JP7655003B2 - Relay device, relay method, relay program, and communication system - Google Patents

Description

The present invention relates to a relay device, a relay method, a relay program, and a communication system, and is suitable for use in, for example, a gateway device.

Conventionally, gateway devices that are widely used are, for example, devices that are connected to different networks (also called communication networks) and relay data by appropriately converting the data to suit each network.

In addition, a concept called IoT (Internet of Things) has been proposed, which involves installing numerous sensor devices in various locations. In this IoT, methods are being explored for obtaining new knowledge by collecting data obtained from the sensor devices in a server device or the like on a network and performing advanced analytical processing. In such cases, for example, it is conceivable to form a relatively narrow local area network using numerous sensor devices, and connect it to a wide area network (such as the Internet) via a gateway device.

In recent years, however, problems have arisen over the increase and severity of natural disasters such as river flooding and landslides, as well as the deterioration of highly public buildings and structures such as bridges and tunnels (so-called social infrastructure). For this reason, it has been devised to use various sensor devices, for example, to acquire and analyze various data related to these structures, thereby detecting abnormalities at an early stage and taking measures in advance.

In such cases, the location where the sensor device is to be installed may be a place where it is not necessarily easy to obtain commercial power, such as a riverbank or a bridge pier. As a result, it has been proposed to provide the sensor device with a photovoltaic power generation panel (a so-called solar cell), making it easier to install in places where it is difficult to wire for commercial power (see, for example, Patent Documents 1 and 2).

JP 2014-081860 A JP 2016-170087 A

When installing a sensor device in a location where it is not necessarily easy to obtain a supply of commercial electricity, it is often not easy to lay wiring either, so it is possible to build a narrow area network over a relatively small range and exchange data using wireless communication, for example. In other words, by using solar cells and wireless communication, the sensor device can be installed with much greater freedom. However, the amount of power generated by solar panels is generally relatively small, and the power consumption of wireless communication is limited, so the distance over which wireless connection is possible is relatively short.

In this case, the gateway device that wirelessly communicates with the sensor device will be installed in a location relatively close to the sensor device, i.e., in a location where it is not necessarily easy to obtain a supply of commercial power. On the other hand, a gateway device installed in such a location may use a wireless network such as LTE (Long Term Evolution) as a wide area network. However, with these wireless networks, the power consumption of wireless communication is relatively large due to reasons such as the relatively long communication distance.

As a result, when using power supplied from solar panels or the like in a gateway device, it is difficult to operate the wireless communication circuits for the wide area network properly, and there is a risk that data cannot be relayed properly.

In other words, in gateway devices that run on electricity generated from various sources of so-called natural energy, including not only commercial power sources but also sunlight, wind, hydroelectric power, geothermal power, solar heat, atmospheric heat and other heat found in nature, biomass, etc., there is a risk that data obtained from sensor devices may not be collected by server devices or the like on the network.

The present invention has been made in consideration of the above points, and aims to propose a relay device, relay method, relay program, and communication system that can effectively relay data between different communication networks while increasing the degree of freedom in installation.

In order to solve such problems, the relay device of the present invention comprises a first communication unit connected to a first communication network, a second communication unit connected to a second communication network, a control unit that controls the supply of power to the second communication unit after the first communication unit receives data from the first communication network and causes the second communication unit to transmit the data to the second communication network, and a power generation unit that generates power to be supplied to the first communication unit, the second communication unit, and the control unit, and the control unit is configured to control the supply of power to the second communication unit intermittently .

In addition, the relay method of the present invention includes a receiving step of receiving data by a first communication unit connected to a first communication network, a supply power control step of controlling power supplied from a power generation unit to a second communication unit connected to a second communication network, and a transmitting step of causing the second communication unit to transmit data to the second communication network by the second communication unit supplied with power from the power generation unit , and the supply power control step controls the supply of power to the second communication unit intermittently .

Furthermore, in the relay program of the present invention, the information processing device is caused to execute a receiving step of receiving data by a first communication unit connected to a first communication network, a supply power control step of controlling the power supplied from a power generation unit to a second communication unit connected to a second communication network, and a transmitting step of causing the second communication unit to transmit data to the second communication network by the second communication unit supplied with power from the power generation unit, and the supply power control step is configured to control the supply of power to the second communication unit intermittently .

Furthermore, in the communication system of the present invention, a sensor device and a relay device are connected to a first communication network, and a relay device and a management server are connected to a second communication network, and the relay device includes a first communication unit connected to the first communication network, a second communication unit connected to the second communication network, a control unit that controls the supply of power to the second communication unit after the first communication unit receives data from the first communication network and causes the second communication unit to transmit the data to the second communication network, and a power generation unit that generates power to be supplied to the first communication unit, the second communication unit , and the control unit, and the control unit is configured to control the supply of power to the second communication unit intermittently .

Since the present invention can operate each unit of the relay device using the power generated by the power generation unit, it is not necessary to connect the relay device to a commercial power source, and the degree of freedom in installation can be greatly increased. Furthermore, since the present invention controls the supply of power to the second communication unit intermittently , it is possible to appropriately suppress power consumption by the second communication unit, and the relay device can be stably operated using the limited power generated by the power generation unit.
Furthermore, the relay device of the present invention includes a first communication unit that communicates using a first communication method, a second communication unit that communicates using a second communication method, a control unit that controls the supply of power to the second communication unit after the first communication unit receives first data using the first communication method and causes the second communication unit to transmit the first data using the second communication method, a sensor unit that generates the second data, a power generation unit that generates power to be supplied to the first communication unit, the second communication unit, the control unit, and the sensor unit, and an operation mode setting unit that sets the mode to a gateway mode in which both the first communication unit and the second communication unit are operated, or a sensor mode in which the first communication unit is operated and the second communication unit is stopped, and when the operation mode setting unit is set to the gateway mode, the control unit controls the second communication unit to transmit the first data and/or the second data using the second communication method, and when the operation mode setting unit is set to the sensor mode, controls the first communication unit to transmit the second data using the first communication method.
Furthermore, the relay method of the present invention includes a setting step of setting, by an operation mode setting unit, a gateway mode in which both a first communication unit that communicates using a first communication method and a second communication unit that communicates using a second communication method are operated, or a sensor mode in which the first communication unit is operated and the second communication unit is stopped, and an operation step of operating in the operation mode set by the setting step, wherein, when the operation mode setting unit sets the gateway mode, the operation step operates to receive first data by the first communication unit, supply power from the power generation unit to the second communication unit, and transmit the first data by the second communication unit using the second communication method, and when the operation mode setting unit sets the sensor mode, the operation step operates to generate second data by the sensor unit and transmit the second data by the first communication unit using the first communication method.
Furthermore, in the relay program of the present invention, the information processing device is caused to execute a setting step of setting, by an operation mode setting unit, a gateway mode in which both a first communication unit which communicates using a first communication method and a second communication unit which communicates using a second communication method are operated, or a sensor mode in which the first communication unit is operated and the second communication unit is stopped, and an operation step of operating in the operation mode set by the setting step, wherein, when the operation mode setting unit sets the gateway mode, the operation step operates to receive first data by the first communication unit, supply power from the power generation unit to the second communication unit, and transmit the first data by the second communication unit using the second communication method, and when the operation mode setting unit sets the sensor mode, the operation step operates to generate second data by the sensor unit and transmit the second data by the first communication unit using the first communication method.
Furthermore, in a communication system of the present invention, a sensor device and a relay device are connected to a first communication network, and a relay device and a management server are connected to a second communication network, and the communication system has a device that operates as a relay device or a sensor device, the device having a first communication unit that communicates in a first communication method, a second communication unit that communicates in a second communication method, a control unit that controls the supply of power to the second communication unit after the first communication unit receives first data in the first communication method and causes the second communication unit to transmit the first data in the second communication method, a sensor unit that generates second data, and power provided to the first communication unit, the second communication unit, the control unit, and the sensor unit. The control unit is configured to set the device to a gateway mode in which both the first communication unit and the second communication unit are operated, or to a sensor mode in which the first communication unit is operated and the second communication unit is stopped, and when the device is operated as a relay device, the control unit sets the operation mode setting unit to the gateway mode and controls the second communication unit to transmit the first data and/or the second data using the second communication method, and when the device is operated as a sensor device, the control unit sets the operation mode setting unit to the sensor mode and controls the first communication unit to transmit the second data using the first communication method.

The present invention makes it possible to realize a relay device, a relay method, a relay program, and a communication system that can effectively relay data between different communication networks while increasing the degree of freedom in installation.

1 is a schematic diagram illustrating an overall configuration of a sensor system according to a first embodiment; FIG. 1 is a schematic block diagram showing the configuration of a solar wireless sensor device. FIG. 2 is a schematic block diagram showing the configuration of a solar wireless repeater device. FIG. 2 is a schematic block diagram showing a configuration of an information management server. FIG. 2 is a schematic block diagram showing a configuration of an information storage server. FIG. 2 is a schematic diagram illustrating an external configuration of a gateway device. 2 is a schematic block diagram showing a circuit configuration of a gateway device according to the first embodiment; FIG. 10 is a flowchart showing a power supply mode switching process procedure. FIG. 2 is a schematic diagram showing a communication protocol between devices. 13 is a flowchart showing a data transmission/reception process procedure. 4 is a sequence chart showing an upstream data transfer sequence according to the first embodiment; 4 is a sequence chart showing a downstream data transfer sequence according to the first embodiment. 4 is a sequence chart showing a temperature measurement sequence according to the first embodiment. 4 is a sequence chart showing a wireless reception level measurement sequence according to the first embodiment; FIG. 13 is a schematic diagram illustrating an overall configuration of a sensor system according to a second embodiment. FIG. 11 is a schematic block diagram showing a circuit configuration of a gateway device according to a second embodiment. 10 is a sequence chart showing an upstream data transfer sequence according to the second embodiment; 10 is a sequence chart showing a temperature measurement sequence according to the second embodiment. 10 is a sequence chart showing a wireless reception level measurement sequence according to the second embodiment; FIG. 13 is a schematic block diagram showing a circuit configuration of a gateway device according to a third embodiment. 13 is a flowchart showing an operation mode activation change process procedure. FIG. 13 is a schematic diagram illustrating a configuration of a gateway device according to another embodiment.

Below, the form for implementing the invention (hereinafter referred to as embodiment) will be explained with reference to the drawings.

1. First embodiment
[1-1. Sensor system configuration]
1, the sensor system 1 according to the first embodiment is configured such that a plurality of communication devices are connected to each other via a plurality of networks. Specifically, the sensor system 1 includes a plurality of solar wireless (SW) sensor devices 10 (10A, 10B, and 10C), a plurality of solar wireless (SW) relay devices 20 (20A, 20B, 20C, 20D, and 20E), a gateway device 30, an information management server 50, and an information storage server 60.

The SW sensor device 10, SW relay device 20, and gateway device 30 of the sensor system 1 are installed, for example, on riverbanks or bridge piers in mountainous areas, or in their vicinity, where it is difficult to supply commercial power to any of them. For this reason, the SW sensor device 10, SW relay device 20, and gateway device 30 each have a solar power generation panel and are designed to operate using power generated by the solar power generation panel (described in detail below). Meanwhile, the information management server 50 and information storage server 60 are installed, for example, in a specified building not shown, and are constantly operated using commercial power supply.

The SW sensor device 10, SW relay device 20, and gateway device 30 are each wirelessly connected to a short-range wireless network 2. The short-range wireless network 2 is a wireless communication network that uses the 920 MHz band and complies with standards such as IEEE802.15.4 established by the Institute of Electrical and Electronics Engineers (IEEE). In this short-range wireless network 2, various data can be transmitted and received between each node (the SW sensor device 10, the SW relay device 20, and the gateway device 30) using a multi-hop method. Hereinafter, the short-range wireless network 2 is also referred to as a short-range wireless network or a first communication network.

In Japan, laws and ministerial ordinances stipulate that in principle a license must be obtained to operate a radio station that transmits radio waves. However, if the radio equipment meets certain technical standards and is certified as conforming to the technical standards, it can be operated as a radio station that does not require a license, a so-called license-exempt station. These technical standards specify in detail, for example, the type of radio waves, frequency, and antenna power, and also stipulate that the 920 MHz band used by the narrow-area wireless network 2 is part of the frequency band that can be used by license-exempt stations.

In the sensor system 1, each of the wireless devices that make up the short-range wireless network 2, namely the SW sensor device 10, the SW relay device 20, and the gateway device 30, is designed and manufactured to comply with technical standards and corresponds to the above-mentioned license-free radio. Therefore, the short-range wireless network 2 of the sensor system 1 corresponds to a privately operated telecommunications equipment network (so-called privately operated network).

In addition, radio waves in the 920 MHz band tend to travel in a less direct direction and have better reach than higher frequency bands, and have a higher transmission speed due to a larger transmission capacity per band compared to lower frequency bands. As a result, the short-range wireless network 2 can establish a stable communication connection between wireless devices and transmit and receive data at high speeds. Note that the short-range wireless network 2 is not limited to the 920 MHz band, and can also use various other frequency bands specified by law, ministerial ordinance, such as the 2.4 GHz band or the 429 MHz band.

Furthermore, the gateway device 30 is connected to a wide area wireless network 3. The wide area wireless network 3 is a wireless network configured using wireless communication technologies defined, for example, in IEEE 802.16-2004, IEEE 802.16e, IEEE 802.11, etc., formulated by the IEEE, or LTE (Long Term Evolution) formulated by 3GPP (Third Generation Partnership Project). This wide area wireless network 3 forms a wireless network that is deployed over a much wider area than the narrow area wireless network 2. Hereinafter, the wide area wireless network 3 is also referred to as a wide area wireless network or a second communication network.

In addition to various wireless devices (not shown), this wide area wireless network 3 is also connected to a higher level network 5 via a base station 4. The higher level network 5 is composed of a wired LAN that complies with standards such as IEEE802.3 (IEEE802.3u/ab/an/ae). In addition to the base station 4, the higher level network 5 is also connected to an information management server 50 and an information storage server 60, and is further connected to other networks such as the Internet (not shown).

The gateway device 30 can therefore transmit and receive various data between the information management server 50 and the information storage server 60 via the wide area wireless network 3, the base station 4, and the upper network 5.

In this sensor system 1, each SW sensor device 10 generates data by detecting, for example, the water level of a river or the vibration of a bridge pier using its respective sensor. The SW sensor device 10 then transmits the generated data into the short-range wireless network 2, where it is received by the gateway device 30 via the SW relay device 20 as appropriate. The gateway device 30 relays this data and transmits it to the wide-area wireless network 3, where it is received by the information management server 50 via the base station 4 and upper network 5. The information management server 50 performs a specified conversion process on this data, and then transmits it to the information storage server 60 for storage.

In this way, in the sensor system 1, data generated by each SW sensor device 10 is transmitted over each network as appropriate, and the data is relayed between networks by the gateway device 30, and is ultimately stored in the information storage server 60.

[1-1-1. Configuration of SW sensor device]
Next, a description will be given of the configuration of the SW sensor device 10. As shown in the block diagram of Fig. 2, the SW sensor device 10 is configured as an information processing device centered around a control unit 11. A storage unit 12, a wireless communication unit 13, a sensor unit 14, a temperature measurement unit 15, and a power supply unit 16 are connected to the control unit 11.

