Communication system, terminal device, and status notification method

Abstract

To reduce the time it takes for a higher-level device to detect a communication failure between it and a device that is currently in operation. [Solution] One upper-level terminal 2 -1 When a communication failure is detected between the management device 3 and the other device, one of the higher-level terminals 2 -1 The system broadcasts fault status information via BLE advertisement, and another higher-level terminal 2 receives it. -2 By notifying the management device 3 of the fault status information via the communication network, one higher-level terminal 2 -1 In communication between the and the management device 3, without a certain timeout period elapsed, one higher-level terminal 2 -1 From another higher-end device 2 -2 The fault status information is pushed to the management device 3 via the above, and one of the higher-level terminals 2 -1 This allows the management device 3 to quickly detect any communication failures that occur between the two parties.

Description

[Technical Field]

[0001] The present invention relates to a communication system, a terminal device, and a status notification method, and is particularly suitable for use in a communication system in which multiple terminal devices and a host device are connected via a communication network. [Background technology]

[0002] Conventionally, failover technology has been known that can improve system availability by automatically switching to another device to communicate when a communication failure occurs with a device that is currently in operation (see, for example, Patent Documents 1 and 2). The system described in Patent Document 1 comprises multiple sets of configurations in which multiple sensing devices are connected to one gateway, and is configured to switch to another gateway when any gateway is unavailable.

[0003] The system described in Patent Document 2 comprises multiple sensors, multiple sensor nodes that each output measurement data, multiple gateway devices connected to the sensor nodes by wireless communication means such as Bluetooth (registered trademark; the same applies hereinafter) that transfer measurement data transmitted from the sensor nodes to a data management server, and a monitoring server that detects the occurrence of a gateway device failure. If the monitoring server determines that a gateway device has failed, it extracts another gateway device that can connect to the sensor node managed by the failed gateway device and has it take over the processing.

[0004] Failover technology requires a higher-level device to detect communication failures between it and the operational device. For example, a technique called keep-alive is known for verifying that the connection between networked devices is valid. This technique involves devices communicating periodically at predetermined intervals. In this technique, if the higher-level device sends a keep-alive message and no response is received from the other device, or if the other device does not send a keep-alive message to the higher-level device for an extended period, the higher-level device determines that the connection with the other device has been lost.

[0005] However, in order for the upper device to detect that a communication failure has occurred with the operating device, it is necessary to have a certain timeout period elapse. Therefore, there has been a problem that a time lag occurs from when the communication failure occurs until it is detected by the upper device.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0007] The present invention has been made to solve the above problems, and an object thereof is to shorten the time required for the upper device to detect that a communication failure has occurred with the operating device.

Means for Solving the Problems

[0008] In order to solve the above problems, in the present invention, in a communication system including a plurality of terminal devices and an upper device connected to the plurality of terminal devices via a communication network, each of the plurality of terminal devices has, when detecting a communication failure with the upper device, a transmitting means for transmitting failure status information by a communication means different from the communication network, and a notifying means for notifying the upper device of the failure status information via the communication network when receiving the failure status information.

Effects of the Invention

[0009] According to the present invention configured as described above, among a plurality of terminal devices connected to a host device via a communication network, when a communication failure between a host device and one terminal device is detected in one terminal device, failure status information is transmitted from the one terminal device by a communication means different from the communication network, and the failure status information is notified to the host device via the communication network from another terminal device that has received it. For this reason, without having a certain timeout period elapse in the communication performed between the one terminal device in which the communication failure has occurred and the host device, the host device can promptly detect, based on the failure status information notified from the one terminal device via another terminal device, that a communication failure has occurred between the one terminal device and the host device. Thereby, the time taken until the host device detects that a communication failure has occurred with an operating terminal device can be shortened.

Brief Description of the Drawings

[0010] [Figure 1] It is a diagram showing an overall configuration example of a service providing system to which the communication system according to this embodiment is applied. [Figure 2] It is a diagram showing an operation example when a communication failure occurs between the host terminal and the management device. [Figure 3] It is a block diagram showing a functional configuration example of the host terminal according to this embodiment. [Figure 4] It is a flowchart showing an operation example of the host terminal according to this embodiment.

