Alarm system, alarm, relay route setting method, and program

Abstract

To provide a technology for suppressing an increase in power consumption in alarms included in a multi-hop network.SOLUTION: An n+3-th fire alarm 600n+3 derives a first cost for a first relay route for communicating with a relay device 700 via an n+1-th fire alarm 600n+1, and derives a second cost for a second relay route for communicating with the relay device 700 via an n+2-th fire alarm 600n+2. The n+3-th fire alarm 600n+3 preferentially selects the first relay route when the first cost is smaller than the second cost. When power consumption in the n+1-th fire alarm 600n+1 becomes greater than a threshold, the n+1-th fire alarm 600n+1 sends a notification to the n+3-th fire alarm 600n+3. When receiving the notification from the n+1-th fire alarm 600n+1, the n+3-th fire alarm 600n+3 makes it difficult to select the first relay route.SELECTED DRAWING: Figure 8

Description

[Technical Field]

[0001] The present disclosure relates to alarm technology, and more particularly to an alarm system, an alarm device, a relay route setting method, and a program that use a multi-hop network. [Background technology]

[0002] A fire alarm issues an alarm when it detects a fire. By equipping such fire alarms with wireless communication capabilities and forming a multi-hop network with multiple fire alarms, it becomes possible for one fire alarm to issue an alarm when another fire alarm detects a fire (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-35468 Summary of the Invention [Problem to be solved by the invention]

[0004] When a fire alarm is battery-powered, it is required to have low power consumption. However, since a fire alarm included in a relay route of a multi-hop network forwards signals, the power consumption of the fire alarm increases as the forwarding frequency increases.

[0005] The present disclosure has been made in light of these circumstances, and its purpose is to provide technology that suppresses increases in power consumption in alarm devices included in a multi-hop network. [Means for solving the problem]

[0006] In order to solve the above problems, an alarm system according to one aspect of the present disclosure comprises multiple alarm devices that form a multi-hop network extending from a relay device. The multiple alarm devices include a first alarm device, a second alarm device, and a third alarm device, the third alarm device is capable of communicating with the first alarm device and the second alarm device, the third alarm device exchanges link quality information with the first alarm device to derive a first cost for a first relay route for communicating with the relay device via the first alarm device, and derives a second cost for a second relay route for communicating with the relay device via the second alarm device by exchanging link quality information with the second alarm device, the third alarm device selects the first relay route with priority if the first cost is smaller than the second cost, and when the power consumption in the first alarm device becomes greater than a threshold value the first alarm device sends a notification to the third alarm device indicating the increase in power consumption, the third alarm device derives a first cost based on a first index corresponding to link quality information between the third alarm device and the first alarm device, and a second index corresponding to the power consumption of the first alarm device; When the third alarm receives a notification from the first alarm, By increasing the influence of the second indicator on the first cost, Makes it more difficult to select the first relay route.

[0007] Another aspect of the present disclosure is an alarm device. This alarm device is one of a number of alarm devices that make up a multi-hop network spreading out from a relay device, and is equipped with a communication unit that is capable of communicating with a first alarm device and a second alarm device among the multiple alarm devices, and a control unit that derives a first cost for a first relay route for communicating with the relay device via the first alarm device by exchanging link quality information with the first alarm device via the communication unit, and derives a second cost for a second relay route for communicating with the relay device via the second alarm device by exchanging link quality information with the second alarm device via the communication unit, and then preferentially selects the first relay route if the first cost is smaller than the second cost. When power consumption in the first alarm device becomes greater than a threshold value, the communication unit receives a notification from the first alarm device indicating an increase in power consumption, the control unit derives the first cost based on a first index corresponding to link quality information with the first alarm device and a second index corresponding to the power consumption of the first alarm device, When the control unit receives a notification from the first alarm device, By increasing the influence of the second indicator on the first cost, Makes it more difficult to select the first relay route.