The control unit 11 is a processing unit that controls various operations of the SW sensor device 10. For example, the control unit 11 has a CPU (Central Processing Unit), ROM (Read Only Memory), RAM (Random Access Memory), and a timer circuit (not shown). This control unit 11 uses the RAM as a work area and executes programs read from the ROM, memory unit 12, etc., by the CPU to realize various functions and perform various processes. In addition, the control unit 11 can recognize the current date and time and measure the elapsed time from a specified point in time using the timer circuit (not shown).

The storage unit 12 has a non-volatile storage medium such as an EEPROM (Electronically Erasable and Programmable Read Only Memory), an SSD (Solid State Drive), a hard disk drive, etc. This storage unit 12 stores various programs, setting information, data generated by the sensor unit 14, etc.

The wireless communication unit 13 is a part that performs wireless communication conforming to standards such as IEEE802.15.4, and has a signal processing circuit and an antenna, not shown. This wireless communication unit 13 establishes a wireless connection with other wireless devices that make up the short-range wireless network 2 (FIG. 1), i.e., the SW relay device 20 and the gateway device 30, and can transmit and receive various data. The wireless communication unit 13 also performs intermittent operation, for example, every two seconds.

The sensor unit 14 is a part that performs sensing. In this embodiment, the term "sensing" is used to mean detection of estimated quantities (or detection of increase/decrease or occurrence) of various physical quantities such as vibration (tremor), temperature, humidity, inclination, etc., as well as detection of occurrence (or detection of increase/decrease or estimated quantity) of smoke, chemical substances, radiation, current, voltage, static electricity, etc. In addition to the above-mentioned detection, the term "sensing" is also used to mean the process of converting the detected contents into an analog-format electrical signal, and the process of converting the electrical signal into digital-format data. In addition to the above-mentioned detection, the term "sensing" is also used to mean measuring or determining the detected contents.

Specifically, the sensor unit 14 is configured as, for example, an ultrasonic sensor, and has a generating circuit that generates ultrasonic waves and an acquiring circuit that acquires the ultrasonic waves (neither of which are shown). This sensor unit 14 generates ultrasonic waves and radiates them in a predetermined direction, acquires ultrasonic waves that have returned due to reflection or the like, converts them into electrical signals, and generates data by performing predetermined signal processing, conversion processing, etc., and sends this data to the control unit 11.

In response to this, the control unit 11 can associate the date and time information obtained, for example, from a clock circuit (not shown) with the data, and store it in the memory unit 12 or transmit it from the wireless communication unit 13 to the short-range wireless network 2.

The sensor unit 14 is not limited to an ultrasonic sensor, and may be various sensors such as a temperature sensor, a humidity sensor, a vibration (vibration) sensor, a tilt sensor, a pressure sensor, a human sensor, an illuminance sensor, a biosensor, a radioactivity sensor, a soil sensor, an image sensor, etc. The sensor unit 14 may also be various sensors such as a position sensor using an artificial satellite such as GPS (Global Positioning System)/GNSS (global navigation satellite system), an odor sensor, a count sensor that counts vehicles and people, a smoke sensor, a chemical substance sensor, a current sensor, a voltage sensor, and a static electricity sensor. Furthermore, the sensor unit 14 is not limited to a single number and a single type of sensor, and may be provided with multiple numbers of sensors and multiple types of sensors.

The temperature measurement unit 15 detects the outside air temperature at the location where the SW sensor device 10 is installed, generates temperature information based on the detected temperature, and supplies it to the control unit 11. In response, the control unit 11 performs a temperature correction process based on the temperature information supplied from the temperature measurement unit 15 on the data generated by, for example, the sensor unit 14. This temperature measurement unit 15 measures the temperature, for example, once every 5 to 10 minutes.

Incidentally, when the SW sensor device 10 receives a specific operation instruction from a worker or the like via the wireless communication unit 13, for example during installation work or maintenance work, the control unit 11 can perform calculation processing of a correction value according to the installation environment based on the temperature information generated by the temperature measurement unit 15.

The power supply unit 16 is a part that supplies power to each component of the SW sensor device 10, and has a solar cell 17, a charge/discharge control unit 18, and a secondary battery 19. The solar cell 17 is also called a solar power generation panel, and is a photoelectric conversion device that generates electricity (i.e., generates electricity) using solar energy. The solar cell 17 can be made of various types of silicon, such as crystalline silicon or amorphous silicon, or made of various inorganic or organic compounds. The solar cell 17 is provided, for example, on the top surface of the housing (not shown) of the SW sensor device 10. When the SW sensor device 10 is installed, the installation position, installation angle, etc. are appropriately adjusted so that the solar cell 17 is sufficiently exposed to direct sunlight.

The charge/discharge control unit 18 cooperates with the control unit 11 to charge the power generated by the solar cell 17 into the secondary battery 19, or to discharge power from the secondary battery 19 and supply it to each unit such as the control unit 11. The charge/discharge control unit 18 also obtains various information related to the power in the power supply unit 16 (hereinafter referred to as power supply information) and notifies the control unit 11 upon request. This power supply information includes, for example, whether or not power is being generated by the solar cell 17, the voltage and current values supplied from the solar cell 17, the output voltage of the secondary battery 19, the amount of power stored in the secondary battery 19, etc.

The secondary battery 19 is a battery that can store (i.e., charge) and release (i.e., discharge) electricity using chemical reactions, and is composed of, for example, a lithium-ion secondary battery, a nickel-cadmium storage battery, a lead storage battery, etc.

The control unit 11 also controls each part of the SW sensor device 10 to operate intermittently, thereby reducing power consumption. Specifically, the control unit 11 controls, for example, the sensing operation by the sensor unit 14 and the temperature measurement operation by the temperature measurement unit 15 to be performed once every 5 to 10 minutes. The control unit 11 also controls, for example, the communication operation by the wireless communication unit 13 to be performed once every 2 seconds.

[1-1-2. Configuration of SW relay device]
Next, the configuration of the SW relay device 20 (FIG. 1) will be described. As shown in FIG. 2 and FIG. 3 corresponding to each other, the SW relay device 20 has a configuration similar to that of the SW sensor device 10, and is configured as an information processing device centered around a control unit 21. A storage unit 22, a wireless communication unit 23, and a power supply unit 26 are connected to the control unit 21.

Like the control unit 11 (FIG. 2) of the SW sensor device 10, the control unit 21 has a CPU, ROM, RAM, and a timer circuit (not shown). This control unit 21 uses the RAM as a work area and executes programs read from the ROM, memory unit 22, etc., by the CPU, thereby realizing various functions and performing various processes. Also, like the control unit 11, the control unit 21 can recognize the current date and time, and measure the elapsed time from a specified point in time, using a timer circuit (not shown).

The memory unit 22, like the memory unit 12 (FIG. 2) of the SW sensor device 10, has a non-volatile storage medium such as an EEPROM, SSD, or hard disk drive. This memory unit 22 stores various programs, setting information, or data received by the wireless communication unit 23. Like the wireless communication unit 13 (FIG. 2) of the SW sensor device 10, the wireless communication unit 23 is a part that performs wireless communication conforming to standards such as IEEE802.15.4, and has a signal processing circuit and an antenna (not shown). This wireless communication unit 23 can wirelessly connect with other wireless devices that constitute the narrow-area wireless network 2 (FIG. 1), i.e., the SW sensor device 10, other SW relay devices 20, or the gateway device 30, and transmit and receive various data.

The power supply unit 26 is configured similarly to the power supply unit 16 (Fig. 2) of the SW sensor device 10, and is a part that supplies power to each component of the SW relay device 20. Specifically, the power supply unit 26 has a solar cell 27, a charge/discharge control unit 28, and a secondary battery 29 that are configured similarly to the solar cell 17, charge/discharge control unit 18, and secondary battery 19 of the SW sensor device 10 (Fig. 2), respectively. Similarly to the control unit 11 of the SW sensor device 10, the control unit 21 controls each unit of the SW relay device 20 to operate intermittently, thereby reducing power consumption. Specifically, the control unit 21 controls the communication operation of the wireless communication unit 23 to be performed once every two seconds, for example.

[1-1-3. Configuration of information management server]
Next, the configuration of the information management server 50 (FIG. 1) will be described. As shown in the block diagram of FIG. 4, the information management server 50 is configured as an information processing device centered around a control unit 51. A storage unit 52, a communication unit 53, a display unit 54, and an operation unit 55 are connected to the control unit 51.

The control unit 51, like the control unit 11 (FIG. 2) of the SW sensor device 10, has a CPU, ROM, RAM, and a timer circuit (not shown). This control unit 51 uses the RAM as a work area and executes programs read from the ROM, memory unit 52, etc., by the CPU, thereby realizing various functions and performing various processes.

The memory unit 52, like the memory unit 12 (FIG. 2) of the SW sensor device 10, has a non-volatile storage medium such as an EEPROM, SSD, or hard disk drive. This memory unit 52 stores various programs and setting information, or data received by the communication unit 53. The communication unit 53 is an interface for a wired LAN that complies with standards such as IEEE 802.3, and can transmit and receive various data to and from the upper network 5 (FIG. 1).

The display unit 54 has a display panel such as a liquid crystal panel or an organic EL (Electro Luminescence) panel, and displays various information such as characters, figures, or images based on the control of the control unit 51. The operation unit 55 is, for example, a keyboard, a mouse, a touch pad, a touch panel, etc., and receives operations from the user and notifies the control unit 51.

[1-1-4. Configuration of Information Storage Server]
Next, the configuration of the information storage server 60 (FIG. 1) will be described. As shown in the block diagram of FIG. 5 corresponding to FIG. 4, the information storage server 60 is configured as an information processing device centered around a control unit 61. A storage unit 62 and a communication unit 63 are each connected to the control unit 61.

The control unit 61, like the control unit 51 (FIG. 4) of the information management server 50, has a CPU, ROM, RAM, and a timer circuit (not shown). This control unit 61 uses the RAM as a work area and executes programs read from the ROM, storage unit 62, etc., by the CPU, thereby realizing various functions and performing various processes.

The memory unit 62, like the memory unit 52 (FIG. 4) of the information management server 50, has a non-volatile storage medium such as an EEPROM, SSD, or hard disk drive. This memory unit 62 stores various programs and setting information, or data received by the communication unit 63. The communication unit 63 is an interface for a wired LAN that complies with standards such as IEEE 802.3, and can transmit and receive various data to and from the upper network 5.

[1-2. Configuration of Gateway Device]
Next, a configuration of the gateway device 30 will be described. As shown in the schematic external view of Fig. 6, the gateway device 30 as a relay device is composed of a main body 30A1, an attachment part 30A2, and a sensor exposed part 30A3. The gateway device 30 is attached to an arm part P2 extending from a pillar P1 erected near a river bank RB of a river R toward the river.

The main body 30A1 has an overall shape similar to a rectangular parallelepiped, and the entire outer periphery is covered by a specified housing. The attachment part 30A2 is composed of a mounting bracket of a specified shape, and positions the main body 30A1 on the upper side of the arm P2 and fixes the main body 30A1 so as to maintain it in a specified position. The sensor exposure part 30A3 is located below the attachment part 30A2, and is fixed to the underside of the arm P2 by the attachment part 30A2.

[1-2-1. Circuit configuration of gateway device]
2 and 3, the gateway device 30 is configured as an information processing device centered around a control unit 31. To this control unit 31, a storage unit 32, a first wireless communication unit 33, a second wireless communication unit 34, a sensor unit 35, a temperature measurement unit 36, and a power supply unit 46 are connected.

Like the control unit 11 (FIG. 2) of the SW sensor device 10, the control unit 31 has a CPU, ROM, RAM, and a timer circuit (not shown). This control unit 31 uses the RAM as a work area and executes programs read from the ROM, memory unit 32, etc., by the CPU, thereby realizing various functions and performing various processes. Also, like the control unit 11, the control unit 31 can recognize the current date and time, and measure the elapsed time from a specified point in time, using a timer circuit (not shown).

The memory unit 32, like the memory unit 12 (FIG. 2) of the SW sensor device 10, has a non-volatile storage medium such as an EEPROM, SSD, or hard disk drive. This memory unit 32 stores various programs and setting information, or data received by the first wireless communication unit 33, etc.

The first wireless communication unit 33, like the wireless communication unit 13 (FIG. 2) of the SW sensor device 10, is a part that performs wireless communication conforming to standards such as IEEE802.15.4, and has a signal processing circuit and an antenna (not shown). This first wireless communication unit 33 can wirelessly connect with other wireless devices that make up the short-range wireless network 2 (FIG. 1), i.e., the SW sensor device 10 and the SW relay device 20, and transmit and receive various data.

The second wireless communication unit 34 is a part that performs wireless communication conforming to wireless communication technologies defined by, for example, IEEE 802.16-2004, IEEE 802.16e, IEEE 802.11, or standards such as LTE for third-generation mobile communication systems and fourth-generation mobile communication systems, and has a signal processing circuit, an antenna, and the like (not shown). This second wireless communication unit 34 is connected to the base station 4 via the wide area wireless network 3 (FIG. 1), and is further connected to the information management server 50 via the upper network 5, and can transmit and receive various data.

Incidentally, a wireless network using wireless communication technology defined by IEEE802.16-2004, IEEE802.16e, IEEE802.11, LTE, or the like, such as the wide area wireless network 3, may become a telecommunications network (public network) by providing telecommunications services. When the wide area wireless network 3 is a telecommunications network (public network), the gateway device 30 can communicate with the wide area wireless network 3 and various other devices (not shown) connected to the upper network 5 by performing wireless communication via the wide area wireless network 3.

The sensor unit 35 is configured similarly to the sensor unit 14 (FIG. 2) of the SW sensor device 10, and functions as, for example, an ultrasonic sensor. The sensor unit 35 has, for example, a generating circuit that generates ultrasonic waves and an acquiring circuit that acquires the ultrasonic waves, a part of which is provided in the sensor exposed portion 30A3 (FIG. 6), and the remainder is provided within the main body portion 30A1.

The sensor unit 35 generates ultrasonic waves and radiates them downward from the sensor exposed portion 30A3 (Figure 6), and the reflected ultrasonic waves that are formed when part of the ultrasonic waves are reflected by the water surface of the river R are acquired by the sensor exposed portion 30A3. Furthermore, the sensor unit 35 converts the acquired reflected ultrasonic waves into electrical signals and generates data by performing predetermined signal processing, conversion processing, etc., and sends this data to the control unit 31. This data represents the distance from the sensor exposed portion 30A3 to the water surface of the river R, and by performing predetermined calculation processing, it becomes a value that represents the water level of the river R.

The temperature measurement unit 36 is configured in the same manner as the temperature measurement unit 15 (FIG. 2) of the SW sensor device 10, and detects the outside air temperature at the location where the gateway device 30 is installed, generates temperature information based on the detected temperature, and supplies it to the control unit 31. In response to this, the control unit 31 performs a temperature correction process based on the temperature information supplied from the temperature measurement unit 36 on the data generated by, for example, the sensor unit 35.

The power supply unit 46 is configured similarly to the power supply unit 16 (FIG. 2) of the SW sensor device 10, and is a part that supplies power to each component of the gateway device 30. Specifically, the power supply unit 46 has a solar cell 47, a charge/discharge control unit 48, and a secondary battery 49 that are configured similarly to the solar cell 17, charge/discharge control unit 18, and secondary battery 19, respectively, of the SW sensor device 10 (FIG. 2).