Mode for Carrying Out the Invention

[0011] Hereinafter, one embodiment of the present invention will be described with reference to the drawings. Figure 1 is a diagram showing an example of the overall configuration of a service provision system to which the communication system according to this embodiment is applied. The service provision system shown in Figure 1 comprises a plurality of lower-level terminals 1 having wireless communication means, a plurality of upper-level terminals 2 also having wireless communication means, and a management device 3 connected to the plurality of upper-level terminals 2 via a communication network. The management device 3 includes an MQTT broker 31 and a Web server 32. The upper-level terminals 2 and the management device 3 correspond to the terminal device and upper-level device in the claims, respectively, and the communication system according to this embodiment is composed of the upper-level terminals 2 and the management device 3.

[0012] The wireless communication method is, for example, BLE (Bluetooth Low Energy). In this case, the lower-level terminal 1 operates as a BLE slave (peripheral), and the upper-level terminal 2 operates as a BLE master (central). Note that the wireless communication method is not limited to BLE; it may also be, for example, Bluetooth, Wi-Fi (registered trademark), or other wireless LAN. Wireless communication between multiple lower-level terminals 1 and multiple upper-level terminals 2 takes place between terminals within communication range.

[0013] The lower-level terminal 1 communicates wirelessly with the upper-level terminal 2, and its operation is controlled by the upper-level terminal 2. The lower-level terminal 1 also transmits its own information to the upper-level terminal 2. For example, the lower-level terminal 1 transmits its own identification information to the upper-level terminal 2. However, the information transmitted is not limited to this. For example, it may transmit information indicating the operation status of switches and buttons, battery voltage detected by a voltage sensor, ambient temperature detected by a temperature sensor, information identifying the image currently displayed on the display (such as the number of a fixed image being displayed (1-8) or a number indicating that an arbitrary image is being displayed (0)), its own model information, firmware version information, etc.

[0014] The upper-level terminal 2 communicates wirelessly with the lower-level terminal 1 and also communicates with the management device 3 via the internet and / or a mobile phone network using HTTP (Hyper Text Transfer Protocol) and MQTT (Message Queuing Telemetry Transport). Here, MQTT communication takes place between the upper-level terminal 2 and the MQTT broker 31, and HTTP communication takes place between the upper-level terminal 2 and the web server 32. The upper-level terminal 2 controls the lower-level terminal 1 according to the operation instructions received from the management device 3. In addition, the upper-level terminal 2 registers the identification information obtained from the lower-level terminal 1 with the management device 3 and notifies the management device 3 of at least a portion of the information obtained from the lower-level terminal 1 as status information.

[0015] The MQTT broker 31 of the management device 3 operates as a base station server between the upper-level terminal 2 and the web server 32, enabling real-time push communication from the web server 32 to the upper-level terminal 2 and from the upper-level terminal 2 to the web server 32. The transmission of operation instructions from the management device 3 to the upper-level terminal 2, and the transmission of status information from the upper-level terminal 2 to the management device 3, are performed via MQTT communication using the MQTT broker 31.

[0016] MQTT is a communication protocol that exchanges lightweight information between a web server 32 and a higher-level terminal 2 via an MQTT broker 31. The web server 32 maintains a constant connection with the MQTT broker 31 in order to send and receive arbitrary information in real time. The higher-level terminal 2 also maintains a constant connection with the MQTT broker 31 in order to send and receive arbitrary information in real time. In other words, the web server 32 and the higher-level terminal 2 are constantly connected to the MQTT broker 31 as clients to achieve low-latency information transmission and reception. This makes it possible for the web server 32 to push arbitrary information to the higher-level terminal 2 via the MQTT broker 31 at the required time, and for the higher-level terminal 2 to push arbitrary information to the web server 32 via the MQTT broker 31 at the required time.

[0017] When the Web server 32 of the management device 3 receives an HTTP request from the upper-level terminal 2, it responds to the upper-level terminal 2 via HTTP with information corresponding to that request. For example, when performing the initial setup (kitting) to register the identification information of the lower-level terminal 1 with the management device 3, the upper-level terminal 2 uses HTTP communication with the Web server 32 to register the identification information obtained from the lower-level terminal 1 with the management device 3. This registration of identification information may also be performed via MQTT communication.