[0008] Yet another aspect of the present disclosure is a relay route setting method for an alarm device among multiple alarm devices that make up a multi-hop network spreading from a relay device, the alarm device being capable of communicating with a first alarm device and a second alarm device among the multiple alarm devices, the method comprising the steps of: deriving a first cost for a first relay route for communicating with the relay device via the first alarm device by exchanging link quality information with the first alarm device, and deriving a second cost for a second relay route for communicating with the relay device via the second alarm device by exchanging link quality information with the second alarm device; preferentially selecting the first relay route if the first cost is smaller than the second cost; and receiving a notification from the first alarm device indicating an increase in power consumption when power consumption in the first alarm device becomes greater than a threshold value. a step of deriving a first cost based on a first index corresponding to link quality information with the first alarm device and a second index corresponding to the power consumption of the first alarm device; When a notification is received from the first alarm, By increasing the influence of the second indicator on the first cost, and making it difficult to select the first relay route.

[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, it is possible to suppress increases in power consumption in alarm devices included in a multi-hop network. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a diagram showing a configuration of an alarm system according to an embodiment of the present invention; [Figure 2] FIG. 2 is a diagram showing the configuration of the fire alarm device of FIG. [Figure 3] 3(a)-(d) are diagrams showing the structure of a superframe used in the alarm system of FIG. [Figure 4] FIG. 2 is a diagram illustrating a configuration of a relay device in FIG. [Figure 5]FIG. 2 is a diagram showing an example of time slot allocation in the alarm system of FIG. [Figure 6] FIG. 2 is a diagram showing an outline of downstream communication in the alarm system of FIG. [Figure 7] FIG. 2 is a diagram showing an outline of upstream communication in the alarm system of FIG. [Figure 8] FIG. 2 is a diagram showing an overview of routing in the alarm system of FIG. 1; [Figure 9] FIG. 2 is a sequence diagram showing a routing procedure in the alarm system of FIG. [Figure 10] 10(a) and 10(b) are diagrams showing the data structure of a table held in the 1n+1th fire alarm device of FIG. [Figure 11] 11(a) and 11(b) are diagrams showing the data structure of a table held in the 1n+3 fire alarm device of FIG. [Figure 12] 12(a)-(b) are diagrams showing an outline of the installation of the alarm system of FIG. [Figure 13] FIG. 12(b) is a diagram showing the configuration of the external device in FIG. [Figure 14] FIG. 14 is a diagram showing a screen displayed on the display unit of FIG. 13. [Figure 15] 15(a)-(b) are diagrams showing the configuration of a part of the alarm system of FIG. [Figure 16] FIG. 15(b) is a diagram showing an outline of downstream communication in the alarm system of FIG. [Figure 17] 17(a)-(b) are diagrams showing an outline of downstream communication in the alarm system of FIG. 15(b). DETAILED DESCRIPTION OF THE INVENTION

[0012] Before describing the present disclosure in detail, an overview will be provided. This embodiment 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 via a wireless multi-hop network. In such a network, the management device corresponds to the upper side, and the fire alarms that are the furthest hops from the relay device correspond to the lower side. When a fire alarm detects a fire, it forwards the detection result to the relay device, and the relay device forwards the detection result to the management device. When the management device receives the detection result, it selects one or more fire alarms to sound and sends a sounding instruction to the selected one or more fire alarms as the final destination. The relay device and the fire alarm forward the sounding instruction to the fire alarm at the final destination, and the fire alarm at the final destination sounds the alarm upon receiving the sounding instruction.

[0013] Here, the line for a signal from the relay device to the fire alarm device with the greatest number of hops from the relay device is called the "downlink," while the line for a signal from the fire alarm device with the greatest number of hops to the relay device is called the "uplink." In this embodiment, one frame is formed by arranging multiple time slots, and one superframe is formed by arranging multiple frames. Furthermore, one fire alarm device is assigned to one time slot for the downlink (hereinafter referred to as the "downlink communication time slot") and one time slot for the uplink (hereinafter referred to as the "uplink communication time slot"). The downlink communication time slot is used for transfer on the downlink, and the uplink communication time slot is used for transfer on the uplink.

