Alarm system, relay device, channel determination method, and program

Abstract

To provide a technique for simplifying channel management even when channel switching occurs.SOLUTION: A first repeating device 200a transmits a beacon signal to a first fire alarm 100a or the like by a first channel. The first fire alarm 100a or the like transmits a response signal to a first repeating device 200a by the first channel when receiving the beacon signal. The first repeating device 200a transmits the beacon signal to the first fire alarm 100a or the like by a second channel when not receiving the response signal from a second fire alarm 100b. When the first fire alarm 100a or the like transmits the response signal to the first repeating device 200a by the second channel when receiving the beacon signal. The first repeating device 200a determines to use the second channel in an alarm system 1000 when receiving the response signal from the first fire alarm 100a or the like.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to alarm technology, and more particularly to an alarm system, a relay device, a channel determination method, and a program that use any one of a plurality of channels. [Background technology]

[0002] Residential fire alarms (hereinafter referred to as "fire alarms") detect fires in homes and issue an alarm. In addition, multiple fire alarms communicate with each other, so that abnormal information from one fire alarm is also reported by the other fire alarms. As the number of fire alarms increases, the occurrence of collisions between wireless signals transmitted from the fire alarms also increases. To avoid collisions, TDMA (Time Division Multiple Access) is used (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2009-169552 Summary of the Invention [Problem to be solved by the invention]

[0004] Multiple channels are provided for wireless communication between multiple fire alarm devices. Under normal conditions, the relay device and multiple fire alarm devices communicate using one channel. If a communication abnormality occurs between the relay device and one of the fire alarm devices, the channel used between the relay device and that fire alarm device is switched. On the other hand, the channel used between the relay device and other fire alarm devices cannot be switched. Therefore, multiple channels are used for communication between the relay device and multiple fire alarm devices. As a result, channel management becomes complicated.

[0005] The present disclosure has been made in view of these circumstances, and its purpose is to provide a technique that simplifies channel management even when channel switching occurs. [Means for solving the problem]

[0006] In order to solve the above problems, an alarm system according to one embodiment of the present disclosure comprises a relay device, and a first alarm device and a second alarm device capable of communicating with the relay device. The relay device transmits a beacon signal to the first alarm device and the second alarm device on a first channel, and if the first alarm device and the second alarm device receive the beacon signal on the first channel, they transmit a response signal on the first channel to the relay device, and if the relay device receives a response signal from the first alarm device and the second alarm device on the first channel, it decides to use the first channel in the alarm system, and if the relay device does not receive a response signal from at least one of the first alarm device and the second alarm device on the first channel, it transmits a beacon signal to the first alarm device and the second alarm device on a second channel different from the first channel, and if the first alarm device and the second alarm device receive a beacon signal on the second channel, they transmit a response signal on the second channel to the relay device, and if the relay device receives a response signal from the first alarm device and the second alarm device on the second channel, it decides to use the second channel in the alarm system.

[0007] Another aspect of the present disclosure is a relay device. This device comprises a communication unit capable of communicating with a first alarm device and a second alarm device, and a control unit that controls the communication unit. The communication unit transmits a beacon signal to the first alarm device and the second alarm device on a first channel, and the first alarm device and the second alarm device transmit a response signal on the first channel when they receive the beacon signal on the first channel, and if the communication unit receives a response signal from the first alarm device and the second alarm device on the first channel, the control unit decides to use the first channel in the alarm system, and if the communication unit does not receive a response signal from at least one of the first alarm device and the second alarm device on the first channel, the communication unit transmits a beacon signal to the first alarm device and the second alarm device on a second channel different from the first channel, and the first alarm device and the second alarm device transmit a response signal on the second channel when they receive the beacon signal on the second channel, and if the communication unit receives a response signal from the first alarm device and the second alarm device on the second channel, the control unit decides to use the second channel in the alarm system.

[0008] Yet another aspect of the present disclosure is a channel determination method comprising the steps of transmitting a beacon signal to a first alarm device and a second alarm device on a first channel, the first alarm device and the second alarm device transmitting a response signal on the first channel when the beacon signal is received on the first channel, and determining to use the first channel in the alarm system if a response signal from the first alarm device and the second alarm device is received on the first channel, transmitting a beacon signal to the first alarm device and the second alarm device on a second channel different from the first channel when a response signal from at least one of the first alarm device and the second alarm device is not received on the first channel, and the first alarm device and the second alarm device transmitting a response signal on the second channel when the beacon signal is received on the second channel, and determining to use the second channel in the alarm system if a response signal from the first alarm device and the second alarm device is received on the second channel.

[0009] Any combination of the above components, and conversion of the present disclosure into a method, device, system, recording medium, computer program, etc., are also valid aspects of the present disclosure. [Effects of the Invention]