As shown in FIG. 6, the solar cell 47 is provided on the upper surface of the main body 30A1. The position and orientation of the main body 30A1 are adjusted so that it is well irradiated with direct sunlight, and the main body 30A1 is fixed to the arm P2 by the attachment part 30A2.

[1-2-2. Power supply control of gateway device]
As described above, in the sensor system 1 (FIG. 1), when the gateway device 30 receives data from the SW sensor device 10 or the SW relay device 20 via the narrow area wireless network 2, the gateway device 30 relays the data and transmits it to the wide area wireless network 3. To receive data from the narrow area wireless network 2, the gateway device 30 needs to operate the first wireless communication unit 33, and to transmit data to the wide area wireless network 3, the gateway device 30 needs to operate the second wireless communication unit 34.

On the other hand, like the control unit 11 of the SW sensor device 10, the control unit 31 controls each unit of the gateway device 30 to operate intermittently, i.e. at a predetermined cycle, thereby reducing power consumption. Specifically, the control unit 31 controls, for example, the sensing operation by the sensor unit 35 and the temperature measurement operation by the temperature measurement unit 36 to be performed once every 5 to 10 minutes. The control unit 31 also controls, for example, the communication operation by the first wireless communication unit 33 to be performed once every 2 seconds, and the communication operation by the second wireless communication unit 34 to be performed, for example, once every 5 minutes.

In this way, in the gateway device 30, there is a possibility that the timing of operating the first wireless communication unit 33 and the second wireless communication unit 34 may not coincide with each other. Therefore, the control unit 31 temporarily stores data received from one network in the memory unit 32, and the next time it connects to the other network, it reads the data from the memory unit 32 and transmits it.

In other words, when the control unit 31 receives data to be transmitted to the information management server 50 from the narrow area wireless network 2 via the first wireless communication unit 33, the control unit 31 stores the data in the memory unit 32, and the next time the control unit 31 operates the second wireless communication unit 34 to connect to the wide area wireless network 3, it reads out and transmits the data stored in the memory unit 32.

When the control unit 31 receives data to be transmitted to the SW sensor device 10 or the like from the wide area wireless network 3 via the second wireless communication unit 34, the control unit 31 stores the data in the memory unit 32, and the next time the control unit 31 operates the first wireless communication unit 33 to connect to the narrow area wireless network 2, it reads out and transmits the data stored in the memory unit 32.

However, the gateway device 30 requires a relatively large amount of power to operate the second wireless communication unit 34. Therefore, the control unit 31 switches the power supply mode according to the state of the power supply unit 46, thereby switching the cycle of power supply to the second wireless communication unit 34, i.e., the cycle of intermittent operation of the second wireless communication unit 34, before transmitting and receiving data.

Specifically, when the power is turned on, the control unit 31 reads out and executes a wide area wireless network connection program from the storage unit 32, thereby starting the power supply mode switching process procedure RT1 shown in FIG. 8, and proceeds to the first step SP1. In step SP1, the control unit 31 obtains power supply information from the charge/discharge control unit 48, which includes various information related to the power in the power supply unit 46, and proceeds to the next step SP2.

In step SP2, the control unit 31 reads the current amount of power generated by the solar cell 47 from the acquired power source information and determines whether the amount of power generated is equal to or exceeds a predetermined reference amount. This reference amount is set in advance, for example, based on the amount of power when power is supplied to each part of the gateway device 30, including the second wireless communication unit 34. If a positive result is obtained in step SP2, this indicates that the current amount of power generated by the solar cell 47 is relatively large, and therefore the second wireless communication unit 34 can be operated at relatively short intervals. At this time, the control unit 31 proceeds to the next step SP6.

On the other hand, if a negative result is obtained in step SP2, this indicates that the current amount of power generated by the solar cell 47 is relatively small, or power is not being generated at night, etc., and therefore the second wireless communication unit 34 should not be operated at relatively short intervals. In this case, the control unit 31 proceeds to the next step SP3.

In step SP3, the control unit 31 determines whether the secondary voltage, which is the voltage of the secondary battery 49, is equal to or higher than a predetermined reference voltage, i.e., whether the amount of power stored in the secondary battery 49 is sufficient. If a positive result is obtained here, this indicates that there is at least enough power remaining in the secondary battery 49 to operate the second wireless communication unit 34. At this time, the control unit 31 proceeds to the next step SP4.

In step SP4, the control unit 31 compares the data values stored in the memory unit 32, i.e., the data values acquired from the SW sensor device 10 and the data values generated by the sensor unit 35, with a predetermined alert threshold, and proceeds to the next step SP5. This alert threshold is set to a value that corresponds to the water level at which there is a risk of flooding of the river R (Figure 6), for example, and is stored in advance in the memory unit 32.

In step SP5, the control unit 31 determines whether the data value is equal to or greater than the alert threshold. If a positive result is obtained here, this indicates that the data should be sent to the information management server 50 at short intervals, for example, when there is a risk of flooding of river R. In this case, the control unit 31 proceeds to the next step SP6.

In step SP6, the control unit 31 sets the power supply mode to the short cycle mode, and proceeds to the next step SP9. In this short cycle mode, the cycle for intermittent operation of the second wireless communication unit 34 is a relatively short time (e.g., 5 minutes).

On the other hand, if a negative result is obtained in step SP5, this indicates that there is no need to transmit data to the information management server 50 at short intervals. In this case, the control unit 31 proceeds to the next step SP7.

In step SP7, the control unit 31 sets the power supply mode to the long cycle mode, and proceeds to the next step SP9. In this long cycle mode, the cycle for intermittently operating the second wireless communication unit 34 is a relatively long time (e.g., 60 minutes).

On the other hand, if a negative result is obtained in step SP3, this indicates that the secondary voltage is relatively low and sufficient power is not stored in the secondary battery 49. In this case, the control unit 31 proceeds to the next step SP8, sets the power supply mode to the pause mode, and proceeds to the next step SP11. In this pause mode, the second wireless communication unit 34 is paused, and no transmission or reception is allowed.

In step SP9, the control unit 31 determines whether or not the standby time (i.e., period) corresponding to the current power supply mode has elapsed since the second wireless communication unit 34 was last operated. If a negative result is obtained, the control unit 31 repeats step SP9 to wait for the standby time to elapse.

On the other hand, if a positive result is obtained in step SP9, the control unit 31 proceeds to the next step SP10, and performs wide area wireless network connection processing (described in detail later) as a subroutine to power and operate the second wireless communication unit 34, and transmits the data stored in the memory unit 32 to the wide area wireless network 3, and then proceeds to the next step SP11.

In step SP11, the control unit 31 ends the power supply mode switching process procedure RT1. Incidentally, the control unit 31 executes the power supply mode switching process procedure RT1 at predetermined intervals (e.g., every 5 minutes) and sequentially switches the power supply mode in response to changes in the power generation state of the solar cell 47, changes in the data values, etc.

In addition, from the viewpoint of reducing power consumption, the control unit 31 of the gateway device 30 intermittently operates not only the second wireless communication unit 34 but also the first wireless communication unit 33, the sensor unit 35, and the temperature measurement unit 36. In this case, it is desirable that the cycle of intermittent operation of the first wireless communication unit 33, the sensor unit 35, and the temperature measurement unit 36 is synchronized with the cycle of intermittent operation of the second wireless communication unit 34. That is, in the gateway device 30, it is desirable that the second wireless communication unit 34 transmits data and temperature immediately after they are acquired by the sensor unit 35 and the temperature measurement unit 36, and it is also desirable that the second wireless communication unit 34 transmits the data immediately after the first wireless communication unit 33 acquires the data.

[1-2-3. Data transmission and reception via wide area wireless network]
Incidentally, as described above, in the sensor system 1, the gateway device 30 does not operate the second wireless communication unit 34 all the time, but operates it by intermittently supplying power to it. Therefore, in the sensor system 1, even if there is data to be transmitted from the information management server 50 to the gateway device 30 or the SW sensor device 10, there is a possibility that a connection with the gateway device 30 cannot be established depending on the timing.

As shown in FIG. 9, in the sensor system 1, when there is data to be sent from the gateway device 30 to the information management server 50, the data is sent by a request of the HTTPS (Hypertext Transfer Protocol Secure) protocol. Also, in the sensor system 1, when the information management server 50 sends a response of the HTTPS protocol to the gateway device 30, data is embedded in the response and sent.

In addition, in the sensor system 1, data is sent and received between the information management server 50 and the information storage server 60 using the MQTT (Message Queuing Telemetry Transport) protocol. For this reason, the information management server 50 transmits data received from the gateway device 30 to the information storage server 60 by appropriately converting the format and protocol of various data, and also transmits data to be sent to the gateway device 30 by embedding it in a response of the HTTPS protocol.

Here, a detailed description will be given of a case where data is sent from the gateway device 30 to the information management server 50 based on the HTTPS communication protocol. In this case, the control unit 31 of the gateway device 30 functions as an HTTPS client together with the second wireless communication unit 34 by reading and executing a specific HTTPS client program from the storage unit 32. The control unit 51 of the information management server 50 functions as an HTTPS server together with the communication unit 53 by reading and executing a specific HTTP server program from the storage unit 52.

Incidentally, the HTTPS client may be a standalone program related to the HTTPS client, or may be a program related to the HTTPS client built into the operating system (OS), middleware, or application software executed by the gateway device 30. In this case, specifically, it may be a program related to the HTTPS client built into various application software (programs) such as a web browser, a web robot, a text editor, database management software, image editing software, or security software.

The HTTPS client of the gateway device 30 and the HTTPS server of the information management server 50 communicate (transmit and receive) between each other while controlling each other, and transmit data from the second wireless communication unit 34 of the gateway device 30 to the communication unit 53 of the information management server 50.

In this case, the HTTPS client of the gateway device 30 sends data to the HTTPS server of the information management server 50 using an HTTPS request message. In response, the HTTPS server of the information management server 50, which has acquired the data, sends an HTTPS response message to the HTTPS client of the gateway device 30 in response to the HTTPS request message.

Here, the HTTPS server of the information management server 50 sets a specific URL (Uniform Resource Locator) as a value (resource identification information) indicating the location of the public information to be made public on the HTTPS server. This URL is, for example, "https://xxx.yyy.zzz/sensor/upload.do".

When sending data, the HTTPS client of the gateway device 30 performs encrypted communication (handshake: generation of common key information using public key encryption technology, etc.) with the HTTPS server of the information management server 50 based on the communication protocol of SSL (Secure Sockets Layer) or TLS (Transport Layer Security). As a result, the HTTPS client of the gateway device 30 generates (calculates) common key information to be used for encryption processing by both the HTTPS client and the HTTPS server.

Furthermore, the gateway device 30 pre-stores the IP address of the gateway device 30 in the wide area wireless network 3, the IP address of the information management server 50 in the upper network 5, the communication port number for HTTPS on the information management server 50, and the URL.

The HTTPS client of the gateway device 30 generates an HTTPS request that includes at least the POST method (letters "POST") or PUT method (letters "PUT") and the URL in the request line, and data in the message body. The HTTPS client of the gateway device 30 then provides data to the HTTPS server of the information management server 50 by sending a packet including at least the sender's address, sender's communication port number, receiver's address, receiver's port number, and HTTPS request to the wide area wireless network 3. The sender's address is the IP address of the gateway device 30. The sender's communication port number is, for example, 60123, which is randomly assigned. The receiver's address is the IP address of the information management server 50. The receiver's port number is, for example, 443, which represents HTTPS.

The HTTPS server of the information management server 50 that receives this data generates an HTTPS response that includes at least a status code (characters "200" or "201") in the status line of the message header. The HTTPS server of the information management server 50 then sends a packet including the sender's address, sender's communication port number, receiver's address, receiver's port number, and HTTPS response to the upper network 5, thereby providing the HTTPS client of the gateway device 30 with the result of receiving the HTTPS request (i.e., data). The sender's communication port number is, for example, 443, which represents HTTPS. The receiver's address is the IP address of the gateway device 30. The receiver's port number is 60123, which was used when sending the packet including the HTTPS request.

In this way, the data transmitted from the second wireless communication unit 34 of the gateway device 30 based on the HTTPS communication protocol is transferred sequentially within the wide area wireless network 3 and the upper network 5 according to a predetermined routing method, and then received by the communication unit 53 of the information management server 50 based on the HTTPS communication protocol.

Next, the process in which the gateway device 30 transmits and receives data to and from the information management server 50 via the wide area wireless network 3 will be described. When the control unit 31 of the gateway device 30 proceeds to step SP10 in the power supply mode switching process procedure RT1 (FIG. 8) described above, it starts the wide area wireless network connection process procedure RT2 shown in FIG. 10 as a subroutine and proceeds to the first step SP21.

In step SP21, the control unit 31 starts supplying power to the second wireless communication unit 34, thereby starting operation of the second wireless communication unit 34, and proceeds to the next step SP22. In step SP22, the control unit 31 connects the second wireless communication unit 34 to the wide area wireless network 3, and proceeds to the next step SP23.

In step SP23, the control unit 31 transmits the data stored in the memory unit 32 from the second wireless communication unit 34 to the information management server 50 using the HTTPS protocol, and proceeds to the next step SP24. The transmitted data is transmitted from the second wireless communication unit 34 of the gateway device 30 through the wide area wireless network 3 (FIG. 1), the base station 4, and the upper network 5 in this order, and then reaches and is received by the information management server 50.

At this time, the information management server 50 performs format conversion, protocol conversion, etc. of the received data, and transmits the data to the information storage server 60 by the MQTT protocol for storage. The information management server 50 also transmits an HTTPS protocol response to the gateway device 30. At this time, if data to be transmitted to the gateway device 30 is stored in the storage unit 52, the information management server 50 transmits a response with the data embedded therein.

In step SP24, the control unit 31 receives a response from the information management server 50 via the second wireless communication unit 34, and proceeds to the next step SP25. In step SP25, the control unit 31 determines whether data has been received from the information management server 50, specifically, whether data has been embedded in the received response. If a positive result is obtained here, this indicates that the received data needs to be extracted and, in some cases, forwarded to a final destination. In this case, the control unit 31 proceeds to the next step SP26.

In step SP26, the control unit 31 extracts the received data from the HTTPS protocol response and stores it in the memory unit 32, and then proceeds to the next step SP27. In step SP27, the control unit 31 disconnects the second wireless communication unit 34 from the wide area wireless network 3, and then proceeds to the next step SP28. In step SP28, the control unit 31 ends the power supply to the second wireless communication unit 34, and then proceeds to the next step SP29.

In step SP29, the control unit 31 determines whether the destination of the received data is itself (i.e., the gateway device 30). If a positive result is obtained here, the control unit 31 proceeds to the next step SP30, executes appropriate processing on the received data, and proceeds to the next step SP35. For example, if the data is an update value for various setting values, the control unit 31 updates the setting values stored in the memory unit 32.

On the other hand, if a negative result is obtained in step SP29, this indicates that the destination of the received data is a node connected to the short-range wireless network 2. In this case, the control unit 31 proceeds to the next step SP31. In step SP31, the control unit 31 determines a route to the destination within the short-range wireless network 2 (FIG. 1) (details will be described later), and proceeds to the next step SP32. In step SP32, the control unit 31 causes the first wireless communication unit 33 to transmit the data to the short-range wireless network 2, and proceeds to the next step SP35.

