Communication system, communication device, mobile body, and computer program

Abstract

To maintain a collection of information from each sensor in a collection device even in the case where fault occurs in a communication path between a sensor and the collection device.SOLUTION: A communication apparatus comprises: a first communication part that communicates with a plurality of terminal devices in radio in a first communication protocol; a second communication part that communicates with a second communication protocol that is different from the first communication protocol; and a control part that communicates with a collection device in a normal path by using the second communication part in the case where it can be communicated with the collection device in the normal path as a communication path communicated with the collection device in the second communication protocol, and that communicates with the collection device in an alternative path as a communication path that is different from the normal path by using the first communication part in the case where it is not communicated with the collection device in the normal path.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to communication technology.

Background Art

[0002] In recent years, with the advancement of IoT (Internet of Things) technology, various sensors have been placed in various locations, and it has become possible to acquire and centrally manage their information through wireless communication or the like. For example, in the technology disclosed in Patent Document 1, in a river and flood control information system, information acquired by sensors such as water level gauges and rain gauges is aggregated via a network and managed in a collection device such as a server.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, if an abnormality occurs in the communication environment due to the occurrence of a disaster or the like, it may become difficult to transmit information from each sensor to the collection device. Such a problem is not limited to the occurrence of a disaster, but is a common problem when a failure occurs in the communication path between the sensor and the collection device. In view of the above circumstances, an object of the present invention is to provide a technology that enables the collection device to maintain the collection of information from each sensor even when a failure occurs in the communication path between the sensor and the collection device.

Means for Solving the Problems

[0005] One aspect of the present invention is a communication system including a communication device and a relay device. The communication device includes a first communication unit that wirelessly communicates with a plurality of terminal devices using a first communication protocol, a second communication unit that communicates using a second communication protocol different from the first communication protocol, and a control unit that, when it is possible to communicate with the collection device via a normal path, which is a communication path for communicating with the collection device using the second communication protocol, communicates with the collection device via the normal path using the second communication unit, and when it is not possible to communicate with the collection device via the normal path, communicates with the collection device via an alternative path, which is a communication path different from the normal path, using the first communication unit. The relay device includes a first communication unit that wirelessly communicates with the first communication protocol, a second communication unit that communicates using a second communication protocol different from the first communication protocol, and a control unit that, when receiving data from the communication device using the first communication protocol, transmits the received data to the collection device using the second communication unit.

[0006] One aspect of the present invention is a communication device including a first communication unit that wirelessly communicates with a plurality of terminal devices using a first communication protocol, a second communication unit that communicates using a second communication protocol different from the first communication protocol, and a control unit that, when it is possible to communicate with the collection device via a normal path, which is a communication path for communicating with the collection device using the second communication protocol, communicates with the collection device via the normal path using the second communication unit, and when it is not possible to communicate with the collection device via the normal path, communicates with the collection device via an alternative path, which is a communication path different from the normal path, using the first communication unit.

[0007] One aspect of the present invention is the above communication device, wherein when the control unit receives communication data including information encrypted with an encryption key corresponding to each device from a plurality of terminal devices, it generates and transmits data by associating the encrypted information of each terminal device with identification information indicating each terminal device.

[0008] One aspect of the present invention is the above communication device, wherein the control unit changes the size of data transmitted from the terminal device according to the SF value.

[0009] One aspect of the present invention is the above-described communication device, wherein the first communication protocol is LoRaWAN.

[0010] One aspect of the present invention is the above-described communication device, further comprising a battery for storing power for driving the device itself.

[0011] One aspect of the present invention is a relay device comprising: a first communication unit that wirelessly communicates using a first communication protocol used by a terminal device and a communication device for wireless communication; a second communication unit that communicates using a second communication protocol different from the first communication protocol; and a control unit that, when receiving data by the first communication protocol from the communication device, transmits the received data to a collection device using the second communication unit.

[0012] One aspect of the present invention is a moving body equipped with the above-described relay device.