[0010] According to the present disclosure, even when channel switching occurs, channel management can be simplified. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a diagram illustrating a configuration of an alarm system according to a first embodiment. [Figure 2] FIG. 2 is a diagram illustrating the configuration of the fire alarm and relay device of FIG. [Figure 3] FIG. 2 is a diagram illustrating an outline of communication between the fire alarm device and the relay device in FIG. [Figure 4] FIG. 3 is a diagram showing an outline of a channel determination process in the fire alarm and relay device of FIG. 2. [Figure 5] 3 is a diagram showing an outline of another channel determination process in the fire alarm and relay device of FIG. 2. FIG. [Figure 6] FIG. 6 is a diagram showing an outline of high-speed intermittent reception processing in the fire alarm device of FIG. 5. [Figure 7] 3 is a flowchart showing a channel determination procedure performed by the relay device of FIG. 2. [Figure 8] FIG. 10 is a diagram illustrating an outline of a channel determination process in a fire alarm and a relay device according to a second embodiment. [Figure 9] 10 is a flowchart illustrating a channel determination procedure performed by a relay device according to a second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0012] Example 1 Before describing the present disclosure in detail, an overview will be provided. Example 1 relates to an alarm system installed in facilities such as apartment buildings, detached houses, offices, and hospitals. In the alarm system, a relay device is connected to a management device, and multiple fire alarms are connected to the relay device. In this tree structure, the management device corresponds to the upper side, and the fire alarms correspond to the lower side. When any fire alarm detects a fire, it transmits the detection result to the relay device. The relay device relays the detection result and transmits it to the management device. When the management device receives the detection result, it selects a fire alarm to sound. The management device transmits a sounding instruction to the selected fire alarm via the relay device. The fire alarm that receives the sounding instruction sounds an alarm.

[0013] When signals are transmitted from multiple fire alarm devices to a relay device, the more fire alarm devices there are, the more likely the signals are to collide. To prevent signal collisions, TDMA is used for communication between the relay device and multiple fire alarm devices. In TDMA, the relay device and multiple fire alarm devices are each assigned a different time slot, and the multiple time slots are arranged on a time axis. The relay device transmits signals in the assigned time slot, and the fire alarms receive signals in the time slot assigned to the relay device. Each fire alarm transmits signals in its assigned time slot, and the relay device receives signals in the time slot assigned to each fire alarm. Here, the line for signals from the relay device to the fire alarm is called the "downlink," while the line for signals from the fire alarms to the relay device is called the "uplink."

[0014] Such an alarm system defines a frame that includes one communication time slot for the downlink (hereinafter referred to as "downlink communication time slot") and multiple communication time slots for the uplink (hereinafter referred to as "uplink communication time slots"). A superframe is formed by arranging multiple frames on the time axis. Furthermore, the alarm system can use multiple channels, and any one of the channels is used for communication. For example, the relay device switches channels when it is unable to communicate with any of the fire alarm devices. In order to simplify channel management even when channel switching occurs, the alarm system according to this embodiment performs the following processing.

[0015] If a communication abnormality occurs, the relay device sends a channel change request to all fire alarm devices, causing all fire alarm devices to switch to the same channel. After sending the channel change request, the relay device sequentially switches channels for each frame and transmits a beacon signal. When a fire alarm device that is not experiencing a communication abnormality receives the channel change request, it receives a beacon signal while sequentially switching channels for each frame. On the other hand, a fire alarm that is experiencing a communication abnormality performs high-speed intermittent reception on all channels, thereby receiving a beacon signal whose channel changes as it goes. When all fire alarms receive a beacon signal, they send a response signal (ACK signal) to the relay device. When the relay device receives ACK signals from all fire alarm devices, it decides which channel to use at that time.

[0016] 1 shows the configuration of an alarm system 1000. The alarm system 1000 includes a first fire alarm device 100a through a sixth fire alarm device 100f collectively referred to as fire alarm devices 100, a first relay device 200a and a second relay device 200b collectively referred to as relay devices 200, and a management device 300. The number of fire alarm devices 100 is not limited to six, and the number of relay devices 200 is not limited to two.

[0017] The alarm system 1000 is applied to facilities such as homes, offices, and commercial facilities, and is a system that detects fires and notifies the occurrence of a fire. The multiple fire alarms 100 are, for example, residential fire alarms and are equipped with fire detection sensors. The multiple fire alarms 100 are installed, for example, on the ceiling of the facility, but may also be installed on the wall, etc.

[0018] The first fire alarm device 100a to the third fire alarm device 100c communicate wirelessly with the first relay device 200a, and the fourth fire alarm device 100d to the sixth fire alarm device 100f communicate wirelessly with the second relay device 200b. In other words, a star-shaped network topology is formed with the first relay device 200a and the second relay device 200b at the center of the network. The first relay device 200a and the second relay device 200b can communicate with the management device 300 via wired or wireless communication.

[0019] The management device 300 is, for example, a controller for a Home Energy Management System (HEMS) installed in a facility. The management device 300 is capable of communicating with multiple devices installed in the facility. The multiple devices include, for example, air conditioners, lighting equipment, water heaters, and the like, which have communication functions. The management device 300 is also capable of communicating with a first relay 200a and a second relay 200b installed in the facility. The management device 300 is also capable of communicating with multiple fire alarms 100 via the first relay 200a and the second relay 200b.

[0020] Fig. 2 shows the configuration of the fire alarm 100 and the relay device 200. The fire alarm 100 includes a communication unit 120, a processing unit 122, a control unit 124, a fire detection sensor 150, and a buzzer 152, and the relay device 200 includes a communication unit 220, a processing unit 222, and a control unit 224. In Fig. 2, the communication function of the relay device 200 with the management device 300 is omitted.

[0021] The fire detection sensor 150 in the fire alarm 100 may use known technology. For example, the fire detection sensor 150 may be an optical smoke detection sensor, which may detect a fire by utilizing diffuse reflection of light to detect smoke during a fire. For example, the fire detection sensor 150 may be a heat detection sensor, which may detect a fire by detecting heat during a fire. For example, the fire detection sensor 150 may be a carbon monoxide detection sensor, which may detect a fire by detecting the concentration of carbon monoxide generated by combustion during a fire. For example, the fire detection sensor 150 may be an infrared detection sensor, which may detect a fire by detecting infrared rays emitted by combustion during a fire.