On the other hand, if a negative result is obtained in step SP25, this indicates that the received response did not contain data. In this case, the control unit 31 performs the same processes as steps SP27 and SP28 in steps SP33 and SP34, respectively, to disconnect the second wireless communication unit 34 from the wide area wireless network 3 and terminate power supply to the second wireless communication unit 34, and proceeds to the next step SP35. In step SP35, the control unit 31 terminates the wide area wireless network connection processing procedure RT2 and returns to the original power supply mode switching processing procedure RT1 (Figure 8).

[1-2-4. Sending and receiving data using other protocols]
In the sensor system 1, the protocol used between the gateway device 30 and the information management server 50 can be a protocol other than HTTPS. As the other protocol, for example, File Transfer Protocol (FTP), Teletype network (Telnet), Secure Shell (SSH), Simple Mail Transfer Protocol (SMTP), or HyperText Transfer Protocol (HTTP) can be used. Compared to the above-mentioned HTTPS protocol, the HTTP protocol omits the part related to encrypted communication using a communication protocol such as SSL/TLS, but the other parts are common. The following describes specific operations when each protocol other than HTTP is used.

[1-2-4-1. Use of FTP protocol]
Here, a case will be described in which data is sent from the gateway device 30 to the information management server 50 based on the FTP communication protocol. In this case, the control unit 31 of the gateway device 30 reads out a predetermined FTP client program from the storage unit 32 and executes it, thereby functioning as an FTP client together with the second wireless communication unit 34. The control unit 51 of the information management server 50 reads out a predetermined FTP server program from the storage unit 52 and executes it, thereby functioning as an FTP server together with the communication unit 53.

The control unit 31 of the gateway device 30 also stores in advance in the storage unit 32 the IP address of the second wireless communication unit 34 in the wide area wireless network 3, the IP address of the information management server 50 in the upper network 5, and the communication port number for FTP on the information management server 50.

The control unit 31 of the gateway device 30, acting as an FTP client, initiates communication between the FTP client and the FTP server by sending a specific packet to the wide area wireless network 3. This packet contains at least the IP address of the gateway device 30, which is the sender's address, the sender's communication port number (e.g., randomly assigned 60123, etc.), the IP address of the information management server 50, which is the receiver's address, and the receiver's port number (e.g., 21, which indicates FTP), and also contains data.

In this way, the data transmitted from the second wireless communication unit 34 of the gateway device 30 based on the FTP communication protocol is transferred sequentially within the wide area wireless network 3 and the upper network 5 according to a predetermined routing method, and is then received by the communication unit 53 of the information management server 50 based on the FTP communication protocol.

[1-2-4-2. Use of Telnet protocol]
Here, a case will be described in which data is sent from the gateway device 30 to the information management server 50 based on the Telnet communication protocol. In this case, the control unit 31 of the gateway device 30 reads out a predetermined Telnet client program from the storage unit 32 and executes it, thereby functioning as a Telnet client together with the second wireless communication unit 34. The control unit 51 of the information management server 50 reads out a predetermined Telnet server program from the storage unit 52 and executes it, thereby functioning as an FTP server together with the communication unit 53.

The control unit 31 of the gateway device 30 also stores in advance in the storage unit 32 the IP address of the second wireless communication unit 34 in the wide area wireless network 3, the IP address of the information management server 50 in the upper network 5, and the communication port number for Telnet on the information management server 50.

The control unit 31 of the gateway device 30, acting as a Telnet client, starts communication between the Telnet client and the Telnet server by sending a specific packet to the wide area wireless network 3. This packet contains at least the IP address of the gateway device 30, which is the sender's address, the sender's communication port number (e.g., randomly assigned 60123, etc.), the IP address of the information management server 50, which is the receiver's address, and the receiver's port number (e.g., 23, which indicates Telnet), and also contains data.

The Telnet client of the gateway device 30 and the Telnet server of the information management server 50 also have a binary transfer means (program) that allows for communication (sending and receiving) based on binary transfer protocols such as Kermit, XMODEM, YMODEM, and ZMODEM. Therefore, when the Telnet client of the gateway device 30 sends data to the Telnet server of the information management server 50, it can have the Telnet server obtain the data by binary transferring the order information based on a binary transfer protocol such as Kermit, XMODEM, or YMODEM.

In this way, the data transmitted from the second wireless communication unit 34 of the gateway device 30 based on the Telnet communication protocol is transferred sequentially within the wide area wireless network 3 and the upper network 5 according to a predetermined routing method, and then received by the communication unit 53 of the information management server 50 based on the Telnet communication protocol.

[1-2-4-3. Use of SSH protocol]
Here, a case will be described in which data is sent from the gateway device 30 to the information management server 50 based on the SSH communication protocol. In this case, the control unit 31 of the gateway device 30 reads out a predetermined SSH client program from the storage unit 32 and executes it, thereby functioning as an SSH client together with the second wireless communication unit 34. The control unit 51 of the information management server 50 reads out a predetermined SSH server program from the storage unit 52 and executes it, thereby functioning as an SSH server together with the communication unit 53.

The control unit 31 of the gateway device 30 also stores in advance in the storage unit 32 the IP address of the second wireless communication unit 34 in the wide area wireless network 3, the IP address of the information management server 50 in the upper network 5, and the communication port number for SSH on the information management server 50.

The control unit 31 of the gateway device 30, acting as an SSH client, initiates communication between the SSH client and the SSH server by sending a specific packet to the wide area wireless network 3. This packet contains at least the IP address of the gateway device 30, which is the sender's address, the sender's communication port number (e.g., randomly assigned 60123, etc.), the IP address of the information management server 50, which is the receiver's address, and the receiver's port number (e.g., 22, which indicates SSH), and also contains data.

The SSH client of the gateway device 30 and the SSH server of the information management server 50 each have a secure copy means (program) so that they can communicate (send and receive) based on the Secure Copy Protocol (SCP). Therefore, when the SSH client of the gateway device 30 provides data to the SSH server, the SSH client can have the SSH server of the information management server 50 obtain the data by file-transferring the data based on the Secure Copy Protocol.

In this way, the data transmitted from the second wireless communication unit 34 of the gateway device 30 based on the SSH communication protocol is transferred sequentially within the wide area wireless network 3 and the upper network 5 according to a predetermined routing method, and then received by the communication unit 53 of the information management server 50 based on the SSH communication protocol.

[1-2-4-4. Use of SMTP protocol]
Here, a case will be described in which data is sent from the gateway device 30 to the information management server 50 based on the SMTP communication protocol. In this case, the control unit 31 of the gateway device 30 reads out a predetermined SMTP client program from the storage unit 32 and executes it, thereby functioning as an SMTP client together with the second wireless communication unit 34. The control unit 51 of the information management server 50 reads out a predetermined SMTP server program from the storage unit 52 and executes it, thereby functioning as an SMTP server together with the communication unit 53.

The control unit 31 of the gateway device 30 also stores in advance in the memory unit 32 the IP address of the second wireless communication unit 34 in the wide area wireless network 3, the IP address of the information management server 50 in the upper network 5, and the communication port number for SMTP on the information management server 50.

The control unit 31 of the gateway device 30, acting as an SMTP client, starts communication between the SMTP client and the SMTP server by sending a specific packet to the wide area wireless network 3. This packet contains at least the IP address of the gateway device 30, which is the sender's address, the sender's communication port number (e.g., randomly assigned 60123, etc.), the IP address of the information management server 50, which is the receiver's address, and the receiver's port number (e.g., 25, which indicates SMTP), and also contains data.

When the SMTP client provides data to the SMTP server, the SMTP client of the gateway device 30 can provide data to the SMTP server of the information management server 50 by forming and sending an email with the data as an attachment or an email with the data in the body.

In this way, the data transmitted from the second wireless communication unit 34 of the gateway device 30 based on the SMTP communication protocol is transferred sequentially within the wide area wireless network 3 and the upper network 5 according to a predetermined routing method, and is then received by the communication unit 53 of the information management server 50 based on the SMTP communication protocol.

In addition, if an SMTP server is run by another server device (not shown) other than the information management server 50, it is also possible to operate both the gateway device 30 and the information management server 50 as SMTP clients and transmit data between the two.

In this case, data can be handed over from the second wireless communication unit 34 of the gateway device 30 to the communication unit 53 of the information management server 50 through communication (sending and receiving) between the SMTP client of the gateway device 30 and the SMTP server, and communication (sending and receiving) between the SMTP server and the SMTP client of the information management server 50.

When the SMTP client provides data to the SMTP server, the SMTP client of the gateway device 30 provides the order information to the SMTP server by forming and sending an email with the data as an attachment or an email containing the data in the body. When the SMTP server provides the order information to the SMTP client, the SMTP server provides the data to the SMTP client of the information management server 50 by sending an email with the data as an attachment or an email containing the data in the body (an email received from the SMTP client of the gateway device 30). In this way, data can also be sent from the gateway device 30 to the information management server 50 by using a relay of an SMTP server running on another server device.

[1-3. Determining routes in short-range wireless networks]
In the narrow-area wireless network 2, the gateway device 30 is set as a parent device, and each SW sensor device 10 and each SW relay device 20 is set as a child device. Therefore, when each SW sensor device 10 and each SW relay device 20, which are child devices, transmits data to each device connected to the upper network 5, the SW sensor device 10 and each SW relay device 20 first transmits the data to the gateway device 30, which is the parent device, in the narrow-area wireless network 2.

In addition, in the short-range wireless network 2 (FIG. 1), as described above, each node (SW sensor device 10, SW relay device 20, and gateway device 30) is connected to each other using a multi-hop method. In this short-range wireless network 2, data is transmitted and received between each node using a method such as that described in Patent Document 3.

JP 2011-205556 A (FIG. 1, etc.)

In particular, in the short-range wireless network 2, as described above, the wireless communication units of each node, i.e., the wireless communication unit 13 of the SW sensor device 10, the wireless communication unit 23 of the SW relay device 20, and the first wireless communication unit 33 of the gateway device 30, are all controlled to operate intermittently. Therefore, in the short-range wireless network 2, when data is transmitted from one node to another node, the data is transmitted by searching for a route that reaches the destination node via only the SW relay device 20 that is operating at that time.

In other words, in the short-range wireless network 2, for example, when transmitting data from the SW sensor device 10 to the gateway device 30, the SW sensor device 10 searches for a route to the gateway device 30 via only the SW relay device 20 that is currently operating, and sets the destination, etc., of the data according to this route before transmitting. Also, in the short-range wireless network 2, for example, when transmitting data from the gateway device 30 to the SW sensor device 10, the gateway device 30 searches for a route to the SW sensor device 10 via only the SW relay device 20 that is currently operating, and sets the destination, etc., of the data according to this route before transmitting.

[1-4. Data transfer in sensor systems]
Next, a description will be given of how data is transmitted and received while being transferred by each device in the sensor system 1 (FIG. 1). Hereinafter, data sequentially transferred from the SW sensor device 10 to the information storage server 60 will be referred to as upstream data, and data sequentially transferred from the information storage server 60 to the SW sensor device 10 will be referred to as downstream data.

[1-4-1. Upstream data transfer]
First, a process for sequentially transmitting upstream data from the SW sensor device 10 to the information storage server 60 in the sensor system 1 will be described with reference to the sequence chart of FIG.

First, the control unit 11 of the SW sensor device 10 starts the upstream data transmission processing procedure RT11 by reading and executing a predetermined upstream data transmission program from the memory unit 12, and proceeds to the first step SP111. In step SP111, the control unit 11 generates data using the sensor unit 14, and proceeds to the next step SP112. In step SP112, the control unit 11 searches for a route to the gateway device 30 via only the SW relay devices 20 operating within the short-range wireless network 2 (Figure 1) at this time, and proceeds to the next step SP113. Here, it is assumed that a route to the gateway device 30 via one SW relay device 20 has been selected.

In step SP113, the control unit 11 transmits data to the SW relay device 20 in the narrow-area wireless network 2 via the wireless communication unit 13, and then proceeds to the next step SP114. The data transmitted at this time includes not only the data generated by the sensor unit 14, but also information such as the amount of power generated by the solar cell 17 in the power supply unit 16, the voltage value of the secondary battery 19, or the temperature measured by the temperature measurement unit 15. In step SP114, the control unit 11 ends this upstream data transmission processing procedure RT11.

The control unit 21 of the SW relay device 20 starts the upstream data relay processing procedure RT12 by previously reading and executing a predetermined upstream data relay program from the storage unit 22. When the control unit 21 receives data from the SW sensor device 10 via the wireless communication unit 23, it proceeds to step SP121. In step SP121, the control unit 21 relays the received data via the wireless communication unit 23, i.e., it transmits the received data as is to the gateway device 30, and proceeds to the next step SP122. In step SP122, the control unit 21 ends the upstream data relay processing procedure RT12.

The control unit 31 of the gateway device 30 starts the upstream data reception and transmission processing procedure RT13 by previously reading and executing a predetermined upstream data reception and transmission program from the storage unit 32. When the control unit 31 receives data from the SW relay device 20 via the first wireless communication unit 33, it proceeds to step SP131. In step SP131, the control unit 31 stores the data received by the first wireless communication unit 33 in the storage unit 32, and proceeds to step SP132. In step SP132, the control unit 31 transmits the data to the wide area wireless network 3 by performing wide area wireless network connection processing, and proceeds to the next step SP133.

Specifically, the control unit 31 executes the power supply mode switching process procedure RT1 shown in FIG. 8 as a subroutine, thereby operating the second wireless communication unit 34 at a period based on the state of the power supply unit 46. Next, in step SP10 of the power supply mode switching process procedure RT1 (FIG. 8), the control unit 31 executes the wide area wireless network connection process procedure RT2 (FIG. 10) as a subroutine, and in step SP23, causes the second wireless communication unit 34 to transmit data to the wide area wireless network 3 (FIG. 1) in response to a request of the HTTPS protocol. The transmitted data reaches the base station 4 in the wide area wireless network 3, and then reaches the information management server 50 via the upper network 5. In step SP133, the control unit 31 ends the upstream data reception/transmission process procedure RT13.

The control unit 51 of the information management server 50 starts the upstream data conversion relay processing procedure RT14 by previously reading and executing a predetermined upstream data conversion relay program from the storage unit 52. When the control unit 51 receives data from the gateway device 30 via the communication unit 53, it proceeds to step SP141. In step SP141, the control unit 51 generates MQTT protocol data by performing a predetermined conversion process on the received data, and proceeds to the next step SP142. In step SP142, the control unit 51 transmits the MQTT protocol data to the upper network 5 (Figure 1) via the communication unit 53, and proceeds to the next step SP143. In step SP143, the control unit 51 ends the upstream data conversion relay processing procedure RT14.

The control unit 61 of the information storage server 60 starts the upstream data reception and storage processing procedure RT15 by previously reading and executing a predetermined upstream data reception and storage program from the storage unit 62. When the control unit 61 receives data from the information management server 50 via the communication unit 63, it proceeds to step SP151. In step SP151, the control unit 61 stores the received data in the storage unit 62, and proceeds to the next step SP152. In step SP152, the control unit 61 ends the upstream data reception and storage processing procedure RT15.

In this way, in the sensor system 1, the data generated in the SW sensor device 10 (i.e., the upstream data) can be stored in the information storage server 60 by sequentially receiving and transmitting the data from each device.

[1-4-2. Downstream data transfer]
Next, a process for sequentially transferring downstream data from the information storage server 60 to the SW sensor device 10 in the sensor system 1 will be described with reference to the sequence chart of FIG.

