Wireless communication unit

Abstract

To deliver device information from a sensor to a base station even when the reception level of radio waves is low.SOLUTION: A wireless communication unit (1) includes a main wireless device (2) that transmits device information from a sensor to a base station (4) according to a first communication scheme, and a standby wireless device (3) that transmits the device information transferred in response to a drop in the wireless wave reception level of the main wireless device (2) to the base station (4) according to a second communication scheme which has a wider communicable area than the first communication method.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a wireless communication unit that transmits device information detected by a sensor to a base station. [Background technology]

[0002] In recent years, communication networks using wireless communication methods such as LTE (Long Term Evolution) have been established as a social infrastructure. Services such as monitoring the safety of family members far away are provided by linking wireless communication devices connected to cloud servers via wireless base stations using this LTE wireless communication method with sensors such as cameras and motion sensors. In such services, data transmitted from wireless communication devices to cloud servers ranges from large-volume data such as videos captured by cameras to small-volume data detected by motion sensors to determine the presence or absence of people. In addition, wireless communication methods include communication methods with relatively high communication speeds such as LTE Cat.1 (Long Term Evolution Category 1) and LTE Cat.4 (Long Term Evolution Category 4), and communication methods called LPWA (Low Power Wide Area) represented by LTE Cat.M1 (Long Term Evolution Category M1), which has a relatively slow communication speed but a relatively wide communication area.

[0003] A data communication system is known in which vehicle information is sent from the vehicle (terminal) to a center device using a communication method with a relatively wide communication area, and large-scale content data corresponding to the vehicle information is sent from the center device to the vehicle using a communication method with a relatively fast communication speed (Patent Document 1). This allows for efficient distribution of content data. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2020-057256 A Summary of the Invention [Problem to be solved by the invention]

[0005] In services that utilize wireless communication methods, wireless communication may not be established or may be unstable depending on the location and environment in which the wireless communication device is located. In particular, in wireless communication methods with relatively high communication speeds, wireless communication devices are prone to being unable to communicate wirelessly due to a decrease in the reception level of radio waves received from a base station and multipath. In such a situation, device information acquired by a device with a connected sensor does not reach the base station, and important device information is missing from the data sent to the cloud server, which may cause the service to fail.

[0006] The present invention aims to realize a wireless communication unit that can deliver device information detected by a sensor to a base station even if the reception level of radio waves received by a wireless communication device relating to a specific wireless communication method from a base station decreases. [Means for solving the problem]

[0007] In order to solve the above problems, a wireless communication unit according to one embodiment of the present invention is characterized in that it comprises a primary wireless device that transmits device information detected by a sensor to a base station according to a first communication method, and a backup wireless device that transmits the device information transferred from the primary wireless device to the base station in response to a decrease in the reception level of radio waves from the base station according to a second communication method having a wider communication area than the first communication method. Effect of the Invention

[0008] The wireless communication unit of the present invention can deliver device information detected by the sensor to the base station even if the reception level of radio waves received by a wireless communication device related to a specific wireless communication method from a base station drops. [Brief description of the drawings]

[0009] [Figure 1] 1 is a diagram illustrating a configuration of a communication network to which a wireless communication unit according to an embodiment is connected. [Diagram 2] 2 is a diagram showing a communication area of ​​a communication method used by the wireless communication unit. FIG. [Diagram 3] 2 is a functional configuration diagram of a main wireless device and a backup wireless device provided in the wireless communication unit. FIG. [Figure 4] 4 is a schematic diagram showing radio wave strength and communication availability level of a first communication method followed by the main wireless device and a second communication method followed by the backup wireless device. FIG. [Diagram 5] 11 is a graph showing a time-series relationship between the radio wave intensity received by the main wireless device and the first and second thresholds. [Figure 6] FIG. 2 is a sequence diagram of a communication network to which the wireless communication unit is connected. [Figure 7] 11 is another sequence diagram of the communication network to which the wireless communication unit is connected. [Figure 8] 11 is still another sequence diagram of the communication network to which the wireless communication unit is connected. FIG. [Figure 9] 11 is still another sequence diagram of the communication network to which the wireless communication unit is connected. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, one embodiment of the present invention will be described in detail.

[0011] <Communication network configuration> FIG. 1 shows a configuration diagram of a communication network to which a wireless communication unit 1 according to the embodiment is connected.

[0012] The communication network of embodiment 1 includes a wireless communication unit 1, a base station 4 that communicates wirelessly with the wireless communication unit 1, an Internet line 7 connected to the base station 4, a cloud server 5 connected to the Internet line 7, and a terminal device 6 (terminal) connected to the Internet line 7.

[0013] The wireless communication unit 1 includes a main wireless device 2 and a backup wireless device 3. The main wireless device 2 is connected to a device 8 having at least one of a camera and a human presence sensor. The device 8 supplies device information detected by the camera and the human presence sensor to the main wireless device 2. The device 8 may have a sensor other than the camera and the human presence sensor.

[0014] The primary wireless device 2 transmits the device information provided from the device 8 to the base station 4 in accordance with the first communication method. The backup wireless device 3 transmits the device information transferred from the primary wireless device 2 in response to a drop in the reception level of radio waves from the base station 4 to the base station 4 in accordance with the second communication method, which has a wider communication area than the first communication method.

[0015] In response to the decrease in the reception level, the backup wireless device 3 generates simplified device information by simplifying the device information transferred from the main wireless device 2. Then, the backup wireless device 3 transmits this simplified device information to the base station 4 in accordance with the second communication method.

[0016] Moreover, it is preferable that the backup wireless device 3 transmits reception level state information indicating the reception level state of the primary wireless device 2 to the base station 4 according to the second communication method in response to the decrease in the reception level.

[0017] The backup wireless device 3 transmits a monitor signal to the main wireless device 2 for monitoring the operating state of the main wireless device 2. If the backup wireless device 3 does not receive a response to the monitor signal from the main wireless device 2, the backup wireless device 3 transmits a restart signal to the main wireless device 2 for restarting the main wireless device 2. The main wireless device 2 is restarted by the restart signal.