[0022] The communication unit 120 performs wireless communication with the relay device 200. The processing unit 122 processes signals received by the communication unit 120 and generates signals to be transmitted from the communication unit 120. The control unit 124 controls the operations of the communication unit 120 and the processing unit 122. The buzzer 152 is capable of emitting a buzzer sound. The fire alarm 100 may not include the buzzer 152 but may include the fire detection sensor 150, that is, may have both a detection function and a communication function. Such a fire alarm 100 can also be said to be a sensor that is capable of issuing an alarm when a fire is detected.

[0023] The communication unit 220 in the relay device 200 performs wireless communication with the fire alarm device 100. The processing unit 222 processes signals received by the communication unit 220 and generates signals to be transmitted from the communication unit 220. The control unit 224 controls the operations of the communication unit 220 and the processing unit 222.

[0024] FIG. 3 shows an overview of communication between the fire alarm device 100 and the relay device 200. The horizontal axis in FIG. 2 represents time, and "1," "2," ..., and "m" represent slot numbers. Slot "1" is a time slot for downstream communication, and slots "2," ..., and "m" represent time slots for upstream communication. A frame is formed by arranging multiple slots on the time axis. Here, the frames are represented in chronological order as "frame 1" to "frame 6." Furthermore, a superframe is formed by arranging multiple frames on the time axis.

[0025] The first relay 200a transmits a beacon signal in downstream communication time slot "1" of the first frame. The first fire alarm 100a to the third fire alarm 100c receive the beacon signal and generate a frame, a superframe, synchronized with the first relay 200a. The first relay 200a can transmit a signal containing predetermined information (hereinafter also referred to as a "communication signal") in downstream communication time slots other than the downstream communication time slot in which the beacon signal should be transmitted. In the downstream communication time slot, the first fire alarm 100a to the third fire alarm 100c operate to receive the communication signal from the first relay 200a.

[0026] The first fire alarm device 100a is assigned the upstream communication time slot "2" and is able to transmit a communication signal in this upstream communication time slot. The second fire alarm device 100b is assigned the upstream communication time slot "3" and is able to transmit a communication signal in this upstream communication time slot. The third fire alarm device 100c is assigned the upstream communication time slot "m" and is able to transmit a communication signal in this upstream communication time slot. In the upstream communication time slots "2" to "m", the first relay 200a operates to receive communication signals from the first fire alarm device 100a to the third fire alarm device 100c.

[0027] For example, if the fire detection sensor 150 of the first fire alarm 100a detects a fire, the first fire alarm 100a wirelessly transmits the detection result to the first relay 200a. The detection result includes identification information of the first fire alarm 100a, which is the transmission source. When the first relay 200a receives the detection result from the first fire alarm 100a, it transmits the detection result to the management device 300. When the management device 300 receives the detection result, it identifies the fire alarm 100 to be sounded based on the identification information included in the detection result. The correspondence between the identification information and the information of the fire alarm 100 to be sounded is stored in advance in the management device 300. The management device 300 transmits an instruction to sound the fire alarm to the first relay 200a or the second relay 200b, with the identified fire alarm 100 as the final destination. The first relay device 200a or the second relay device 200b transmits an instruction to sound the fire alarm 100 identified by the management device 300. When the fire alarm 100 receives the instruction to sound the fire alarm, it sounds the buzzer 152. The relay device 200 may have a light-emitting device that flashes. The detection result and the instruction to sound the fire alarm are examples of communication signals.

[0028] The alarm system 1000 defines multiple channels that can be used for communication between the fire alarm devices 100 and the relay device 200. The relay device 200 selects one channel from the multiple channels and communicates with the multiple fire alarm devices 100 using the selected channel. The first relay device 200a and the second relay device 200b select different channels to reduce interference. For example, if five channels, "1ch" to "5ch," are defined in the alarm system 1000, the first relay device 200a selects "1ch" and the second relay device 200b selects "5ch."

[0029] Under such circumstances, if the relay device 200 is unable to communicate with any of the fire alarm devices 100, it switches channels. If multiple channels are used for communication due to channel switching, channel management becomes complicated. Therefore, it is desirable to simplify channel management even when channel switching occurs. Therefore, the alarm system 1000 according to this embodiment executes the following processing.

[0030] FIG. 4 shows an overview of the channel determination process in the fire alarm 100 and the relay 200. The horizontal axis represents time. One superframe contains "n" frames, and one frame contains "m" slots. Here, it is assumed that the first relay 200a uses "ch1," but the channel used by the first relay 200a is not limited to "ch1." The first relay 200a transmits a beacon signal to each fire alarm 100 in the downstream communication time slot "1" of "ch1." The beacon signal can be transmitted, for example, by broadcast transmission.

[0031] The first fire alarm device 100a to the third fire alarm device 100c receive the beacon signal in the downstream communication time slot "1" of "ch1." In response to this, the first fire alarm device 100a transmits an ACK signal to the first relay 200a in the upstream communication time slot "2" of "ch1." The first relay 200a receives the ACK signal from the first fire alarm device 100a in the upstream communication time slot "2" of "ch1." The second fire alarm device 100b transmits an ACK signal to the first relay 200a in the upstream communication time slot "3" of "ch1." The first relay 200a receives the ACK signal from the second fire alarm device 100b in the upstream communication time slot "3" of "ch1." The third fire alarm device 100c transmits an ACK signal to the first relay 200a in the upstream communication time slot "m" of "ch1." The first relay 200a receives the ACK signal from the third fire alarm device 100c in the upstream communication time slot "m" of "ch 1".

