Communication terminal, communication system, control method, and program

Abstract

The purpose of one aspect of the present disclosure is to provide a communication terminal capable of positioning with high accuracy in the vicinity of a region boundary. A communication terminal (102) according to one aspect of the present disclosure is provided with: a reception unit (403) that receives a first signal (111a) radiated from a first transmission terminal (101a) and a second signal (111b) radiated from a second transmission terminal (101b); a recording unit (405) that records a first radio wave intensity indicating the radio wave intensity of the first signal (111a) and a second radio wave intensity indicating the radio wave intensity of the second signal (111b); and a trigger generation unit (406) that generates a first trigger (413a) when a transition from a state in which the first radio wave intensity is greater than the second radio wave intensity to a state in which the first radio wave intensity is less than the second radio wave intensity. A second trigger (413b) is generated when transitioning from a state in which the first radio wave intensity is less than the second radio wave intensity to a state in which the first radio wave intensity is greater than the second radio wave intensity.

Description

Technical Field

[0001] The present disclosure relates to a communication terminal, a communication system, a control method, and a program. This application claims priority based on Japanese Patent Application No. 2022-193987 filed in Japan on December 5, 2022, and the content thereof is incorporated herein by reference. Background Art

[0002] Patent Document 1 discloses the following technology: over time, information related to the received signal strength when a terminal device receives radio waves transmitted from a plurality of communication terminals arranged in a space, and information related to the received signal strength when the plurality of communication terminals receive radio waves transmitted from the terminal device are acquired. For each of the plurality of communication devices, a displacement vector starting from the position of the terminal device is generated, and based on the composite vector obtained by combining the displacement vectors, the moving direction of the terminal device is estimated, and based on the estimated moving direction, the position of the terminal device is estimated. Prior Art Documents Patent Documents

[0003] Patent Document 1: Japanese Patent Laid-Open No. 2016-075669 Summary of the Invention Technical Problem to be Solved by the Invention

[0004] In the technology disclosed in Patent Document 1, it is necessary to arrange three or more communication devices in a space to estimate the position of the terminal device. In addition, in the technology disclosed in Patent Document 1, radio waves transmitted from the communication terminal and radio waves transmitted from the terminal device may be absorbed by building materials and the like arranged at the boundary of the region in the space. Therefore, near the boundary of the region in the space, the positioning accuracy of the position may be relatively reduced. In view of this, an object of one aspect of the present disclosure is to provide a communication terminal, a communication system, a control method, and a program capable of highly accurately positioning near the region boundary. Solution to the Problem

[0005] A communication terminal according to one aspect of the present disclosure includes: a receiving unit that receives a first signal and a second signal; a recording unit that records a first radio wave intensity indicating the radio wave intensity of the first signal and a second radio wave intensity indicating the radio wave intensity of the second signal; and a trigger generation unit that generates a first trigger when the state changes from a state where the first radio wave intensity is greater than the second radio wave intensity to a state where the first radio wave intensity is less than the second radio wave intensity, and generates a second trigger when the state changes from a state where the first radio wave intensity is less than the second radio wave intensity to a state where the first radio wave intensity is greater than the second radio wave intensity.

[0006] The terminal system according to an aspect of the present disclosure includes: a first transmitting terminal that transmits a first signal; a second transmitting terminal that transmits a second signal; and a communication terminal. The communication terminal includes: a receiving unit that receives the first signal and the second signal; a recording unit that records a first radio wave intensity indicating the radio wave intensity of the first signal and a second radio wave intensity indicating the radio wave intensity of the second signal; and a trigger generation unit that generates a first trigger when the state changes from a state where the first radio wave intensity is greater than the second radio wave intensity to a state where the first radio wave intensity is less than the second radio wave intensity, and generates a second trigger when the state changes from a state where the first radio wave intensity is less than the second radio wave intensity to a state where the first radio wave intensity is greater than the second radio wave intensity.

[0007] The control method according to an aspect of the present disclosure includes: a step of receiving a first signal and a second signal; a step of recording a first radio wave intensity indicating the radio wave intensity of the first signal and a second radio wave intensity indicating the radio wave intensity of the second signal; and generating a first trigger when the state changes from a state where the first radio wave intensity is greater than the second radio wave intensity to a state where the first radio wave intensity is less than the second radio wave intensity, and generating a second trigger when the state changes from a state where the first radio wave intensity is less than the second radio wave intensity to a state where the first radio wave intensity is greater than the second radio wave intensity.

[0008] The program according to an aspect of the present disclosure causes a computer to execute: a function of recording a first radio wave intensity indicating the radio wave intensity of a first signal and a second radio wave intensity indicating the radio wave intensity of a second signal; and a function of generating a first trigger when the state changes from a state where the first radio wave intensity is greater than the second radio wave intensity to a state where the first radio wave intensity is less than the second radio wave intensity, and generating a second trigger when the state changes from a state where the first radio wave intensity is less than the second radio wave intensity to a state where the first radio wave intensity is greater than the second radio wave intensity. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 is a block diagram showing an example of the overall configuration of the communication system. Figure 2 is a diagram showing an example of the positions where the first transmitting terminal and the second transmitting terminal are provided. Figure 3A is a block diagram showing an example of the configuration of the first transmitting terminal. Figure 3B is a block diagram showing an example of the configuration of the second transmitting terminal. Figure 4 is a block diagram showing an example of the configuration of the communication terminal. Figure 5It is a block diagram showing an example of the configuration of a server. Figure 6 It is a flowchart showing an example of the operation of a communication terminal according to the first embodiment. Figure 7 It is a diagram showing an example of a movement path when a person carries a communication terminal and moves between a first area and a second area. Figure 8 It is a graph showing an example of a first radio wave intensity recorded in a received signal log and a second radio wave intensity recorded in the received signal log. Figure 9 It is a block diagram showing an example of the configuration of a communication terminal according to a modified example of the first embodiment. Figure 10A It is a graph showing an example of a radio wave intensity of a first signal and a radio wave intensity of a second signal. Figure 10B It shows Figure 10A The moving average of the radio wave intensity of the first signal exemplified by Figure 10A And a graph showing an example of the moving average of the radio wave intensity of the second signal exemplified by Figure 11A It is a diagram showing an example of a movement path when a communication terminal moves between a first area and a second area. Figure 11B It shows that when a communication terminal moves along Figure 11A The movement path exemplified by Figure 12A It is a diagram showing an example of a movement path when a communication terminal moves within a first area. Figure 12B It shows that when a communication terminal moves along Figure 12A The movement path shown by Figure 13 It is a diagram showing an example of the configuration of a first transmission terminal and a second transmission terminal in a communication system according to the fourth embodiment. Figure 14 It is a diagram showing an example of an environment in which a plurality of first transmission terminals and a plurality of second transmission terminals are arranged in a first area and a second area. Detailed implementation mode

[0010] (First embodiment) Refer to Figures 1 to 8, the first embodiment will be described. In addition, in the drawings, the same or equivalent elements are denoted by the same reference numerals, and redundant descriptions are omitted.