[0018] As a result, when communication by the first communication method is impossible due to a malfunction of the main wireless device 2, such as freezing, the main wireless device 2 can be restored using the spare wireless device 3.

[0019] Furthermore, it is preferable that the spare wireless device 3 cuts off communication between the main wireless device 2 and the base station 4 when the reception level drops below a first threshold T1 (FIG. 5), and resumes communication between the main wireless device 2 and the base station 4 when the reception level recovers and becomes equal to or greater than a second threshold T2 that is greater than the first threshold T1.

[0020] When the spare wireless device 3 does not receive a response from the main wireless device 2 to a monitoring signal for monitoring the operating status of the main wireless device 2, the spare wireless device 3 may transmit no-response state information indicating a state in which there is no response from the main wireless device 2 to the base station 4.

[0021] This makes it possible to notify the cloud server 5 and the terminal device 6, using the base station 4 and the backup wireless device 3, of a state in which communication is not possible using the first communication method due to a malfunction such as a freeze of the main wireless device 2.

[0022] When the backup wireless device 3 receives a restart instruction signal representing an instruction to restart the primary wireless device 2 from the cloud server 5 or the terminal device 6 via the base station 4, the backup wireless device 3 may transmit a restart signal to the primary wireless device 2 to restart the primary wireless device 2.

[0023] This makes it possible to use the cloud server 5, the terminal device 6, the base station 4, and the backup wireless device 3 to recover from a state in which communication is not possible using the first communication method due to a malfunction such as a freeze of the main wireless device 2.

[0024] The base station 4 transmits the simplified device information, the reception level state information, or the no-response state information transmitted from the spare wireless device 3 to the cloud server 5 via the Internet line 7. The cloud server 5 transfers the simplified device information, the reception level state information, or the no-response state information to the terminal device 6.

[0025] It is preferable that the main radio device 2 and the backup radio device 3 are integrated and housed in a single package.

[0026] The first communication method includes LTE Cat. 1 or LTE Cat. 4. The second communication method includes LPWA.

[0027] The device information that the device 8 supplies to the main wireless device 2 includes a video captured by a camera and human detection data detected by a human sensor.

[0028] The cloud server 5 accumulates the device information, simplified device information, reception level status information, and no-response status signal supplied from the base station 4, and provides them to the terminal device 6.

[0029] The terminal device 6 is connected to the cloud server 5 via an Internet line 7, and provides the user with device information, simplified device information, reception level status information, and no-response status information. For example, the terminal device 6 is a smartphone, a mobile phone, a PC (Personal Computer), a tablet terminal, etc.

[0030] When the reception level from the base station 4 drops, the backup wireless device 3 communicates with the base station 4 instead of the main wireless device 2. The backup wireless device 3 transmits a control signal, described later, to the main wireless device 2 based on the strength of the radio wave received from the base station 4. In response to this control signal, the main wireless device 2 transfers device information to the backup wireless device 3. Then, the backup wireless device 3 transmits reception level state information and simple device information to the base station 4 according to the second communication method.

[0031] When the backup wireless device 3 does not receive a response from the main wireless device 2 to a monitoring signal for monitoring the operating status of the main wireless device 2, the backup wireless device 3 transmits a restart signal to the main wireless device 2 for restarting the main wireless device 2.

[0032] The base station 4 is connected to an Internet line 7. The base station 4 transmits the reception level state information, the no-response state signal, and the simple device information transmitted from the spare wireless device 3 to the cloud server 5 via the Internet line 7. For example, the second communication method is LTE Cat.M1.

[0033] The cloud server 5 transmits the reception level status information, the no-response status signal, and the simple device information to the terminal device 6 via the Internet line 7.

[0034] The device information is information acquired from a device 8 connected to the main wireless device 2. The device 8 is provided with a camera and a human presence sensor. The device information includes, for example, moving images and still images captured by the camera, and information on the presence or absence of a person detected by the human presence sensor.

[0035] In this specification, status information refers to information that the backup wireless device 3 transmits to the base station 4 according to the second communication method to indicate the status of the primary wireless device 2, and includes reception level status information and no-response status information.

[0036] The reception level status information is information indicating that the main wireless device 2 cannot transmit device information to the base station 4 in the first communication method because the reception level from the base station 4 has decreased. By knowing the reception level status information transmitted from the backup wireless device 3, the user can know that the information displayed on the terminal device 6 is simple device information, which will be described later.

[0037] In contrast, the no-response state information is information indicating a state in which the backup wireless device 3 does not receive a response from the primary wireless device 2 to a monitoring signal transmitted by the backup wireless device 3 to monitor the operating state of the primary wireless device 2. This no-response state information allows the user to know, via the terminal device 6, the occurrence of a malfunction other than a drop in the reception level, such as freezing of the primary wireless device 2. Then, as a measure to restore the primary wireless device 2, the terminal device 6 can transmit a restart instruction signal to the backup wireless device 3 to restart the primary wireless device 2.

[0038] The simplified device information is information with a low communication volume that is obtained by converting the device information acquired by the main wireless device 2 from the device 8 by the backup wireless device 3. For example, if the device information acquired by the main wireless device 2 from the device 8 is a moving image, the simplified device information converted from the device information by the backup wireless device 3 may be a still image that is a part of the moving image. Alternatively, if the device information is a still image, the simplified device information may be a coarse still image obtained by reducing the number of pixels of the still image.

[0039] The control signal is a signal by which the backup wireless device 3 controls whether to permit or deny communication by the primary wireless device 2 using the first communication method, based on the reception level of radio waves received from the base station 4. When a control signal indicating permission of communication is transmitted from the backup wireless device 3 to the primary wireless device 2, the primary wireless device 2 communicates with the base station 4 using the first communication method. When a control signal indicating denial of communication is transmitted from the backup wireless device 3 to the primary wireless device 2, the backup wireless device 3 communicates with the base station 4 using the second communication method instead of the primary wireless device 2.

[0040] In this way, when the reception level from the base station 4 drops, the wireless communication unit 1 according to the first embodiment communicates with the base station 4 in the second communication method instead of the primary wireless device 2. This allows the user to obtain simplified device information and reception level status information from the terminal device 6 instead of device information.

