Terminal, search system, and search method

Abstract

A terminal that wirelessly communicates with a search device used for searching for mountain survivors includes: a public wireless communication unit that communicates with a server via a public wireless network; a satellite reception unit that receives a satellite signal from a satellite; and a control unit that transmits, to the server, position information of the terminal acquired on the basis of the satellite signal and the identifier of the terminal.

Description

Terminal, search system, and search method

[0001] The present disclosure relates to a terminal, a search system, and a search method.

[0002] Patent Document 1 proposes a victim search support system used to rescue victims. This victim search support system has a mountain climber carry a transmitter that emits radio waves selected from the VHF to UHF frequency range and radio waves selected from the MF frequency range, and searches for the victim using these multiple radio waves in the event of a disaster.

[0003] For example, in the case of a mountain climber who is lost, the victim search support system of Patent Document 1 searches for the transmitter from the sky (helicopter) using radio waves selected from the VHF to UHF frequency range. After searching for the transmitter from the sky, a ground search team searches for the transmitter using radio waves selected from the MF frequency range.

[0004] Japanese Patent Application Laid-Open No. 2005-229449

[0005] However, in Patent Document 1, if, for example, a mountain climbing report has not been submitted and the mountain the victim climbed is unknown, it may not be possible to search for the victim from the air.

[0006] Non-limiting examples of the present disclosure contribute to providing a terminal, a search system, and a search method that can appropriately search for mountain victims who are lost.

[0007] A terminal according to one embodiment of the present disclosure is a terminal that communicates wirelessly with a search device used to search for mountain survivors, and includes a public wireless communication unit that communicates with a server via a public wireless network, a satellite receiving unit that receives satellite signals from satellites, and a control unit that transmits to the server the location information of the terminal obtained based on the satellite signals and an identifier of the terminal.

[0008] A search system according to one embodiment of the present disclosure is a search system comprising a terminal that communicates wirelessly with a search device used to search for mountain survivors, and a server, wherein the terminal comprises a public wireless communication unit that communicates with the server via a public wireless network, a satellite receiving unit that receives satellite signals from a satellite, and a control unit that transmits to the server location information of the terminal acquired based on the satellite signals and an identifier of the terminal, and the server comprises a control unit, a location information DB (database) that stores the location information transmitted from the terminal in association with the identifier, and a user information DB that stores user information in association with the identifier of the terminal, and when user information is input, the control unit of the server refers to the user information DB to acquire the identifier corresponding to the user information, and then refers to the location information DB to acquire the location information corresponding to the acquired identifier.

[0009] In one embodiment of the search method disclosed herein, a terminal that wirelessly communicates with a search device used to search for mountain survivors communicates with a server via a public wireless network, receives satellite signals from a satellite, and transmits to the server the location information of the terminal obtained based on the satellite signals and an identifier of the terminal.

[0010] In one embodiment of the search method disclosed herein, a terminal that communicates wirelessly with a search device used to search for mountain survivors communicates with a server via a public wireless network, receives satellite signals from a satellite, and transmits to the server location information of the terminal obtained based on the satellite signals and an identifier of the terminal, the server associates the location information sent from the terminal with the identifier and stores them in a location information DB (database), and when user information is input, the server references the user information DB that stores user information and terminal identifiers in association with each other to obtain the identifier corresponding to the user information, and obtains the location information corresponding to the obtained identifier by referring to the location information DB.

[0011] According to an embodiment of the present disclosure, mountain climbers who are lost can be appropriately searched for.

[0012] FIG. 1 is a diagram showing an example of the configuration of a search system according to the present disclosure. FIG. 2 is a sequence diagram showing an example of the operation of the search system when a terminal is present within a communication area of ​​a 3GPP network. FIG. 3 is a diagram showing an example of the configuration of a location information DB of a server. FIG. 4 is a diagram showing an example of the configuration of a user information DB of a server. FIG. 5 is a diagram showing a movement route of a terminal. FIG. 6 is a flowchart showing an example of the operation of a terminal when the terminal is present outside the communication area of ​​a 3GPP network. FIG. 7 is a flowchart showing an example of the operation of a search device. FIG. 8 is a block diagram of a terminal. FIG. 9 is a diagram showing the relationship between battery voltage and time. FIG. 10 is a block diagram of a server. FIG. 11 is a block diagram of a search device. FIG. 12 is a sequence diagram showing an example of the operation of a search system according to a second embodiment. FIG. 13 is a diagram showing the relationship between battery voltage and time.