[0011] Figure 1 FIG. is a block diagram showing an example of the overall configuration of the communication system 100. The communication system 100 includes a first transmission terminal 101a, a second transmission terminal 101b, a communication terminal 102, and a server 103. The communication terminal 102 and the server 103 are connected via a network 104. For example, the network 104 is a mobile communication network, Wi-Fi (registered trademark), or the like.

[0012] The first transmission terminal 101a transmits a first signal 111a at a plurality of frequencies by means of short-range wireless communication. The first signal 111a includes identification information of the first transmission terminal 101a. For example, the identification information of the first transmission terminal 101a is a Bluetooth (registered trademark) device address (Bluetooth Device Address).

[0013] The second transmission terminal 101b transmits a second signal 111b at a plurality of frequencies by means of short-range wireless communication. The second signal 111b includes identification information of the second transmission terminal 101b. For example, the identification information of the second transmission terminal 101b is a Bluetooth device address (Bluetooth Device Address).

[0014] The communication terminal 102 generates first signal data 112a showing the association between the identification information of the first transmission terminal 101a and the radio wave intensity of the first signal 111a, and transmits the generated first signal data 112a to the server 103. For example, when the radio wave intensity of the first signal 111a is equal to or greater than the radio wave intensity of the second signal 111b, the communication terminal 102 transmits the generated first signal data 112a to the server 103.

[0015] Alternatively, the communication terminal 102 generates second signal data 112b showing the association between the identification information of the second transmission terminal 101b and the radio wave intensity of the second signal 111b, and transmits the generated second signal data 112b to the server 103. For example, when the radio wave intensity of the first signal 111a is less than the radio wave intensity of the second signal 111b, the communication terminal 102 transmits the generated second signal data 112b to the server 103. For example, the communication terminal 102 is a smart watch, a card-type device, a ring-type device, a glasses-type device, a clothing-type device, or the like.

[0016] The server 103 can communicate with the communication terminal 102. The server 103 stores the first signal data 112a and the second signal data 112b sent from the communication terminal 102, and analyzes the stored first signal data 112a and second signal data 112b. Then, the server 103 outputs an analysis result related to at least one of the stored first signal data 112a and second signal data 112b.

[0017] For example, when the radio wave intensity of the first signal 111a is equal to or greater than that of the second signal 111b, the server 103 locates the position of the communication terminal 102 by analyzing the identification information of the first transmitting terminal 101a represented by the first signal data 112a and the radio wave intensity of the first signal 111a. Alternatively, when the radio wave intensity of the first signal 111a is less than that of the second signal 111b, the server 103 locates the position of the communication terminal 102 by analyzing the identification information of the second transmitting terminal 101b represented by the second signal data 112b and the radio wave intensity of the second signal 111b.

[0018] Figure 2 FIG. is an example showing the positions where the first transmitting terminal 101a and the second transmitting terminal 101b are set.

[0019] The first transmitting terminal 101a has a first main radiation direction toward the inside of the first area 201, and transmits the first signal 111a by radiating the first signal 111a. The first main radiation direction is the direction with the maximum radio wave intensity in the first signal 111a. Therefore, the first signal 111a has a stronger radio wave intensity toward the inside of the first area 201 than toward the outside of the first area 201.

[0020] The second transmitting terminal 101b has a second main radiation direction toward the inside of the second area 202, and transmits the second signal 111b by radiating the second signal 111b. The second main radiation direction is the direction with the maximum radio wave intensity in the second signal 111b. Therefore, the second signal 111b has a stronger radio wave intensity toward the inside of the second area 202 than toward the outside of the second area 202.

[0021] The first transmitting terminal 101a and the second transmitting terminal 101b are arranged along the boundary between the first area 201 and the second area 202. Additionally, the first transmitting terminal 101a and the second transmitting terminal 101b may be separated from each other. When the communication terminal 102 is in the same orientation relative to the first transmitting terminal 101a and the second transmitting terminal 101b, the environmental factors of the radio wave intensity of the first signal 111a and the radio wave intensity of the second signal 111b are the same.

[0022] For example, the first transmitting terminal 101a and the second transmitting terminal 101b are arranged back to back with each other. In this case, the first main radiation direction and the second main radiation direction are opposite directions. In addition, as long as the radio wave intensity of the first transmitting terminal 101a and the second transmitting terminal 101b has directivity, the positions where the first transmitting terminal 101a and the second transmitting terminal 101b are arranged are not restricted.

[0023] For example, when the communication terminal 102 is present in the first area 201, the radio wave intensity of the first signal 111a is greater than that of the second signal 111b. Then, when the communication terminal 102 moves from the first area 201 to the second area 202, the state where the radio wave intensity of the first signal 111a is greater than that of the second signal 111b changes to the state where the radio wave intensity of the first signal 111a is less than that of the second signal 111b. In addition, when the communication terminal 102 moves from the second area 202 to the first area 201, the state where the radio wave intensity of the first signal 111a is less than that of the second signal 111b changes to the state where the radio wave intensity of the first signal 111a is greater than that of the second signal 111b.

[0024] In addition, the first transmitting terminal 101a and the second transmitting terminal 101b are arranged along the boundary between the first area 201 and the second area 202, and when the person 203 carrying the communication terminal 102 exists between the first transmitting terminal 101a and the second transmitting terminal 101b and the communication terminal 102, the radio waves transmitted from the first transmitting terminal 101a and the second transmitting terminal 101b are both absorbed by the person 203. Thereby, it is prevented that the person 203 absorbs the radio waves transmitted only from one of the first transmitting terminal 101a or the second transmitting terminal 101b. Therefore, when the person 203 moves between the first area 201 and the second area 202, it is less likely that the communication terminal 102 only receives the signals transmitted from only one of the first transmitting terminal 101a and the second transmitting terminal 101b.

[0025] Therefore, in the case of giving priority to the signal with a relatively large radio wave intensity, before and after the person 203 moves between the first area 201 and the second area 202, the prioritized signal among the first signal 111a and the second signal 111b is reversed. Therefore, the communication terminal 102 can detect the movement between the first area 201 and the second area by comparing the radio wave intensities of the first signal 111a and the second signal 111b.