The control unit 61 of the information storage server 60 starts the downstream data transmission processing procedure RT25 by reading and executing a specified downstream data transmission program from the memory unit 62, and proceeds to the first step SP251. In step SP251, the control unit 61 reads data to be transmitted to the SW sensor device 10 from the memory unit 62, transmits this data from the communication unit 63 to the information management server 50 via the upper network 5 (Figure 1) using the MQTT protocol, and proceeds to the next step SP252. In step SP252, the control unit 61 ends the downstream data transmission processing procedure RT25.

The control unit 51 of the information management server 50 performs the downstream data conversion relay processing procedure RT24 by previously reading and executing a predetermined downstream data conversion relay program from the storage unit 52. When the control unit 51 receives data from the information storage server 60 via the communication unit 53, the control unit 51 proceeds to step SP241. In step SP241, the control unit 51 converts the received MQTT protocol data into a format that can be stored in an HTTPS protocol response, and proceeds to the next step SP242. In step SP242, the control unit 51 stores the converted data in the storage unit 52, and proceeds to the next step SP243.

In step SP243, the control unit 51 determines whether or not upstream data has been received from the gateway device 30. If a negative result is obtained here, this indicates that upstream data has not been received from the gateway device 30, and therefore data cannot be sent in response to the gateway device 30. In this case, the control unit 51 waits to receive upstream data from the gateway device 30 by repeating this step SP243.

The control unit 31 of the gateway device 30 starts the downstream data reception and transmission processing procedure RT23 by previously reading and executing a predetermined downstream data reception and transmission program from the storage unit 32, and proceeds to the first step SP231. In step SP231, the control unit 31 executes the power supply mode switching processing procedure RT1 shown in FIG. 8 as a subroutine, thereby operating the second wireless communication unit 34 at a period based on the state of the power supply unit 46. Next, in step SP10 of the power supply mode switching processing procedure RT1 (FIG. 8), the control unit 31 executes the wide area wireless network connection processing procedure RT2 (FIG. 10) as a subroutine, and in step SP23, causes the second wireless communication unit 34 to transmit data to the wide area wireless network 3 (FIG. 1) in response to a request of the HTTPS protocol.

In response to this, when the control unit 51 of the information management server 50 receives this data via the communication unit 53, a positive result is obtained in step SP243, and the process proceeds to the next step SP244. In step SP244, the control unit 51 transmits the data stored in the memory unit 52 (i.e., downstream data) embedded in an HTTPS protocol response from the communication unit 53 to the gateway device 30, and proceeds to the next step SP245. In step SP245, the control unit 51 ends the downstream data conversion relay processing procedure RT24.

In response to this, the control unit 31 of the gateway device 30 receives an HTTPS protocol response from the information management server 50 in step SP24 of the wide area wireless network connection processing procedure RT2 (FIG. 10). Furthermore, in step SP31 of this wide area wireless network connection processing procedure RT2 (FIG. 10), the control unit 31 determines a route to the destination in the narrow area wireless network 2 (FIG. 1), and in the following step SP32, transmits data from the first wireless communication unit 33 to the SW relay device 20, and then ends the wide area wireless network connection processing procedure RT2. Thereafter, the control unit 31 returns to the downstream data reception and transmission processing procedure RT23 (FIG. 12), and proceeds to the next step SP232 to end the downstream data reception and transmission processing procedure RT23.

The control unit 21 of the SW relay device 20 starts the downstream data relay processing procedure RT22 by previously reading and executing a predetermined downstream data relay program from the storage unit 22. When the control unit 21 receives data from the gateway device 30 via the wireless communication unit 23, the process proceeds to step SP221. In step SP221, the control unit 21 relays the received data via the wireless communication unit 23, i.e., transmits the received data directly to the SW sensor device 10, and then proceeds to the next step SP222. In step SP222, the control unit 21 ends the downstream data relay processing procedure RT22.

The control unit 11 of the SW sensor device 10 starts the downstream data reception processing procedure RT21 by reading and executing a specific downstream data reception program from the memory unit 12. When the control unit 11 receives data from the SW relay device 20 via the wireless communication unit 13, the control unit 11 proceeds to step SP211. In step SP211, the control unit 11 stores the received data in the memory unit 12 and proceeds to the next step SP212. In step SP212, the control unit 11 ends the downstream data reception processing procedure RT21.

In this way, in the sensor system 1, data transmitted from the information storage server 60 (i.e., downstream data) can be received and transmitted sequentially by each device, and stored in the SW sensor device 10.

[1-5. Remote maintenance in sensor systems]
Next, a description will be given of remote maintenance of the sensor system 1. This remote maintenance is a process in which, based on operation instructions from a user held by the information management server 50, a request is made to the SW sensor device 10 or the like to generate data using the sensor unit 14 (FIG. 2), measure temperature, or measure wireless reception levels, etc., and the obtained measurement data is transmitted to the information management server 50.

[1-5-1. Temperature measurement]
Here, we will explain the processing performed in the sensor system 1 when the SW sensor device 10 measures temperature based on instructions from the information management server 50 and transmits the obtained measurement data to the information management server 50, with reference to the sequence chart in Figure 13.

First, the control unit 51 of the information management server 50 receives an instruction to measure the temperature using the SW sensor device 10 through a user's operation via the operation unit 55 (Figure 4). The control unit 51 then reads out a temperature measurement request program from the memory unit 52 and executes it to start the temperature measurement request processing procedure RT34, and proceeds to the first step SP341.

In step SP341, the control unit 51 transmits a temperature measurement request to the gateway device 30 from the communication unit 53 via the upper network 5. Incidentally, similar to the case of the downstream data conversion relay processing procedure RT24 (FIG. 12), when the control unit 51 receives upstream data from the gateway device 30 in response to an HTTPS protocol request, it transmits the temperature measurement request in a state where the request is embedded in an HTTPS protocol response.

The control unit 31 of the gateway device 30 starts the temperature measurement request reception and transmission processing procedure RT33 by previously reading and executing a temperature measurement request reception and transmission program from the memory unit 32. When the second wireless communication unit 34 receives a temperature measurement request from the information management server 50 via the wide area wireless network 3, the process proceeds to step SP331. In step SP331, the control unit 31 transmits a temperature measurement request from the first wireless communication unit 33 to the SW relay device 20 via the narrow area wireless network 2.

The control unit 21 of the SW relay device 20 starts the temperature measurement request relay processing procedure RT32 by previously reading and executing a temperature measurement request relay program from the storage unit 22, and when it receives a temperature measurement request from the gateway device 30 via the wireless communication unit 23, it proceeds to step SP321. In step SP321, the control unit 21 transmits a temperature measurement request from the wireless communication unit 23 to the SW sensor device 10.

The control unit 11 of the SW sensor device 10 starts the temperature measurement processing procedure RT31 by previously reading and executing a temperature measurement program from the memory unit 12, and when it receives a temperature measurement request from the SW relay device 20 via the wireless communication unit 13, it proceeds to step SP311. In step SP311, the control unit 11 causes the temperature measurement unit 15 to measure the temperature, obtains the generated temperature data, and proceeds to the next step SP312. In step SP312, the control unit 11 transmits the obtained temperature data as measurement data to the SW relay device 20 via the wireless communication unit 13. Thereafter, the control unit 11 proceeds to the next step SP313 and ends the temperature measurement processing procedure RT31.

When the control unit 21 of the SW relay device 20 receives the measurement data from the SW sensor device 10 via the wireless communication unit 23, the control unit 21 proceeds to step SP322 and transmits the measurement data to the gateway device 30 via the wireless communication unit 23. After that, the control unit 21 proceeds to the next step SP323 and ends the temperature measurement request relay processing procedure RT32.

When the control unit 31 of the gateway device 30 receives the measurement data from the SW relay device 20 via the first wireless communication unit 33, the process proceeds to step SP332, where the second wireless communication unit 34 transmits the measurement data to the information management server 50 via the wide area wireless network 3. Incidentally, the control unit 31 then executes the power supply mode switching process procedure RT1 (FIG. 8) to operate the second wireless communication unit 34 at a period based on the state of the power supply unit 46, and transmits the measurement data. Thereafter, the control unit 31 proceeds to the next step SP333, where the temperature measurement request reception and transmission process procedure RT33 is terminated.

When the control unit 51 of the information management server 50 receives the measurement data from the gateway device 30 via the communication unit 53, the process proceeds to step SP342, where the control unit 51 stores the measurement data in the memory unit 52. The control unit 51 also displays the numerical values of the received measurement data and graphs based on the measurement data on the display unit 54, based on operation instructions from the user via the operation unit 55, etc. After that, the control unit 51 proceeds to the next step SP343, where the temperature measurement request processing procedure RT34 is terminated.

In this way, in the sensor system 1, when the information management server 50 is instructed to measure the temperature using the SW sensor device 10, the temperature measurement request can be relayed by each device in sequence and reach the SW sensor device 10. Also, in the sensor system 1, the temperature measurement data generated by the SW sensor device 10 based on the temperature measurement request can be relayed by each device in sequence and reach the information management server 50.

In the sensor system 1, if the temperature measurement data obtained from the SW sensor device 10 deviates from the normal range and an abnormality in the SW sensor device 10 is suspected, the generation of data by the sensor unit 14 of the SW sensor device 10 can be stopped by issuing a predetermined operation instruction to the information management server 50 (a sensor stop request is relayed from the information management server 50 by each device in sequence to reach the SW sensor device 10). Also, in the sensor system 1, for example, by issuing a predetermined operation instruction to the information management server 50 (a request to display an abnormality is relayed from the information management server 50 by each device in sequence to reach the SW sensor device 10), the SW sensor device 10 can control the light-emitting unit (not shown) such as an LED (Light Emitting Diode) to turn on, off, blink, change color, etc., to indicate an abnormality in the sensor unit 14.

[1-5-2. Measuring wireless reception level]
Next, the process of measuring the wireless reception level using the SW sensor device 10 based on instructions from the information management server 50 and transmitting the obtained measurement data to the information management server 50 in the sensor system 1 will be described with reference to the sequence chart of Figure 14 corresponding to Figure 13.

First, the control unit 51 of the information management server 50 receives an instruction to measure the wireless reception level using the SW sensor device 10 through a user's operation via the operation unit 55 (Figure 4). Next, the control unit 51 reads out a wireless reception level measurement request program from the memory unit 52 and executes it to start the wireless reception level measurement request processing procedure RT44, and proceeds to the first step SP441.

In step SP441, the control unit 51 transmits a wireless reception level measurement request to the gateway device 30 from the communication unit 53 via the upper network 5. Incidentally, when the control unit 51 receives upstream data from the gateway device 30 in response to an HTTPS protocol request, it transmits the wireless reception level measurement request in a state where the data is embedded in an HTTPS protocol response, as in the case of the downstream data conversion relay processing procedure RT24 (FIG. 12) and the temperature measurement request processing procedure RT34 (FIG. 13).

The control unit 31 of the gateway device 30 starts the wireless reception level measurement request reception and transmission processing procedure RT43 by previously reading and executing a wireless reception level measurement request reception and transmission program from the storage unit 32. When the control unit 31 receives a wireless reception level measurement request from the information management server 50 via the wide area wireless network 3 by the second wireless communication unit 34, the control unit 31 proceeds to step SP431. In step SP431, the control unit 31 transmits a wireless reception level measurement request from the first wireless communication unit 33 to the SW relay device 20 via the narrow area wireless network 2.

The control unit 21 of the SW relay device 20 starts the wireless reception level measurement request relay processing procedure RT42 by previously reading and executing a temperature measurement request relay program from the storage unit 22, and when the wireless communication unit 23 receives a wireless reception level measurement request from the gateway device 30, the process proceeds to step SP421. In step SP421, the control unit 21 transmits a wireless reception level measurement request from the wireless communication unit 23 to the SW sensor device 10.

The control unit 11 of the SW sensor device 10 starts the wireless reception level measurement processing procedure RT41 by previously reading and executing a wireless reception level measurement program from the storage unit 12, and when the wireless communication unit 13 receives a wireless reception level measurement request from the SW relay device 20, the process proceeds to step SP411. In step SP411, the control unit 11 transmits a wireless transmission request from the wireless communication unit 13 to the SW relay device 20.

When the control unit 21 of the SW relay device 20 receives a wireless transmission request from the SW sensor device 10 via the wireless communication unit 23, the control unit 21 proceeds to step SP422 and causes the wireless communication unit 23 to transmit a predetermined wireless signal addressed to the SW sensor device 10. This wireless signal contains a predetermined signal pattern suitable for measuring the wireless reception level.

When the control unit 11 of the SW sensor device 10 receives a wireless signal from the SW relay device 20 via the wireless communication unit 13, the process proceeds to step SP412, where the wireless communication unit 13 measures the received signal strength (RSSI: Received Signal Strength Indication) value based on the amplitude, etc., of the received wireless signal, and the process proceeds to the next step SP413. In step SP413, the control unit 11 transmits the obtained received signal strength data as measurement data to the SW relay device 20 via the wireless communication unit 13. Thereafter, the control unit 11 proceeds to the next step SP414, where the wireless reception level measurement processing procedure RT41 is terminated.

When the control unit 21 of the SW relay device 20 receives the measurement data from the SW sensor device 10 via the wireless communication unit 23, the process proceeds to step SP423, where the control unit 21 transmits the measurement data to the gateway device 30 via the wireless communication unit 23. After that, the control unit 21 proceeds to the next step SP424, where the wireless reception level measurement request relay process procedure RT42 is terminated.

When the control unit 31 of the gateway device 30 receives the measurement data from the SW relay device 20 via the first wireless communication unit 33, the control unit 31 proceeds to step SP432, and transmits the measurement data to the information management server 50 via the wide area wireless network 3 via the second wireless communication unit 34. Incidentally, the control unit 31 then executes the power supply mode switching processing procedure RT1 (FIG. 8) to operate the second wireless communication unit 34 at a period based on the state of the power supply unit 46, and transmits the measurement data. Thereafter, the control unit 31 proceeds to the next step SP433, and ends the wireless reception level measurement request reception and transmission processing procedure RT43.

When the control unit 51 of the information management server 50 receives the measurement data from the gateway device 30 via the communication unit 53, the process proceeds to step SP442, where the control unit 51 stores the measurement data in the memory unit 52. Based on an operation instruction by the user via the operation unit 55, the control unit 51 also displays the numerical values of the received measurement data of the wireless reception level and a graph based on the measurement data on the display unit 54. Thereafter, the control unit 51 proceeds to the next step SP443, where the wireless reception level measurement request processing procedure RT44 is terminated.

In this way, in the sensor system 1, when the information management server 50 is instructed to measure the wireless reception level using the SW sensor device 10, the wireless reception level measurement request can be relayed in sequence by each device and reach the SW sensor device 10. Also, in the sensor system 1, the measurement data of the wireless reception level generated in the SW sensor device 10 based on the wireless reception level measurement request can be relayed in sequence by each device and reach the information management server 50.