[0013] One aspect of the present invention is a computer program for causing a computer to function as the above-described communication device or relay device.

[0014] One aspect of the present invention is a moving body equipped with the above-described communication device.

[0015] One aspect of the present invention is the above-described communication device, wherein the terminal device is a device capable of acquiring predetermined safety information.

[0016] One aspect of the present invention is the above-described communication device, which communicates with the collection device via the alternative path even if it was communicable via the normal path when the test function is set to on.

Advantages of the Invention

[0017] According to the present invention, even when a failure occurs in the communication path between the sensor and the collection device, it is possible to maintain the collection of information from each sensor in the collection device.

Brief Description of the Drawings

[0018]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Embodiments for Carrying Out the Invention

[0019] Hereinafter, specific configuration examples of the present invention will be described with reference to the drawings. FIG. 1 is a schematic block diagram showing the system configuration of the communication system 100 of the present invention. The communication system 100 includes a plurality of terminal devices 10, a communication device 20, a collection device 30, and a relay device 40. The terminal device 10 and the communication device 20 perform data communication with each other by wireless communication using a predetermined protocol. The communication device 20, the collection device 30, and the relay device 40 can communicate with each other via a communication network 90. The communication network 90 may be configured using a wireless communication network or may be configured using a wired communication network. The communication network 90 may be configured by combining a plurality of types of networks. The communication network 90 may be a network including, for example, the Internet.

[0020] The terminal device 10 is configured using sensors. The sensors applied to the terminal device 10 can be of any type. For example, it can be a so-called IoT (Internet of Things) device. For example, sensors for acquiring information such as water level, temperature, atmospheric pressure, sound, wind speed, pressure, etc. may be used. For example, a device for reading an image (an image in which information is encoded) such as a two-dimensional barcode may be used as the terminal device 10. As a specific example of such a terminal device 10, there is an information device equipped with a camera (for example, a single-board computer or a microcomputer). The terminal device 10 includes a storage battery, a wireless communication device, and a processor. The terminal device 10 operates with the power stored in the storage battery. The terminal device 10 may include a generator (for example, a solar power generator or a wind power generator, etc.) and operate with the power generated by the generator. The terminal device 10 generates data including the information acquired by the sensors and transmits the data to the communication device 20 using a predetermined wireless communication protocol. Any wireless communication protocol may be used between the terminal device 10 and the communication device 20. However, it is desirable to use a wireless communication protocol with lower power consumption per unit time. For example, the LPWA (Low Power Wide Area) network standard may be applied. More specifically, LoRaWAN may be applied. The activation method of the terminal device 10 may be, for example, the ABP method.

[0021] The terminal device 10 may generate and transmit communication data including encrypted data (encrypted data). A plurality of terminal devices 10 transmit communication data at timings set for each of them. The encryption key used for generating the encrypted data is a different encryption key for each terminal device 10. The communication device 20 may store in association a predetermined communication timing for each terminal device 10 and a decryption key necessary for decrypting the encrypted data of each terminal device 10. With such a configuration, the communication device 20 that has received the encrypted data can decrypt the encrypted data using the decryption key corresponding to the timing. Further, the communication device 20 may store in association identification information (for example, address information) indicating each terminal device 10 with each decryption key. When generating transfer data including a plurality of communication data, the communication device 20 generates the transfer data in association with the information included in each communication data and the identification information corresponding to the information. With such a configuration, a device (for example, the collection device 30) that has received transfer data including a plurality of information can appropriately decrypt the encrypted data from the transfer data including a plurality of information by storing the identification information and the decryption key in association. When generating transfer data by associating identification information with encrypted information, for example, the identification information and the encrypted information corresponding thereto may be arranged adjacent to each other in the transfer data.

[0022] The communication device 20 generates data (transfer data) including the information received from each terminal device 10 and transmits the transfer data to the collection device 30. The communication device 20 normally transmits the transfer data to the collection device 30 via a predetermined communication path. The communication path used normally is referred to as the "normal path" in the following description. When an abnormality has occurred in the predetermined communication path (hereinafter referred to as "abnormal time"), the communication device 20 transmits the transfer data to the communication device 20 via a communication path different from the normal path (hereinafter referred to as "alternate path").