[0018] The service provision system shown in Figure 1 constitutes a mobile smartphone ordering system as one use case to apply the communication system of this embodiment, and comprises a customer terminal 101, a store management device 102, and a store service server 103. The customer terminal 101 is, for example, a smartphone. Multiple subordinate terminals 1 are placed on multiple tables installed in a restaurant, for example. A two-dimensional code is displayed on the display of the subordinate terminal 1. When the customer terminal 101 reads the two-dimensional code, it becomes possible to access the ordering screen of the web page provided by the store service server 103 and place an order.

[0019] The web server 32 provides the store service server 103 with a Web API for controlling the subordinate terminal 1, and the store service server 103 can use this Web API to control the subordinate terminal 1. For example, the store service server 103 can issue an operation command to the target subordinate terminal 1. In this case, the operation command sent from the store service server 103 to the web server 32 is forwarded to one of the upper-level terminals 2 via MQTT communication through the MQTT broker 31, and then wirelessly transmitted from the upper-level terminal 2 to the target subordinate terminal 1 to control its operation. At this time, the management device 3 sends the operation command to the upper-level terminal 2 among the multiple upper-level terminals 2 that is within communication range of the target subordinate terminal 1.

[0020] As an example of an operation instruction, the store service server 103 can transmit arbitrary information input from the store management device 102 installed in the restaurant to the management device 3, and then forward it from the management device 3 to the lower terminal 1 via the upper terminal 2, thereby displaying the arbitrary information on the display of the lower terminal 1. The arbitrary information may include, for example, information indicating the order status, information indicating the cooking status, information on recommended menu items, and information related to advertising. This information may also be displayed as arbitrary images.

[0021] Furthermore, as an alternative example of an operation instruction, the store service server 103 can transmit a standardized image input from the store management device 102 installed in the restaurant to the management device 3, and then transfer it from the management device 3 to the lower terminal 1 via the upper terminal 2, thereby storing the standardized image in the non-volatile memory of the lower terminal 1. This standardized image is used as an image to be displayed on the display when a standardized operation is performed in the lower terminal 1. Standardized operations in the lower terminal 1 include, for example, inserting batteries or operating switches and buttons, but are not limited to these.

[0022] In addition to the Web API, the Web server 32 also provides an event notification mechanism via Webhooks. For example, when the Web server 32 detects a change in a specific status of a subordinate terminal 1 based on status information sent from the upper terminal 2 to the management device 3, it can use the Webhook function to call the Web API of the store service server 103 to notify it of the status change. This allows the store service server 103 to notify it of the status change without having to periodically execute (poll) the Web API of the Web server 32 until it obtains the status change of the specific subordinate terminal 1.

[0023] The above operations are normal operations when there are no communication failures in the communication network between the multiple upper-level terminals 2 and the management device 3. On the other hand, if a communication failure occurs in the communication network between one of the multiple upper-level terminals 2 and the MQTT broker 31, even if the Web API of the Web server 32 is executed, MQTT communication will not be available, and operation commands will not reach the upper-level terminal 2. In this case, it is possible to detect the occurrence of a communication failure by not receiving a success response despite sending an operation command to one upper-level terminal 2 by executing the Web API, or by using the MQTT keep-alive mechanism, but in either case, a certain timeout period must be allowed to elapse.

[0024] In contrast, this embodiment introduces a mechanism that enables the management device 3 to quickly detect when a communication failure occurs between it and a higher-level terminal 2. The outline of this mechanism is explained below with reference to Figure 2.

[0025] Figure 2 shows two upper-level terminals 2 -1 ,2 -2 One of the higher-end terminals 2 -1 This figure shows an example of operation when a communication failure occurs in the communication network between the device and the management device 3 (MQTT broker 31), along with an example of normal operation. Figure 2(a) shows two upper-level terminals 2 -1 ,2 -2 Figure 2(b) shows the normal operation when no communication failure occurs between the first upper-level terminal 2 -1 This shows the operation when a communication failure occurs between the MQTT broker 31 and the MQTT broker 31.