[0026] Figure 3AIt is a block diagram showing an example of the configuration of the first transmission terminal 101a. The first transmission terminal 101a includes a transmission unit 301a, etc. The transmission unit 301a transmits a first signal 111a at multiple frequencies by means of short-range wireless communication.

[0027] Figure 3B It is a block diagram showing an example of the configuration of the second transmission terminal 101b. The second transmission terminal 101b includes a transmission unit 301b, etc. The transmission unit 301b transmits a second signal 111b at multiple frequencies by means of short-range wireless communication.

[0028] Figure 4 It is a block diagram showing an example of the configuration of the communication terminal 102. The communication terminal 102 includes a terminal storage unit 401, a reception unit 403, a control unit 404, a transmission unit 402, etc.

[0029] The terminal storage unit 401 is a recording medium capable of recording various data, programs, etc., and is composed of, for example, a hard disk, an SSD (Solid State Drive), a semiconductor memory, etc. In the terminal storage unit 401, a reception signal log 412, a switching period 414, etc. are stored. In the reception signal log 412, the temporal change of the first radio wave intensity 411a indicating the radio wave intensity of the first signal 111a and the temporal change of the second radio wave intensity 411b indicating the radio wave intensity of the second signal 111b are recorded.

[0030] The reception unit 403 receives the first signal 111a and the second signal 111b. Specifically, the reception unit 403 switches the selected channel every switching period 414 and receives the first signal 111a and the second signal 111b using the selected channel.

[0031] The control unit 404 executes various processes according to the programs and data stored in the terminal storage unit 401. The control unit 404 is implemented by a processor such as a CPU (Central Processing Unit), etc.

[0032] The control unit 404 includes a recording unit 405, a trigger generation unit 406, etc.

[0033] The recording unit 405 records the first radio wave intensity 411a and the second radio wave intensity 411b. Specifically, the recording unit 405 records the first radio wave intensity 411a and the second radio wave intensity 411b in the reception signal log 412.

[0034] When changing from a state where the first radio wave intensity 411a is greater than the second radio wave intensity 411b to a state where the first radio wave intensity 411a is less than the second radio wave intensity 411b, the trigger generation unit 406 generates a first trigger 413a. Additionally, when changing from a state where the first radio wave intensity 411a is less than the second radio wave intensity 411b to a state where the first radio wave intensity 411a is greater than the second radio wave intensity 411b, the trigger generation unit 406 generates a second trigger 413b.

[0035] When the first trigger 413a is generated, the transmission unit 402 transmits the first trigger 413a to the server 103. Additionally, when the second trigger 413b is generated, the transmission unit 402 transmits the second trigger 413b to the server 103. Alternatively, the transmission unit 402 can not only transmit the first trigger 413a and the second trigger 413b to the server 103, but also transmit data indicating the temporal change of the first radio wave intensity 411a recorded in the received signal log 412 and the temporal change of the second radio wave intensity 411b recorded in the received signal log 412 to the server 103.

[0036] Figure 5 is a block diagram showing an example of the configuration of the server 103. The server 103 includes a server storage unit 501, a communication unit 502, a control unit 503, etc.

[0037] The server storage unit 501 is a recording medium capable of recording various data, programs, etc., and is composed of, for example, a hard disk, an SSD, a semiconductor memory, etc.

[0038] In the server storage unit 501, the identification information of the first transmission terminal 101a and the position of the first transmission terminal 101a are stored in association with each other. Furthermore, in the server storage unit 501, the identification information of the second transmission terminal 101b and the position of the second transmission terminal 101b are stored in association with each other.

[0039] The communication unit 502 is an interface for connecting to the network 104 to communicate. The communication unit 502 receives the first trigger 413a and the second trigger 413b from the communication terminal 102 via the network 104.

[0040] The control unit 503 executes various processes according to the programs and data stored in the server storage unit 501. For example, the control unit 503 is implemented by a processor such as a CPU. The control unit 503 includes a determination unit 504, etc.

[0041] When the communication unit 502 receives the first trigger 413a, the determination unit 504 determines that the communication terminal 102 has moved from the first area 201 to the second area 202. In this case, the determination unit 504 determines that the communication terminal 102 belongs to the second area 202 until a new second trigger 413b is received. Further, when the communication unit 502 receives the second trigger 413b, the determination unit 504 determines that the communication terminal 102 has moved from the second area 202 to the first area 201. In this case, the determination unit 504 determines that the communication terminal 102 belongs to the first area 201 until a new first trigger 413a is received.

[0042] Furthermore, when the determination unit 504 determines that the communication terminal 102 belongs to the first area 201, it locates the position of the communication terminal 102 in the first area 201 based on the identification information of the first transmitting terminal 101a represented by the first signal data 112a and based on the first radio wave intensity 411a. In addition, when determining that the communication terminal 102 belongs to the second area 202, the determination unit 504 locates the position of the communication terminal 102 in the second area 202 based on the identification information of the second transmitting terminal 101b represented by the second signal data 112b and based on the second radio wave intensity 411b.

[0043] Figure 6 It is a flowchart showing an example of the operation of the communication terminal 102 according to the present embodiment.

[0044] In step S601, the receiving unit 403 receives the first signal 111a and the second signal 111b. In step S602, the recording unit 405 records the first radio wave intensity 411a indicating the radio wave intensity of the received first signal 111a and the second radio wave intensity 411b indicating the radio wave intensity of the received second signal 111b in the received signal log 412.

[0045] In step S603, the trigger generation unit 406 determines whether there has been a change from a state where the first radio wave intensity 411a is greater than the second radio wave intensity 411b to a state where the first radio wave intensity 411a is less than the second radio wave intensity 411b.

[0046] When, in step S603, the state changes from a state where the first radio wave intensity 411a is greater than the second radio wave intensity 411b to a state where the first radio wave intensity 411a is less than the second radio wave intensity 411b, in step S604, the trigger generation unit 406 generates the first trigger 413a. Then, in step S605, the transmitting unit 402 transmits the first trigger 413a to the server 103. Then, the control unit 404 returns the process to step S601.

[0047] On the other hand, when the state does not change from the state where the first radio wave intensity 411a is greater than the second radio wave intensity 411b to the state where the first radio wave intensity 411a is less than the second radio wave intensity 411b in step S603, the control unit 404 transfers the process to step S606.

[0048] In step S606, the trigger generation unit 406 determines whether a change has occurred from the state where the first radio wave intensity 411a is less than the second radio wave intensity 411b to the state where the first radio wave intensity 411a is greater than the second radio wave intensity 411b.

