment will be mainly described.

  The configuration of the communication system 1 and the configuration of the mobile terminal 30 are basically the same as those in the first embodiment. However, the changing unit 315 changes the reference distance or the reference period according to the communication method used by the communication unit 33 in communication with the server device 10.

  FIG. 16 is a flowchart showing change processing according to the fourth embodiment. Similar to the first embodiment, this change process may be performed before the position information transmission process shown in FIG. 4 or may be performed in parallel with this transmission process. Alternatively, the change process may be performed at a predetermined timing regardless of the position information transmission process.

  In step S501, the changing unit 315 determines whether or not the communication method used by the communication unit 33 is the second communication method. Specifically, when the communication unit 33 is connected to the base station 20 corresponding to the first communication method, it is determined that the communication unit 33 uses the first communication method. On the other hand, when the communication unit 33 is connected to the base station 20 corresponding to the second communication method, it is determined that the communication unit 33 uses the second communication method. When the communication unit 33 uses the first communication method (step S501: NO), the change process ends by skipping the process of step S502. On the other hand, when the communication unit 33 uses the second communication method (step S501: YES), the change process proceeds to step S502.

  In step S502, the changing unit 315 changes the reference distance or the reference period so that the reference distance or the reference period decreases. FIG. 17 is a diagram illustrating an example of changing the reference period according to the fourth embodiment. In this example, the reference period is set to 30 seconds in advance. For example, when the communication unit 33 uses the second communication method, the reference period is changed from 30 seconds to 10 seconds. In this case, the position information transmission interval is smaller than when the reference period is 30 seconds.

  In the fourth embodiment, when the communication unit 33 uses the second communication method in communication with the server device 10, the reference distance or the reference period is reduced, and the position information transmission interval is reduced. Thereby, the precision which pinpoints the position of the mobile terminal 30 can be improved.

5. Modifications The present invention is not limited to the first to fourth embodiments described above. For example, the first to fourth embodiments may be modified as follows. Further, the following modifications may be combined.

  In the third embodiment described above, the third threshold value used in step S402 shown in FIG. 14 may be changed according to the communication method used by the communication unit 33. For example, the changing unit 315 determines whether or not the communication method used by the communication unit 33 is the second communication method, similar to step S501 illustrated in FIG. When the communication unit 33 uses the second communication method, the changing unit 315 increases the third threshold value. As described above, the increase in the third threshold value makes it difficult for the reference distance or the reference period to be changed, so that an increase in the transmission interval of the position information is suppressed.

  In the third embodiment described above, the server device 10 calculates the number of other mobile terminals 30, but the mobile terminal 30 directly communicates with other mobile terminals 30 existing within a predetermined second range. Thus, the number of other mobile terminals 30 may be calculated. In this case, the mobile terminal 30 includes, for example, a second communication unit that performs short-range wireless communication, and communicates with another mobile terminal 30 to thereby have another mobile terminal 30 that exists within a predetermined second range. Is detected. In this modification, a communication area for short-range wireless communication is used as the second range. Subsequently, the mobile terminal 30 calculates the number of other detected mobile terminals 30. Even with such a method, the number of other mobile terminals 30 existing in the vicinity of the mobile terminal 30 can be calculated.

  In the second embodiment described above, the density of the base station 20 is calculated based on the map information 361. However, the method of calculating the density of the base station 20 is not limited to this method. For example, the calculation unit 316 calculates the number of base stations 20 based on the radio waves received from the base station 20 by the communication unit 33, and uses the calculated number of base stations 20 and the area of the range in which the radio waves can be received. The density of the base station 20 may be calculated. Even with such a method, the density of the base station 20 can be calculated.

  In the second embodiment described above, the mobile terminal 30 calculates the density of the base station 20, but the server apparatus 10 may calculate the density of the base station 20 and transmit the calculated density to the mobile terminal 30. . In this case, map information 361 is stored in the server device 10. The server device 10 calculates the density of the base stations 20 installed in a predetermined first range including the mobile terminal 30 based on the map information 361, similarly to step S301 shown in FIG. Note that the position of the mobile terminal 30 is specified based on the position information received from the mobile terminal 30. According to this modification, since the mobile terminal 30 does not have to calculate the density of the base station 20, the processing load on the mobile terminal 30 is reduced.