[0026] As shown in Figure 2(a), the upper terminal 2 -1 ,2 -2During normal operation when it is properly connected to the MQTT broker 31 via a communication network, it operates as a BLE master for multiple lower-level terminals 1, receives advertisements from the lower-level terminals 1, and receives the identification information (hereinafter sometimes referred to as the lower-level terminal ID) and status information of the lower-level terminals 1, and transmits this information to the MQTT broker 31. An advertisement is an operation in which the lower-level terminal 1 broadcasts information as a BLE slave (peripheral).

[0027] In contrast, as shown in Fig. 2(b), when one upper-level terminal 2 -1 detects a communication failure in the communication network between it and the MQTT broker 31, the one upper-level terminal 2 -1 switches to operate as a slave from the BLE master, and broadcasts its own identification information (hereinafter sometimes referred to as the upper-level terminal ID) and failure status information by performing an advertisement. The failure status information is information indicating that a communication failure has occurred between the upper-level terminal 2 and the MQTT broker 31. Another upper-level terminal 2 -1 around the one upper-level terminal 2 -1 receives the failure status information broadcast, and notifies the received failure status information to the MQTT broker 31 via the communication network. -2 receives the failure status information broadcast, and notifies the received failure status information to the MQTT broker 31 via the communication network.

[0028] Note that Fig. 2 shows an example in which two upper-level terminals 2 -1 , 2 -2 exist, but three or more upper-level terminals 2 may exist. Here, when two or more other upper-level terminals 2 exist within the communicable range from the one upper-level terminal 2 that has detected a communication failure with the MQTT broker 31, the failure status information broadcast by the advertisement is received by the two or more other upper-level terminals 2, and the failure status information is notified to the management device 3 from the two or more other upper-level terminals 2.

[0029] Also, Fig. 2 shows a situation where a communication failure has occurred between one upper-level terminal 2 -1 and the MQTT broker 31, but one upper-level terminal 2 -1The system operates in the same manner as in Figure 2(b) even if a communication failure occurs between it and the Web server 32.

[0030] Figure 3 is a block diagram showing an example of the functional configuration of the host terminal 2 according to this embodiment. As shown in Figure 3, the host terminal 2 of this embodiment has a functional configuration comprising a device search unit 21, a status notification unit 22, an advertising unit 23, a communication failure detection unit 24, and an operation switching unit 25. The device search unit 21 and the status notification unit 22 constitute the means for notifying the claims, and the advertising unit 23 constitutes the means for transmitting the claims.

[0031] The above-mentioned functional blocks 21 to 25 perform the following processes, for example, through the cooperation of hardware and software. For example, the processes of the above-mentioned functional blocks 21 to 25 are executed by the operation of programs stored in storage media such as RAM, ROM, hard disk, or semiconductor memory, under the control of a processor configured by a microcomputer equipped with a CPU, RAM, ROM, etc. In addition to the microcomputer, a DSP (Digital Signal Processor) may also be provided. Alternatively, instead of a program, the functional blocks 21 to 25 realized by the program may be configured by hardware.

[0032] The device search unit 21 searches for a lower-level terminal 1 that is within communication range of the upper-level terminal 2, and obtains identification information of the found lower-level terminal 1 from the lower-level terminal 1. Here, the device search unit 21 receives the lower-level terminal ID that is periodically transmitted at predetermined time intervals by BLE advertisement by the lower-level terminal 1. In the event of a communication failure as shown in Figure 2(b), one upper-level terminal 2 that detected the communication failure... -1 Another higher-end device 2 -2 The device discovery unit 21 searches for the IDs of one or more lower-level terminals 1 that are within communication range, as well as the IDs of one higher-level terminal 2 that is within communication range. -1 It receives the upstream terminal ID and failure status information.

[0033] Furthermore, the device discovery unit 21 sends a scan command to the lower terminal 1, which has received the lower terminal ID through advertisement, and receives response information from the lower terminal 1. Scanning is an operation in which the upper terminal 2, acting as a BLE master (central), explicitly searches for BLE slave devices in the vicinity. The response information includes the lower terminal ID and optional additional information. Examples of additional information include information indicating the operating status of switches, buttons, etc., of the lower terminal 1, the battery voltage detected by the voltage sensor, the ambient temperature detected by the temperature sensor, information identifying the image currently displayed on the display, the model information of the lower terminal 1, and firmware version information. Note that these are just examples of additional information and are not limited to these.