[0049] When the state does not change from the state where the first radio wave intensity 411a is less than the second radio wave intensity 411b to the state where the first radio wave intensity 411a is greater than the second radio wave intensity 411b in step S606, the control unit 404 returns the process to step S601. On the other hand, when the state changes from the state where the first radio wave intensity 411a is less than the second radio wave intensity 411b to the state where the first radio wave intensity 411a is greater than the second radio wave intensity 411b in step S606, in step S607, the trigger generation unit 406 generates the second trigger 413b. Then, the transmission unit 402 transmits the second trigger 413b to the server 103. Then, the control unit 404 returns the process to step S601.

[0050] Figure 7 FIG. is an example of a movement path when the person 701 carries the communication terminal 102 and moves between the first area 201 and the second area 202. After the person 701 moves from the first area 201 to the second area 202 along the movement path 702, the person moves within the second area along the movement paths 703 to 704, and moves from the second area 202 to the first area 201 along the movement path 705.

[0051] Figure 8 FIG. is a graph showing an example of the first radio wave intensity 411a recorded in the received signal log 412 and the second radio wave intensity 411b recorded in the received signal log 412 when the person 701 carries the communication terminal 102 and moves along the movement paths 702 to 705. In Figure 8 the horizontal axis represents time, and the vertical axis represents the radio wave intensity.

[0052] First, at time T801, it is assumed that the person 701 carries the communication terminal 102 and moves from the first area 201 to the second area 202 along Figure 7 the movement path 702 illustrated in. As Figure 8 illustrated, before the person 701 carrying the communication terminal 102 moves to the second area 202, the first radio wave intensity 411a is in a state greater than the second radio wave intensity 411b.

[0053] Then, when the communication terminal 102 moves from the first area 201 to the second area 202, there is a change from the state where the first radio wave intensity 411a is greater than the second radio wave intensity 411b to the state where the first radio wave intensity 411a is less than the second radio wave intensity 411b. That is, when giving priority to the signal with a relatively large radio wave intensity, before and after the communication terminal 102 moves from the first area 201 to the second area 202, the prioritized signal among the first signal 111a and the second signal 111b is reversed.

[0054] Then, at time T802, it is assumed that the person 701 is carrying the communication terminal 102 and moving within the second area 202 along the Figure 7 mobile path 703 to mobile path 704 illustrated in. In this case, as Figure 8 illustrated, the first radio wave intensity 411a is in a state of being less than the second radio wave intensity 411b.

[0055] Then, at time T803, it is assumed that the person 701 is carrying the communication terminal 102 and moving from the second area 202 to the first area 201 along the Figure 7 mobile path 705 illustrated in. When the communication terminal 102 has moved from the second area 202 to the first area 201, there is a change from the state where the first radio wave intensity 411a is less than the second radio wave intensity 411b to the state where the first radio wave intensity 411a is greater than the second radio wave intensity 411b. That is, before and after the communication terminal 102 moves from the second area 202 to the first area 201, the radio wave intensities of the first radio wave intensity 411a and the second radio wave intensity 411b are reversed. Therefore, as Figure 8 illustrated, after the person 701 moves the communication terminal 102 to the first area 201, the first radio wave intensity 411a is in a state of being greater than the second radio wave intensity 411b.

[0056] As described above, according to the distances between the first transmitting terminal 101a and the second transmitting terminal 101b and the communication terminal 102, the first radio wave intensity 411a and the second radio wave intensity 411b change. Therefore, the communication terminal 102 compares the first radio wave intensity 411a and the second radio wave intensity 411b relatively, and can generate a trigger indicating that the communication terminal 102 moves between the first area 201 and the second area 202. That is, the communication terminal 102 can detect the situation where the communication terminal 102 moves between the first area 201 and the second area 202 near the area boundary. In addition, the communication terminal 102 sends a trigger indicating that the communication terminal 102 moves between the first area 201 and the second area 202 to the server 103. Thereby, the server 103 can determine whether the communication terminal 102 has moved between areas based on the received trigger.

[0057] (Modified Example) As a modified example of the communication system 100 according to the first embodiment, the communication terminal 102 may also detect and determine whether it has moved to a different area. Figure 9 FIG. is a block diagram showing an example of the configuration of the communication terminal 102 according to this modified example. Figure 9 The illustrated communication terminal 102 is different from Figure 4 the illustrated communication terminal 102 in that: Figure 9 the illustrated communication terminal 102 is provided with a detection unit 901 instead of the transmission unit 402.

[0058] When the first trigger 413a is generated, the detection unit 901 detects the movement from the first area 201 to the second area 202. Additionally, when the second trigger 413b is generated, the detection unit 901 detects the movement from the second area 202 to the first area 201. Thus, the communication terminal 102 according to this modified example can detect whether it has moved to a different area without transmitting the first trigger 413a and the second trigger 413b to the server 103.

[0059] (Second Embodiment) Refer to Figures 10A to 10B , and the second embodiment will be described. In addition, in the drawings, the same or equivalent elements are denoted by the same reference numerals, and repeated descriptions are omitted. In the following embodiments, the configurations and processes having substantially the same functions as those of other embodiments are referred to by common reference numerals, and the descriptions are omitted, and the aspects different from other embodiments are described.

[0060] The configuration of the communication terminal 102 according to this embodiment is the same as that of Figure 4 the illustrated communication terminal 102.

[0061] The trigger generation unit 406 according to this embodiment calculates the moving average of the radio wave intensity of the first signal 111a as the first radio wave intensity 411a. The moving average of the radio wave intensity of the first signal 111a is the moving average over a period having a length of more than the switching period 414. Moreover, the trigger generation unit 406 calculates the moving average of the radio wave intensity of the second signal 111b as the second radio wave intensity 411b. The moving average of the radio wave intensity of the second signal 111b is the moving average over a period having a length of more than the switching period 414. That is, the first radio wave intensity 411a according to this embodiment represents the moving average of the radio wave intensity of the first signal 111a. Additionally, the second radio wave intensity 411b according to this embodiment represents the moving average of the radio wave intensity of the second signal 111b.

[0062] Figure 10AIt is a graph showing an example of the radio wave intensity of the first signal 111a and the radio wave intensity of the second signal 111b. In Figure 10A , the horizontal axis represents time, and the vertical axis represents the radio wave intensity. During the period T1001, the communication terminal 102 belongs to the first area 201. In addition, during the period T1002, the communication terminal 102 belongs to the second area 202. Here, at the moment t1015 which is the boundary between the period T1001 and the period T1002, the state where the radio wave intensity of the first signal 111a is greater than the radio wave intensity of the second signal 111b changes to the state where the radio wave intensity of the first signal 111a is less than the radio wave intensity of the second signal 111b. Therefore, it is speculated that at the moment t1015, the communication terminal 102 moves from the first area 201 to the second area 202.