[0041] The second communication method has a feature that the communication area is wider than that of the first communication method, but the communication volume is smaller.

[0042] FIG. 2 is a diagram showing communication areas 9 and 10 in which the communication method used by the wireless communication unit 1 can communicate.

[0043] The communication area 9 indicates an area in which communication with the base station 4 is possible by LTE Cat.1 or LTE Cat.4 related to the first communication method. The communication area 10 indicates an area in which communication with the base station 4 is possible by LPWA related to the second communication method. The communication area 10 is larger than the communication area 9 and includes the communication area 9.

[0044] The reception level decreases as the location is farther away from the base station 4. LTE Cat.1, 4 according to the first communication method cannot communicate with the base station 4 unless the reception level is higher than that of LTE Cat.M1 according to the second communication method.

[0045] Therefore, at point A within the communication area 9, both a wireless device compatible with LTE Cat.1,4 related to the first communication method and a wireless device compatible with LTE Cat.M1 related to the second communication method can communicate with the base station 4. However, at point B within a communication area 10 outside the communication area 9, a wireless device compatible with LTE Cat.M1 related to the second communication method can communicate with the base station 4, but a wireless communication device compatible with LTE Cat.1,4 related to the first communication method cannot communicate.

[0046] The primary wireless device 2 communicates with the base station 4 using LTE Cat.1,4, which is related to the first communication method and has a high communication speed, in order to send video data. However, if the primary wireless device 2 is in a place with a low reception level, it cannot communicate with the base station 4. In such a situation, the backup wireless device 3 plays a supporting role. The backup wireless device 3 is a device compatible with LTE Cat.M1, which is related to the second communication method, and monitors and controls the primary wireless device 2. When the primary wireless device 2 cannot communicate with the base station 4, the primary wireless device 2 transfers device information to the backup wireless device 3. The device information includes video data and human detection data. The backup wireless device 3 extracts and converts the data of the device information into simplified device information suitable for LTE Cat.M1, which is related to the second communication method. Examples of simplified device information include extracted human detection data and still image data converted from video data. The spare wireless device 3 transmits this simplified device information to the base station 4 in the LTE Cat.M1 system related to the second communication system and transmits it to the cloud server 5, so that the minimum necessary simplified device information can be provided to the terminal device 6 even in a situation where the main wireless device 2 cannot communicate with the base station 4. This makes it possible to prevent the operation of the wireless communication unit 1 from collapsing as a service.

[0047] In this way, by giving the wireless communication unit 1 of embodiment 1 the function of being able to communicate using both the first communication method and the second communication method, when communication is not possible using the first communication method, it is possible to avoid a situation in which communication is interrupted by communicating using the second communication method.

[0048] <Functional configuration of wireless communication system> FIG. 3 shows a functional configuration diagram of the wireless communication unit 1 according to the first embodiment.

[0049] (Main wireless equipment 2) The main wireless device 2 includes an antenna 11 for transmitting and receiving radio waves, a wireless communication module 12 connected to the antenna 11 and equipped with a communication function, a SIM (Subscriber Identity Module) 13 in which an ID number of a service subscriber is recorded, and a microcomputer 14 for controlling the operation of the main wireless device 2. The microcomputer 14 includes a control unit 16 for controlling the operation of the main wireless device 2, and a transfer unit 15 for transferring device information supplied from the device 8 to the backup wireless device 3.

[0050] The wireless communication module 12 transmits the device information to the base station 4 in the first communication method. The device information is information acquired from the device 8 connected to the main wireless device 2.

[0051] The transfer unit 15 transfers the device information to the backup wireless device 3 in response to a drop in the reception level of the radio wave from the base station 4. The transfer method may be wireless communication such as WiFi (registered trademark) (Wireless Fidelity), or may be electrically connected by wire. The main wireless device 2 may transfer the reception level of the radio wave from the base station 4 to the backup wireless device 3. The main wireless device 2 also receives a control signal transmitted from the backup wireless device 3 for permitting or not permitting the main wireless device 2 to communicate using the first communication method. When the reception level of the main wireless device 2 drops and the main wireless device 2 cannot communicate using the first communication method, the main wireless device 2 transfers the acquired device information to the backup wireless device 3 via the transfer unit 15.

[0052] The wireless communication module 12 receives radio waves in the first communication method transmitted from the base station 4. The reception level of the radio waves in the first communication method may be transferred to the backup wireless device 3 by the transfer unit 15.

[0053] (Back-up radio device 3) Like the main wireless device 2, the backup wireless device 3 also includes an antenna 17 for transmitting and receiving radio waves, a wireless communication module 18 connected to the antenna 17 and equipped with a communication function, a SIM 19 in which the ID number of the service subscriber is recorded, and a microcomputer 20 for controlling the operation of the backup wireless device 3. The microcomputer 20 includes a control unit 21 for controlling the operation of the backup wireless device 3, a conversion unit 24 for converting the device information transferred from the transfer unit 15 into simplified device information, a monitoring unit 22 for monitoring the reception level of radio waves, and a main device control unit 23 for disconnecting communication between the main wireless device 2 and the base station 4 and controlling the main wireless device 2 to resume communication.

[0054] The monitoring unit 22 monitors whether communication between the primary wireless device 2 and the base station 4 has been established. If communication has not been established due to a drop in the reception level, the primary device control unit 23 of the microcomputer 20 enables the transfer unit 15 of the microcomputer 14 in the primary wireless device 2, and controls the transfer unit 15 so that the device information is transferred to the backup wireless device 3. The conversion unit 24 of the microcomputer 20 in the backup wireless device 3 extracts and converts data from the transferred device information to generate simplified device information. The generated simplified device information is sent to the wireless communication module 18, transmitted from the antenna 17 to the base station 4, and transmitted to the cloud server 5.

[0055] The monitoring unit 22 of the microcomputer 20 in the spare wireless device 3 monitors whether communication between the main wireless device 2 and the base station 4 has been established, and whether there is a problem such as a component failure. The result of monitoring whether communication between the main wireless device 2 and the base station 4 has been established in terms of the reception level is sent to the wireless communication module 18 as reception level status information of the main wireless device 2, and is then transmitted by radio waves from the antenna 17 to the base station 4, and the reception level status information is then transmitted to the cloud server 5.