[0032] When the control unit 224 of the first relay 200a receives ACK signals on "ch1" from all registered fire alarm devices 100, it recognizes that communication with all fire alarm devices 100 is possible on "ch1." The control unit 224 decides to continue using "ch1," which it had been using up until then. This processing may be performed, for example, in each frame, or in the first frame of each superframe. Figure 4 can be said to be normal operation in which it is confirmed that communication with all fire alarm devices 100 is possible.

[0033] Fig. 5 shows an overview of another channel determination process in the fire alarm device 100 and the relay device 200. This is shown in the same way as Fig. 4. The first relay device 200a transmits a beacon signal to each fire alarm device 100 in the downstream communication time slot "1" of "ch1", just like Fig. 4.

[0034] The first fire alarm device 100a and the third fire alarm device 100c receive the beacon signal in the downstream communication time slot "1" of "ch1." In response, the first fire alarm device 100a transmits an ACK signal to the first relay 200a in the upstream communication time slot "2" of "ch1." The first relay 200a receives the ACK signal from the first fire alarm 100a in the upstream communication time slot "2" of "ch1." The third fire alarm device 100c transmits an ACK signal to the first relay 200a in the upstream communication time slot "m" of "ch1." The first relay 200a receives the ACK signal from the third fire alarm 100c in the upstream communication time slot "m" of "ch1." However, since the second fire alarm device 100b cannot receive the beacon signal in the downstream communication time slot "1" of "ch1," it does not transmit an ACK signal in the upstream communication time slot "3" of "ch1." The first relay 200a does not receive an ACK signal from the second fire alarm device 100b in the upstream communication time slot "3" of "ch1".

[0035] If the control unit 224 of the first relay 200a does not receive an ACK signal on "ch1" from at least one of the registered fire alarm devices 100, it recognizes that it is unable to communicate with at least one fire alarm device 100 on "ch1." The control unit 224 decides to switch "ch1" to another channel, for example, "ch2." Before switching to "ch2," the first relay 200a transmits a channel change request to each fire alarm 100 in the downstream communication time slot "1" of the next frame on "ch1." The channel change request is a signal requesting a channel change. Changing the channel also includes changing the channel on a frame-by-frame basis.

[0036] The first fire alarm device 100a transmits an ACK signal to the first relay 200a in the upstream communication timeslot "2" of "ch1". The first relay 200a receives the ACK signal from the first fire alarm device 100a in the upstream communication timeslot "2" of "ch1". The third fire alarm device 100c transmits an ACK signal to the first relay 200a in the upstream communication timeslot "m" of "ch1". The first relay 200a receives the ACK signal from the third fire alarm device 100c in the upstream communication timeslot "m" of "ch1".

[0037] The control unit 224 of the first relay 200a switches the channel from "ch 1" to "ch 2" in the next frame. The first relay 200a transmits a beacon signal to each fire alarm device 100 in the downstream communication time slot "1" of "ch 2".

[0038] The first fire alarm device 100a and the third fire alarm device 100c receive the beacon signal in the downstream communication time slot "1" of "ch2." In response to this, the first fire alarm device 100a transmits an ACK signal to the first relay 200a in the upstream communication time slot "2" of "ch2." The first relay 200a receives the ACK signal from the first fire alarm device 100a in the upstream communication time slot "2" of "ch2." The third fire alarm device 100c transmits an ACK signal to the first relay 200a in the upstream communication time slot "m" of "ch2." The first relay 200a receives the ACK signal from the third fire alarm device 100c in the upstream communication time slot "m" of "ch2."

[0039] Because the second fire alarm device 100b has not received a channel change request, the control unit 124 of the second fire alarm device 100b does not recognize that a beacon signal is being transmitted on a channel other than "1ch." If the control unit 124 cannot receive a beacon signal in the downlink communication time slot "1" on "1ch," it causes the communication unit 120 to perform high-speed intermittent reception.

[0040] FIG. 6 shows an overview of high-speed intermittent reception processing in the fire alarm 100. The horizontal axis represents time. A beacon signal has a fixed length. In high-speed intermittent reception processing, the channel on standby in the communication unit 120 is switched in a short period of time. In FIG. 6, switching from "1ch reception" to "5ch reception" is performed sequentially during the period of the beacon signal. Even if a channel change request has not been received and therefore the channel on which the beacon signal is transmitted is not known, by performing high-speed intermittent reception processing, part of the beacon signal can be received on one of the channels. Return to FIG. 5.

[0041] The second fire alarm device 100b cannot receive a beacon signal in the downstream communication time slot "1" of "2ch," and therefore does not transmit an ACK signal in the upstream communication time slot "3" of "2ch." The first relay 200a does not receive an ACK signal from the second fire alarm device 100b in the upstream communication time slot "3" of "2ch."

[0042] If the control unit 224 of the first relay 200a does not receive an ACK signal on "ch2" from at least one of the registered fire alarm devices 100, it recognizes that it cannot communicate with at least one fire alarm device 100 on "ch2." The control unit 224 decides to switch "ch2" to another channel, for example, "ch3." The first relay 200a does not transmit a channel change request on "ch2" before switching to "ch3." The control unit 224 of the first relay 200a switches the channel from "ch2" to "ch3" in the next frame. The first relay 200a transmits a beacon signal to each fire alarm 100 in the downstream communication time slot "1" on "ch3."