[0063] However, at the moment t1011, the moment t1013, and the moment t1017, there are also changes where the state where the radio wave intensity of the first signal 111a is greater than the radio wave intensity of the second signal 111b changes to the state where the radio wave intensity of the first signal 111a is less than the radio wave intensity of the second signal 111b. In addition, at the moment t1012, the moment t1014, and the moment t1016, the state where the radio wave intensity of the first signal 111a is greater than the radio wave intensity of the second signal 111b changes to the state where the radio wave intensity of the first signal 111a is less than the radio wave intensity of the second signal 111b.

[0064] In this way, when the communication terminal 102 does not move between the first area 201 and the second area 202, and when the fluctuations in the radio wave intensity of the first signal 111a and the fluctuations in the radio wave intensity of the second signal 111b are relatively large, sometimes the signal with the relatively larger radio wave intensity is temporarily reversed.

[0065] Figure 10B It is a graph showing Figure 10A an example of the moving average of the radio wave intensity of the first signal 111a illustrated in Figure 10A and the moving average of the radio wave intensity of the second signal 111b illustrated in Figure 10B . In

[0066] At time t1051, the state where the moving average of the radio wave intensity of the first signal 111a is greater than the moving average of the radio wave intensity of the second signal 111b changes to the state where the moving average of the radio wave intensity of the first signal 111a is less than the moving average of the radio wave intensity of the second signal 111b. On the other hand, within period T1001 and period T1002, there is no change from the state where the moving average of the radio wave intensity of the first signal 111a is greater than the moving average of the radio wave intensity of the second signal 111b to the state where the moving average of the radio wave intensity of the first signal 111a is less than the moving average of the radio wave intensity of the second signal 111b. Therefore, in the communication terminal 102 according to the present embodiment, by representing the moving average of the radio wave intensity of the first signal 111a with the first radio wave intensity 411a and representing the moving average of the radio wave intensity of the second signal 111b with the second radio wave intensity 411b, it is possible to prevent the trigger generation unit 406 from generating the first trigger 413a or the first trigger 413a when there is no movement between the first area 201 and the second area 202.

[0067] (Modification example) As a modification example of the communication system 100 according to the first embodiment, when giving priority to a signal with a relatively large radio wave intensity, the communication terminal 102 may also generate the first trigger 413a or the second trigger 413b when the signal given priority between the first radio wave intensity 411a and the second radio wave intensity 411b is reversed within the time representing half of the switching period 414. Specifically, the trigger generation unit 406 may also generate the first trigger 413a when a change occurs from the state where the time when the first radio wave intensity 411a is greater than the second radio wave intensity 411b occupies more than half of the switching period 414 to the state where the time when the first radio wave intensity 411a is less than the second radio wave intensity 411b occupies more than half of the switching period 414. In addition, the trigger generation unit 406 may also generate the second trigger 413b when a change occurs from the state where the time when the first radio wave intensity 411a is less than the second radio wave intensity 411b occupies more than half of the switching period 414 to the state where the time when the first radio wave intensity 411a is greater than the second radio wave intensity 411b occupies more than half of the switching period 414.

[0068] That is, when the communication terminal 102 according to this modification is stable with the first radio wave intensity 411a being greater than the second radio wave intensity 411b for more than half of the occupancy switching period 414, the first trigger 413a is generated. Similarly, when the communication terminal 102 according to this modification is stable with the first radio wave intensity 411a being smaller than the second radio wave intensity 411b for more than half of the occupancy switching period 414, the second trigger 413b is generated. Therefore, when the communication terminal 102 does not move between the first area 201 and the second area 202, the moving average is not calculated, and it is possible to prevent the first trigger 413a or the first trigger 413a from being erroneously generated.

[0069] (Third Embodiment) Refer to Figures 11A to 12B and explain the third embodiment. In addition, in the drawings, the same or equivalent elements are denoted by the same reference numerals, and repeated explanations are omitted. In the following embodiments, the configurations and processes having substantially the same functions as those of other embodiments are referred to by common reference numerals, and the explanations are omitted, and the aspects different from other embodiments are explained.

[0070] The configuration of the communication terminal 102 according to this embodiment is as Figure 4 shown.

[0071] Before and after the moment when the state changes from the state where the first radio wave intensity 411a is greater than the second radio wave intensity 411b to the state where the first radio wave intensity 411a is smaller than the second radio wave intensity 411b, when the first radio wave intensity 411a decreases and the second radio wave intensity 411b increases, the trigger generation unit 406 according to this embodiment generates the first trigger 413a. In addition, before and after the moment when the state changes from the state where the first radio wave intensity 411a is smaller than the second radio wave intensity 411b to the state where the first radio wave intensity 411a is greater than the second radio wave intensity 411b, when the first radio wave intensity 411a increases and the second radio wave intensity 411b decreases, the trigger generation unit 406 generates the second trigger 413b.

[0072] Figure 11A FIG. is an example of a moving path 1101 showing the movement of the communication terminal 102 between the first area 201 and the second area 202. Figure 11B is a diagram showing the communication terminal 102 along Figure 11A In the case of moving along the moving path 1101 illustrated, it is a graph showing an example of the temporal change of the first radio wave intensity 411a and the temporal change of the second radio wave intensity 411b. In Figure 11B , the horizontal axis represents time, and the vertical axis represents the radio wave intensity.

[0073] Before time t1102, the communication terminal 102 belongs to the first area 201. On the other hand, at a time after time t1102, the communication terminal 102 belongs to the second area 202. In addition, around time t1102, the state changes from a state where the first radio wave intensity 411a is greater than the second radio wave intensity 411b to a state where the first radio wave intensity 411a is smaller than the second radio wave intensity 411b. Moreover, from a time before time t1102 to a time after time t1102, the first radio wave intensity 411a decreases and the second radio wave intensity 411b increases. That is, when moving between the first area 201 and the second area 202, in the temporal change of the first radio wave intensity 411a and the temporal change of the second radio wave intensity 411b, the slopes of the first radio wave intensity 411a and the second radio wave intensity 411b are different reference numerals.