[0056] In addition, if the main wireless device 2 is in a frozen state due to a trouble condition other than a decrease in reception level, such as a component failure, no-response state information indicating a state in which no response is received from the main wireless device 2 is sent to the wireless communication module 18, transmitted by radio waves from the antenna 17 to the base station 4, and the no-response state information is transmitted to the cloud server 5.

[0057] The backup wireless device 3 transmits the device simplified information, the reception level state information, and the no-response state information to the base station 4 by the second communication method. When communication related to the first communication method between the main wireless device 2 and the base station 4 is not established, the backup wireless device 3 communicates with the base station 4 by the second communication method instead of the main wireless device 2, and transmits the reception level state information, the device simplified information, and the no-response state information to the base station 4.

[0058] The monitoring unit 22 communicates with the main wireless device 2. The communication method may be wireless communication such as WiFi (registered trademark), or may be electrically connected by wire. The monitoring unit 22 may receive the reception level of the main wireless device 2 transferred from the transfer unit 15. The main device control unit 23 transmits to the main wireless device 2 a control signal for permitting or not permitting communication by the first communication method of the main wireless device 2. When the main wireless device 2 cannot establish communication with the base station 4 according to the first communication method due to a decrease in the reception level, the backup wireless device 3 receives the device information acquired by the main wireless device 2 via the transfer unit 15.

[0059] When the reception level from the base station 4 is low and the primary wireless device 2 cannot communicate with the base station 4 in the first communication method, the monitoring unit 22 generates reception level status information of the primary wireless device 2. The generated reception level status information is transmitted from the wireless communication module 18 of the backup wireless device 3 to the base station 4 in the second communication method.

[0060] Furthermore, the monitoring unit 22 transmits a monitoring signal to the main wireless device 2 for monitoring the operation state of the main wireless device 2. When the monitoring unit 22 does not receive a response from the main wireless device 2 to the monitoring signal, the monitoring unit 22 transmits a restart signal to the main wireless device 2 for restarting the main wireless device 2. The main wireless device 2 is restarted by the restart signal.

[0061] When the monitoring unit 22 does not receive a response from the primary wireless device 2 to the monitoring signal, the monitoring unit 22 may generate no-response state information indicating a state in which there is no response from the primary wireless device 2, and transmit the no-response state information to the base station 4 via the wireless communication module 18.

[0062] The conversion unit 24 converts the device information transferred from the main wireless device 2 into simplified device information which has a smaller communication volume than the device information. Only when the wireless communication module 12 of the main wireless device 2 cannot communicate with the base station 4 in the first communication method due to a decrease in the reception level, the backup wireless device 3 receives the device information from the main wireless device 2, converts it into simplified device information in the conversion unit 24, and transmits it from the wireless communication module 18 to the base station 4 in the second communication method.

[0063] The control unit 21 controls the operation of the backup wireless device 3 .

[0064] In this way, in the wireless communication unit 1 of embodiment 1, when the main wireless device 2 is unable to communicate with the base station 4 using the first communication method due to a decrease in reception level or a malfunction such as freezing of the main wireless device 2, the spare wireless device 3 communicates with the base station 4 using the second communication method and transmits reception level status information, no-response status information, and device simplified information of the main wireless device 2 to the user's terminal device 6 via the base station 4 and the cloud server 5, thereby avoiding communication interruption.

[0065] <Control process of wireless communication system> FIG. 4 is a schematic diagram showing the relationship between the radio wave intensity and the communication level of the main wireless device 2 and the backup wireless device 3. In FIG.

[0066] A primary wireless device 2 conforming to a first communication method (e.g., LTE Cat. 1, 4) can communicate when the radio wave strength is strength S1 or greater, but communication becomes unstable when the radio wave strength is strength S2 or greater but less than strength S1, and communication becomes impossible when the strength falls below strength S2.

[0067] A backup wireless device 3 conforming to a second communication method (e.g., LTE Cat.M1) can communicate when the radio wave strength is equal to or greater than strength S3, which is weaker than strength S2, and communication becomes unstable when the radio wave strength is equal to or greater than strength S4 but less than strength S3, and communication becomes impossible when the strength falls below S4.

[0068] In this way, the backup wireless device 3 is capable of communication even if the reception level is lower than that of the main wireless device 2.

[0069] The backup wireless device 3 detects the reception level (radio wave intensity) from the base station 4 by the antenna 17, and has a first threshold T1 and a second threshold T2 that are stronger than intensity S1 for the reception level. When the reception level drops below the first threshold T1, the backup wireless device 3 performs control to cut off communication between the main wireless device 2 and the base station 4. When the reception level rises above the second threshold T2, the backup wireless device 3 performs control to resume communication between the main wireless device 2 and the base station 4.

[0070] Fig. 5 shows an example of the change over time in the reception level. Fig. 5 shows a rapid change over time in the reception level, where the radio wave strength of the primary wireless device 2 drops from a level at which communication with the base station 4 is possible to a level at which communication is impossible at time t1, and then the radio wave strength recovers and enters an unstable communication level. At the unstable communication level, the primary wireless device 2 is sometimes able to communicate with the base station 4 using the first communication method and sometimes unable to do so, so that the cloud server 5 may receive device information from the primary wireless device 2 and simplified device information from the backup wireless device 3, which may cause information confusion. In a situation where the reception level is prone to fluctuation, the radio wave strength is likely to return to an unstable communication level even if it recovers to a level at which communication is possible.

[0071] In response to this, when the reception level becomes equal to or lower than the first threshold T1, the communication between the main wireless device 2 and the base station 4 in the first communication method is disconnected, and thereafter, when the reception level becomes equal to or higher than the second threshold T2, the communication between the main wireless device 2 and the base station 4 is resumed. This makes it possible to prevent the main wireless device 2 from sending device information to the base station 4 until the communication of the main wireless device 2 becomes stable. As a result, it is possible to avoid confusion of information.