[0023] FIG. 2 is a diagram showing an outline of a normal route. In FIG. 2, a communication path 91 that connects to the communication network 90 without passing through the relay device 40 from the communication device 20 and reaches the collection device 30 via the communication network 90 corresponds to the normal route.

[0024] FIG. 3 is a diagram showing an outline of an alternative route. In FIG. 3, a communication path 92 that connects to the communication network 90 via the relay device 40 from the communication device 20 and reaches the collection device 30 via the communication network 90 corresponds to the alternative route. In the alternative route, it is possible to reach the collection device 30 without using the network that connects the communication device 20 and the communication network 90 in the normal route or the communication network in the area physically close to the communication device 20 in the communication network 90.

[0025] For example, in FIG. 3, by communicating using the alternative route, the communication device 20 can transmit transfer data to the collection device 30 without passing through the communication section shown as the target section. Therefore, even if a communication failure occurs due to a disaster or the like in the target section, the communication device 20 can transmit transfer data to the collection device 30 by using the alternative route. Specific examples of such failures include communication failures caused by the stoppage of communication equipment due to a power outage in the target section. Another specific example of such a failure is a communication failure caused by a large-scale congestion occurring in the target section.

[0026] FIG. 4 is a diagram showing a specific example of the configuration of the communication device 20. The communication device 20 is configured using communication equipment. The communication device 20 includes a first communication section 21, a second communication section 22, a communication condition storage section 23, a control section 24, and a storage battery 25.

[0027] The first communication unit 21 is configured using a network interface. The first communication unit 21 communicates with other devices via wireless communication. The first communication unit 21 may communicate, for example, using LoRaWAN. The first communication unit 21 communicates with the terminal device 10 via wireless communication using a predetermined wireless communication protocol, for example, during normal times. At this time, two-way communication can be realized in the wireless communication between the terminal device 10 and the first communication unit 21. The first communication unit 21 communicates with the relay device 40 via wireless communication using a predetermined wireless communication protocol, for example, during abnormal times.

[0028] The second communication unit 22 is configured using a network interface. The second communication unit 22 communicates with other devices via a communication path. The second communication unit 22 communicates with the collection device 30 via a normal path, for example. The second communication unit 22 may be connected to the communication network 90 by wired communication and communicate with the collection device 30, for example. In this case, the communication path from the second communication unit 22 to the communication network 90 via the wired communication path is also part of the normal path. The second communication unit may be connected to the communication network 90 by mobile communication and communicate with the collection device 30, for example. In this case, the second communication unit 22 may be provided with a SIM card, for example. In this case, the communication path from the second communication unit 22 to the communication network 90 via the base station device of the mobile communication network is also part of the normal path. The second communication unit 22 may communicate using, for example, the TCP / IP protocol or the UDP protocol.

[0029] The communication condition storage unit 23 is configured using a storage device such as a magnetic hard disk device or a semiconductor storage device. The communication condition storage unit 23 stores information indicating conditions (communication conditions) for determining whether an abnormality has occurred in the normal path. The communication condition storage unit 23 may store, for example, as a condition that a Ping command is sent to the collection device 30 and no Ping returns even after a predetermined time has elapsed. The communication condition storage unit 23 may store any conditions as long as they are conditions indicating communication abnormalities. How to define communication abnormalities based on what conditions may be appropriately determined by the designers or operators of the communication system 100.