[0043] The first fire alarm device 100a to the third fire alarm device 100c receive the beacon signal in the downstream communication time slot "1" of "ch3". In response to this, the first fire alarm device 100a transmits an ACK signal to the first relay 200a in the upstream communication time slot "2" of "ch3". The first relay 200a receives the ACK signal from the first fire alarm device 100a in the upstream communication time slot "2" of "ch3". The second fire alarm device 100b transmits an ACK signal to the first relay 200a in the upstream communication time slot "3" of "ch3". The first relay 200a receives the ACK signal from the second fire alarm device 100b in the upstream communication time slot "3" of "ch3". The third fire alarm device 100c transmits an ACK signal to the first relay 200a in the upstream communication time slot "m" of "ch3". The first relay device 200a receives the ACK signal from the third fire alarm device 100c in the upstream communication time slot "m" of "3ch."

[0044] When the control unit 224 of the first relay 200a receives ACK signals on "ch3" from all registered fire alarm devices 100, it recognizes that communication with all fire alarm devices 100 is possible on "ch3." The control unit 224 decides to use "ch3." If the control unit 224 of the first relay 200a decides to use "ch3," the first relay 200a transmits a channel determination request to each fire alarm 100 in the downstream communication time slot "1" of the next frame on "ch4." The channel determination request is a signal for causing the fire alarm 100 to stop switching channels, and has a pattern different from that of a beacon signal, for example.

[0045] When the first fire alarm device 100a and the third fire alarm device 100c, which had received a channel change request, receive a channel confirmation request on "ch4", their control units 124 decide to use "ch3". On the other hand, when the second fire alarm device 100b, which had not received a channel change request, receives a channel confirmation request on "ch4", the control unit 124 decides to use "ch3". Thereafter, the first relay 200a and the first fire alarm devices 100a to the third fire alarm devices 100c use "ch3" and perform the processing shown in FIG. 3.

[0046] When the control unit 224 of the first relay 200a receives ACK signals on "2ch" from all registered fire alarm devices 100, it recognizes that communication with all fire alarm devices 100 is possible on "2ch." The control unit 224 decides to use "2ch." The processing that follows is as described above, so a description thereof will be omitted here. Figure 5 can be said to be the operation when a communication abnormality occurs with at least one fire alarm 100 and the channel is switched.

[0047] The subject of the device, system, or method of the present disclosure includes a computer. The computer executes a program to realize the functions of the subject of the device, system, or method of the present disclosure. The computer includes, as its main hardware component, a processor that operates according to the program. The processor may be of any type, as long as it can realize the functions by executing the program. The processor may be composed of one or more electronic circuits, including a semiconductor integrated circuit (IC) or a large-scale integration (LSI). The electronic circuits may be integrated into a single chip or may be provided on multiple chips. The multiple chips may be integrated into a single device or may be provided on multiple devices. The program is recorded on a non-transitory recording medium, such as a computer-readable ROM, optical disk, or hard disk drive. The program may be pre-stored on the recording medium or may be supplied to the recording medium via a wide-area communication network, including the Internet.

[0048] The operation of the alarm system 1000 configured as described above will now be described. FIG. 7 is a flowchart showing the channel determination procedure performed by the relay device 200. The communication unit 220 transmits a beacon signal (S10). If ACK signals have not been received from all of the fire alarm devices 100 (N in S12), the communication unit 220 transmits a channel change request (S14). The control unit 224 switches the channel (S16), and the communication unit 220 transmits a beacon signal (S18). If ACK signals have not been received from all of the fire alarm devices 100 (N in S20), or if there is a switchable channel (Y in S22), the process returns to step 16. If ACK signals have been received from all of the fire alarm devices 100 (Y in S20), or if there is no switchable channel (N in S22), the control unit 224 determines the channel to use (S24). The communication unit 220 transmits a channel determination request (S26). If ACK signals have been received from all of the fire alarm devices 100 (Y in S12), the process ends.

[0049] According to this embodiment, if there is a fire alarm device 100 that does not receive an ACK signal in response to a beacon signal, the channel is changed and a beacon signal is transmitted until ACK signals are received from all fire alarm devices 100, making it possible to detect the optimal channel. Furthermore, if there is no fire alarm device 100 that does not receive an ACK signal in response to a beacon signal, the channel to be used at that time is determined, making it possible to simplify channel management even when channel switching occurs. Furthermore, after a channel change request is sent to request a channel change, the channel is changed for each frame, making it possible to automatically change the channel. Furthermore, because the channel is changed automatically, it is possible to suppress a decrease in frame utilization efficiency. Furthermore, once a channel has been determined, a channel confirmation request is sent, making it possible to notify the device of the channel to be used.

[0050] An overview of one aspect of the present disclosure is as follows: An alarm system (1000) of one aspect of the present disclosure comprises a relay device (200), and a first alarm device and a second alarm device that are capable of communicating with the relay device (200). The relay device (200) transmits a beacon signal on a first channel to the first alarm device (100) and the second alarm device (100), and when the first alarm device (100) and the second alarm device (100) receive the beacon signal on the first channel, they transmit a response signal on the first channel to the relay device (200), and when the relay device (200) receives response signals on the first channel from the first alarm device (100) and the second alarm device (100), it decides to use the first channel in the alarm system (1000), and the relay device (200) decides to use the first channel in the alarm system (1000), and when the relay device (200) receives response signals on the first channel from the first alarm device (100) and the second alarm device (100), it decides to use the first channel in the alarm system (1000), and the relay device (200) decides to use the first alarm device (100) and the second alarm device (100). If a response signal from at least one of the alarm devices (100) and (100) is not received on the first channel, a beacon signal is transmitted to the first alarm device (100) and the second alarm device (100) on a second channel different from the first channel, and if the first alarm device (100) and the second alarm device (100) receive a beacon signal on the second channel, they transmit a response signal on the second channel to the repeater device (200), and if the repeater device (200) receives a response signal from the first alarm device (100) and the second alarm device (100) on the second channel, it decides to use the second channel in the alarm system (1000).