[0013] [First embodiment] <System configuration> Fig. 1 is a diagram showing an example configuration of a search system 1 according to the present disclosure. As shown in Fig. 1, the search system 1 includes a terminal 11, a server 12, and a search device 13. In addition to the search system 1, Fig. 1 also shows a satellite 14, a base station 15, and a network 16.

[0014] The three terminals 11 shown in Fig. 1 are the same terminal, and the diagram illustrates the movement of the same terminal 11. For example, the terminal 11 indicated by the arrow A1a in Fig. 1 is a terminal located at the home of user X (the user who owns the terminal 11). The terminal 11 indicated by the arrow A1b in Fig. 1 is a terminal that has moved from the home to the trailhead of Mt. Z, for example. The terminal 11 indicated by the arrow A1c in Fig. 1 is a terminal that has moved from the trailhead of Mt. Z to the middle of Mt. Z, for example.

[0015] The terminal 11 has a direct communication unit (not shown) that directly communicates wirelessly with the search device 13, a satellite receiving unit (not shown) that receives GPS (Global Positioning System) signals from a satellite 14, and a public wireless communication unit (not shown) that wirelessly communicates with a base station 15.

[0016] The direct communication unit has a function of directly communicating wirelessly with the searching device 13, and has a function of transmitting and receiving specific low-power radio waves such as in the 920 MHz band. The public wireless communication unit has a public wireless communication function that complies with the 3GPP (registered trademark) specifications, such as 4G or 5G, which allows bidirectional communication in both uplink and downlink.

[0017] The terminal 11 does not have a power switch. The terminal 11 has a charging terminal such as a USB (Universal Serial Bus) terminal, and becomes operational when the built-in battery is charged via the charging terminal. Therefore, before going out to climb a mountain, the user X charges the terminal 11 and makes the terminal 11 operational.

[0018] In the operating state, the direct communication unit of the terminal 11 continues to operate. In other words, in the operating state, the terminal 11 is in a state where it can be searched by the searching device 13 (a state where it can communicate wirelessly with the searching device 13). The power consumption of the direct communication unit is small, and even if the direct communication unit continues to operate, the battery consumption of the terminal 11 is small.

[0019] The server 12 is connected to a network 16, such as the Internet. The terminal 11 communicates with the server 12 via a wireless access network (public wireless network) including a base station 15 and the network 16.

[0020] The search device 13 is used to search for mountain survivors and is used by search teams searching for mountain survivors. The search device 13 is, for example, carried on a helicopter or mounted on a drone, and wirelessly communicates with the terminal 11 from the sky. The search device 13 identifies the location of the terminal 11 based on the wireless communication with the terminal 11.

[0021] For example, the communication area of ​​a public wireless network that complies with the 3GPP specifications covers areas where there are a certain number of people or where there is a certain amount of human traffic. On the other hand, from the trailhead to the summit, it is generally assumed that there are fewer people, and there are places that are not covered by the communication area of ​​the public wireless network. Also, in the mountains, there are places that are out of line of sight due to various obstacles such as mountain undulations, trees, and rocks.

[0022] In the following description, it is assumed that the home of user X who owns terminal 11 is within the communication area of ​​the public wireless network. It is assumed that there are areas from the trailhead toward the summit that are not covered by the communication area of ​​the public wireless network.

[0023] In the following description, the public wireless network is assumed to be a 3GPP network, and the terminal 11 is assumed to include a public wireless communication unit that complies with the 3GPP specifications for 3G, 4G, 5G or later.

[0024] In the above description, the search device 13 is carried on a helicopter and communicates wirelessly with the terminal 11 from the sky, but this is not limiting. The search device 13 may be carried by a search team on land and may also communicate wirelessly with the terminal 11 from the land. In the following description, the search device 13 is described as being carried on a helicopter and communicating wirelessly with the terminal 11 from the sky.