[0030] The control unit 24 includes a processor and a memory connected by a bus. By executing a control program, the control unit 24 functions as a communication control unit 241 and a determination unit 242. Note that all or part of each function of the communication control unit 241 and the determination unit 242 may be realized using hardware such as an ASIC (Application Specific Integrated Circuit), a PLD (Programmable Logic Device), or an FPGA (Field Programmable Gate Array). The control program may be recorded on a computer-readable recording medium. A computer-readable recording medium is, for example, a portable medium such as a flexible disk, a magneto-optical disk, a ROM, a CD-ROM, a semiconductor storage device (e.g., SSD: Solid State Drive), or a storage device such as a hard disk or a semiconductor storage device built into a computer system. The control program may be transmitted via a telecommunication line.

[0031] The communication control unit 241 controls the operation of the communication device 20. For example, when the communication control unit 241 receives communication data from the terminal device 10, it extracts the information included in the payload of the received communication data and generates transfer data. The destination of the transfer data may be the collection device 30. One transfer data may include information from the payloads of a plurality of communication data. In such a case, the transfer data is generated by associating the information of each payload with the identification information (e.g., address) of the terminal device 10 that is the source of that payload. With this configuration, even if information from a plurality of communication data (especially encrypted data) is included in one transfer data, the receiving device (e.g., the collection device 30) can decrypt each encrypted data with an appropriate decryption key. The communication control unit 241 transmits the generated transfer data to the collection device 30 using the communication path determined by the determination unit 242.

[0032] For example, when the communication control unit 241 determines that the normal path is to be used by the determination unit 242, it transmits the transfer data via the normal path using the second communication unit 22. On the other hand, when the determination unit 242 determines that the alternative path is to be used, it transmits the transfer data via the alternative path using the first communication unit 21. Specifically, it operates as follows. When the determination unit 242 determines that the alternative path is to be used, the first communication unit 21 transmits the transfer data to the alternative path including the relay device 40 instead of communicating with the terminal device 10 (for example, stopping the communication). In other words, the first communication unit 21 serves as the receiver of the terminal device 10 and the transmitter to the relay device 40. The communication control unit 241 may change the data size of the communication data transmitted from each terminal device 10 according to the SF value (Spreading Factor value). Such control may be performed, for example, by the communication control unit 241 transmitting a predetermined control signal to each terminal device 10.

[0033] The determination unit 242 determines whether to use the normal path or the alternative path. The determination unit 242 determines the path based on whether a predetermined condition (communication condition) is satisfied for the normal path. For example, when the condition indicated by the communication condition (a condition indicating that an abnormality has occurred) is satisfied, the determination unit 242 determines to use the alternative path. On the other hand, when the condition indicated by the communication condition (a condition indicating that an abnormality has occurred) is not satisfied, the determination unit 242 determines to use the normal path.

[0034] The storage battery 25 stores electric power for the operation of the communication device 20. The amount of electric power that the storage battery 25 can store is appropriately determined by the designer or operator of the communication system 100. The storage battery 25 is preferably configured to store an amount of electric power that enables it to operate for at least the period during which it is desired to collect the information acquired by the terminal device 10.

[0035] The collection device 30 is configured using an information processing device such as a server device. Specific examples of the collection device 30 include, for example, a data server, a combination of a data server and an application server, and the like. The collection device 30 communicates with the communication device 20 via a communication path and receives transfer data from the communication device 20. The collection device 30 acquires the information acquired by each terminal device 10 from the payload of the received transfer data.

[0036] FIG. 5 is a diagram showing a specific example of the configuration of the relay device 40. The relay device 40 is configured using communication equipment (such as an embedded microcomputer or a personal computer, etc.). The relay device 40 may be configured as a mobile body equipped with communication equipment. Specific examples of such mobile bodies include automobiles, railway vehicles, airplanes, drones, artificial satellites (especially low-earth orbit satellites), and the like. The relay device 40 includes a first communication unit 41, a second communication unit 42, a communication control unit 43, and a storage battery 44.