[0051] If the relay device (200) does not receive a response signal on the second channel from at least one of the first alarm device (100) and the second alarm device (100), it transmits a beacon signal to the first alarm device (100) and the second alarm device (100) on a third channel that is different from the first and second channels, and if the first alarm device (100) and the second alarm device (100) receive a beacon signal on the third channel, they transmit a response signal on the third channel to the relay device (200), and if the relay device (200) receives a response signal on the third channel from the first alarm device (100) and the second alarm device (100), it decides to use the third channel in the alarm system (1000).

[0052] The relay device (200) transmits a channel change request for requesting a channel change on a first channel, and then changes the first channel to a second channel, and the relay device (200) changes the second channel to a third channel without transmitting the channel change request on the second channel.

[0053] When the relay device (200) decides to use the second channel, it transmits a channel determination request to notify the determined channel, and when the relay device (200) decides to use the third channel, it transmits a channel determination request.

[0054] Another aspect of the present disclosure is a relay device (200). This device comprises a communication unit (220) capable of communicating with a first alarm device (100) and a second alarm device (100), and a control unit (224) that controls the communication unit (220). The communication unit (220) transmits a beacon signal to the first alarm device (100) and the second alarm device (100) on a first channel, and when the first alarm device (100) and the second alarm device (100) receive a beacon signal on the first channel, they transmit a response signal on the first channel, and when the communication unit (220) receives a response signal from the first alarm device (100) and the second alarm device (100) on the first channel, the control unit (224) decides to use the first channel in the alarm system (1000), and the communication unit (220) controls the first alarm device (100) and the second alarm device (100). If a response signal from at least one of the alarm devices is not received on the first channel, a beacon signal is transmitted to the first alarm device (100) and the second alarm device (100) on a second channel different from the first channel, and when the first alarm device (100) and the second alarm device (100) receive a beacon signal on the second channel, they transmit a response signal on the second channel, and if the communication unit (220) receives a response signal from the first alarm device (100) and the second alarm device (100) on the second channel, the control unit (224) decides to use the second channel in the alarm system (1000).

[0055] Yet another aspect of the present disclosure is a channel determination method, which includes the steps of transmitting a beacon signal on a first channel to a first alarm device (100) and a second alarm device (100), the first alarm device (100) and the second alarm device (100) transmitting a response signal on the first channel when the beacon signal is received on the first channel, and determining the use of the first channel in the alarm system (1000) when response signals from the first alarm device (100) and the second alarm device (100) are received on the first channel; the first alarm device (100) and the second alarm device (100) transmit a response signal on the second channel when the response signal is not received on the first channel, and the first alarm device (100) and the second alarm device (100) transmit a response signal on the second channel when they receive the beacon signal on the second channel, and if a response signal from the first alarm device (100) and the second alarm device (100) is received on the second channel, a step of deciding to use the second channel in the alarm system (1000).

[0056] Example 2 Next, a second embodiment will be described. Like the first embodiment, the second embodiment relates to an alarm system including a relay device and a plurality of fire alarm devices. The first and second embodiments relate to the relay device switching channels when there is a fire alarm device that cannot communicate with the relay device. The fire alarm device in the first embodiment automatically switches channels for each frame when it receives a channel change request from the relay device. On the other hand, the fire alarm device in the second embodiment switches channels every time it receives a channel change request from the relay device. The alarm system 1000, fire alarm 100, and relay device 200 according to the second embodiment are of the same type as those shown in FIGS. 1 and 2. Here, the differences from the first embodiment will be mainly described.

[0057] Fig. 8 shows an overview of the channel determination process in the fire alarm device 100 and the relay device 200. This is shown in the same way as Fig. 5. The first relay device 200a transmits a beacon signal to each fire alarm device 100 in the downstream communication time slot "1" of "ch1".

[0058] The first fire alarm device 100a and the third fire alarm device 100c receive the beacon signal in the downstream communication time slot "1" of "ch1." In response, the first fire alarm device 100a transmits an ACK signal to the first relay 200a in the upstream communication time slot "2" of "ch1." The first relay 200a receives the ACK signal from the first fire alarm 100a in the upstream communication time slot "2" of "ch1." The third fire alarm device 100c transmits an ACK signal to the first relay 200a in the upstream communication time slot "m" of "ch1." The first relay 200a receives the ACK signal from the third fire alarm 100c in the upstream communication time slot "m" of "ch1." However, since the second fire alarm device 100b cannot receive the beacon signal in the downstream communication time slot "1" of "ch1," it does not transmit an ACK signal in the upstream communication time slot "3" of "ch1." The first relay 200a does not receive an ACK signal from the second fire alarm device 100b in the upstream communication time slot "3" of "ch1".

[0059] If the control unit 224 of the first relay 200a does not receive an ACK signal on "ch1" from at least one of the registered fire alarm devices 100, it recognizes that it is unable to communicate with at least one fire alarm device 100 on "ch1." The control unit 224 decides to switch "ch1" to another channel, for example, "ch2." Before switching to "ch2," the first relay 200a transmits a channel change request to each fire alarm 100 in the downstream communication time slot "1" of the next frame on "ch1." The channel change request is a signal requesting a channel change and includes information about the destination channel. Here, "ch2," the destination channel, is indicated.