[0025] <Operation of Search System> Operation when Terminal 11 is in the communication area of ​​the 3GPP network Suppose that user X, who owns terminal 11, goes out to climb Mount Z. When user X leaves his home, the terminal is in the communication area of ​​the 3GPP network.

[0026] 2 is a sequence diagram showing an example of the operation of the search system 1 when the terminal 11 is present within the communication area of ​​the 3GPP network. As described above, when the terminal 11 is in an operating state, it is in a state where it can wirelessly communicate with the search device 13.

[0027] The terminal 11 receives a GPS signal from the satellite 14 (S1).

[0028] The terminal 11 acquires location information of the terminal 11 using the GPS signals from the satellite 14 (S2). The location information may be, for example, latitude and longitude.

[0029] The terminal 11 transmits the acquired location information and an identifier for identifying the terminal 11 to the server 12 via the base station 15 (3GPP network) and the network 16 (not shown in FIG. 2) (S3a, S3b). Note that the identifier of the terminal 11 is stored in advance in a non-volatile storage unit such as a ROM (Read Only Memory), for example, at the time of manufacture or shipment.

[0030] The server 12 stores the location information transmitted from the terminal 11, the identifier of the terminal 11, and the reception time in the storage unit (S4).

[0031] The terminal 11 repeats the processes of S1, S2, and S3a and S3b at regular intervals while it is within the communication area of ​​the 3GPP network. For example, the terminal 11 repeats the processes of S1, S2, and S3a and S3b at regular intervals while the user X moves through an urban area or the like from his home toward the trailhead of Mt. Z. Therefore, the server 12 stores in a memory unit location information of the user X moving from his home toward the trailhead of Mt. Z and an identifier of the terminal 11 carried by the user X.

[0032] It should be noted that, for example, if the terminal 11 enters a tunnel and is unable to receive GPS signals, or if the terminal 11 is located outside the communication area of ​​the 3GPP network, the terminal 11 does not transmit the location information and the identifier to the server 12 .

[0033] 3 is a diagram showing an example of the configuration of a location information DB (database) of the server 12. As shown in FIG. 3, the location information DB stores an identifier, a reception time, and location information. The location information DB is constructed in the storage unit of the server 12.

[0034] 2, the server 12 stores in the storage unit the location information, the identifier, and the reception time transmitted from the terminal 11. As shown in FIG. 3, the server 12 stores the identifier, the reception time, and the location information in a location information DB in the storage unit in association with each other.

[0035] Although FIG. 3 only shows the identifier, reception time, and location information of terminal 11, the location information DB of server 12 also stores the identifiers, reception times, and location information of other terminals (terminals of users other than user X).

[0036] 4 is a diagram showing an example of the configuration of the user information DB of the server 12. As shown in FIG. 4, the user information DB stores identifiers and user information. The user information DB is constructed in the storage unit of the server 12.

[0037] For example, the user information DB stores the identifier of the terminal 11 in association with user information such as the name and address of the user X who owns the terminal 11 .

[0038] 4 is stored in the user information DB of the server 12 when, for example, the user X subscribes to the mountain rescue service. The terminal 11 is assigned to the user X when, for example, the user X subscribes to the mountain rescue service.

[0039] Although Figure 4 only shows the identifier of terminal 11 and the user information of user X to whom terminal 11 is assigned, the user information DB of server 12 also stores identifiers of other terminals (terminals of users other than user X) and user information of users to whom other terminals are assigned.

[0040] Fig. 5 is a diagram showing the movement route of the terminal 11. As described in Fig. 2 and Fig. 3, the storage unit (position information DB) of the server 12 stores the position information of the terminal 11. Therefore, as shown in Fig. 5, by plotting the position information of the terminal 11 stored in the position information DB of the server 12 on a map, the movement route of the terminal 11 can be determined.

[0041] For example, A in Fig. 5 indicates the location of the home of user X who owns terminal 11. For example, B in Fig. 5 indicates the middle of Mount Z. The multiple black arrowheads in Fig. 5 indicate the points from which terminal 11 obtained location information.

[0042] Even in the mountains, if the communication area of ​​the 3GPP network is covered, the location information of user X in the mountains is stored in the server 12.