[0072] The communication possible level of the main wireless device 2 shown in FIG. 4 indicates that communication is possible in the first communication method because the strength of the radio waves received by the main wireless device 2 is strong.

[0073] The communication instability level of the main wireless device 2 indicates that communication is unstable in the main wireless device 2, as the strength of the radio waves received by the main wireless device 2 is insufficient, causing the state in which communication is sometimes possible using the first communication method to fluctuate and sometimes not.

[0074] The communication inability level of the primary wireless device 2 indicates that communication is not possible using the first communication method because the strength of the radio waves received by the primary wireless device 2 is weak.

[0075] The communication capability level of the backup wireless device 3 indicates that communication is possible in the second communication method because the strength of the radio waves received by the backup wireless device 3 is strong.

[0076] The communication instability level of the backup wireless device 3 indicates that communication is unstable in the backup wireless device 3 due to fluctuations in the state in which communication is sometimes possible and sometimes not possible using the second communication method due to insufficient strength of the radio waves received by the backup wireless device 3.

[0077] The communication inability level of the backup wireless device 3 indicates that communication is not possible in the second communication method because the strength of the radio waves received by the backup wireless device 3 is weak.

[0078] The first communication method of the primary wireless device 2 allows communication at a signal strength S1 or higher, and the second communication method of the backup wireless device 3 allows communication at a signal strength S3 or higher that is weaker than the signal strength S1. Therefore, as shown in Fig. 4, the range of signal strength in which the first communication method allows communication is narrower than the range of signal strength in which the second communication method allows communication.

[0079] The first threshold T1 is a value slightly higher than the strength S1 that is close to the border between a communication possible level and an unstable communication level of the first communication method. When the radio wave strength falls below the first threshold T1 and further falls below the strength S1, communication using the first communication method becomes unstable or impossible.

[0080] When the radio wave strength exceeds the second threshold T2, it is considered that the radio wave strength still exceeds the first threshold T1 even if it fluctuates slightly, so it is expected that stable communication will be maintained using the first communication method.

[0081] The vertical axis of Fig. 5 indicates the strength of the radio wave received from the base station 4, and the horizontal axis indicates the passage of time. The radio wave strength changes with the passage of time. At time t0, the radio wave strength is high and exceeds the second threshold T2, but at time t1, the radio wave strength drops sharply to the first threshold T1, and once the time t1 has passed, it becomes lower than the first threshold T1. The radio wave strength then rises gradually while repeatedly rising and falling, and at time t2, the radio wave strength reaches the second threshold T2. Next, after time t2, the radio wave strength rises and falls repeatedly, and finally recovers to the radio wave strength at time t0.

[0082] During the period from time t0 to time t1, the radio wave strength is greater than the first threshold T1, and therefore the radio wave strength is within the range of a communication possible level. At this time, the primary device control unit 23 of the backup wireless device 3 transmits a control signal to the primary wireless device 2 to permit communication by the first communication method.

[0083] During the period from time t1 to time t2, the radio wave strength is smaller than the first threshold T1, and therefore the radio wave strength transitions from the unstable communication level to the communication impossible level, or from the unstable communication level only to the communication possible level. During this period from time t1 to time t2, the primary device control unit 23 of the backup wireless device 3 transmits a control signal indicating that communication by the first communication method is not permitted to the primary wireless device 2.

[0084] After time t2, the radio wave strength is equal to or greater than the second threshold T2, and therefore falls within the range where communication is possible. After time t2, the primary device control unit 23 of the backup wireless device 3 transmits a control signal indicating permission for communication by the first communication method to the primary wireless device 2.

[0085] In this way, the primary device control unit 23 transmits a control signal indicating whether communication is permitted or not permitted for the primary wireless device 2 using the first communication method, to the primary wireless device 2, depending on the radio wave intensity received by the antenna 17 of the backup wireless device 3. This prevents fluctuations in radio wave intensity that may or may not allow communication using the first communication method for the primary wireless device 2.

[0086] In addition, after the radio wave strength falls below the first threshold T1 and communication by the primary wireless device 2 using the first communication method is not permitted, communication by the first communication method is continued to be not permitted even if the radio wave strength reaches the first threshold T1, and communication by the first communication method is permitted when the radio wave strength reaches the second threshold T2 or more. The reason for this is as follows.

[0087] That is, when the communication in the first communication method is at an unstable communication level, the wireless communication module 12 of the primary wireless device 2 may or may not be able to communicate with the base station 4. Therefore, if communication in the first communication method were permitted using the first threshold T1 instead of the second threshold T2, there is a risk of information confusion occurring as device information from the primary wireless device 2 and simplified device information from the backup wireless device 3 are sent to the cloud server 5.

[0088] In a situation where the radio wave strength is prone to change, even if the communication level of the first communication method becomes unstable and communication is possible, the communication level of the first communication method is likely to return to the unstable communication level. In response to this, when the radio wave strength falls below the first threshold T1, the communication of the primary wireless device 2 according to the first communication method is not permitted, and when the radio wave strength rises from below the first threshold T1 to exceed the first threshold T1 and then further rises to above the second threshold T2, the communication of the primary wireless device 2 according to the first communication method is permitted and resumed. This prevents the primary wireless device 2 from transmitting device information to the base station 4 using the first communication method until the strength of the radio wave received by the primary wireless device 2 stabilizes. As a result, the above-mentioned confusion of information can be avoided.

[0089] FIG. 6 shows a sequence diagram of a control process of a communication network when the radio wave intensity is greater than the first threshold T1.

[0090] First, the monitoring unit 22 of the backup wireless device 3 compares the strength of the radio wave received by the antenna 17 with the first threshold value T1 (S101). When the monitoring unit 22 determines that the strength of the radio wave is not greater than the first threshold value T1 (NO in S101), the process proceeds to step S201 in FIG.

[0091] When the monitoring unit 22 determines that the radio wave strength is greater than the first threshold T1 (YES in S101), the primary device control unit 23 transmits a control signal indicating permission for communication using the first communication method to the control unit 16 of the primary wireless device 2 (S102).

[0092] Thereafter, the control unit 16 transmits the device information acquired from the device 8 connected to the main wireless device 2 from the wireless communication module 12 to the cloud server 5 via the base station 4 (S103).