[0060] The first fire alarm device 100a transmits an ACK signal to the first relay 200a in the upstream communication timeslot "2" of "ch1". The first relay 200a receives the ACK signal from the first fire alarm device 100a in the upstream communication timeslot "2" of "ch1". The third fire alarm device 100c transmits an ACK signal to the first relay 200a in the upstream communication timeslot "m" of "ch1". The first relay 200a receives the ACK signal from the third fire alarm device 100c in the upstream communication timeslot "m" of "ch1".

[0061] The control unit 224 of the first relay 200a switches the channel from "ch 1" to "ch 2" in the next frame. The first relay 200a transmits a beacon signal to each fire alarm device 100 in the downstream communication time slot "1" of "ch 2".

[0062] The first fire alarm device 100a and the third fire alarm device 100c receive the beacon signal in the downstream communication time slot "1" of "ch2." In response to this, the first fire alarm device 100a transmits an ACK signal to the first relay 200a in the upstream communication time slot "2" of "ch2." The first relay 200a receives the ACK signal from the first fire alarm device 100a in the upstream communication time slot "2" of "ch2." The third fire alarm device 100c transmits an ACK signal to the first relay 200a in the upstream communication time slot "m" of "ch2." The first relay 200a receives the ACK signal from the third fire alarm device 100c in the upstream communication time slot "m" of "ch2."

[0063] Because the second fire alarm device 100b has not received a channel change request, the control unit 124 of the second fire alarm device 100b does not recognize that a beacon signal is being transmitted on a channel other than "1ch." Therefore, when the control unit 124 cannot receive a beacon signal in the downstream communication time slot "1" of "1ch," it causes the communication unit 120 to perform high-speed intermittent reception. Because the second fire alarm device 100b cannot receive a beacon signal in the downstream communication time slot "1" of "2ch," it does not transmit an ACK signal in the upstream communication time slot "3" of "2ch." The first relay 200a does not receive an ACK signal from the second fire alarm device 100b in the upstream communication time slot "3" of "2ch."

[0064] If the control unit 224 of the first relay 200a does not receive an ACK signal on "ch2" from at least one of the registered fire alarm devices 100, it recognizes that it is unable to communicate with at least one fire alarm device 100 on "ch2." The control unit 224 decides to switch "ch2" to another channel, for example, "ch3." Before switching to "ch3," the first relay 200a transmits a channel change request to each fire alarm 100 in the downstream communication time slot "1" of the next frame on "ch2." The channel change request indicates the destination channel, "ch3."

[0065] The first fire alarm device 100a transmits an ACK signal to the first relay 200a in the upstream communication time slot "2" of "ch2." The first relay 200a receives the ACK signal from the first fire alarm device 100a in the upstream communication time slot "2" of "ch2." The third fire alarm device 100c transmits an ACK signal to the first relay 200a in the upstream communication time slot "m" of "ch2." The first relay 200a receives the ACK signal from the third fire alarm device 100c in the upstream communication time slot "m" of "ch2."

[0066] The control unit 224 of the first relay 200a switches the channel from "ch 2" to "ch 3" in the next frame. The first relay 200a transmits a beacon signal to each fire alarm device 100 in the downstream communication time slot "1" of "ch 3".

[0067] The first fire alarm device 100a to the third fire alarm device 100c receive the beacon signal in the downstream communication time slot "1" of "ch3". In response to this, the first fire alarm device 100a transmits an ACK signal to the first relay 200a in the upstream communication time slot "2" of "ch3". The first relay 200a receives the ACK signal from the first fire alarm device 100a in the upstream communication time slot "2" of "ch3". The second fire alarm device 100b transmits an ACK signal to the first relay 200a in the upstream communication time slot "3" of "ch3". The first relay 200a receives the ACK signal from the second fire alarm device 100b in the upstream communication time slot "3" of "ch3". The third fire alarm device 100c transmits an ACK signal to the first relay 200a in the upstream communication time slot "m" of "ch3". The first relay device 200a receives the ACK signal from the third fire alarm device 100c in the upstream communication time slot "m" of "3ch."

[0068] When the control unit 224 of the first relay 200a receives ACK signals on "3ch" from all registered fire alarm devices 100, it recognizes that it is possible to communicate with all fire alarm devices 100 on "3ch." The control unit 224 then decides to use "3ch." The first relay 200a and the first to third fire alarm devices 100a to 100c then use "3ch" to perform the process shown in FIG. 3.

[0069] When the control unit 224 of the first relay 200a receives ACK signals on "2ch" from all registered fire alarm devices 100, it recognizes that it is possible to communicate with all fire alarm devices 100 on "2ch." The control unit 224 decides to use "2ch." The processing that follows is as described above, so a description thereof will be omitted here.

[0070] The operation of the alarm system 1000 configured as described above will now be described. FIG. 9 is a flowchart showing the channel determination procedure performed by the relay device 200. The communication unit 220 transmits a beacon signal (S50). If ACK signals have not been received from all of the fire alarm devices 100 (N in S52), the communication unit 220 transmits a channel change request (S54). The control unit 224 switches the channel (S56), and the communication unit 220 transmits a beacon signal (S58). If ACK signals have not been received from all of the fire alarm devices 100 (N in S60), or if there is a switchable channel (Y in S62), the process returns to step 54. If ACK signals have been received from all of the fire alarm devices 100 (Y in S60), or if there is no switchable channel (N in S62), the control unit 224 determines the channel to use (S64). If ACK signals have been received from all of the fire alarm devices 100 (Y in S52), the process ends.

[0071] According to this embodiment, the channel change is performed after the channel change request is sent, so the channel change can be executed reliably. Furthermore, the channel change request includes information about the new channel, so the new channel can be notified reliably.