[0074] Figure 12A FIG. is an example of a movement path 1201 showing the communication terminal 102 moving within the first area 201. Figure 12B is a diagram showing that the communication terminal 102 moves along Figure 12A In the case of moving along the movement path 1201 illustrated, it is a graph showing an example of the temporal change of the first radio wave intensity 411a and the temporal change of the second radio wave intensity 411b. In Figure 12B the horizontal axis represents time and the vertical axis represents the radio wave intensity.

[0075] Around time t1202, the state changes from a state where the first radio wave intensity 411a is greater than the second radio wave intensity 411b to a state where the first radio wave intensity 411a is smaller than the second radio wave intensity 411b. However, from a time before time t1202 to a time after time t1202, both the first radio wave intensity 411a and the second radio wave intensity increase.

[0076] Therefore, the trigger generation unit 406 according to the present embodiment can determine whether to generate the first trigger 413a or the second trigger 413b without calculating the moving average of the first radio wave intensity 411a and the moving average of the second radio wave intensity 411b.

[0077] Moreover, when calculating the moving average of the first radio wave intensity 411a and the moving average of the second radio wave intensity 411b, the trigger generation unit 406 cannot determine whether to generate the first trigger 413a or the second trigger 413b until a period having a length equal to or greater than the switching period 414 has elapsed.

[0078] On the other hand, the trigger generation unit 406 according to the present embodiment does not need to calculate the moving average of the first radio wave intensity 411a and the moving average of the second radio wave intensity 411b, and can determine whether to generate the first trigger 413a or the second trigger 413b before a period longer than the switching period 414 has elapsed.

[0079] Therefore, when the communication terminal 102 according to the present embodiment does not move between the first area 201 and the second area 202, it is possible to prevent the first trigger 413a or the second trigger 413b from being erroneously generated, and it is possible to determine whether to generate the first trigger 413a or the second trigger 413b within a relatively short time.

[0080] (Fourth Embodiment) Refer to Figure 13 , and the fourth embodiment will be described. In addition, in the drawings, the same or equivalent elements are denoted by the same reference numerals, and repeated descriptions are omitted. In the following embodiments, components and processes having substantially the same functions as those of other embodiments are referred to by common reference numerals, and the descriptions are omitted, and aspects different from other embodiments are described.

[0081] The configuration of the communication terminal 102 according to the present embodiment is as Figure 4 shown.

[0082] Figure 13 is a diagram showing an example of the configurations of the first transmission terminal 101a and the second transmission terminal 101b in the communication system 100 according to the present embodiment. The communication system 100 according to the present embodiment further includes a first radio wave reflector 1301a and a second radio wave reflector 1301b. In addition, the radio wave reflector can be replaced with a radio wave absorber. Examples of materials for the radio wave absorber include polyurethane, rubber, water, etc.

[0083] The first radio wave reflector 1301a is arranged on the side of the second area 202 and gives the first transmission terminal 101a the first main radiation direction. For example, the first radio wave reflector 1301a is provided on the surface facing the first area 201 in the wall material 1302 arranged at the boundary between the first area 201 and the second area 202.

[0084] The first radio wave reflector 1301a is made of metal and has an area larger than that of the first transmission terminal 101a. For example, the first radio wave reflector 1301a has an area of 10 times or more the area of the surface on the second area 202 side of the first transmission terminal 101a.

[0085] By arranging the first radio wave reflector 1301a on the second region 202 side, the first signal 111a transmitted from the first transmitting terminal 101a to the second region 202 side is reflected by the first radio wave reflector 1301a. As a result, the radio wave intensity of the first signal 111a transmitted from the first transmitting terminal 101a to the second region 202 side is weaker than the radio wave intensity of the first signal 111a transmitted from the first transmitting terminal 101a to the first region 201 side. Consequently, the first transmitting terminal 101a has a first main radiation direction within the first region 201, and the radio wave intensity can be directional.

[0086] In addition, in the case where the first radio wave reflector 1301a is replaced with a radio wave absorber, the first signal 111a transmitted from the first transmitting terminal 101a to the second region 202 side is absorbed by the radio wave absorber. As a result, the radio wave intensity of the first signal 111a transmitted from the first transmitting terminal 101a to the second region 202 side is weaker than the radio wave intensity of the first signal 111a transmitted from the first transmitting terminal 101a to the first region 201 side. Consequently, the first transmitting terminal 101a has a first main radiation direction within the first region 201, and the radio wave intensity can be directional.

[0087] The second radio wave reflector 1301b is arranged on the first region 201 side and gives the second transmitting terminal 101b a second main radiation direction. For example, the second radio wave reflector 1301b is provided on the surface of the wall material 1302 facing the second region 202.

[0088] The second radio wave reflector 1301b is made of metal and has a relatively larger area than the second transmitting terminal 101b. For example, the second radio wave reflector 1301b has an area more than 10 times that of the surface of the second transmitting terminal 101b on the first region 201 side.

[0089] By arranging the second radio wave reflector 1301b on the first region 201 side, the second signal 111b transmitted from the second transmitting terminal 101b to the first region 201 side is reflected by the second radio wave reflector 1301b. As a result, the radio wave intensity of the second signal 111b transmitted from the second transmitting terminal 101b to the first region 201 side is weaker than the radio wave intensity of the second signal 111b transmitted from the second transmitting terminal 101b to the second region 202 side. Consequently, the second transmitting terminal 101b has a first main radiation direction within the second region 202, and the radio wave intensity can be directional.

[0090] In addition, in the case where the second radio wave reflector 1301b is replaced with a radio wave absorber, the second signal 111b transmitted from the second transmission terminal 101b toward the first region 201 side is absorbed by the radio wave absorber. As a result, the radio wave intensity of the second signal 111b transmitted from the second transmission terminal 101b toward the first region 201 side is weaker than the radio wave intensity of the second signal 111b transmitted from the second transmission terminal 101b toward the second region 202 side. As a result, the second transmission terminal 101b has a first main radiation direction within the second region 202, and the radio wave intensity can be directional.

[0091] As described above, by arranging the first radio wave reflector 1301a, the first transmission terminal 101a can have directivity in terms of radio wave intensity. Similarly, by arranging the second radio wave reflector 1301b, the second transmission terminal 101b can have directivity in terms of radio wave intensity. Thus, when a person carries the communication terminal 102 and moves from the first region 201 to the second region 202, the state changes from a state where the first radio wave intensity 411a is greater than the second radio wave intensity 411b to a state where the first radio wave intensity 411a is smaller than the second radio wave intensity 411b. In addition, when a person carries the communication terminal 102 and moves from the second region 202 to the first region 201, the state changes from a state where the first radio wave intensity 411a is smaller than the second radio wave intensity 411b to a state where the first radio wave intensity 411a is greater than the second radio wave intensity 411b.