[0093] Then, the cloud server 5 transmits the device information to the user's terminal device 6 (S104).

[0094] In this way, when the radio wave intensity is greater than the first threshold T1, the device information can be transmitted from the primary wireless device 2 to the user's terminal device 6 via the base station 4 and the cloud server 5 in the first communication method.

[0095] FIG. 7 shows a sequence diagram of the control process of the wireless communication unit 1 when the radio wave intensity is equal to or lower than the first threshold T1.

[0096] When the monitoring unit 22 of the backup wireless device 3 determines that the radio wave intensity is equal to or lower than the first threshold value T1, it transmits a control signal indicating that communication in the first communication method is not permitted to the control unit 16 of the primary wireless device 2 (S201).

[0097] Then, the monitoring unit 22 generates reception level status information indicating that communication using the first communication method is not possible with the main wireless device 2, and transmits the reception level status information from the wireless communication module 18 to the cloud server 5 via the base station 4 (S202).

[0098] Next, the cloud server 5 transmits the received reception level state information to the terminal device 6 (S203).

[0099] The user learns the reception level state information from the terminal device 6 and learns that the primary wireless device 2 is unable to communicate in the first communication method due to a drop in the reception level.

[0100] Then, when the transfer unit 15 of the main wireless device 2 receives the control signal indicating that the communication is not permitted, it transmits the device information acquired from the device 8 to the conversion unit 24 of the backup wireless device 3 (S204).

[0101] Next, the conversion unit 24 generates simplified device information by simplifying the received device information, thereby generating simplified device information that requires less communication traffic than the device information.

[0102] Thereafter, the conversion unit 24 transmits the generated simplified device information from the wireless communication module 18 to the cloud server 5 via the base station 4 (S206).

[0103] Then, the cloud server 5 transmits the received simplified device information to the terminal device 6 (S207).

[0104] Although the user cannot obtain the device information from the terminal device 6, the user can obtain simplified device information corresponding to the device information instead.

[0105] Next, the monitoring unit 22 determines whether the radio wave intensity, which fell below the first threshold T1, has recovered to a level equal to or higher than a second threshold T2 that is greater than the first threshold T1 (S208), and if the radio wave intensity has reached the second threshold or higher, the process proceeds to step S210 in Fig. 8. Otherwise (NO in S208), the process proceeds to step S301 in Fig. 9.

[0106] FIG. 8 shows a sequence diagram of the control processing of the wireless communication unit 1 when the radio wave strength becomes equal to or lower than the first threshold T1 and a control signal not allowing communication is transmitted to the main wireless device 2, and then the radio wave strength becomes equal to or higher than the second threshold T2.

[0107] When the radio wave intensity, which has fallen below the first threshold T1, recovers and becomes equal to or greater than a second threshold T2 that is greater than the first threshold T1, the monitoring unit 22 transmits a control signal to permit resumption of communication between the primary wireless device 2 and the base station 4 using the first communication method (S210).

[0108] Then, the control unit 16 of the main wireless device 2 transmits the device information acquired from the device 8 from the wireless communication module 12 to the cloud server 5 via the base station 4 (S211).

[0109] The cloud server 5 transmits the received device information to the terminal device 6 (S212).

[0110] The user had been obtaining simplified device information from the terminal device 6, but since the radio wave strength has recovered from an unstable or impossible communication level for the first communication method to a communication possible level, the user can obtain device information instead of the simplified device information.

[0111] FIG. 9 shows a sequence diagram of the control process of the wireless communication unit when the radio wave strength is lower than the second threshold T2 after the radio wave strength becomes lower than the first threshold T1 and a control signal not allowing communication is transmitted to the main wireless device 2.

[0112] When the monitoring unit 22 of the backup wireless device 3 determines that the radio wave intensity is lower than the second threshold T2, it transmits a control signal indicating that communication in the first communication method is not permitted to the control unit 16 of the primary wireless device 2 (S301).

[0113] Then, the monitor 22 generates reception level status information and transmits the reception level status information from the wireless communication module 18 to the cloud server 5 via the base station 4 (S302).

[0114] Next, the cloud server 5 transmits the received reception level status information to the terminal device 6 (S303).

[0115] The user learns the reception level state information from the terminal device 6 and learns that the primary wireless device 2 is unable to communicate in the first communication method due to a drop in the reception level.

[0116] When the transfer unit 15 of the main wireless device 2 receives a control signal indicating that communication using the first communication method is not permitted from the monitoring unit 22 of the backup wireless device 3, it transfers the device information acquired from the device 8 to the conversion unit 24 of the backup wireless device 3 (S304).

[0117] The conversion unit 24 then generates simplified device information by simplifying the transferred device information, resulting in the generation of simplified device information that requires less communication traffic than the device information (S305).

[0118] Next, the conversion unit 24 transmits the generated simplified device information from the wireless communication module 18 to the cloud server 5 via the base station 4 (S306).

[0119] Thereafter, the cloud server 5 transmits the received simplified device information to the terminal device 6 (S307).

[0120] The user has obtained the simplified device information from the terminal device 6, but since communication using the first communication method of the main wireless device 2 is still not possible, the user will continue to obtain the simplified device information transmitted from the backup wireless device 3.

[0121] Other embodiments In the above embodiment, the main wireless device 2 and the backup wireless device 3 each constitute an independent device, but the main wireless device 2 and the backup wireless device 3 may be constituted by a single device as long as they are connected by wire or wirelessly.

[0122] [Software implementation example] The transfer unit 15, control unit 16 of the main wireless device 2 and the control unit 21, monitoring unit 22, main device control unit 23, and conversion unit 24 of the backup wireless device 3 may be realized by a logic circuit (hardware) formed in an integrated circuit (IC chip) or the like, or by software.