[0014] In addition to ringing instructions, signals for establishing synchronization in the multi-hop network (hereinafter referred to as "synchronization signals") are periodically transferred on the downlink. On the other hand, detection results are mainly transferred on the uplink. In the following description, the synchronization signals, detection results, and ringing instructions may be collectively referred to as "communication signals."

[0015] The present embodiment will be explained below in the order of (1) basic configuration, (2) routing, (3) installation, and (4) time slot allocation modification. (1) Basic configuration 1 shows the configuration of an alarm system 1000. The alarm system 1000 includes a first fire alarm 600a through a ninth fire alarm 600i collectively referred to as fire alarms 600, a first relay device 700a through a third relay device 700c collectively referred to as relay devices 700, and a management device 800. The number of fire alarms 600 is not limited to "9", and the number of relay devices 700 is not limited to "3".

[0016] 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 600 are, for example, residential fire alarms and are equipped with fire detection sensors. The multiple fire alarms 600 are installed, for example, on the ceiling of the facility, but may also be installed on the wall, etc.

[0017] Here, the first fire alarm device 600a to the sixth fire alarm device 600f form a wireless multi-hop network extending from the first relay device 700a. For example, a relay route is formed connecting the first relay device 700a, the first fire alarm device 600a, and the second fire alarm device 600b, and a relay route is formed connecting the first relay device 700a, the fourth fire alarm device 600d, the fifth fire alarm device 600e, and the third fire alarm device 600c. A relay route is also formed connecting the first relay device 700a, the fourth fire alarm device 600d, the fifth fire alarm device 600e, and the sixth fire alarm 600f, and a relay route is also formed connecting the first relay device 700a and the seventh fire alarm device 600g. These relay routes are determined by each fire alarm device 600 and are shared by the first relay device 700a and the management device 800.

[0018] In these relay routes, the first fire alarm 600a, the fourth fire alarm 600d, and the seventh fire alarm 600g can communicate with the first relay 700a via one hop. The second fire alarm 600b and the fifth fire alarm 600e can communicate with the first relay 700a via two hops. The third fire alarm 600c and the sixth fire alarm 600f can communicate with the first relay 700a via three hops.

[0019] The second relay 700b, the third relay 700c, the eighth fire alarm 600h, and the ninth fire alarm 600i are configured similarly to the first relay 700a and the first fire alarm 600a. For example, a multi-hop network originating from the first relay 700a is installed on the first floor of a facility, a multi-hop network originating from the second relay 700b is installed on the second floor of the facility, and a multi-hop network originating from the third relay 700c is installed on the third floor of the facility. Different frequencies are used for the multi-hop network originating from the first relay 700a, the multi-hop network originating from the second relay 700b, and the multi-hop network originating from the third relay 700c. Furthermore, the first relay 700a, the second relay 700b, and the third relay 700c communicate with each other wirelessly or via wires.

[0020] In this way, the relay device 700 performs wireless communication with the multiple fire alarm devices 600 that make up the multi-hop network, and also performs wireless or wired communication with other relay devices 700. It can also be said that the relay device 700 relays communication between the multiple fire alarm devices 600 included in the multi-hop network. Furthermore, the first relay device 700a is connected to the management device 800 by a cable, and performs wired communication with the management device 800.

[0021] The management device 800 is, for example, a controller for a Home Energy Management System (HEMS) installed in a facility. The management device 800 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, all of which have communication functions. The management device 800 is also capable of communicating with a first relay 700a installed in the facility. Furthermore, the management device 800 is also capable of communicating with a second relay 700b, a third relay 700c, and each of the fire alarms 600 via the first relay 700a.