  In the first embodiment described above, the mobile terminal 30 measures the moving speed. However, the mobile terminal 30 may use the moving speed measured by another device without measuring the moving speed. For example, the traveling speed measured by the speedometer of the vehicle 3 may be used as the traveling speed of the mobile terminal 30. In this case, the second acquisition unit 314 acquires the traveling speed measured by the speedometer by communicating with the speedometer. According to this modification, the mobile terminal 30 may not have the function of measuring the moving speed.

  In the first embodiment described above, the reference distance and the reference period are set to small values in advance, and the reference distance or the reference period is increased when the moving speed of the mobile terminal 30 is smaller than the first threshold. However, on the contrary, the reference distance and the reference period may be set to large values in advance, and the reference distance or the reference period may be reduced when the moving speed is equal to or higher than the first threshold value. Similarly, in the second embodiment, the reference distance and the reference period may be set to large values in advance, and the reference distance or the reference period may be reduced when the density of the base stations 20 is equal to or higher than the second threshold. In the third embodiment, the reference distance and the reference period may be set to large values in advance, and the reference distance or the reference period may be reduced when the number of other mobile terminals 30 is equal to or smaller than the third threshold. In the fourth embodiment, the reference distance and the reference period may be set to small values in advance, and the reference distance or the reference period may be increased when the communication unit 33 uses the first communication method.

  In the first embodiment described above, the reference distance and the reference period are set in advance, but the reference distance or the reference period may be set according to the moving speed. In this case, when the moving speed is smaller than the first threshold, a larger reference distance or reference period is set when the moving speed is equal to or higher than the first threshold. Similarly, in the second embodiment, when the density of the base stations 20 is smaller than the second threshold, a larger reference distance or reference period may be set when the density of the base stations 20 is equal to or higher than the second threshold. Good. In the third embodiment, when the number of other mobile terminals 30 is greater than the third threshold, a larger reference distance or reference period may be set when the number of other mobile terminals 30 is less than or equal to the third threshold. Good. In the fourth embodiment, when the communication unit 33 uses the second communication method, a reference distance or a reference period that is smaller than when the first communication method is used may be set.

  In the first to fourth embodiments described above, the current position of the mobile terminal 30 is measured using GPS, but the current position of the mobile terminal 30 may be measured by other methods. For example, the server device 10 may measure the current position of the mobile terminal 30 according to the strength of radio waves received by the mobile terminal 30 from the base station 20. In this case, the server device 10 transmits position information indicating the measured current position to the mobile terminal 30. The first acquisition unit 310 of the mobile terminal 30 acquires the position information received from the server device 10 by the communication unit 33. According to this modification, even when GPS cannot be used, the location information of the mobile terminal 30 can be transmitted to the server device 10.

  The reference distance and the reference period are not limited to the examples described in the first to fourth embodiments, and any values may be used. In the first embodiment, the reference distance or the reference period may be changed so that the increase in the reference distance or the reference period increases as the moving speed decreases. Similarly, in the second embodiment, the reference distance or the reference period may be changed so that the increase in the reference distance or the reference period increases as the density of the base stations 20 decreases. In the third embodiment, the reference distance or the reference period may be changed so that the increase in the reference distance or the reference period increases as the number of other mobile terminals 30 increases.

  You may combine at least 2 of 1st Embodiment mentioned above-4th Embodiment. In the first to fourth embodiments described above, either the reference distance or the reference period is changed, but both the reference distance and the reference period may be changed. That is, the changing unit 315 moves the moving speed of the mobile terminal 30, the density of the base stations 20 installed in the first range including the mobile terminal 30, and other mobiles existing in the second range including the mobile terminal 30. The reference distance or the reference period may be changed according to the number of terminals 30 and at least one of the communication methods used by the communication unit 33 in communication with the server device 10.

  In the first to fourth embodiments described above, the functions shown in FIGS. 3 and 10 are realized by software, but at least a part of these functions may be realized by hardware. For example, the timer unit 312 may be realized by a hardware timer.