[0043] 6 is a flowchart showing an example of the operation of the terminal 11 when the terminal 11 is outside the communication area of ​​the 3GPP network. As described above, when the terminal 11 is in an operating state, the terminal 11 is in a state where it can wirelessly communicate with the searching device 13.

[0044] The terminal 11 turns off the satellite receiving unit and stops receiving GPS signals (S11).

[0045] The terminal 11 determines whether or not the terminal 11 is located within the communication area of ​​the 3GPP network (S12).

[0046] If the terminal 11 determines that it is not located within the communication area of ​​the 3GPP network (No in S12), it repeats the process of S12.

[0047] On the other hand, if the terminal 11 determines that it is located within the communication area of ​​the 3GPP network (Yes in S12), it turns on the satellite receiving unit and starts (resumes) receiving GPS signals (S13).Then, the terminal 11 ends the processing of this flowchart.

[0048] When the terminal 11 finishes the processing of this flowchart, it executes (resumes) the processing of S1, S2, S3a, and S3b described in Fig. 2. That is, the terminal 11 acquires its location information from the GPS signal and transmits it to the server 12.

[0049] Here, for example, suppose that a distress report is filed by a family member of user X. The search team accesses the server 12 and acquires the route that user X has taken.

[0050] For example, the search team inputs user information such as the name and address of user X who has filed a distress report to the server 12. Based on the input user information, the server 12 refers to the user information DB shown in Fig. 4 and acquires the identifier of the terminal 11 owned by user X. Based on the acquired identifier of terminal 11, the server 12 refers to the location information DB shown in Fig. 3 and acquires location information of terminal 11. Based on the acquired location information, the server 12 displays the movement route of terminal 11 (user X) on a display (see, for example, Fig. 5).

[0051] This allows the search team to estimate or narrow down the location of user X's distress based on, for example, user X's travel route and / or last location information, and to limit the search range from the air using the search device 13. In particular, if the communication area of ​​the 3GPP network covers even in the mountains, it may be possible to further limit the search range from the air using the search device 13.

[0052] Furthermore, for example, even if the family of user X does not know the mountain that user X climbed, or if user X forgets to submit a mountain climbing notification, the search team can estimate the mountain (or mountain range) that user X climbed from the movement route and / or last position information of terminal 11 stored in server 12. Then, the search team can limit the search range from the air using search device 13.

[0053] 7 is a flowchart showing an example of the operation of the searching device 13. As described above, when the terminal 11 is in an operating state, it is in a state in which it can communicate wirelessly with the searching device 13.

[0054] The search device 13 determines whether or not wireless communication has been established with the terminal 11 (S21). The search device 13 is carried, for example, on a helicopter, and attempts to establish wireless communication with the terminal 11 from the sky.

[0055] If wireless communication with the terminal 11 has not been established (No in S21), the searching device 13 repeats the process of S21.

[0056] When wireless communication with the terminal 11 is established (Yes in S21), the searching device 13 calculates location information such as the distance and direction to the terminal 11 based on the signal transmitted from the terminal 11 (S22).

[0057] The search device 13 displays the calculated position information on the display (S23).

[0058] By the operations described with reference to FIGS. 2 to 7, the search system 1 can appropriately search for the user X who is lost in the mountains.

[0059] <Block Configuration> Fig. 8 is a block diagram of the terminal 11. As shown in Fig. 8, the terminal 11 has a control unit 21, a storage unit 22, a public wireless communication unit 23, a satellite receiving unit 24, a direct communication unit 25, a battery 26, and a terminal 27.

[0060] The control unit 21 controls the entire terminal 11. The control unit 21 may be configured, for example, by a CPU (Central Processing Unit).

[0061] The storage unit 22 stores an operating system (OS) program for the control unit 21 to operate, application programs, data, and an identifier for identifying the terminal 11. The storage unit 22 may be configured, for example, with a ROM and a RAM (Random Access Memory).

[0062] The public wireless communication unit 23 communicates wirelessly with the base station 15 via, for example, a 3GPP public wireless network. The public wireless communication unit 23 may be configured, for example, by an IC (Integrated Circuit) chip.