[0022] FIG. 2 shows the configuration of a fire alarm 600. The fire alarm 600 includes a communication unit 620, a processing unit 622, a control unit 624, a fire detection sensor 630, and a buzzer 632. The fire detection sensor 630 may use known technology. For example, the fire detection sensor 630 may be an optical smoke detection sensor that may detect a fire by detecting smoke during a fire using diffuse reflection of light. For example, the fire detection sensor 630 may be a heat detection sensor that may detect a fire by detecting heat during a fire. For example, the fire detection sensor 630 may be a carbon monoxide detection sensor that may detect a fire by detecting the concentration of carbon monoxide generated by combustion during a fire. For example, the fire detection sensor 630 may be an infrared detection sensor that may detect a fire by detecting infrared rays emitted by combustion during a fire.

[0023] The communication unit 620 performs wireless communication with other fire alarm devices 600 or relay devices 700. The processing unit 622 processes signals received by the communication unit 620 and generates signals to be transmitted from the communication unit 620. The control unit 624 controls the operation of the communication unit 620 and the processing unit 622. Details of the processing by the control unit 624 will be described later. The buzzer 632 is capable of sounding a buzzer sound. The fire alarm 600 may not include the buzzer 632 but may include the fire detection sensor 630, that is, may have both a detection function and a communication function. Such a fire alarm 600 can also be said to be a sensor that is capable of issuing an alarm when a fire is detected.

[0024] Figures 3(a)-(d) show the structure of a superframe used in the alarm system 1000. As shown in Figure 3(a), a certain period is defined as a superframe 1010. The superframe 1010 is arranged repeatedly. The superframe 1010 is divided into a plurality of frames 1020. As shown in Figure 3(b), one frame 1020 is divided into a plurality of time slots 1030. Figure 3(c) shows one time slot 1030. A communication signal is transmitted within the time slot 1030. The duration of the communication signal is shorter than the duration of one time slot 1030.

[0025] Figure 3(d) shows how the multiple time slots 1030 included in the frame 1020 shown in Figure 3(b) are used. Of the multiple time slots 1030, one or more time slots 1030 at the beginning are used as "downstream communication time slots." One time slot 1030 following the downstream communication time slot is used as an "upstream communication time slot." One or more time slots 1030 following the upstream communication time slot are used as "spare" slots. The number of downstream communication time slots and the number of upstream communication time slots are the same and are equal to or greater than the number of fire alarm devices 600 included in the multi-hop network. Spare slots are not required.

[0026] 4 shows the configuration of a relay device 700. The relay device 700 can also be said to be a control device for a plurality of fire alarm devices 600 that make up a multi-hop network. The relay device 700 includes a communication unit 710 and a control unit 720, the communication unit 710 including an output unit 712, and the control unit 720 including an allocation unit 722. The communication unit 710 has a communication function for communicating with the plurality of relay devices 700, and also has a communication function for communicating with a management device 800. The control unit 720 controls the operation of the relay device 700.

[0027] The communication unit 710 communicates with the multiple fire alarm devices 600 that make up the multi-hop network, and receives the results of routing performed by each fire alarm device 600. The routing performed by each fire alarm device 600 will be described later, but the routing results show each relay route as shown in Figure 1.

[0028] Based on the routing result, the allocation unit 722 allocates a combination of one downstream communication time slot and one upstream communication time slot shown in Fig. 3(d) to one fire alarm device 600. The allocation by the allocation unit 722 will also be described later, but the combination of downstream communication time slots and upstream communication time slots is changed for each fire alarm 600. The output unit 712 outputs the allocation result by the allocation unit 722 to multiple fire alarm devices 600. The allocation result indicates the correspondence between the combination of downstream communication time slots and upstream communication time slots and the fire alarm devices 600.