[0037] The first communication unit 41 is configured using a network interface. The first communication unit 41 communicates with other devices by wireless communication. The first communication unit 41 communicates with the communication device 20 by wireless communication using, for example, a predetermined wireless communication protocol. Such a predetermined wireless communication protocol may be, for example, the same communication protocol used when the terminal device 10 and the communication device 20 communicate. A specific example is LoRaWAN. The first communication unit 41 includes a directional antenna 411 and a drive unit 412. The directional antenna 411 receives wireless signals flying from a specific direction with higher sensitivity by forming beamforming. The drive unit 412 is an actuator that changes the direction of the directional antenna 411. The directional antenna 411 and the drive unit 412 may be controlled by, for example, the communication control unit 43.

[0038] The second communication unit 22 is configured using a network interface. The second communication unit 22 communicates with other devices via a communication path. The second communication unit 22 communicates with the collection device 30, for example, via a properly operating communication path. The second communication unit 22 may be connected to the communication network 90 by wired communication and communicate with the collection device 30. In this case, the communication path from the communication network 90 connected via the wired communication path from the second communication unit 22 to the collection device 30 is in a communicable state. Thus, it is desirable that the communication path from the second communication unit 22 to the collection device 30 be appropriately set by, for example, the operator of the relay device 40 or the like.

[0039] The communication control unit 43 includes a processor and a memory connected by a bus. The communication control unit 43 functions by executing a communication control program. Note that all or part of the functions of the communication control unit 43 may be realized using hardware such as an ASIC, a PLD, or an FPGA. The communication control program may be recorded on a computer-readable recording medium. A computer-readable recording medium is, for example, a portable medium such as a flexible disk, a magneto-optical disk, a ROM, a CD-ROM, a semiconductor storage device (e.g., SSD: Solid State Drive), or a storage device such as a hard disk or a semiconductor storage device built into a computer system. The control program may be transmitted via a telecommunication line.

[0040] The communication control unit 43 controls the operation of the relay device 40. For example, when the communication control unit 43 receives transfer data from the communication device 20, it transmits the received transfer data to the collection device 30.

[0041] The communication control unit 43 may control beamforming in the directional antenna 411 of the first communication unit 41. For example, the communication control unit 43 may determine the parameters for each antenna used for beamforming and control the first communication unit 41 to operate with the determined parameters. When executing beamforming, the communication control unit 43 may determine the relative positional relationship between the communication device 20 that is the communication partner and the relay device 40 based on the reception intensity etc. of each antenna of the relay device 40. The communication control unit 43 may control the direction of the directional antenna 411 by driving the drive unit 412.

[0042] The storage battery 44 stores the power for the relay device 40 to operate. How much power the storage battery 44 can store is appropriately determined by the designer or operator of the communication system 100. The storage battery 44 is desirably configured to store power to such an extent that it can operate for at least the period during which it is desired to collect information acquired by the terminal device 10 using an alternative path in the event of an abnormality.

[0043] FIG. 6 is a flowchart showing an operation example of the communication device 20. Hereinafter, the operation example of the communication device 20 will be described with reference to FIG. 6. When the communication device 20 is activated, it waits to receive data from the terminal device 10 (step S101). The waiting state is maintained until a radio signal of communication data is received (step S102 - NO).

[0044] When a radio signal of communication data is received (step S102 - YES), the communication control unit 241 acquires data from the received communication data and stores it in the memory (step S103). The determination unit 242 determines whether communication is possible via the normal path (step S104). If communication is possible via the normal path (step S104 - YES), the communication control unit 241 generates transfer data including the stored information and transmits the transfer data via the normal path (step S105).

[0045] When communication is not possible via the normal route (step S104 - NO), the determination unit 242 determines whether communication is possible via an alternative route (step S106). When communication is possible via the alternative route (step S106 - YES), the communication control unit 241 generates transfer data including the accumulated information and transmits the transfer data via the alternative route (step S107). When communication is not possible even via the alternative route (step S106 - NO), the process returns to the process of step S101. When transfer data is generated in the subsequent process, information of a plurality of communication data may be included in one transfer data.