[0034] The status notification unit 22 notifies the management device 3 via the communication network, along with its own superior terminal ID, of the subordinate terminal IDs and additional information of one or more subordinate terminals 1 discovered by the device discovery unit 21 as status information. Here, each time the status notification unit 22 receives a subordinate terminal ID that is periodically transmitted at predetermined time intervals by the advertisement of the subordinate terminal 1, it notifies the management device 3 of the received one or more subordinate terminal IDs along with additional information as status information.

[0035] In the event of a communication failure as shown in Figure 2(b), one higher-level terminal 2 detects the communication failure. -1 Another higher-end device 2 -2 However, the first higher-end terminal 2 -1 When fault status information advertised by is received, the other higher-level terminal 2 -2 The status notification unit 22 provides status information for one or more lower-level terminals 1 within communication range, as well as status information for one higher-level terminal 2 -1 The higher-level terminal ID and failure status information are notified to the management device 3 via the communication network.

[0036] The management device 3 receives fault status information that is pushed in real time from the status notification unit 22 to the MQTT broker 31 using the MQTT mechanism, thereby enabling one of the higher-level terminals 2 -1It is possible to quickly recognize when a communication failure occurs between the two. The management device 3 is connected to one of the higher-level terminals 2. -1 After recognizing a communication failure between the two, the Web API of the Web server 32 immediately returns a failure result when called from the store service server 103, or the higher-level terminal 2 experiencing the communication failure. -1 It is possible to perform control such as not sending operation commands.

[0037] When the advertising unit 23 detects a communication failure with the management device 3 using the communication failure detection unit 24 (described later), it broadcasts failure status information along with its own higher-level terminal ID via BLE advertising. Here, the advertising unit 23 periodically transmits the higher-level terminal ID and failure status information at predetermined time intervals.

[0038] The communication failure detection unit 24 detects communication failures that occur with the management device 3. Examples of communication failures to be detected include disconnection of the connection between the host terminal 2 and the MQTT broker 31, disconnection of the connection between the host terminal 2 and the web server 32, or disconnection of the internet connection itself.

[0039] The operation switching unit 25 switches whether the upper-level terminal 2 operates as a BLE master (central) or a slave (peripheral) depending on the status of communication failure detection by the communication failure detection unit 24. When the communication failure detection unit 24 has not detected a communication failure, that is, when the upper-level terminal 2 is normally connected to the management device 3, the operation switching unit 25 controls the upper-level terminal 2 to operate as a BLE master. In this case, the operation switching unit 25 activates the device discovery unit 21 and the status notification unit 22, and stops the operation of the advertisement unit 23.

[0040] On the other hand, if the communication failure detection unit 24 detects a communication failure with the management device 3, the operation switching unit 25 controls the upper-level terminal 2 to operate as a BLE slave device. In this case, the operation switching unit 25 stops the operation of the device discovery unit 21 and the status notification unit 22, and activates the advertisement unit 23.

[0041] As shown in Figure 2(b), in this embodiment, one host terminal 2 operates as a slave unit. -1 In this configuration, the advertising unit 23 advertises its own higher-level terminal ID and failure status information. -1 Another higher-level terminal 2 received the advertisement from the parent device. -2 Then, the first higher-level terminal 2 that received the advertisement... -1 The status notification unit 22 notifies the management device 3 of the higher-level terminal ID and fault status information via the communication network.

[0042] Note that in Figure 2(b), the first upper-level terminal 2 -1 The above shows an example of operation when a communication failure occurs between the first and the management device 3, but it is also possible to configure it to operate in the same way as in Figure 2(b) when the communication failure is restored. That is, one of the higher-level terminals 2 -1 When the communication failure detection unit 24 detects the recovery of a communication failure, the advertising unit 23 may broadcast failure recovery status information indicating that the communication failure has been recovered, along with its own higher-level terminal ID, via BLE advertising. As another example, a higher-level terminal 2 that has recovered from a communication failure -1 The device itself may also be configured to notify the management device 3 of its own fault recovery status.