[0092] (Fifth Embodiment) Refer to Figure 14 , and the fifth embodiment will be described. In addition, in the drawings, the same or equivalent elements are denoted by the same reference numerals, and repeated descriptions are omitted. In the following embodiments, the configurations and processes having substantially the same functions as those of other embodiments are referred to by common reference numerals, and the descriptions are omitted, and the aspects different from other embodiments are described.

[0093] The configuration of the communication terminal 102 according to the present embodiment is as Figure 9 shown. In addition, the configuration of the server 103 according to the present embodiment is exemplified as Figure 5 .

[0094] The trigger generation unit 406 according to the present embodiment calculates the moving average of the radio wave intensity of the first signal 111a as the first radio wave intensity 411a. The moving average of the radio wave intensity of the first signal 111a according to the present embodiment is the moving average during the period corresponding to the region to which the communication terminal 102 belongs.

[0095] In addition, the trigger generation unit 406 calculates a moving average of the radio wave intensity of the second signal 111b as the second radio wave intensity 411b. The moving average of the radio wave intensity of the second signal 111b according to the present embodiment is a moving average during a period corresponding to the area to which the communication terminal 102 belongs.

[0096] When the first trigger 413a is generated, the detection unit 901 according to the present embodiment detects the movement of the communication terminal 102 from the first area 201 to the second area 202 and switches the transmission interval from the first transmission interval to the second transmission interval. In addition, when the second trigger 413b is generated, the communication terminal 102 detects the movement from the second area 202 to the first area 201 and switches the transmission interval from the second transmission interval to the first transmission interval.

[0097] When the communication terminal 102 belongs to the first area 201, the transmission unit 402 according to the present embodiment transmits the first signal 111a to the server 103 at the first transmission interval. In addition, when the communication terminal 102 belongs to the second area 202, the transmission unit 402 transmits the second signal 111b to the server 103 at the second transmission interval.

[0098] For example, in the position measurement based on the reception intensity of the first signal 111a and the position measurement based on the reception intensity of the second signal 111b, when the communication terminal 102 belongs to an area where the position measurement accuracy can be relatively reduced, the period for calculating the moving average of the radio wave intensity is relatively extended. For example, when the communication terminal 102 belongs to an area where the positioning accuracy can be relatively reduced, the trigger generation unit 406 calculates the moving average of the radio wave intensity within 1 minute.

[0099] On the other hand, for example, when the communication terminal 102 belongs to an area where relatively high positioning accuracy is required, the period for calculating the moving average of the radio wave intensity is relatively shortened. For example, when the communication terminal 102 belongs to an area where relatively high positioning accuracy is required, the trigger generation unit 406 calculates the moving average of the radio wave intensity within 10 seconds.

[0100] In addition, the transmitting unit 402 may also transmit the first signal data 112a or the second signal data 112b to the server 103 at a transmission interval corresponding to the area to which the communication terminal 102 belongs. For example, when the communication terminal 102 belongs to an area that requires relatively high positioning accuracy, the transmitting unit 402 shortens the transmission interval for transmitting the first signal data 112a or the second signal data 112b to the server 103 compared to the case where the communication terminal 102 belongs to an area with relatively low positioning accuracy. Or, when the communication terminal 102 belongs to an area with relatively low positioning accuracy, the transmitting unit 402 may not transmit the first signal data 112a and the second signal data 112b to the server 103.

[0101] Figure 14 FIG. is an example of an environment in which the first transmitting terminal 101a and the second transmitting terminal 101b are arranged in the first area 201 and the second area 202.

[0102] For example, in a medical institution, it is assumed that the first area 201 is a ward where beds are arranged, and the second area 202 is a nurse station. Moreover, the positioning accuracy requirement for the ward is relatively higher than that for the nurse station. Furthermore, it is assumed that the first transmitting terminal 101a is arranged in the ward, and the second transmitting terminal 101b is arranged in the nurse station.

[0103] For example, when the communication terminal 102 belongs to the first area 201, the period for calculating the moving average of the radio wave intensity is relatively shortened compared to the case where the communication terminal 102 belongs to the second area 202. In addition, when the communication terminal 102 belongs to the first area 201, the transmitting unit 402 may also transmit the first signal data 112a to the server 103 at a relatively short transmission interval. In this case, based on the identification information represented by the received first signal data 112a and based on the first radio wave intensity 411a, the determination unit 504 can locate the position of the communication terminal 102 within the first area 201 at a relatively high frequency. That is, when the communication terminal 102 belongs to an area that requires relatively high positioning accuracy, by performing positioning at a relatively high frequency, a relatively high positioning accuracy can be ensured.

[0104] On the other hand, when the communication terminal 102 belongs to the second area 202, the transmitting unit 402 transmits the second signal data 112b to the server 103 at a relatively long transmission interval. Or, when the communication terminal 102 belongs to the second area 202, the transmitting unit 402 does not transmit the first signal data 112a and the second signal data 112b to the server 103. Thereby, when the communication terminal 102 belongs to an area where the positioning accuracy can be relatively low, power consumption can be suppressed.

[0105] As described above, in the communication system 100 according to the present embodiment, the communication terminal 102 and the server 103 communicate at a communication interval corresponding to the area to which the communication terminal 102 belongs, whereby the position of the communication terminal 102 can be located with an accuracy corresponding to the area to which the communication terminal 102 belongs.

[0106] Each process executed in the present embodiment is not limited to the processing method exemplified in each embodiment. The above functional blocks can also be implemented using either a logic circuit (hardware) formed in an integrated circuit or the like, or software using a CPU. Each process executed in the above embodiment can also be executed by a plurality of computers. For example, the processes executed by the respective functional blocks of the control unit 404 of the communication terminal 102 can be partially executed by other computers, or all the processes can be executed by a plurality of computers in a shared manner.

[0107] The present disclosure is not limited to the above embodiments, and can also be replaced with a configuration that is substantially the same as the configuration shown in the above embodiments, a configuration that exhibits the same effects, or a configuration that can achieve the same purpose. In the present disclosure, embodiments obtained by appropriately combining technical solutions separately disclosed in different embodiments are also included in the technical scope of the present disclosure. Moreover, new technical features can be formed by combining the technical methods separately disclosed in each embodiment.

Claims

1. A communication terminal, characterized in that, Comprising: A receiving unit that receives a first signal and a second signal; A recording unit that records a first radio wave intensity representing the radio wave intensity of the first signal and a second radio wave intensity representing the radio wave intensity of the second signal; and A trigger generation unit that generates a first trigger when changing from a state where the first radio wave intensity is greater than the second radio wave intensity to a state where the first radio wave intensity is less than the second radio wave intensity, and generates a second trigger when changing from a state where the first radio wave intensity is less than the second radio wave intensity to a state where the first radio wave intensity is greater than the second radio wave intensity.