[0046] Figure 7 is a sequence chart showing an operation example of the communication system 100 when communication is possible via the normal route. The terminal device 10 transmits communication data to the communication device 20 (step S201). When the communication device 20 receives the communication data, it accumulates it in the memory by recording the data included in the received communication data (step S202). The communication device 20 determines whether communication is possible via the normal route based on the communication conditions (step S203). In the case of Figure 7, since communication is possible via the normal route, the communication device 20 transmits transfer data to the collection device 30 using the normal route (step S204).

[0047] Figure 8 is a sequence chart showing an operation example of the communication system 100 when communication is not possible via the normal route. The terminal device 10 transmits communication data to the communication device 20 (step S301). When the communication device 20 receives the communication data, it accumulates it in the memory by recording the data included in the received communication data (step S302). The communication device 20 determines whether communication is possible via the normal route based on the communication conditions (step S303). In the case of Figure 8, since communication is not possible via the normal route, the communication device 20 transmits transfer data to the collection device 30 using the alternative route. Specifically, the communication device 20 transmits the transfer data to the relay device 40 using the first communication unit 21 (step S304). When the relay device 40 receives the transfer data from the communication device 20, it transmits the received transfer data to the collection device 30 (step S305).

[0048] In the communication system 100 configured as described above, even when a failure occurs in the communication path between the terminal device 10 (sensor) and the collection device 30 (especially the communication path between the communication device 20 and the collection device 30), the collection device 30 can maintain the collection of information from each terminal device 10.

[0049] Also, in the communication system 100, alternative communication is realized using a communication protocol such as LoRaWAN with the first communication unit 21, which is a communication function originally possessed by the communication device 20. Therefore, while suppressing the introduction cost and running cost of the communication system 100, communication can be continued in case of an abnormality.

[0050] Conventionally, the use of a satellite communication line required not only firmware rewriting but also hardware modification. Therefore, providing a separate satellite communication line incurred a running cost. To address such problems, in the communication system 100, communication with a satellite is performed using a communication protocol such as LoRaWAN with the first communication unit 21, which is a communication function originally possessed by the communication device 20. Therefore, it is possible to realize communication via an alternative route using a satellite communication line while suppressing the running cost.

[0051] (Modification example) The relay device 40 may be provided with a device for acquiring its own position information. For example, the relay device 40 may be provided with a device of a satellite positioning system (GNSS: Global Navigation Satellite System) such as GPS (Global Positioning System). By being configured in this way, the relay device 40 can acquire its own position information. The communication control unit 43 of the relay device 40 may control the drive unit 412 to direct the direction of the directional antenna 411 toward the communication device 20 based on its own position information and the position information of the communication device 20 that is the communication partner. The position information of the communication device 20 that is the communication partner may be stored in the relay device 40 in advance, for example, or may be set by an operator or the like.

[0052] The relay device 40 may be configured to operate not constantly but only when necessary (i.e., when an alternative route is used).

[0053] The following devices may be used as the terminal device 10. Specific examples of the following devices include personal computers, tablet terminals, smartphones, microcontrollers, single-board computers, and the like. · A device that reads an image such as a two-dimensional barcode (an image in which information is encoded) · A device that reads information on an IC card or the like by non-contact communication · A device that can be photographed with a camera

[0054] By using these devices, safety information in the event of a disaster may be collected. More specifically, the communication device 10 reads the two-dimensional barcode described on the My Number card and transmits it to the collection device 30, whereby safety information may be collected. The information collected as safety information does not necessarily have to be limited to the information described on the My Number card. For example, a face image may be collected as safety information by photographing a person's face. For example, an image obtained by photographing a medium used for personal identification such as a driver's license may be collected as safety information.

[0055] The communication system 100 may be provided with a test function for disaster prevention training or the like. For example, the communication device 20 of the communication system 100 may be provided with such a test function. When the test function is set to on, communication using an alternative route is executed even if communication is possible via the normal route. Such an on operation of the test function may be performed by operating the communication device 20 itself, or may be realized by an operation on the collection device 30, the relay device 40, or other control devices.