  The mobile terminal 30 is not limited to a mobile phone or a smartphone, and may be any terminal. For example, the mobile terminal 30 may be a tablet computer or a notebook personal computer.

  The program executed by the processor 31 of the mobile terminal 30 may be downloaded via a communication line such as the Internet. The program is provided in a state of being recorded on a computer-readable recording medium such as a magnetic recording medium (magnetic tape, magnetic disk, etc.), an optical recording medium (optical disk, etc.), a magneto-optical recording medium, or a semiconductor memory. May be.

1: communication system, 10: server device, 20: base station, 30: mobile terminal, 31: processor, 32: main memory, 33: communication unit, 34: input unit, 35: display unit, 36: storage unit, 37 : Positioning unit, 38: acceleration sensor, 310: first acquisition unit, 311: measurement unit, 312: timing unit, 313: transmission control unit, 314: second acquisition unit, 315: change unit, 316: calculation unit

Claims (8)

A communication unit that communicates with the server device;
A measuring unit that measures the distance traveled by the terminal;
A first acquisition unit that acquires position information indicating the position of the terminal;
A time measuring unit for measuring a time elapsed from the transmission time of the position information;
Every time it measures that the measuring unit has moved a reference distance, it is determined whether the length of time measured by the time measuring unit is equal to or longer than a reference period, and the length is equal to or longer than the reference period, A transmission control unit for transmitting the position information acquired by the first acquisition unit from the communication unit to the server device;
The moving speed of the own terminal, the density of base stations installed in the first range including the own terminal, the number of other mobile terminals existing in the second range including the own terminal, and communication with the server device And a changing unit that changes at least one of the reference distance and the reference period according to at least one of the communication methods used by the communication unit. A second acquisition unit for acquiring the moving speed;
The mobile terminal according to claim 1, wherein the changing unit increases at least one of the reference distance and the reference period when the moving speed acquired by the second acquiring unit is smaller than a first threshold. . A second acquisition unit for acquiring the density;
The movement according to claim 1 or 2, wherein the changing unit increases at least one of the reference distance or the reference period when the density acquired by the second acquisition unit is smaller than a second threshold. Terminal. A second acquisition unit for acquiring the number of the other mobile terminals;
The change unit increases at least one of the reference distance or the reference period when the number of the other mobile terminals acquired by the second acquisition unit is larger than a third threshold. 4. The mobile terminal according to any one of 3. The communication unit corresponds to both the first communication method and the second communication method having a higher communication speed than the first communication method,
The mobile terminal according to claim 4, wherein the changing unit increases the third threshold when the communication unit uses the second communication method in communication with the server device. The communication unit corresponds to both the first communication method and the second communication method having a higher communication speed than the first communication method,
The said change part reduces at least one of the said reference distance or the said reference period, when the said communication part uses a said 2nd communication system in communication with the said server apparatus. The mobile terminal according to item 1. Measuring the movement distance of the terminal;
Obtaining position information representing the position of the terminal;
Measuring the time elapsed from the transmission time of the position information;
Each time it is measured that the reference distance has been moved, it is determined whether the measured length of time is greater than or equal to a reference period, and if the length is greater than or equal to the reference period, the acquired position information is Transmitting from the communication unit to the server device;
The moving speed of the own terminal, the density of base stations installed in the first range including the own terminal, the number of other mobile terminals existing in the second range including the own terminal, and communication with the server device And changing the reference distance and / or the reference period according to at least one of the communication methods used by the communication unit. On the computer,
Measuring the movement distance of the terminal;
Obtaining position information representing the position of the terminal;
Measuring the time elapsed from the transmission time of the position information;
Each time it is measured that the reference distance has been moved, it is determined whether the measured length of time is greater than or equal to a reference period, and if the length is greater than or equal to the reference period, the acquired position information is Transmitting from the communication unit to the server device;
The moving speed of the own terminal, the density of base stations installed in the first range including the own terminal, the number of other mobile terminals existing in the second range including the own terminal, and communication with the server device And a step of changing at least one of the reference distance and the reference period according to at least one of the communication methods used by the communication unit.

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