In the sensor system 1, if the measurement data of the wireless reception level obtained from the SW sensor device 10 deviates from the normal range, various setting values in the wireless communication unit 13 can be changed by a predetermined operation instruction to the information management server 50 so as to bring it within the normal range. In addition, in the sensor system 1, if an abnormality in the wireless communication unit 13 in the SW sensor device 10 is suspected, the wireless communication unit 13 of the SW sensor device 10 can be stopped by a predetermined operation instruction to the information management server 50 (a request to stop the wireless communication unit is relayed from the information management server 50 by each device in sequence to reach the SW sensor device 10), and the occurrence of a communication abnormality in the narrow-area wireless network 2 can be prevented in advance. In addition, in the sensor system 1, for example, by a predetermined operation instruction to the information management server 50 (a request to display an abnormality is relayed from the information management server 50 by each device in sequence to reach the SW sensor device 10), the SW sensor device 10 can be controlled to turn on, off, blink, change color, etc., on a light-emitting unit (not shown) such as an LED in the SW sensor device 10 to indicate an abnormality in the wireless communication unit 13.

[1-6. Time Synchronization]
Meanwhile, in the wide area wireless network 3 of the sensor system 1, each device connected to the network can obtain the accurate time by using mechanisms such as the third generation communication system and LTE. Specifically, in the wide area wireless network 3, for example, the base station 4 has a highly accurate clock (not shown), and each device connected to the wide area wireless network 3 synchronizes its internal clock with the clock of the base station 4.

For this reason, when the control unit 31 of the gateway device 30 (Figure 7) connects to the wide area wireless network 3 via the second wireless communication unit 34 depending on the state of the power supply unit 46, the control unit 31 synchronizes the timing circuit within the control unit 31 with the clock of the base station 4 to maintain accurate time.

Furthermore, in the short-range wireless network 2, each connected device obtains the accurate time from the gateway device 30 and synchronizes its own internal clock (timekeeping circuit) with the clock (timekeeping circuit) of the gateway device 30.

[1-7. Effects, etc.]
In the above configuration, the gateway device 30 of the sensor system 1 according to the first embodiment is connected to the narrow-area wireless network 2 by the first wireless communication unit 33, and is connected to the wide-area wireless network 3 by the second wireless communication unit 34 (FIGS. 1 and 7). The gateway device 30 also operates each unit with power supplied from a power supply unit 46 having a solar cell 47, a secondary battery 49, etc. (FIGS. 6 and 7).

Therefore, the gateway device 30 can operate in places where it is difficult to connect to a commercial power source, as long as the location is exposed to direct sunlight. In addition, in the sensor system 1, the SW sensor device 10 and the SW relay device 20 can also obtain power from the power supply unit 16 and the power supply unit 26, respectively, which are similar to the power supply unit 46.

In general, when installing sensor devices, relay devices, etc. in mountainous areas, a gateway device will also be installed within a range where wireless communication is possible with the sensor devices and relay devices. In such cases, it is conceivable to construct a building near the sensor devices, etc., and install commercial power supply equipment and generators inside the building to supply power to the sensor devices and gateway devices, etc. However, in this case, relatively large-scale construction work such as building the building and laying the wiring will be required, and the costs will be relatively high.

In this respect, in this embodiment, all devices connected to the short-range wireless network 2, i.e., the SW sensor device 10, the SW relay device 20, and the gateway device 30, are each equipped with a solar cell 17, a secondary battery 49, etc., so there is no need to supply power to each device from outside, and the degree of freedom in installation can be greatly increased. As a result, in the sensor system 1, all devices connected to the short-range wireless network 2 can be installed in various locations where it is difficult to connect to a commercial power source, such as mountainous areas and coastal areas, and the obtained data can be delivered to the information storage server 60 and stored without delay.

However, in recent years, localized heavy rains caused by so-called abnormal weather have caused frequent river flooding. Measures to prevent river flooding using civil engineering and construction are conceivable, but from the standpoint of cost and time, it is difficult to apply these to all rivers. As such, it is conceivable to install sensors that measure the water level of each river, and based on the obtained water level values, provide information such as evacuation warnings to appropriate targets at appropriate times. Installation of such sensors can be completed in a relatively short time compared to civil engineering and construction measures, and costs can also be kept down. Sensor system 1 is an extremely useful solution for such applications.

Of these, information such as evacuation warnings can be provided, for example, as follows. First, in step SP141 (Figure 11), the control unit 51 of the information management server 50 compares the received data with a predetermined alert threshold (for example, the water level at which river R (Figure 6) is at risk of flooding) before performing a predetermined conversion process on the data. Next, if the control unit 51 determines that information such as an evacuation warning should be provided based on the obtained comparison result, it provides the information on the evacuation warning on the display unit 54, or notifies a predetermined notification destination, or uploads it to a web server (not shown) on the Internet as a homepage.

The gateway device 30 also operates the second wireless communication unit 34, which consumes relatively large amounts of power, intermittently, and changes the cycle depending on the amount of power generated by the solar cell 47 in the power supply unit 46 and the amount of power stored in the secondary battery 49 (Figure 8). Therefore, in the sensor system 1, the second wireless communication unit 34 can be operated in the shortest possible cycle within the range in which power can be supplied by the gateway device 30, and the amount of delay until data acquired from the SW sensor device 10 etc. reaches the information storage server 60 can be kept as short as possible.

In general communication devices, in order to reduce power consumption for energy conservation, a method is used in which the communication connection in the wireless communication unit is logically disconnected, i.e., by software control. In contrast, in the gateway device 30 according to this embodiment, when the operation of the second wireless communication unit 34 is stopped, the communication is not logically disconnected, but the supply of power to the second wireless communication unit 34 is terminated. This allows the gateway device 30 to suppress even the slightest power consumption by the circuit portion of the second wireless communication unit 34, and thoroughly reduce unnecessary power consumption.

Furthermore, the gateway device 30 is provided with a sensor unit 35 that functions as an ultrasonic sensor and generates data corresponding to the water level of the river R (Figure 6). Therefore, in the sensor system 1, the gateway device 30 can be used as a device that generates data in the same way as the SW sensor device 10, rather than as a device dedicated to communication.

In addition, in the sensor system 1, the HTTPS protocol, which is a protocol that is used very frequently in various networks, is used in the communication between the gateway device 30 and the information management server 50 (FIG. 9). As a result, in the sensor system 1, the HTTPS protocol is very unlikely to be blocked due to restrictions such as security measures in various communication devices (not shown) provided in the upper network 5, and data can be communicated stably.

Furthermore, in the sensor system 1, when data is transmitted from the information management server 50 to the gateway device 30, the data is embedded in the response transmitted immediately after the gateway device 30 transmits an HTTPS protocol request (Figure 9). Therefore, in the sensor system 1, the gateway device 30 is configured to be intermittently connected to the wide area wireless network 3, and yet necessary data can be reliably transmitted from the information management server 50 to the gateway device 30.

Furthermore, in the sensor system 1, as remote maintenance using a mechanism for sequentially relaying data by each device, the SW sensor device 10 measures temperature and wireless reception levels based on operational instructions to the information management server 50, and transmits the obtained measurement data to the information management server 50 (FIGS. 13 and 14). In the sensor system 1, the SW relay device 20 and gateway device 30 can also transmit measurement data to the information management server 50 using a similar procedure.

Therefore, in the sensor system 1, the operating status of the SW sensor device 10 can be confirmed via the information management server 50 without the need for a maintenance worker to travel to mountainous areas where the SW sensor devices 10 are installed, and instructions can be given to change various settings or stop operation. In addition, in the sensor system 1, the operating status of each SW sensor device 10, each SW relay device 20, and gateway device 30 can be confirmed collectively via the information management server 50, and instructions can be given to change various settings or stop operation for each. As a result, the sensor system 1 can quickly detect the occurrence of an abnormality in each device and immediately take possible measures remotely, significantly reducing the frequency with which maintenance workers must travel to the installation locations of the SW sensor devices 10, etc., thereby improving the efficiency of maintenance work and reducing the costs involved.

In other words, by intermittently operating the second wireless communication unit 34 in the gateway device 30, the sensor system 1 can improve the reliability, availability, serviceability, integrity, security, etc. of the entire system.

According to the above configuration, the sensor system 1 according to the first embodiment connects to the narrow-area wireless network 2 by the first wireless communication unit 33 of the gateway device 30, and connects to the wide-area wireless network 3 by the second wireless communication unit 34. The gateway device 30 also operates each unit with power supplied from the power supply unit 46, and operates the second wireless communication unit 34, which consumes relatively large amounts of power, intermittently, and further changes the cycle according to the state of the power supply unit 46. Therefore, in the sensor system 1, the gateway device 30 and the like can be installed in places where it is difficult to connect to a commercial power source, and various data can be exchanged between each device of the wide-area wireless network 3 or upper network 5 and each device of the narrow-area wireless network 2 by the gateway device 30.

2. Second embodiment
1, the sensor system 201 according to the second embodiment differs from the sensor system 1 according to the first embodiment in that the sensor system 201 has three gateway devices 230 (230S, 230R, and 230G) instead of the SW sensor device 10A, the SW relay device 20A, and the gateway device 30. The sensor system 201 is configured similarly to the sensor system 1 in other respects.

[2-1. Configuration of Gateway Device and Switching of Operation Modes]
As shown in FIG. 16 which corresponds to FIG. 7, the gateway device 230 differs from the gateway device 30 according to the first embodiment in that it has a control unit 231 and a memory unit 232 instead of the control unit 31 and the memory unit 32, and in that it has an operation mode setting unit 241 and a setting switch 242, but is otherwise configured in the same manner.

Like the control unit 31, the control unit 231 has a CPU, ROM, RAM, and a timer circuit (not shown). Like the control unit 31, this control unit 231 uses the RAM as a work area and executes a program read from the ROM, the storage unit 232, etc., by the CPU, thereby performing processing that differs in part from that of the first embodiment. Also, like the control unit 31, the control unit 231 can recognize the current date and time and measure the elapsed time from a predetermined point in time by using a timer circuit (not shown).

Like the storage unit 32, the storage unit 232 has a non-volatile storage medium such as an EEPROM, SSD, or hard disk drive. This storage unit 232 stores programs and setting information that are partially different from those in the first embodiment, or data received by the first wireless communication unit 33, etc.

The gateway device 230 has three operating modes: gateway mode, sensor mode, and relay mode, and can be set to any of these modes using the operating mode setting unit 241 and setting switch 242.

The setting switch 242 is, for example, a 10-contact rotary switch, and can be set to one of 10 numbers from "0" to "9" by rotating a specific knob. The operation mode setting unit 241 reads the setting value from the setting switch 242, and can switch the operation mode of the gateway device 230 based on this setting value. Here, the relationship between the setting value of the setting switch 242 and the operation mode is as shown in Table 1.

Of these, the gateway mode is also called the first mode, and is an operation mode in which the gateway device 230 functions in the same manner as the gateway device 30 in the first embodiment. Hereinafter, the gateway device 230 operating in the gateway mode is also referred to as the gateway device 230G.

The sensor mode, also called the second mode, is an operation mode in which the gateway device 230 functions in the same manner as the SW sensor device 10 in the first embodiment. Hereinafter, the gateway device 230 operating in the sensor mode is also referred to as the gateway device 230S.

The relay mode, also called the third mode, is an operation mode in which the gateway device 230 functions in the same manner as the SW relay device 20 in the first embodiment. Hereinafter, the gateway device 230 operating in the relay mode is also referred to as the gateway device 230R.

The gateway device 230 also switches the operating state of each unit (the first wireless communication unit 33, the second wireless communication unit 34, the sensor unit 35, the temperature measurement unit 36, etc.), for example, between enabled and disabled, depending on the operating mode. The operating state of each unit of the gateway device 230 in each operating mode can be summarized as shown in Table 2 below.

Furthermore, the gateway device 230 is configured to switch data transfer operations depending on the operation mode. The transfer operations of the gateway device 230 in each operation mode can be summarized as shown in Table 3 below.

In this way, the gateway device 230 can operate in substantially the same manner as the gateway device 30, SW sensor device 10, or SW relay device 20 in the first embodiment by switching the operating mode.

Incidentally, the gateway device 230 is configured to switch the operation mode by the control unit 231 cooperating with the operation mode setting unit 241, for example, immediately after the power is turned on or when the gateway device 230 is restarted.

[2-2. Data transfer in sensor systems]
Next, a case where upstream data is sequentially transferred from the gateway device 230S in the sensor mode to the information storage server 60 in the sensor system 201 (FIG. 15) will be described with reference to the sequence chart of FIG. 17 corresponding to FIG.

Here, in the short-range wireless network 2, upstream data is sequentially transferred from the gateway device 230S in sensor mode, via the gateway device 230R in relay mode, to the gateway device 230G in gateway mode. In other words, the sequence chart in FIG. 17 is a replacement of the SW sensor device 10 in FIG. 11 with the gateway device 230S in sensor mode, the SW relay device 20 with the gateway device 230R in relay mode, and the gateway device 30 with the gateway device 230G in gateway mode.

The control unit 231 of the gateway device 230S in sensor mode executes an upstream data transmission process procedure RT61 (FIG. 17) that is substantially similar to the upstream data transmission process procedure RT11 (FIG. 11) to transmit data generated by the sensor unit 35 (FIG. 16) to the gateway device 230R in relay mode.

The control unit 231 of the gateway device 230R in relay mode transmits the data received from the gateway device 230S to the gateway device 230G in gateway mode by executing an upstream data relay processing procedure RT62 (FIG. 17) that is substantially similar to the upstream data relay processing procedure RT12 (FIG. 11).

The control unit 231 of the gateway device 230G in gateway mode executes an upstream data reception/transmission processing procedure RT63 (FIG. 17) that is substantially the same as the upstream data reception/transmission processing procedure RT13 (FIG. 11). As a result, the control unit 231 transmits the data received from the gateway device 230R by the first wireless communication unit 33 to the information management server 50 from the second wireless communication unit 34 via the wide area wireless network 3.

The control unit 51 of the information management server 50 executes an upstream data conversion relay processing procedure RT64 (FIG. 17) that is substantially similar to the upstream data conversion relay processing procedure RT14 (FIG. 11) to convert the data received from the gateway device 230G and transmit it to the information storage server 60.

The control unit 61 of the information storage server 60 executes an upstream data reception and storage process procedure RT65 (FIG. 17) that is substantially similar to the upstream data reception and storage process procedure RT15 (FIG. 11) to store the data received by the information management server 50 in the storage unit 62.

Thus, in the sensor system 201, similar to the first embodiment, data generated by the sensor unit 35 in the gateway device 230S in sensor mode can be sequentially transferred to the information storage server 60 and stored therein.

Incidentally, in the sensor system 201, when downstream data is transferred sequentially from the information storage server 60 to the gateway device 230S in sensor mode, each device performs processing similar to that shown in the sequence chart of FIG. 12.

[2-3. Remote maintenance in sensor systems]
Next, remote maintenance in the sensor system 201 will be described for the cases where temperature and wireless reception level are measured in the same manner as in the first embodiment.

[2-3-1. Temperature measurement]
First, in the sensor system 201, a case will be described with reference to the sequence chart of FIG. 18 corresponding to FIG. 13 in which temperature is measured by the gateway device 230S in sensor mode based on instructions from the information management server 50, and the obtained measurement data is transmitted to the information management server 50.

The control unit 51 of the information management server 50 executes a temperature measurement request processing procedure RT74 (FIG. 18) that is substantially similar to the temperature measurement request processing procedure RT34 (FIG. 13) to transmit a temperature measurement request to the gateway device 230G in gateway mode via the upper network 5 in step SP741.