[0043] First upper-level terminal 2 -1 Another higher-end device that received an advertisement from 2 -2 The device discovery unit 21 is a higher-level terminal 2 -1 The system receives the higher-level terminal ID and fault recovery status information transmitted by the advertisement. The status notification unit 22 then receives the higher-level terminal ID and fault recovery status information from one of the higher-level terminals 2 -1 The higher-level terminal ID and fault recovery status information received from the device are notified to the management device 3 via the communication network.

[0044] After the status notification unit 22 has completed notifying the management device 3 of the fault recovery status information, the operation switching unit 25 will switch to one of the higher-level terminals 2 -1Switch back from operating as a BLE slave device to operating as a master device. In other words, the first upper-level terminal 2 -1 The operation switching unit 25 activates the device discovery unit 21 and the status notification unit 22, and stops the operation of the advertisement unit 23.

[0045] Figure 4 is a flowchart showing an example of the operation of the upper-level terminal 2 according to this embodiment configured as described above (an example of the processing procedure for the status notification method). Figure 4 shows the flow of processing executed in one upper-level terminal 2.

[0046] First, the communication failure detection unit 24 determines whether or not a communication failure has been detected with the management device 3 (step S1). If no communication failure has been detected, the operation switching unit 25 controls the upper-level terminal 2 to operate as a BLE master (step S2).

[0047] In this case, the device discovery unit 21 obtains the lower terminal ID advertised by the lower terminal 1, which is within communication range of the upper terminal 2, from the lower terminal 1 (step S3). If a communication failure has been detected between another upper terminal 2 and the management device 3, the upper terminal ID and failure status information have been advertised from that other upper terminal 2. In this case, if the other upper terminal 2 where the communication failure was detected is within communication range, the device discovery unit 21 also obtains the upper terminal ID and failure status information advertised from that other upper terminal 2.

[0048] Next, the status notification unit 22 notifies the management device 3 of the status information, along with its own upper-level terminal ID, of one or more lower-level terminals 1 obtained by the device discovery unit 21 (step S4). If the upper-level terminal ID and failure status information have been obtained from another upper-level terminal 2 where a communication failure has been detected, the status notification unit 22 also notifies the management device 3 of that information.

[0049] Subsequently, the host terminal 2 determines whether or not an instruction to terminate the operation has been given (step S5). An instruction to terminate the operation may be, for example, an operation to stop the execution of the program or an operation to turn off the power of the host terminal 2. If no instruction to terminate the operation has been given, the process returns to step S1. On the other hand, if an instruction to terminate the operation has been given, the process shown in the flowchart in Figure 4 is terminated.

[0050] In step S1 above, if a communication failure is detected, the operation switching unit 25 controls the upper-level terminal 2 to operate as a BLE slave (step S6). In this case, the advertising unit 23 broadcasts failure status information along with its own upper-level terminal ID via BLE advertising (step S7). Subsequently, the communication failure detection unit 24 determines whether the communication failure that occurred between the management device 3 and the terminal has been resolved (step S8). If the resolution of the communication failure has not been detected, the process returns to step S7.

[0051] On the other hand, if the recovery of the communication failure is detected, as an example of the process, the advertising unit 23 broadcasts the failure recovery status information along with its own higher-level terminal ID via BLE advertising (step S9). As mentioned above, the higher-level terminal 2 that detected the recovery of the communication failure may also notify the management device 3 of its own failure recovery status information. After that, the process proceeds to step S2. As a result, the operation switching unit 25 switches the higher-level terminal 2 back from operating as a BLE slave to operating as a master.

[0052] As explained in detail above, in this embodiment, each of the multiple upper-level terminals 2 used in the communication system is equipped with a transmission means that transmits fault status information by BLE advertisement when it detects a communication failure with the management device 3, and a notification means that notifies the management device 3 of the fault status information via a communication network such as the Internet when it receives the fault status information via broadcast.

[0053] According to this embodiment, as shown in Figure 2(b), among the multiple upper-level terminals 2 connected to the management device 3 via a communication network, one upper-level terminal 2 -1 When a communication failure is detected between the management device 3 and the higher-level terminal 2, -1 Failure status information is advertised from one terminal and received by another higher-level terminal 2. -2 Fault status information is notified to the management device 3 via the communication network.