[0123] In the latter case, the main radio device 2 and the backup radio device 3 are provided with a computer that executes instructions of a program, which is software that realizes each function. This computer is provided with, for example, at least one processor (control device) and at least one computer-readable recording medium that stores the program. The object of the present invention is achieved by having the processor read the program from the recording medium and execute it in the computer. The processor can be, for example, a CPU (Central Processing Unit). The recording medium can be a "non-transient tangible medium," such as a ROM (Read Only Memory), tape, disk, card, semiconductor memory, programmable logic circuit, or the like. The computer may further include a RAM (Random Access Memory) that expands the program. The program may be supplied to the computer via any transmission medium (such as a communication network or broadcast waves) that can transmit the program. Note that one aspect of the present invention can also be realized in the form of a data signal embedded in a carrier wave, in which the program is embodied by electronic transmission.

[0124] 〔summary〕 A wireless communication unit 1 according to aspect 1 of the present invention includes a main wireless device 2 that transmits device information detected by a sensor to a base station 4 according to a first communication method, and a backup wireless device 3 that transmits the device information transferred from the main wireless device 2 to the base station 4 in response to a decrease in the reception level of radio waves from the base station 4 according to a second communication method that has a wider communication area than the first communication method.

[0125] According to the above configuration, when the reception level of radio waves from the base station decreases, the device information transferred from the primary wireless device is transmitted to the base station according to the second communication method, which has a wider communication area than the first communication method. As a result, even if the reception level of radio waves received from the base station by a wireless communication device related to a specific wireless communication method decreases, the device information detected by the sensor can be delivered to the base station.

[0126] In the wireless communication unit 1 according to aspect 2 of the present invention, in the above aspect 1, it is preferable that the backup wireless device 3 generates simplified device information by simplifying the device information transferred from the main wireless device 2 in response to the decrease in the reception level, and transmits the simplified device information to the base station 4 in accordance with the second communication method.

[0127] According to the above configuration, simplified device information obtained by simplifying the device information can be transmitted to the base station by the second communication method having a slower communication speed than the first communication method.

[0128] In a wireless communication unit 1 according to aspect 3 of the present invention, in the above aspect 1 or 2, the backup wireless device 3 transmits reception level state information representing the reception level state of the main wireless device 2 to the base station 4 according to the second communication method in response to a decrease in the reception level.

[0129] According to the above configuration, it is possible to transmit information indicating the communication state of the primary wireless device in the first communication method to the base station.

[0130] In the wireless communication unit 1 according to aspect 4 of the present invention, in the above aspect 3, it is preferable that when the backup wireless device 3 does not receive a response from the main wireless device 2 to a monitoring signal for monitoring the operating status of the main wireless device 2, the backup wireless device 3 transmits a restart signal to the main wireless device 2 for restarting the main wireless device 2.

[0131] According to the above configuration, when communication according to the first communication method is impossible due to a malfunction of the main wireless device, such as freezing, the main wireless device can be restored using the spare wireless device.

[0132] In the wireless communication unit 1 according to aspect 5 of the present invention, in any one of aspects 1 to 4 above, it is preferable that the backup wireless device 3 disconnects communication between the main wireless device 2 and the base station 4 when the reception level drops and falls below a first threshold T1, and resumes communication between the main wireless device 2 and the base station 4 when the reception level recovers and becomes equal to or greater than a second threshold T2 that is greater than the first threshold T1.

[0133] According to the above configuration, when the reception level has stabilized and recovered, the device information can be transmitted to the base station in place of simplified device information, which is the simplified version of the device information.

[0134] In the wireless communication unit 1 of aspect 6 of the present invention, in aspect 3 above, it is preferable that the base station 4 is connected to a cloud server 5, the cloud server 5 is connected to a terminal (terminal device 6), the base station 4 transmits the simplified device information or the reception level status information to the cloud server 5, and the cloud server 5 transfers the simplified device information or the reception level status information to the terminal (terminal device 6).

[0135] According to the above configuration, in a terminal connected to an Internet line, it is possible to acquire simplified device information that is abbreviated device information transferred from a primary wireless device in response to a decrease in reception level, and information indicating a communication state relating to the first communication method of the primary wireless device.

[0136] In the wireless communication unit 1 according to aspect 7 of the present invention, in aspect 6 above, it is preferable that when the spare wireless device 3 does not receive a response from the main wireless device 2 to a monitoring signal for monitoring the operating status of the main wireless device 2, the spare wireless device 3 transmits a no-response state signal indicating a state in which there is no response from the main wireless device 2 to the base station 4.

[0137] According to the above configuration, a state in which communication is not possible using the first communication method due to a malfunction such as freezing of the main wireless device can be reported to the cloud server and the terminal using the base station and the backup wireless device.

[0138] In a wireless communication unit 1 according to aspect 8 of the present invention, in aspect 6 above, it is preferable that when the backup wireless device receives a restart instruction signal representing an instruction to restart the main wireless device from the cloud server or the terminal via the base station, the backup wireless device transmits a restart signal for restarting the main wireless device to the main wireless device.

[0139] According to the above configuration, a state in which communication is not possible using the first communication method due to a malfunction such as freezing of the main wireless device can be restored by using the cloud server, the terminal, the base station, and the backup wireless device.

[0140] A wireless communication unit 1 according to a ninth aspect of the present invention is any one of the first to eighth aspects above, wherein the main wireless device 2 and the backup wireless device 3 are preferably housed and integrated in a single package.

[0141] According to the above configuration, the reliability of the transfer of device information from the main wireless device to the backup wireless device is improved, and the convenience of handling the wireless communication unit is increased.

[0142] A wireless communication unit 1 according to aspect 10 of the present invention is any one of aspects 1 to 9 above, wherein the first communication method includes LTE Cat.1 or LTE Cat.4, and the second communication method includes LPWA.

[0143] According to the above configuration, when communication becomes unstable using the first communication method, which has a relatively fast communication speed, device information can be transmitted to the base station using the second communication method, which has a relatively slow communication speed but a relatively wide communication area.

[0144] A wireless communication unit 1 according to aspect 11 of the present invention is preferably any one of aspects 1 to 10 above, wherein the sensor includes at least one of a camera and a human presence sensor, and the device information includes at least one of a video captured by the camera and human detection data detected by the human presence sensor.

[0145] According to the above configuration, by transmitting device information from sensors such as cameras and motion sensors to a base station, it is possible to provide services such as monitoring the safety of family members who are far away.