The control unit 231 of the gateway device 230G in gateway mode executes a temperature measurement request receiving and transmitting process procedure RT73 (FIG. 18) that is substantially similar to the temperature measurement request receiving and transmitting process procedure RT33 (FIG. 13). As a result, in step SP731, the control unit 231 transmits the temperature measurement request received from the information management server 50 by the second wireless communication unit 34 to the gateway device 230R in relay mode by the first wireless communication unit 33.

The control unit 231 of the gateway device 230R in relay mode executes a temperature measurement request relay process procedure RT72 (FIG. 18) that is substantially similar to the temperature measurement request relay process procedure RT32 (FIG. 13). As a result, in step SP721, the control unit 231 transmits the temperature measurement request received from the gateway device 230G in gateway mode via the first wireless communication unit 33 to the gateway device 230S in sensor mode via the first wireless communication unit 33.

The control unit 231 of the gateway device 230S in sensor mode executes a temperature measurement process procedure RT71 (FIG. 18) that is substantially the same as the temperature measurement process procedure RT31 (FIG. 13). As a result, the control unit 231 measures the temperature using the temperature measurement unit 36 in step SP711 to generate measurement data, and transmits the measurement data to the gateway device 230R in relay mode via the first wireless communication unit 33 in step SP712.

In step SP722, the control unit 231 of the gateway device 230R in relay mode transmits the measurement data received from the gateway device 230S in sensor mode via the first wireless communication unit 33 to the gateway device 230G in gateway mode via the first wireless communication unit 33 in accordance with the temperature measurement request relay processing procedure RT72.

In accordance with the temperature measurement request receiving and transmitting process procedure RT73, the control unit 231 of the gateway device 230G in gateway mode transmits the measurement data received from the gateway device 230R in relay mode by the first wireless communication unit 33 to the information management server 50 via the wide area wireless network 3 or the like by the second wireless communication unit 34 in step SP732.

The control unit 51 of the information management server 50 stores the measurement data received from the gateway device 230G in gateway mode in the memory unit 52 in step SP742 according to the temperature measurement request processing procedure RT74. At this time, the control unit 51 displays the numerical values of the received measurement data and graphs based on the measurement data on the display unit 54 based on operation instructions by the user via the operation unit 55, as in the first embodiment.

[2-3-2. Measuring wireless reception level]
Next, a case in which in the sensor system 201, the gateway device 230S in sensor mode measures the wireless reception level based on instructions from the information management server 50 and transmits the obtained measurement data to the information management server 50 will be described with reference to the sequence chart of FIG. 19, which corresponds to FIG. 14.

The control unit 51 of the information management server 50 executes a wireless reception level measurement request processing procedure RT84 (FIG. 19) that is substantially similar to the wireless reception level measurement request processing procedure RT44 (FIG. 14) to transmit a wireless reception level measurement request to the gateway device 230G in gateway mode via the upper network 5 in step SP841.

The control unit 231 of the gateway device 230G in gateway mode executes a wireless reception level measurement request receiving and transmitting process procedure RT83 (FIG. 19) that is substantially the same as the wireless reception level measurement request receiving and transmitting process procedure RT43 (FIG. 14). As a result, in step SP831, the control unit 231 transmits the wireless reception level measurement request received from the information management server 50 by the second wireless communication unit 34 to the gateway device 230R in relay mode by the first wireless communication unit 33.

The control unit 231 of the gateway device 230R in relay mode executes a wireless reception level measurement request relay process procedure RT82 (FIG. 19) that is substantially similar to the wireless reception level measurement request relay process procedure RT42 (FIG. 14). As a result, in step SP821, the control unit 231 transmits the wireless reception level measurement request received from the gateway device 230G in gateway mode by the first wireless communication unit 33 to the gateway device 230S in sensor mode by the first wireless communication unit 33.

The control unit 231 of the gateway device 230S in sensor mode executes a wireless reception level measurement process procedure RT81 (FIG. 19) that is substantially similar to the wireless reception level measurement process procedure RT41 (FIG. 14). As a result, in steps SP811 and SP812, the control unit 231 measures the wireless reception level based on the wireless signal received from the gateway device 230R in relay mode, generates measurement data, and in step SP813 transmits the measurement data to the gateway device 230R in relay mode via the first wireless communication unit 33.

The control unit 231 of the gateway device 230R in relay mode transmits the measurement data received from the gateway device 230S in sensor mode by the first wireless communication unit 33 to the gateway device 230G in gateway mode by the first wireless communication unit 33 in step SP823 according to the wireless reception level measurement request relay processing procedure RT82.

The control unit 231 of the gateway device 230G in gateway mode transmits the measurement data received from the gateway device 230R in relay mode by the first wireless communication unit 33 to the information management server 50 via the wide area wireless network 3, etc. by the second wireless communication unit 34 in step SP832, according to the wireless reception level measurement request receiving and transmitting process procedure RT83.

The control unit 51 of the information management server 50 stores the measurement data received from the gateway device 230G in gateway mode in the memory unit 52 in step SP842 according to the wireless reception level measurement request processing procedure RT84. At this time, the control unit 51 displays the numerical values of the received measurement data and graphs based on the measurement data on the display unit 54 based on operation instructions by the user via the operation unit 55, as in the first embodiment.

[2-4. Effects, etc.]
In the above configuration, the gateway device 230 of the sensor system 201 according to the second embodiment is connected to the narrow-area wireless network 2 by the first wireless communication unit 33 and to the wide-area wireless network 3 by the second wireless communication unit 34, as in the first embodiment (FIGS. 15 and 16). Also, the gateway device 230 is configured to operate each unit with power supplied from a power supply unit 46 having a solar cell 47, a secondary battery 49, etc., as in the first embodiment (FIG. 16). Therefore, the gateway device 230 can operate in a place where it is difficult to connect to a commercial power source, as long as it is exposed to direct sunlight, as in the first embodiment.

In addition, in the sensor system 201, the gateway device 230 is provided with an operation mode setting unit 241 and a setting switch 242, and the operation mode of the gateway device 230 can be switched to gateway mode, sensor mode, or relay mode depending on the setting value of the setting switch 242.

Therefore, in the sensor system 201, for example, during installation work or maintenance work, the gateway device 230S in sensor mode or the gateway device 230R in relay mode can be installed instead of the SW sensor device 10 or SW relay device 20 in the first embodiment. As a result, in the sensor system 201, for example, during installation work or maintenance work, only one type of gateway device 230 is prepared, and the same functions as the SW sensor device 10 or SW relay device 20 can be realized simply by switching the operation mode according to the purpose of use. In other words, in the sensor system 201, the cost required for manufacturing and management can be reduced and the work can be simplified by standardizing the devices. In other words, the sensor system 201 can build an extremely practical and economical monitoring system, which can improve the maintenance and management of infrastructure facilities and measures against various natural disasters.

In other respects, the sensor system 201 according to the second embodiment can achieve the same effects as the sensor system 1 according to the first embodiment.

3. Third embodiment
A sensor system 301 ( FIG. 15 ) according to the third embodiment differs from the sensor system 201 according to the second embodiment in that the sensor system 301 includes gateway devices 330 (330S, 330R, and 330G) instead of the gateway devices 230 (230S, 230R, and 230G). The sensor system 301 is configured similarly to the sensor system 201 in other respects.

As shown in FIG. 20, which corresponds to FIG. 16, the gateway device 330 differs from the gateway device 230 according to the second embodiment in that it has a control unit 331, a storage unit 332, and an operation mode setting unit 341 instead of the control unit 231, the storage unit 232, and the operation mode setting unit 241. The gateway device 330 also differs in that it omits the setting switch 242 in the second embodiment, but has an external bus unit 343 and a third wireless communication unit 344. However, in other respects, the gateway device 330 is configured in the same way as the second embodiment.

Like the control unit 231, the control unit 331 has a CPU, ROM, RAM, and a timer circuit (not shown). Like the control unit 231, this control unit 331 uses the RAM as a work area and executes a program read from the ROM, storage unit 332, etc., by the CPU, thereby performing processing that differs in part from that of the second embodiment. Also, like the control unit 231, the control unit 331 can recognize the current date and time and measure the elapsed time from a predetermined point in time by using a timer circuit (not shown).

Like the storage unit 232, the storage unit 332 has a non-volatile storage medium such as an EEPROM, SSD, or hard disk drive. This storage unit 332 stores programs and setting information that are partially different from those in the second embodiment, or data received by the first wireless communication unit 33. The storage unit 332 is also capable of storing in the EEPROM the setting value of the operation mode and operation mode activation information for enabling or disabling the operation mode setting unit 341.

As in the second embodiment, the operation mode setting unit 341 is configured to set the operation mode of the gateway device 330 to either the gateway mode, the sensor mode, or the relay mode. However, unlike the second embodiment, the operation mode setting unit 341 is configured to read a setting value from the EEPROM of the storage unit 332 via the control unit 331, and set an operation mode according to this setting value.

The external bus unit 343 is a wired communication interface that complies with standards such as USB (Universal Serial Bus). This external bus unit 343 can be connected to, for example, a specified maintenance device (not shown) via a USB cable (not shown).

The third wireless communication unit 344 is a wireless communication interface that complies with standards such as Bluetooth (registered trademark). This third wireless communication unit 344 can be connected to, for example, a specified maintenance device (not shown).

When the control unit 331 of the gateway device 330 is connected to a predetermined maintenance device (not shown) via the external bus unit 343 or the third wireless communication unit 344, the control unit 331 can cause the maintenance device to read the setting information, etc. stored in the memory unit 332 and rewrite the setting information, etc.

Specifically, when the control unit 331 is connected to a predetermined maintenance device (not shown) via the external bus unit 343 or the third wireless communication unit 344, it starts the operation mode activation change processing procedure RT91 shown in FIG. 21 by reading and executing an operation mode activation change program from the storage unit 332. In the first step SP901, the control unit 331 obtains an instruction from the maintenance device via the external bus unit 343 or the third wireless communication unit 344, and proceeds to the next step SP902.

In step SP902, the control unit 331 determines whether or not an instruction to enable (activate) the operation mode setting unit 341 has been obtained. If a positive result is obtained here, the control unit 331 proceeds to the next step SP903, where it stores the operation mode enable information in the storage unit 332, and then proceeds to the next step SP907.

On the other hand, if a negative result is obtained in step SP902, the control unit 331 proceeds to the next step SP904, where it determines whether or not an instruction to disable (deactivate) the operation mode setting unit 341 has been acquired. If a positive result is obtained here, the control unit 331 proceeds to the next step SP905, where it stores the operation mode disable information in the memory unit 332, and then proceeds to the next step SP907.

On the other hand, if a negative result is obtained in step SP904, this indicates that an instruction to change the setting value of the operation mode has been received from the maintenance device. In this case, the control unit 331 proceeds to the next step SP906, stores the setting value of the operation mode in the memory unit 332 based on the contents of the instruction, and proceeds to the next step SP907. In step SP907, the control unit 331 ends the operation mode activation change processing procedure RT91.

In this way, the gateway device 330 according to the third embodiment has operation mode activation information stored in the memory unit 332. Therefore, the control unit 331 refers to the operation mode activation information in the memory unit 332, for example, immediately after the power is turned on or when the device is restarted, and if operation mode valid information is stored, the control unit 331 switches the operation mode in cooperation with the operation mode setting unit 341, as in the second embodiment. On the other hand, if operation mode invalid information is stored as the operation mode activation information in the memory unit 332, the control unit 331 operates in the gateway mode regardless of the setting value of the operation mode. Therefore, the gateway device 330 can easily switch whether or not to operate in the operation mode based on the setting value simply by changing the operation mode activation information in the memory unit 332.

In other respects, the sensor system 301 according to the third embodiment can achieve the same effects as the sensor system 1 according to the first embodiment and the sensor system 201 according to the second embodiment.

4. Other embodiments
In the first embodiment described above, the sensor unit 35 of the gateway device 30 is an ultrasonic sensor, and the sensor exposure unit 30A3 that emits and acquires ultrasonic waves is attached to the lower side of the attachment unit 30A2 (FIG. 6). However, the present invention is not limited to this, and the sensor unit 35 may be a water pressure type water level gauge, and a part of the sensor exposure unit 430A3 may be located underwater, as in the gateway device 430 shown in FIG. 22(A). Alternatively, the sensor unit 35 may be an imaging unit (a so-called camera), and the sensor exposure unit 530A3 incorporating a lens, an imaging element, etc. may be provided on the lower side of the attachment unit 530A2, as in the gateway device 530 shown in FIG. 22(B). The same applies to the second and third embodiments.

In the above-mentioned first embodiment, the power supply mode for the second wireless communication unit 34 is switched between three modes, short cycle mode, long cycle mode, and pause mode, depending on the state of the power supply unit 46 in the gateway device 30 and the data value (FIG. 8). However, the present invention is not limited to this, and may be switched between two modes, short cycle mode and pause mode, or the cycle may be calculated by a calculation using the power generation amount of the solar cell 47 or the voltage value of the secondary battery 49. In addition, the cycle for supplying power to the first wireless communication unit 33 may be changed as appropriate, or power may be constantly supplied to the first wireless communication unit 33. The same applies to the second and third embodiments.

Furthermore, in the above-mentioned first embodiment, the power supply mode is switched in the power supply unit 46 of the gateway device 30 based on the amount of power generated by the solar cell 47 and the voltage of the secondary battery 49, as well as the result of comparing the data value with the alert threshold (FIG. 8). However, the present invention is not limited to this, and the power supply mode may be switched based on either the amount of power generated by the solar cell 47 or the voltage of the secondary battery 49. Also, for example, multiple alert thresholds may be set, and the cycle may be switched in multiple stages based on the result of comparing these with the data value. Alternatively, for example, the power supply mode may be switched based only on the amount of power generated by the solar cell 47 and the voltage of the secondary battery 49, regardless of the data value. Furthermore, for example, a weather forecast for the installation location of the gateway device 30 may be supplied from the information management server 50, and the power supply mode may be switched according to the weather. Alternatively, for example, when it is known that the characteristics of the secondary battery 49 vary depending on the temperature, the power supply mode may be switched taking into account the temperature measured by the temperature measurement unit 36. Furthermore, for example, if the time of sunset or sunrise is known, the power supply mode may be switched taking into account other factors, such as the current time. Also, for example, a value determined by the information management server 50 may be used as the period. The same applies to the second and third embodiments.

Furthermore, in the above-mentioned first embodiment, the case where the solar cell 47 is provided on the main body 30A1 of the gateway device 30 (FIG. 6) has been described. However, the present invention is not limited to this, and for example, the solar cell 47 may be provided separately from the main body 30A1. Alternatively, for example, in addition to the solar cell 47 provided on the main body 30A1, another solar cell may be connected. The same applies to the secondary battery 49, and also to the SW sensor device 10 and the SW relay device 20. The same also applies to the second and third embodiments.

Furthermore, in the above-mentioned first embodiment, a case has been described in which a solar cell 47 is provided in the power supply unit 46 of the gateway device 30 (FIGS. 6 and 7). However, the present invention is not limited to this, and the power supply unit 46 may be provided with various power generation devices that utilize so-called natural energy, such as wind power, water power, geothermal power, solar heat, heat in the atmosphere, other heat existing in nature, biomass, etc., or an appropriate combination of these. The same applies to the SW sensor device 10 and the SW relay device 20, and also to the second and third embodiments.