[0029] Fig. 5 shows an example of time slot allocation in the alarm system 1000, and is shown in the same manner as Fig. 3(d). This shows the allocation of multiple time slots 1030 to the first relay 700a and the first fire alarm 600a to the seventh fire alarm 600g in Fig. 1. "M" in Fig. 5 indicates the first relay 700a, and "S1" to "S7" indicate the first fire alarm 600a to the seventh fire alarm 600g, respectively. The downstream communication time slots are allocated to the first relay 700a, the first fire alarm 600a, the fourth fire alarm 600d, the seventh fire alarm 600g, the second fire alarm 600b, the fifth fire alarm 600e, the third fire alarm 600c, and the sixth fire alarm 600f, in order from the front. As described above, the number of hops from the first fire alarm 600a, the fourth fire alarm 600d, and the seventh fire alarm 600g to the first relay 700a is "1." The number of hops from the second fire alarm 600b and the fifth fire alarm 600e to the first relay 700a is "2," and the number of hops from the third fire alarm 600c and the sixth fire alarm 600f to the first relay 700a is "3." In other words, the fire alarm 600 with the fewer hops to the first relay 700a is assigned closer to the front of the downstream communication time slot.

[0030] The upstream communication time slots are allocated to the sixth fire alarm device 600f, the third fire alarm device 600c, the fifth fire alarm device 600e, the second fire alarm device 600b, the seventh fire alarm device 600g, the fourth fire alarm device 600d, the first fire alarm device 600a, and the first relay 700a in order from the front. In other words, the fire alarm 600 with the greater number of hops to the first relay 700a is allocated closer to the front of the upstream communication time slots.

[0031] When focusing on the fifth fire alarm 600e with the number of hops "2," the fifth fire alarm 600e is assigned a downstream communication time slot that is earlier than the sixth fire alarm 600f with the number of hops "3." The downstream communication time slot is used when a signal (communication signal) is transferred in a direction away from the first relay 700a in the multi-hop network. Also, the fifth fire alarm 600e is assigned an upstream communication time slot that is later than the sixth fire alarm 600f. The upstream communication time slot is used when a signal (communication signal) is transferred in a direction approaching the first relay 700a in the multi-hop network. In other words, the relay 700 determines which of the multiple time slots 1030 to assign to each fire alarm 600, depending on the number of hops between each fire alarm 600 and the relay 700.

[0032] The fifth fire alarm device 600e is assigned a downstream communication time slot "S5" and an upstream communication time slot "S5", and the fifth fire alarm device 600e transmits a signal (communication signal) in the downstream communication time slot "S5" or the upstream communication time slot "S5". The sixth fire alarm device 600f is assigned a downstream communication time slot "S6" and an upstream communication time slot "S6", and the sixth fire alarm device 600f transmits a signal (communication signal) in the downstream communication time slot "S6" or the upstream communication time slot "S6".

[0033] The allocation of these time slots 1030 is determined by the allocation unit 722 of the first relay 700a, but may also be determined by the management device 800. For example, the first relay 700a or the management device 800 determines the allocation of the time slots 1030 based on information about the relay route. The first relay 700a or the management device 800 notifies each fire alarm device 600 of the determined allocation of the time slots 1030. Therefore, each fire alarm device 600 also knows the allocation of these time slots 1030. As a result, the fire alarm device 600 knows the time slot 1030 in which it should transmit a communication signal and which has been allocated to itself. The fire alarm device 600 also knows the time slot 1030 in which it can receive a communication signal from an adjacent fire alarm device 600 or relay device 700 on the relay route.

[0034] In such a situation, the communication unit 620 of the fire alarm 600 may perform an intermittent reception operation to reduce power consumption. In the intermittent reception operation in the communication unit 620, the reception operation is performed during a portion of the beginning of the time slot 1030, and if a signal (communication signal) is not received during that portion of the period, the reception operation is stopped for the remainder of the time slot 1030. On the other hand, if a signal is received during that portion of the beginning of the time slot 1030, the reception operation continues for the remainder of the time slot 1030.