[0063] The satellite receiving unit 24 receives satellite signals such as GPS signals transmitted from the satellites 14. The satellite receiving unit 24 may be configured, for example, by an IC chip.

[0064] Direct communication unit 25 communicates directly and wirelessly with searching device 13 using specified low-power radio. Direct communication unit 25 may be configured, for example, with an IC chip. Direct communication unit 25 is capable of wireless communication with searching device 13 when battery 26 is charged and in an operating state.

[0065] The battery 26 is, for example, a secondary battery. The battery 26 is charged via a terminal 27 such as a USB terminal. The battery 26 supplies power to each component.

[0066] The control unit 21 realizes the following functions by executing application programs stored in the storage unit 22, for example.

[0067] The control unit 21 transmits the location information of the terminal 11 acquired based on the satellite signals and the identifier of the terminal 11 to the server 12 via the public wireless network.

[0068] When the terminal 11 is within the communication area of ​​the public wireless network, the control unit 21 turns on the satellite receiving unit 24. For example, the control unit 21 supplies power from the battery 26 to the satellite receiving unit 24 to turn on the satellite receiving unit 24.

[0069] When the terminal 11 is outside the communication area of ​​the public wireless network, the control unit 21 turns off the satellite receiving unit 24. For example, the control unit 21 stops the supply of power from the battery 26 to the satellite receiving unit 24, thereby turning off the satellite receiving unit 24.

[0070] 9 is a diagram showing the relationship between time and the voltage of the battery 26. For example, the user X charges the battery 26 of the terminal 11 at home and goes hiking up Mt. Z with the terminal 11 in hand.

[0071] 9, when the terminal 11 is present within the communication area of ​​the public wireless network, it turns on the satellite receiving unit 24 and acquires location information of the terminal 11 based on the GPS signals received by the satellite receiving unit 24. The terminal 11 transmits the acquired location information and identification information of the terminal 11 to the server 12. The terminal 11 is in a state where it can wirelessly communicate with the search device 13.

[0072] 9, when the terminal 11 is outside the communication area of ​​the public wireless network, the terminal 11 turns off the satellite receiving unit 24. The terminal 11 does not transmit the acquired location information and the identification information of the terminal 11 to the server 12. The terminal 11 is in a state where it can communicate wirelessly with the search device 13.

[0073] Therefore, the voltage drop of the battery 26 when the terminal 11 is outside the communication area of ​​the public wireless network (see waveform A9c in FIG. 9) is slower than the voltage drop when the terminal 11 is inside the communication area of ​​the public wireless network (see waveform A9d in FIG. 9). This allows the terminal 11 to extend its battery life and extend the period in which it can communicate wirelessly with the searching device 13.

[0074] Fig. 10 is a block diagram of the server 12. As shown in Fig. 10, the server 12 includes a control unit 31, a storage unit 32, a communication unit 33, and a display unit .

[0075] The control unit 31 controls the entire server 12. The control unit 31 may be configured with, for example, a CPU.

[0076] The storage unit 32 stores an OS program, application programs, and data for operating the control unit 31. The storage unit 32 may be configured with, for example, a hard disk drive (HDD), a ROM, and a RAM.

[0077] A location information DB 32a and a user information DB 32b are constructed in the storage unit 32. The location information DB 32a stores, for example, the information shown in Fig. 3. The user information DB 32b stores, for example, the information shown in Fig. 4.

[0078] The communication unit 33 communicates with the terminal 11 via the network 16 and the public wireless network.

[0079] The display unit 34 displays an image on a display (not shown) under the control of the control unit 31 .

[0080] The control unit 31 realizes the following functions by processing application programs stored in the storage unit 32, for example.

[0081] When user information is input, the control unit 31 refers to the user information DB 32b and acquires an identifier corresponding to the input user information. The control unit 31 then refers to the location information DB 32a and acquires location information corresponding to the acquired identifier.

[0082] The control unit 31 controls the display unit 34 to display the acquired position information on the display.

[0083] 11 is a block diagram of the search device 13. As shown in FIG. 11, the search device 13 includes a control unit 41, a storage unit 42, a communication unit 43, and a display unit 44.