Furthermore, in the above-mentioned first embodiment, a case has been described in which a sensor unit 35 is provided in the gateway device 30 and data is generated by the sensor unit 35. However, the present invention is not limited to this, and for example, the sensor unit 35 may be omitted from the gateway device 30. The same applies to the second and third embodiments.

Furthermore, in the above-mentioned first embodiment, a case has been described in which the temperature measurement unit 36 is provided in the gateway device 30. However, the present invention is not limited to this, and for example, the temperature measurement unit 36 may be omitted from the gateway device 30. Alternatively, for example, instead of the temperature measurement unit 36, a temperature and humidity measurement unit that measures temperature and humidity may be provided. The same applies to the second and third embodiments.

Furthermore, in the above-mentioned second embodiment, the operation mode of the gateway device 230 is described as being switched between three different modes (Tables 1, 2, and 3). However, the present invention is not limited to this, and the operation mode of the gateway device 230 may be switched between two different modes or four or more different modes. The same applies to the third embodiment.

Furthermore, in the above-mentioned third embodiment, a case has been described in which the gateway device 330 (FIG. 20) is provided with an external bus unit 343 and a third wireless communication unit 344. However, the present invention is not limited to this, and for example, either the external bus unit 343 or the third wireless communication unit 344 may be provided. Also, both the external bus unit 343 and the third wireless communication unit 344 may be omitted, and a maintenance device (not shown) may be connected via the first wireless communication unit 33 or the second wireless communication unit 34.

Furthermore, in the above-mentioned first embodiment, various programs are stored in advance in the storage unit 32 of the gateway device 30, and the control unit 31 reads out and executes the programs from the storage unit 32 to perform various processes. However, the present invention is not limited to this, and for example, the gateway device 30 may acquire (download) various programs from the information management server 50 via the second wireless communication unit 34, and execute the programs to perform various processes. The same applies to the second and third embodiments.

Furthermore, the present invention is not limited to the above-mentioned embodiments and other embodiments. In other words, the scope of application of the present invention extends to embodiments that arbitrarily combine the above-mentioned embodiments with part or all of the other embodiments described above, or to embodiments that extract parts of the above-mentioned embodiments.

Furthermore, in the above-mentioned embodiment, the gateway device 30 as a relay device is configured by the first wireless communication unit 33 as the first communication unit, the second wireless communication unit 34 as the second communication unit, the control unit 31 as the control unit, and the power supply unit 46 as the power generation unit. However, the present invention is not limited to this, and the relay device may be configured by the first communication unit, the second communication unit, the control unit, and the power generation unit having various other configurations.

[4-1. Application examples]
In the above-mentioned first embodiment, it has been described that each SW sensor device 10 and gateway device 30 detects, for example, the water level of a river or the vibration of a bridge pier with the respective sensors to generate data. More specifically, it has been described that each SW sensor device 10 and gateway device 30 are installed as sensors that measure the water level of a river, and information such as an evacuation warning is provided based on the obtained water level value. In addition, the present invention can be used for various sensing.

[4-1-1. Sensing in Agriculture]
However, in recent years, the number of agricultural management entities and employment management entities have both been declining due to the so-called aging population and labor shortages. Possible measures to address this labor shortage in agriculture include recruiting and training labor, and adjusting human resources according to the needs of production areas, but from the perspective of cost and time, it is difficult to apply these measures to the entire agricultural industry. Therefore, as one way of improving the environment to reduce the labor burden, efforts are being made to realize smart agriculture (a new type of agriculture that realizes ultra-labor-saving and high-quality production using robotics and ICT (Information and Communications Technology)).

To achieve high-quality agricultural production, for example, soil sensors that measure moisture levels at multiple points on farmland could be installed, and information such as soil moisture level alerts could be provided to appropriate targets at appropriate times based on the moisture level values obtained. The placement of such sensors can be completed in a relatively short time and at reduced costs, compared to farmers having to identify soil moisture levels visually or based on experience.

For example, when providing information such as a soil moisture level warning in the sensor system 1, the control unit 51 of the information management server 50 compares the data received in step SP141 (FIG. 11) with a predetermined alert threshold (e.g., a level at which the moisture level in farmland may be harmful to the health of crops) before performing a predetermined conversion process on the data. If the control unit 51 then determines that information such as a soil moisture level warning should be provided based on the obtained comparison result, it provides the information on the soil moisture level warning by displaying it on the display unit 54, or by notifying a predetermined notification destination (to a farmer), or by uploading it to a web server (not shown) on the Internet as a homepage.

[4-1-2. Sensing in infectious disease countermeasures]
In recent years, public awareness of infectious diseases has increased due to the influence of the so-called Severe Acute Respiratory Syndrome (SARS), Middle East Respiratory Syndrome (MERS), and COVID-19 (Coronavirus Disease 2019), and there is a need to prevent the spread of infection. To prevent the spread of infection, for example, measures such as detecting and notifying the outbreak of an infectious disease can be considered, but it is difficult to apply manual PCR (Polymerase Chain Reaction) tests to the entire area where an infectious disease is expected to occur due to the cost and time involved. Therefore, as one way of improving the environment to reduce the burden involved in detecting the outbreak of an infectious disease, efforts are being made to realize infectious disease detection using biosensors.

To detect infectious diseases, biosensors that detect viruses, the causative agents, could be installed in multiple locations in areas where infectious diseases are expected to occur, and information such as infectious disease detection alerts could be provided to subjects within an appropriate range at an appropriate time based on the presence or absence of the causative agent detected. The placement of such sensors can be completed in a relatively short time and at a reduced cost compared to infectious disease detection using PCR testing done by hand.

For example, when providing information such as an infectious disease detection alert in the sensor system 1, the control unit 51 of the information management server 50 compares the data received in step SP141 (FIG. 11) with a predetermined alert threshold (e.g., the presence of a virus that is a causative agent that may be harmful to human health) before performing a predetermined conversion process on the data. If the control unit 51 then determines that information such as an infectious disease detection alert should be provided based on the obtained comparison result, it provides the information on the infectious disease detection alert by displaying it on the display unit 54, or by notifying a predetermined notification destination (medical worker), or by uploading it to a web server (not shown) on the Internet as a homepage.

[4-1-3. Sensing in traffic]
In recent years, the optimization of traffic is being promoted due to the influence of so-called chronic traffic congestion. One possible approach to traffic optimization is to detect and report the occurrence of traffic congestion, but it is difficult to apply manual counting of cars to the entire area where traffic congestion is expected to occur due to the cost and time involved. Therefore, as one way of improving the environment to reduce the burden of detecting the occurrence of traffic congestion, efforts are being made to realize traffic congestion detection using vehicle count sensors.

To realize congestion detection, vehicle count sensors could be installed in multiple locations in areas where congestion is expected to occur, which detect and count passing vehicles, and based on the number of detected and counted passing vehicles obtained, information such as congestion detection warnings could be provided to target people within an appropriate range at an appropriate time. The placement of such sensors can be completed in a relatively short time and at a reduced cost compared to congestion detection based on manual counting of cars.

For example, when providing information such as a traffic congestion detection warning in the sensor system 1, the control unit 51 of the information management server 50 compares the data received in step SP141 (FIG. 11) with a predetermined alert threshold (e.g., the number of passing vehicles that may lead to traffic congestion) before performing a predetermined conversion process on the data. Next, when the control unit 51 determines that information such as a traffic congestion detection warning should be provided based on the obtained comparison result, it displays the information on the display unit 54, or notifies a predetermined notification destination (road administrator or road user), or provides it by uploading it as a homepage to a web server (not shown) on the Internet.

The present invention can be used, for example, in a gateway device that connects to two different types of wireless networks.

1, 201, 301...sensor system, 2...narrow area wireless network, 3...wide area wireless network, 4...base station, 5...upper network, 10...SW sensor device, 11, 21, 31, 51, 61, 231, 331...control unit, 12, 22, 32, 52, 62, 232, 332...memory unit, 13, 23...wireless communication unit, 14, 35...sensor unit, 15, 36...temperature measurement unit, 16, 26, 46...power supply unit, 17, 27, 47...solar cell , 18, 28, 48...Charge/discharge control unit, 19, 29, 49...Secondary battery, 20...SW relay device, 30, 230, 330, 430, 530...Gateway device, 33...First wireless communication unit, 34...Second wireless communication unit, 50...Information management server, 53, 63...Communication unit, 54...Display unit, 55...Operation unit, 60...Information storage server, 241, 341...Operation mode setting unit, 242...Setting switch, 343...External bus unit, 344...Third wireless communication unit.

Claims (16)

a first communication unit connected to a first communication network;
a second communication unit connected to a second communication network;
a control unit that controls a supply of power to the second communication unit after the first communication unit receives data from the first communication network, and causes the second communication unit to transmit the data to the second communication network;
a power generation unit that generates the power to be supplied to the first communication unit, the second communication unit, and the control unit ,
The control unit controls the second communication unit to supply the power intermittently.
A relay device comprising : The relay device according to claim 1 , wherein the control unit changes the intermittent interval in accordance with an amount of power generated by the power generation unit. The relay device according to claim 1 , wherein the control unit changes the interval of the intermittent transmission in accordance with the data. The relay device according to claim 1, characterized in that the control unit controls the supply of power to the first communication unit, and when the first communication unit receives the data from the first communication network, controls the supply of power to the second communication unit and causes the second communication unit to transmit the data to the second communication network. A storage unit for storing information,
The relay device according to claim 1, characterized in that, when the power generation unit cannot supply the power necessary for operation of the second communication unit, the control unit stores the data received by the first communication unit from the first communication network in the memory unit and controls the second communication unit not to operate. A memory unit for storing information;
Equipped with
The relay device according to claim 1, characterized in that, when the power generation unit changes from a state in which it is unable to supply the power necessary for the operation of the second communication unit to a state in which it is able to supply the power, the control unit controls the power generation unit to supply the power to the second communication unit and controls the data stored in the memory unit to be transmitted from the second communication unit to the second communication network. a sensor unit that generates second data;
The relay device according to claim 1 , wherein the control unit controls the second data generated by the sensor unit to be transmitted from the second communication unit to the second communication network. an operation mode setting unit that sets an operation mode to a gateway mode in which both the first communication unit and the second communication unit are operated, or a sensor mode in which the first communication unit is operated and the second communication unit is stopped;
The relay device according to claim 7, characterized in that, when the operation mode setting unit is set to the gateway mode, the control unit controls the second communication unit to transmit the data received from the first communication network by the first communication unit and the second data generated by the sensor unit to the second communication network, and when the operation mode setting unit is set to the sensor mode, the control unit controls the first communication unit to transmit the second data generated by the sensor unit to the first communication network. the operation mode setting unit sets the operation mode to the gateway mode, the sensor mode, or a relay mode in which the first communication unit is operated and the second communication unit and the sensor unit are stopped;
The relay device according to claim 8, characterized in that, when the relay mode is set by the operation mode setting unit , the control unit controls the data received from the first communication network by the first communication unit to be transmitted from the first communication unit to the first communication network. a receiving step of receiving data by a first communication unit connected to a first communication network;
a supply power control step of controlling power supplied from the power generation unit to a second communication unit connected to the second communication network;
a transmission step of transmitting the data to the second communication network by the second communication unit to which the power is supplied from the power generation unit ,
The power supply control step controls the power to be supplied to the second communication unit intermittently.
A relay method comprising : For the information processing device,
a receiving step of receiving data by a first communication unit connected to a first communication network;
a supply power control step of controlling power supplied from the power generation unit to a second communication unit connected to the second communication network;
a transmission step of transmitting the data to the second communication network by the second communication unit to which the power is supplied from the power generation unit ;
The power supply control step controls the power to be supplied to the second communication unit intermittently.
A broadcast program for . A communication system in which a sensor device and a relay device are connected to a first communication network, and the relay device and a management server are connected to a second communication network,
The relay device is
A first communication unit connected to the first communication network;
A second communication unit connected to the second communication network;
a control unit that controls a supply of power to the second communication unit after the first communication unit receives data from the first communication network, and causes the second communication unit to transmit the data to the second communication network;
a power generation unit that generates the power to be supplied to the first communication unit, the second communication unit, and the control unit ,
The control unit controls the second communication unit to supply the power intermittently.
A communication system comprising : A first communication unit that communicates in a first communication method;
A second communication unit that communicates in a second communication method;
a control unit that controls a supply of power to the second communication unit after the first communication unit receives first data in the first communication method, and causes the second communication unit to transmit the first data in the second communication method;
A sensor unit that generates second data;
a power generation unit that generates the power to be supplied to the first communication unit, the second communication unit, the control unit, and the sensor unit;
an operation mode setting unit that sets the first communication unit and the second communication unit to a gateway mode in which both the first communication unit and the second communication unit are operated, or to a sensor mode in which the first communication unit is operated and the second communication unit is stopped;
Equipped with
The control unit is
When the operation mode setting unit sets the gateway mode, the first data and/or the second data is controlled so as to be transmitted by the second communication unit in the second communication method;
When the operation mode setting unit sets the operation mode to the sensor mode, the second data is controlled to be transmitted by the first communication unit in the first communication method.
A relay device comprising: a setting step of setting, by an operation mode setting unit, a gateway mode in which both a first communication unit that communicates using a first communication method and a second communication unit that communicates using a second communication method are operated, or a sensor mode in which the first communication unit is operated and the second communication unit is stopped;
an operating step of operating in the operation mode set by the setting step;
having
The operation step includes:
when the operation mode setting unit sets the gateway mode, the first communication unit receives first data, a power generation unit supplies power to the second communication unit, and the second communication unit transmits the first data in the second communication method;
When the operation mode setting unit sets the sensor mode, the sensor unit generates second data, and the first communication unit transmits the second data in the first communication method.
A relay method comprising: For the information processing device,
a setting step of setting, by an operation mode setting unit, a gateway mode in which both a first communication unit that communicates using a first communication method and a second communication unit that communicates using a second communication method are operated, or a sensor mode in which the first communication unit is operated and the second communication unit is stopped;
an operating step of operating in the operation mode set by the setting step;
Run the command,
The operation step includes:
when the operation mode setting unit sets the gateway mode, the first communication unit receives first data, a power generation unit supplies power to the second communication unit, and the second communication unit transmits the first data in the second communication method;
When the operation mode setting unit sets the sensor mode, the sensor unit generates second data, and the first communication unit transmits the second data in the first communication method.
A broadcast program for. A communication system in which a sensor device and a relay device are connected to a first communication network, the relay device and a management server are connected to a second communication network, and the communication system has a device that operates as the relay device or the sensor device,
The apparatus comprises:
A first communication unit that communicates in a first communication method;
A second communication unit that communicates in a second communication method;
a control unit that controls a supply of power to the second communication unit after the first communication unit receives first data in the first communication method, and causes the second communication unit to transmit the first data in the second communication method;
A sensor unit that generates second data;
a power generation unit that generates the power to be supplied to the first communication unit, the second communication unit, the control unit, and the sensor unit;
an operation mode setting unit that sets the first communication unit and the second communication unit to a gateway mode in which both the first communication unit and the second communication unit are operated, or to a sensor mode in which the first communication unit is operated and the second communication unit is stopped;
Equipped with
The control unit is
When the device is operated as the relay device, the operation mode setting unit sets the device to the gateway mode, and controls the second communication unit to transmit the first data and/or the second data in the second communication method;
When the device is operated as the sensor device, the operation mode setting unit sets the device to the sensor mode, and controls the first communication unit to transmit the second data in the first communication method.
A communication system comprising:

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