[0054] Therefore, one higher-level terminal 2 that detected the occurrence of the communication failure -1 In communication between the and the management device 3, without a certain timeout period elapsed, one higher-level terminal 2 -1 From another higher-end device 2 -2 The fault status information is pushed to the management device 3 via the above, and one of the higher-level terminals 2 -1 The management device 3 can detect when a communication failure occurs between it and the operational upper-level terminal 2. This reduces the time it takes for the management device 3 to detect a communication failure between it and the upper-level terminal 2.

[0055] In the above embodiment, one higher-level terminal 2 detects the occurrence of a communication failure in the communication network. -1 This device acts as a BLE client, and uses BLE advertising as a communication method different from the communication network to share fault status information with another higher-level terminal 2. -2While an example of transmission has been described, the system is not limited to this. For example, multiple upper-level terminals 2 may be connected via a LAN, and fault status information may be transmitted in response to a UDP protocol broadcast. In this case, upper-level terminal 2 periodically broadcasts via UDP to multiple upper-level terminals 2 connected via the LAN. When an upper-level terminal 2 that has detected a communication failure receives this broadcast, it responds to the originating upper-level terminal 2 with its own upper-level terminal ID and fault status information. The originating upper-level terminal 2 then notifies the management device 3 of the fault status information obtained from another upper-level terminal 2. In addition, any communication protocol capable of performing broadcast communication may be used in place of the UDP protocol. For example, this function may be implemented using broadcast communication via MQTT, LoRa (Long Range) and LoRaWAN, Wi-SUN, etc.

[0056] Furthermore, although the above embodiment describes an example in which fault status information is broadcast by BLE advertisement, the fault status information may also be included in the response data to the scan command transmitted from the upper-level terminal 2 following the advertisement.

[0057] Furthermore, the service provision system shown in Figure 1 is just one example of how the communication system according to this embodiment can be applied, and the examples of application are not limited to this.

[0058] Furthermore, the above embodiments are merely examples of how the present invention may be implemented, and the technical scope of the invention should not be interpreted as being limited by them. In other words, the present invention can be implemented in various ways without departing from its gist or its main features. [Explanation of Symbols]

[0059] 1 Lower-end device 2. Higher-level terminal (terminal device) 3 Management device (upper device) 21 Device Search Unit 22 Status Notification Section 23 Advertising Department 24 Communication failure detection unit 25 Operation switching section 31 MQTT Broker 32 Web Servers

Claims

1. In a communication system comprising multiple terminal devices and a higher-level device connected to the multiple terminal devices via a communication network, The above terminal device is A transmission means that, when a communication failure is detected between the above-mentioned higher-level device and the above-mentioned communication network, transmits failure status information using a communication means different from the above-mentioned communication network, The system includes a notification means that, upon receiving the above-mentioned fault status information, notifies the above-mentioned higher-level device of the received fault status information via the above-mentioned communication network. A communication system characterized by the following features.

2. The communication system according to claim 1, characterized in that the above-mentioned transmission means transmits the above-mentioned fault status information by advertising BLE.

3. The above terminal device operates as the master unit of the BLE while connected to the above-mentioned higher-level device, and when it detects a communication failure with the above-mentioned higher-level device, it acts as a slave unit of the BLE and advertises the above-mentioned transmitting means. Another terminal device, acting as the master device, receives the above advertisement from one terminal device acting as the slave device, and notifies the above fault status information received through the above advertisement to the above-level device via the above communication network. The communication system according to claim 2, characterized in that it is the same as described in claim 2.

4. The communication system according to claim 1, characterized in that the above-mentioned transmission means transmits the above-mentioned fault status information in response to a predetermined broadcast communication.

5. A transmission means that, when a communication failure is detected between a higher-level device connected via a communication network, transmits failure status information using a communication means different from the aforementioned communication network, The system includes a notification means that, upon receiving the above-mentioned fault status information, notifies the above-mentioned higher-level device of the received fault status information via the above-mentioned communication network. A terminal device characterized by the following features.

6. In a first step, when one of several terminal devices connected to a higher-level device via a communication network detects a communication failure between itself and the higher-level device, the terminal device transmits failure status information using a communication means different from the communication network. The system includes a second step in which, when another terminal device receives the fault status information transmitted from the first terminal device, the other terminal device notifies the higher-level device of the received fault status information via the communication network. A status notification method characterized by the following:

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