[0084] The control unit 41 controls the entire searching device 13. The control unit 41 may be configured with, for example, a CPU.

[0085] The storage unit 42 stores an OS program, application programs, and data for operating the control unit 41. The storage unit 42 may be configured with, for example, a ROM and a RAM.

[0086] The communication unit 43 directly communicates wirelessly with the terminal 11 using specified low-power radio.

[0087] The display unit 44 displays an image on a display (not shown) based on the control of the control unit 41 .

[0088] The control unit 41 realizes the following functions by processing an application program stored in the storage unit 42, for example.

[0089] When the communication unit 43 establishes wireless communication with the terminal 11, the control unit 41 calculates location information such as the distance and direction of the terminal 11 based on a signal transmitted from the terminal 11. The control unit 41 controls the display unit 44 to display the calculated location information and the identified identifier on the display.

[0090] <Summary of First Embodiment> As described above, the terminal 11 wirelessly communicates with the search device 13 used to search for mountain climbers. The terminal 11 communicates with the server 12 via a public wireless network. The terminal 11 receives satellite signals from a satellite 14. The terminal 11 transmits its location information and its identifier, acquired based on the satellite signals, to the server 12 via the public wireless network.

[0091] The server 12 stores in the location information DB 32a the location information transmitted from the terminal 11 in association with the identifier. The server 12 includes a user information DB 32b that stores user information in association with the terminal identifier. When user information is input, the server 12 refers to the user information DB 32b to acquire the identifier corresponding to the user information, and then refers to the location information DB 32a to acquire the location information corresponding to the acquired identifier.

[0092] This operation allows the search team to properly search for the mountain victim. For example, terminal 11 transmits its location information to server 12 via a public wireless network, and server 12 stores the location information of terminal 11. Server 12 acquires the location information (location information of the victim) in the user information of the victim entered by the search team. Based on the location information acquired by server 12, the search team can estimate (narrow down) the location of the victim and properly search for the victim using search device 13.

[0093] <Modification 1> In the above, when the terminal 11 is in an operating state, the direct communication unit 25 is in a state in which it can communicate wirelessly with the search device 13, but this is not limited to this. The direct communication unit 25 may stop being able to communicate wirelessly with the search device 13 while the location information of the terminal 11 is being acquired using satellite signals. For example, the supply of power from the battery 26 to the direct communication unit 25 may be stopped. This allows the terminal 11 to further reduce power consumption.

[0094] <Variation 2> When the searching device 13 transmits a searching signal (calling signal) including an identifier and the terminal 11 receives the searching signal including its own identifier, the terminal 11 may transmit a response signal including its own identifier. When the searching device 13 receives the response signal from the terminal 11, the terminal 11 may transmit a response confirmation signal to the terminal 11. The terminal 11 and the searching device 13 may repeatedly exchange response signals and confirmation signals, and the searching device 13 may calculate the position of the terminal 11 based on the response signal transmitted from the terminal 11.

[0095] <Modification 3> Although the terminal 11 acquires its location information based on a GPS signal, this is not limiting. For example, the terminal 11 may acquire an identifier of the base station 15 (acquire area information of the 3GPP network) and transmit it to the server 12. The server 12 may acquire location information, such as the area where the terminal 11 is located, based on the area information transmitted from the terminal 11. When the terminal 11 transmits area information to the server 12, the terminal 11 does not need to include the satellite receiving unit 24.

[0096] <Modification 4> When the server 12 receives the location information from the terminal 11, the server 12 may transmit a response signal to the terminal 11. For example, when the terminal 11 does not receive a response signal from the server 12 within a predetermined time after transmitting the location information, the terminal 11 may retransmit the location information.

[0097] <Modification 5> Although the terminal 11 has been described as periodically acquiring location information and repeatedly transmitting the location information to the server 12, this is not limiting. The terminal 11 may acquire its location information and transmit it to the server 12 in response to an instruction from the server 12.

[0098] [Second embodiment] In the first embodiment, a public wireless network conforming to the 3GPP specifications has been described as an example. In the second embodiment, a unidirectional public wireless network with only uplink, such as ELTRES (registered trademark), will be described as an example. In the second embodiment, differences from the first embodiment will be described. The base station 15 shown in Fig. 1 is an ELTRES base station. The terminal 11 has a public wireless communication function conforming to the ELTRES specifications.