[0146] A wireless communication unit 1 according to aspect 12 of the present invention includes a main wireless device 2 that transmits device information detected by a sensor to a base station 4 according to a first communication method, and a spare wireless device 3 that, when no response is received from the main wireless device 2 to a monitoring signal for monitoring the operating status of the main wireless device 2, transmits no-response state information indicating a state in which there is no response from the main wireless device 2 to the base station 4 according to a second communication method having a wider communication area than the first communication method.

[0147] According to the above configuration, when a response to a monitoring signal for monitoring the operation state of the primary wireless device is not received from the primary wireless device, no-response state information indicating a state in which there is no response from the primary wireless device is transmitted to the base station according to the second communication method having a wider communication coverage area than the first communication method. As a result, even if a malfunction such as freezing occurs in the operation of a wireless communication device related to a specific wireless communication method, information for recovering from the malfunction can be transmitted.

[0148] In the wireless communication unit 1 of aspect 13 of the present invention, in the above aspect 12, it is preferable that the base station 4 is connected to a cloud server 5, the cloud server 5 is connected to a terminal (terminal device 6), and when the backup wireless device 3 receives a restart instruction signal representing an instruction to restart the main wireless device 2 from the cloud server 5 or the terminal (terminal device 6) via the base station 4, it transmits a restart signal for restarting the main wireless device 2 to the main wireless device 2.

[0149] According to the above configuration, a state in which communication is not possible using the first communication method due to a malfunction such as freezing of the main wireless device can be restored by using the cloud server, the terminal, the base station, and the backup wireless device.

[0150] The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope of the claims. The technical scope of the present invention also includes embodiments obtained by appropriately combining the technical means disclosed in the different embodiments. Furthermore, new technical features can be formed by combining the technical means disclosed in the respective embodiments. [Explanation of symbols]

[0151] 1 Wireless communication unit 2 Main wireless equipment 3 Spare Radio Equipment 4 base station 5. Cloud Server 6 Terminal equipment (terminal) 7. Internet connection 8 Device Equipment 9. Communication area 10 Communication area Point A Point B T1 First threshold T2 Second Threshold

Claims

1. a main wireless device that transmits device information detected by the sensor to a base station in accordance with a first communication method; a backup wireless device that transmits the device information transferred from the primary wireless device to the base station in response to a decrease in a reception level of radio waves from the base station in accordance with a second communication method having a wider communication area than the first communication method, A wireless communication unit characterized in that the standby wireless device transmits a restart signal to the primary wireless device for restarting the primary wireless device when the standby wireless device does not receive a response from the primary wireless device to a monitoring signal for monitoring the operating status of the primary wireless device.

2. The wireless communication unit according to claim 1, wherein the backup wireless device generates simplified device information by simplifying the device information transferred from the main wireless device in response to the decrease in the reception level, and transmits the simplified device information to the base station according to the second communication method.

3. 3. The wireless communication unit according to claim 2, wherein the backup wireless device transmits reception level state information representing a reception level state of the primary wireless device to the base station according to the second communication method in response to the decrease in the reception level.

4. A wireless communication unit as described in any one of claims 1 to 3, wherein the standby wireless device cuts off communication between the main wireless device and the base station when the reception level drops and falls below a first threshold, and resumes communication between the main wireless device and the base station when the reception level recovers and becomes equal to or greater than a second threshold that is greater than the first threshold.

5. The base station is connected to a cloud server, The cloud server is connected to a terminal; The base station transmits the simplified device information or the reception level status information to the cloud server; The wireless communication unit according to claim 3 , wherein the cloud server transfers the simplified device information or the reception level status information to the terminal.

6. A wireless communication unit as described in claim 5, wherein the spare wireless equipment transmits no-response state information indicating a state in which there is no response from the main wireless equipment to the base station when it does not receive a response from the main wireless equipment to a monitoring signal for monitoring the operating status of the main wireless equipment.

7. A main wireless device that transmits device information detected by the sensor to a base station according to a first communication method; a backup wireless device that transmits the device information transferred from the primary wireless device to the base station in response to a decrease in a reception level of radio waves from the base station in accordance with a second communication method having a wider communication area than the first communication method, the backup wireless device generates simplified device information by simplifying the device information transferred from the primary wireless device in response to the decrease in the reception level, and transmits the simplified device information to the base station in accordance with the second communication method; the backup wireless device transmits, to the base station in accordance with the second communication method, reception level state information representing a reception level state of the primary wireless device in response to the decrease in the reception level; The base station is connected to a cloud server; The cloud server is connected to a terminal; The base station transmits the simplified device information or the reception level status information to the cloud server; The cloud server transfers the simplified device information or the reception level status information to the terminal; A wireless communication unit characterized in that when the spare wireless device receives a restart instruction signal representing an instruction to restart the main wireless device from the cloud server or the terminal via the base station, the spare wireless device transmits a restart signal for restarting the main wireless device to the main wireless device.

8. A wireless communication unit described in any one of claims 1 to 6, wherein the main wireless equipment and the backup wireless equipment are contained and integrated in a single package.

9. The first communication method includes LTE Cat. 1 or LTE Cat. 4, The wireless communication unit according to claim 1 , wherein the second communication method includes LPWA.

10. The sensor includes at least one of a camera and a human presence sensor, The wireless communication unit according to claim 1 , wherein the device information includes at least one of a video captured by the camera and human detection data detected by the human detection sensor.

11. A main wireless device that transmits device information detected by a sensor to a base station according to a first communication method; a backup wireless device that, when no response is received from the primary wireless device in response to a monitoring signal for monitoring an operation state of the primary wireless device, transmits no-response state information, which indicates a state in which there is no response from the primary wireless device, to the base station in accordance with a second communication method having a wider communication coverage area than the first communication method, The base station is connected to a cloud server; The cloud server is connected to a terminal; A wireless communication unit characterized in that when the spare wireless device receives a restart instruction signal representing an instruction to restart the main wireless device from the cloud server or the terminal via the base station, the spare wireless device transmits a restart signal for restarting the main wireless device to the main wireless device.

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