[0072] An outline of one aspect of the present disclosure is as follows: A relay device (200) transmits a channel change request to request a channel change on a first channel, then changes the first channel to a second channel, and the relay device (200) transmits a channel change request on the second channel, then changes the second channel to a third channel.

[0073] The channel change request includes information about the channel to change to.

[0074] The present disclosure has been described above based on examples. These examples are merely illustrative, and it will be understood by those skilled in the art that various modifications are possible in the combination of each component or each treatment process, and that such modifications are also within the scope of the present disclosure.

[0075] In the first and second embodiments, the relay device 200 is connected to a fire alarm 100 that has both a fire detection function and an alarm sound generation function. However, this is not a limitation, and for example, the fire alarm 100 may have only a fire detection function. Furthermore, instead of the fire alarm 100, a sensor that detects not only fires but also floods, earthquakes, gas leaks, and CO (carbon monoxide) generation due to incomplete combustion may be used. This modification improves the degree of freedom in the configuration. [Explanation of symbols]

[0076] 100 Fire alarm, 120 Communication unit, 122 Processing unit, 124 Control unit, 150 Fire detection sensor, 152 Buzzer, 200 Relay device, 220 Communication unit, 222 Processing unit, 224 Control unit, 300 Management device, 1000 Alarm system.

Claims

1. A relay device; a first alarm device and a second alarm device capable of communicating with the relay device, the relay device transmits a beacon signal to the first alarm device and the second alarm device over a first channel; When the first alarm device and the second alarm device receive the beacon signal over the first channel, they transmit a response signal over the first channel to the relay device; when the relay device receives the response signals from the first alarm device and the second alarm device over the first channel, it determines to use the first channel in the alarm system; if the relay device does not receive the response signal on the first channel from at least one of the first alarm device and the second alarm device, it transmits the beacon signal to the first alarm device and the second alarm device on a second channel different from the first channel; When the first alarm device and the second alarm device receive the beacon signal over the second channel, they transmit the response signal to the relay device over the second channel; when the relay device receives the response signals from the first alarm device and the second alarm device on the second channel, it determines to use the second channel in the alarm system. Alarm system.

2. if the reply signal from at least one of the first alarm device and the second alarm device is not received on the second channel, the relay device transmits the beacon signal to the first alarm device and the second alarm device on a third channel different from the first channel and the second channel; When the first alarm device and the second alarm device receive the beacon signal over the third channel, they transmit the response signal to the relay device over the third channel; when the relay device receives the response signals from the first alarm device and the second alarm device on the third channel, it determines to use the third channel in the alarm system. The alarm system of claim 1 .

3. the relay device transmits a channel change request for requesting a channel change on the first channel, and then changes the first channel to the second channel; the relay device changes the second channel to the third channel without transmitting the channel change request on the second channel; 3. The alarm system of claim 2.

4. the relay device transmits a channel change request for requesting a channel change on the first channel, and then changes the first channel to the second channel; the relay device transmits the channel change request on the second channel, and then changes the second channel to the third channel; 3. The alarm system of claim 2.

5. The channel change request includes information about the channel to be changed to.

5. An alarm system according to claim 3 or 4.

6. When the relay device determines to use the second channel, the relay device transmits a channel determination request to notify the determined channel; When the relay device determines to use the third channel, the relay device transmits the channel determination request. An alarm system according to any one of claims 3 to 5.

7. a communication unit capable of communicating with the first alarm device and the second alarm device; a control unit that controls the communication unit, the communication section transmits a beacon signal to the first alarm device and the second alarm device over a first channel; When the first alarm device and the second alarm device receive the beacon signal on the first channel, they transmit a response signal on the first channel, and when the communication unit receives the response signals from the first alarm device and the second alarm device on the first channel, the control unit decides to use the first channel in the alarm system, When the response signal from at least one of the first alarm device and the second alarm device is not received on the first channel, the communication unit transmits the beacon signal to the first alarm device and the second alarm device on a second channel different from the first channel, When the first alarm device and the second alarm device receive the beacon signal on the second channel, they transmit the response signal on the second channel, and when the communication unit receives the response signals from the first alarm device and the second alarm device on the second channel, the control unit decides to use the second channel in the alarm system. Relay device.

8. transmitting a beacon signal on a first channel to a first alarm device and a second alarm device; a step of determining that the first alarm device and the second alarm device transmit response signals on the first channel when they receive the beacon signal on the first channel, and that when the response signals from the first alarm device and the second alarm device are received on the first channel, the use of the first channel in the alarm system; transmitting the beacon signal to the first alarm device and the second alarm device on a second channel different from the first channel when the response signal from at least one of the first alarm device and the second alarm device is not received on the first channel; the first alarm device and the second alarm device transmit the response signal on the second channel when they receive the beacon signal on the second channel, and when the response signals from the first alarm device and the second alarm device are received on the second channel, determining the use of the second channel in the alarm system; A channel determination method comprising:

9. transmitting a beacon signal on a first channel to a first alarm device and a second alarm device; a step of determining that the first alarm device and the second alarm device transmit response signals on the first channel when they receive the beacon signal on the first channel, and that when the response signals from the first alarm device and the second alarm device are received on the first channel, the use of the first channel in the alarm system; transmitting the beacon signal to the first alarm device and the second alarm device on a second channel different from the first channel when the response signal from at least one of the first alarm device and the second alarm device is not received on the first channel; the first alarm device and the second alarm device transmit the response signal on the second channel when they receive the beacon signal on the second channel, and when the response signals from the first alarm device and the second alarm device are received on the second channel, determining to use the second channel in the alarm system.

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