2. The communication terminal according to claim 1, wherein The first radio wave intensity represents a moving average of the radio wave intensity of the first signal, The second radio wave intensity represents a moving average of the radio wave intensity of the second signal.

3. The communication terminal according to claim 2, wherein The receiving unit switches the selected channel in each switching period, and receives the first signal and the second signal through the selected channel, The moving average of the radio wave intensity of the first signal is a moving average within a period having a length equal to or greater than the switching period, The moving average of the radio wave intensity of the second signal is a moving average within a period having a length equal to or greater than the switching period.

4. The communication terminal according to claim 2, wherein The moving average of the radio wave intensity of the first signal is a moving average within a period corresponding to the area to which the communication terminal belongs, The moving average of the radio wave intensity of the second signal is a moving average within a period corresponding to the area.

5. The communication terminal according to claim 1, wherein The receiving unit switches the selected channel in each switching period, and receives the first signal and the second signal through the selected channel, The trigger generation unit generates a trigger in the following cases: When changing from a state where the time when the first radio wave intensity is greater than the second radio wave intensity occupies more than half of the switching period to a state where the time when the first radio wave intensity is less than the second radio wave intensity occupies more than half of the switching period, the trigger generation unit generates the first trigger, When changing from a state where the time when the first radio wave intensity is less than the second radio wave intensity occupies more than half of the switching period to a state where the time when the first radio wave intensity is greater than the second radio wave intensity occupies more than half of the switching period, the trigger generation unit generates the second trigger.

6. The communication terminal according to claim 1 or 2, wherein The trigger generation unit generates a trigger in the following cases: Before and after the moment of changing from a state where the first radio wave intensity is greater than the second radio wave intensity to a state where the first radio wave intensity is less than the second radio wave intensity, when the first radio wave intensity decreases and the second radio wave intensity increases, the trigger generation unit generates the first trigger, Before and after the moment when the state changes from the state where the first radio wave intensity is less than the second radio wave intensity to the state where the first radio wave intensity is greater than the second radio wave intensity, when the first radio wave intensity increases and the second radio wave intensity decreases, the trigger generation unit generates the second trigger.

7. The communication terminal according to claim 1 or 2, characterized in that, Comprising: A detection unit that detects the movement of the communication terminal from a first area to a second area when the first trigger is generated, and detects the movement of the communication terminal from the second area to the first area when the second trigger is generated.

8. A communication system, characterized in that, Comprising: A first transmitting terminal that transmits a first signal; A second transmitting terminal that transmits a second signal; And A communication terminal, The communication terminal includes: A receiving unit that receives the first signal and the second signal; A recording unit that records a first radio wave intensity representing the radio wave intensity of the first signal and a second radio wave intensity representing the radio wave intensity of the second signal; A trigger generation unit that generates a first trigger when the state changes from the state where the first radio wave intensity is greater than the second radio wave intensity to the state where the first radio wave intensity is less than the second radio wave intensity, and generates a second trigger when the state changes from the state where the first radio wave intensity is less than the second radio wave intensity to the state where the first radio wave intensity is greater than the second radio wave intensity.

9. The communication system according to claim 8, characterized in that It further includes a server capable of communicating with the communication terminal, The communication terminal further includes a transmitting unit that transmits the first trigger to the server when the first trigger is generated, and transmits the second trigger to the server when the second trigger is generated.

10. The communication system according to claim 9, characterized in that The server includes a determination unit, When receiving the first trigger, the determination unit determines that the communication terminal moves from the first area to the second area, and when receiving the second trigger, the determination unit determines that the communication terminal moves from the second area to the first area.

11. The communication system according to claim 10, characterized in that The first transmitting terminal has a first main radiation direction within the first area, The second transmitting terminal has a second main radiation direction within the second area.

12. The communication system according to claim 11, characterized in that The first main radiation direction and the second main radiation direction are opposite to each other.

13. The communication system according to claim 11, characterized in that The first transmitting terminal and the second transmitting terminal are arranged back to back.

14. The communication system according to claim 11, characterized in that The first transmitting terminal and the second transmitting terminal are arranged along the boundary between the first area and the second area.

15. The communication system according to claim 11, wherein It further includes: A first radio wave reflector that gives the first transmitting terminal the first main radiation direction; and A second radio wave reflector that gives the second transmitting terminal the second main radiation direction.

16. The communication system according to claim 11, characterized in that, It further includes: A first radio wave absorber that gives the first main radiation direction to the first transmitting terminal; and A second radio wave absorber that gives the second main radiation direction to the second transmitting terminal.

17. The communication system according to claim 10, wherein the communication terminal further includes a detection unit,[[]] the detection unit detects the movement of the communication terminal from the first area to the second area when the first trigger is generated, and switches the transmission interval from a first transmission interval to a second transmission interval,[[]] the detection unit detects the movement of the communication terminal from the second area to the first area when the second trigger is generated, and switches the transmission interval from the second transmission interval to the first transmission interval,[[]] when the communication terminal belongs to the first area, the transmission unit transmits the first signal to the server at the first transmission interval,[[]] when the communication terminal belongs to the second area, the transmission unit transmits the second signal to the server at the second transmission interval.[[]] 18. A control method, characterized in that, Including:[[]] A step of receiving the first signal and the second signal;[[]] A step of recording a first radio wave intensity representing the radio wave intensity of the first signal and a second radio wave intensity representing the radio wave intensity of the second signal; and[[]] A step of generating a first trigger when changing from a state where the first radio wave intensity is greater than the second radio wave intensity to a state where the first radio wave intensity is less than the second radio wave intensity, and generating a second trigger when changing from a state where the first radio wave intensity is less than the second radio wave intensity to a state where the first radio wave intensity is greater than the second radio wave intensity.[[]] 19. A program, characterized in that, Cause a computer to execute:[[]] A function of recording a first radio wave intensity representing the radio wave intensity of the first signal and a second radio wave intensity representing the radio wave intensity of the second signal; and[[]] A function of generating a first trigger when changing from a state where the first radio wave intensity is greater than the second radio wave intensity to a state where the first radio wave intensity is less than the second radio wave intensity, and generating a second trigger when changing from a state where the first radio wave intensity is less than the second radio wave intensity to a state where the first radio wave intensity is greater than the second radio wave intensity.[[]]

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