[0056] Although the communication in the normal path of the communication system 100 has been described as communication from the terminal device 10 to the collection device 30 via the communication device 20 (for example, arrow 91 in FIG. 2), communication in the reverse direction may also be performed. That is, communication from the collection device 30 to the terminal device 10 via the communication device 20 may be performed. Although the communication in the alternative path of the communication system 100 has been described as communication from the terminal device 10 to the collection device 30 via the communication device 20 and the relay device 40 (for example, arrow 92 in FIG. 3), communication in the reverse direction may also be performed. That is, communication from the collection device 30 to the terminal device 10 via the relay device 40 and the communication device 20 may be performed.

[0057] As described above, the embodiments of the present invention have been described in detail with reference to the drawings. However, the specific configuration is not limited to this embodiment, and designs and the like within the scope not departing from the gist of the present invention are also included.

Description of Reference Numerals

[0058] 100... communication system, 10... terminal device, 20... communication device, 21... first communication unit, 22... second communication unit, 23... communication condition storage unit, 24... control unit, 241... communication control unit, 242... determination unit, 25... battery, 30... collection device, 40... relay device, 41... first communication unit, 411... directional antenna, 412... drive unit, 42... second communication unit, 43... communication control unit, 44... battery

Claims

1. A communication system comprising a communication device and a relay device, wherein the communication device comprises a first communication unit that wirelessly communicates with a plurality of terminal devices using a first communication protocol, a second communication unit that communicates using a second communication protocol different from the first communication protocol, a storage unit that stores, in association with each other, communication timing predetermined for each terminal device and identification information indicating the terminal device, and a control unit that, when it is possible to communicate with the collection device via a normal path that is a communication path for communicating with the collection device using the second communication protocol, communicates with the collection device via the normal path using the second communication unit, and when it is not possible to communicate with the collection device via the normal path, communicates with the collection device via an alternative path that is a communication path different from the normal path using the first communication unit, and the relay device comprises a first communication unit that wirelessly communicates using the first communication protocol, a second communication unit that communicates using a second communication protocol different from the first communication protocol, and a control unit that, when receiving data from the communication device using the first communication protocol, transmits the received data to the collection device using the second communication unit, and the control unit of the communication device generates and transmits data by associating the encrypted information of each terminal device with the identification information indicating each terminal device determined according to the communication timing of the communication data when receiving communication data including information encrypted with an encryption key corresponding to each device from a plurality of terminal devices. A communication system.

2. A device comprising a first communication unit that wirelessly communicates with a plurality of terminal devices using a first communication protocol, a second communication unit that communicates using a second communication protocol different from the first communication protocol, a storage unit that stores, in association with each other, communication timing predetermined for each terminal device and identification information indicating the terminal device, and a control unit that, when it is possible to communicate with the collection device via a normal path that is a communication path for communicating with the collection device using the second communication protocol, communicates with the collection device via the normal path using the second communication unit, and when it is not possible to communicate with the collection device via the normal path, communicates with the collection device via an alternative path that is a communication path different from the normal path using the first communication unit, and When the control unit receives communication data including information encrypted with an encryption key corresponding to each device from a plurality of terminal devices, the control unit generates and transmits data by associating the encrypted information of each terminal device with identification information indicating each terminal device determined according to the communication timing of the communication data. A communication device.

3. The communication device according to claim 2, wherein the control unit changes the size of data transmitted from the terminal device according to the SF value.

4. The communication device according to claim 2, wherein the first communication protocol is LoRaWAN.

5. The communication device according to claim 2, further comprising a storage battery for storing electric power for driving the own device.

6. The communication device according to claim 2, wherein the terminal device is a device capable of acquiring predetermined safety information.

7. When the test function is set to on, the communication device according to claim 2 communicates with the collection device via the alternative path even if communication is possible via the normal path.

8. A computer program for causing a computer to function as the communication device according to any one of claims 2 to 7.

9. A moving body equipped with the communication device according to any one of claims 2 to 7.

Images