[0099] <Operation of Search System> Fig. 12 is a sequence diagram showing an example of operation of the search system 1 according to the second embodiment. The terminal 11 repeats the processing of the sequence shown in Fig. 12 at regular intervals. Note that, as in the first embodiment, when the terminal 11 is in an operating state, it is in a state in which it can wirelessly communicate with the search device 13.

[0100] The terminal 11 determines whether the remaining battery power of the battery 26 is equal to or less than a threshold (S31). The remaining battery power may be interpreted as the battery voltage.

[0101] When the terminal 11 determines that the remaining battery power is not equal to or less than the threshold (No in S31), the terminal 11 receives a GPS signal from the satellite 14 (S32).

[0102] The terminal 11 acquires its own location information using the GPS signal from the satellite 14 (S33).

[0103] The terminal 11 transmits the acquired location information and an identifier that identifies the terminal 11 to the server 12 via the base station 15 (a network that complies with the ELTRES specifications) and the network 16 (not shown in Figure 12) (S34a, S34b).

[0104] The server 12 stores the location information transmitted from the terminal 11, the identifier of the terminal 11, and the reception time in the storage unit (S35).

[0105] When the terminal 11 determines in S31 that the remaining battery power is equal to or less than the threshold value (Yes in S31), the terminal 11 ends the processing of this sequence.

[0106] 13 is a diagram showing the relationship between time and the voltage of the battery 26. For example, the user X charges the battery 26 of the terminal 11 at home and goes hiking up Mt. Z with the terminal 11 in hand.

[0107] 13 , when the voltage of the battery 26 exceeds the threshold, the terminal 11 turns on the satellite receiving unit 24 and acquires location information of the terminal 11 based on the GPS signals received by the satellite receiving unit 24. The terminal 11 transmits the acquired location information and identification information of the terminal 11 to the server 12. The terminal 11 is in a state where it can wirelessly communicate with the search device 13.

[0108] 13, when the voltage of the battery 26 is equal to or lower than the threshold, the terminal 11 turns off the satellite receiving unit 24. The terminal 11 does not transmit the location information of the terminal 11 and the identification information of the terminal 11 to the server 12. The terminal 11 is in a state where it can communicate wirelessly with the search device 13.

[0109] Therefore, the voltage drop of the battery 26 when the voltage of the battery 26 is below the threshold (see waveform A13c in FIG. 13) is slower than the voltage drop of the battery 26 when the voltage of the battery 26 exceeds the threshold (see waveform A13d in FIG. 13). This allows the terminal 11 to extend the battery life and extend the period in which it can communicate wirelessly with the searching device 13.

[0110] <Block Configuration> The blocks of the terminal 11 are the same as those shown in Fig. 8. However, the public wireless communication unit 23 has a public wireless communication function of ELTRES.

[0111] The control unit 21 realizes the following functions by executing application programs stored in the storage unit 22, for example.

[0112] When the remaining charge of battery 26 exceeds the threshold, control unit 21 turns on satellite receiving unit 24. For example, control unit 21 supplies power from battery 26 to satellite receiving unit 24 to turn on satellite receiving unit 24.

[0113] When the remaining charge of battery 26 is equal to or less than a threshold, control unit 21 turns off satellite receiving unit 24. For example, control unit 21 stops the supply of power from battery 26 to satellite receiving unit 24, thereby turning off satellite receiving unit 24.

[0114] The blocks of the server 12 are similar to those shown in Fig. 10. The blocks of the search device 13 are similar to those shown in Fig. 11.

[0115] <Summary of the second embodiment> Even if the public wireless network is an ELTRES network, the search team can estimate (narrow down) the location of the missing person based on the location information acquired by the server 12, and appropriately search for the missing person using the search device 13.

[0116] ELTRES has a long communication distance, and it is highly likely that the location information of user X in the mountains is stored in the server 12. Therefore, when the ELTRES network is used as the public wireless network, the search team can narrow down the location of the victim and use the search device 13 to search for the victim.

[0117] <Variation 1> The search device 13 may have an ELTRES base station function. The search device 13 having the ELTRES base station function may directly receive location information based on GPS signals from the terminal 11 and display the received location information on a display. In this case, for example, the display of the search device 13 displays location information such as latitude and longitude based on the GPS signals, allowing a search team on board a helicopter to quickly search for a person in distress.

[0118] <Modification 2> The first embodiment and the second embodiment may be combined. The public wireless communication unit 23 of the terminal 11 may have a 3GPP public wireless communication function and an ELTRES public wireless communication function.

[0119] When the terminal 11 is located outside the 3GPP communication area, the public wireless communication unit 23 of the terminal 11 may turn off the 3GPP public wireless communication function and turn on the ELTRES public wireless communication function, and transmit location information via the ELTRES network.

[0120] The disclosures of the specification, drawings and abstract contained in Japanese Patent Application No. 2023-205476, filed December 5, 2023, are incorporated herein by reference in their entirety.

[0121] The terminal and server of the present disclosure are useful for searching for mountain distress victims.

[0122] REFERENCE SIGNS LIST 1 Search system 11 Terminal 12 Server 13 Search device 14 Satellite 15 Base station 16 Network 21, 31, 41 Control unit 22, 32, 42 Storage unit 23 Public wireless communication unit 24 Satellite receiving unit 25 Direct communication unit 26 Battery 27 Terminal 32a Location information DB 32b User information DB 33, 43 Communication unit 34, 44 Display unit

Claims

1. A terminal that wirelessly communicates with a search device used to search for mountain victims, the terminal having: a public wireless communication unit that communicates with a server via a public wireless network; a satellite receiving unit that receives satellite signals from satellites; and a control unit that transmits to the server the location information of the terminal obtained based on the satellite signals and an identifier of the terminal.

2. The terminal of claim 1, wherein the control unit turns on the satellite receiving unit when the terminal is within a communication area of ​​the public wireless network, and turns off the satellite receiving unit when the terminal is outside the communication area of ​​the public wireless network.

3. The terminal according to claim 2, wherein the signal for wireless communication with the search device is a specific low-power radio signal, and the public wireless network is a network conforming to the 3GPP (registered trademark) specifications.

4. The terminal according to claim 1, wherein the control unit turns on the satellite receiving unit when the remaining battery charge of the terminal exceeds a threshold, and turns off the satellite receiving unit when the remaining battery charge of the terminal is equal to or less than the threshold.

5. The terminal according to claim 4, wherein the signal for wireless communication with the search device is a specific low-power radio signal, and the public wireless network is a network conforming to the ELTRES (registered trademark) specification.

6. A search system comprising a terminal which wirelessly communicates with a search device used in searching for mountain survivors, and a server, wherein the terminal comprises: a public wireless communication unit which communicates with the server via a public wireless network; a satellite receiving unit which receives satellite signals from a satellite; and a control unit which transmits to the server location information of the terminal acquired based on the satellite signals and an identifier of the terminal; and the server comprises: a control unit; a location information DB (database) which associates and stores the location information transmitted from the terminal with the identifier; and a user information DB which associates and stores user information with the identifier of the terminal, wherein when user information is input, the control unit of the server refers to the user information DB to acquire the identifier corresponding to the user information, and refers to the location information DB to acquire the location information corresponding to the acquired identifier.

7. A search method in which a terminal that wirelessly communicates with a search device used to search for mountain victims communicates with a server via a public wireless network, receives satellite signals from a satellite, and transmits to the server location information of the terminal obtained based on the satellite signals and an identifier of the terminal.

8. A search method in which a terminal that wirelessly communicates with a search device used to search for mountain victims communicates with a server via a public wireless network, receives satellite signals from a satellite, and transmits to the server location information of the terminal obtained based on the satellite signals and an identifier of the terminal, the server associates the location information and the identifier transmitted from the terminal and stores them in a location information DB (database), when user information is input, refers to a user information DB that associates and stores user information and terminal identifiers to obtain the identifier corresponding to the user information, and refers to the location information DB to obtain the location information corresponding to the obtained identifier.

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