[0035] FIG. 6 shows an overview of downstream communication in the alarm system 1000. This shows the downstream communication time slots in FIG. 5. The first relay 700a periodically transmits a synchronization signal to the multiple fire alarm devices 600 that make up the multi-hop network. The synchronization signal is, for example, a beacon signal. The synchronization signal is transmitted, for example, in the first frame 1020 of the superframe 1010 shown in FIG. 3(a), and is not transmitted in the remaining frames 1020. The first relay 700a transmits the synchronization signal in time slot 1030 “M” of the first frame 1020 of the superframe 1010. When the fourth fire alarm device 600d receives the synchronization signal in time slot 1030 “M”, it forwards the synchronization signal in time slot 1030 “S4”. The fourth fire alarm device 600d also transmits a response signal to the first relay 700a in time slot 1030 “S4”. The response signal is, for example, an Ack (ACKnowledgement). The response signal may be included as part of the synchronization signal.

[0036] The first relay 700a receives the response signal in the time slot 1030 "S4". When the fifth fire alarm device 600e receives the synchronization signal in the time slot 1030 "S4", it transfers the synchronization signal in the time slot 1030 "S5" and also transmits a response signal to the fourth fire alarm device 600d. The fourth fire alarm device 600d receives the response signal in the time slot 1030 "S5". Although omitted in FIG. 11 , the fourth fire alarm device 600d transfers the response signal from the fifth fire alarm device 600e to the first relay 700a in the time slot 1030 "S4" of the next frame.

[0037] When the third fire alarm device 600c receives a synchronization signal in time slot 1030 "S5", it transfers the synchronization signal in time slot 1030 "S3" and transmits a response signal to the fifth fire alarm device 600e. When the sixth fire alarm device 600f receives a synchronization signal in time slot 1030 "S5", it transfers the synchronization signal in time slot 1030 "S6" and transmits a response signal to the fifth fire alarm 600e.

[0038] The fifth fire alarm device 600e receives the response signals in time slots 1030 "S3" and "S6". Although omitted in Fig. 6, the fifth fire alarm device 600e transfers the response signals from the third fire alarm device 600c and the sixth fire alarm device 600f to the fourth fire alarm device 600d in time slot 1030 "S5" of the next frame. The fourth fire alarm 600d further transfers the response signal from the fifth fire alarm device 600e to the first relay 700a in time slot 1030 "S4" of the next frame.

[0039] In this way, the synchronization signal is transferred in frame 1020 in which the first relay 700a transmitted the synchronization signal. Furthermore, each fire alarm 600 that receives the synchronization signal from the first relay 700a establishes timing synchronization with the first relay 700a based on the synchronization signal. Known techniques can be used for timing synchronization, so a description thereof will be omitted here.

[0040] FIG. 7 shows an overview of upstream communication in the alarm system 1000. This shows the upstream communication time slot in FIG. 5. Here, it is assumed that the fire detection sensor 630 of the sixth fire alarm device 600f detects the occurrence of a fire. The processing unit 622 of the sixth fire alarm device 600f causes the communication unit 620 to transmit the detection result. The detection result includes identification information of the sixth fire alarm device 600f that detected the fire. The communication unit 620 of the sixth fire alarm device 600f transmits the detection result in time slot 1030 "S6".

[0041] The fifth fire alarm device 600e receives the detection result in time slot 1030 "S6". Following this, the fifth fire alarm device 600e transfers the detection result in time slot 1030 "S5". The fifth fire alarm device 600e also transmits a response signal to the sixth fire alarm device 600f in time slot 1030 "S5". The response signal may be included as part of the detection result.

[0042] The sixth fire alarm device 600f receives the response signal in the time slot 1030 "S5". The fourth fire alarm device 600d receives the detection result in the time slot 1030 "S5". The fourth fire alarm device 600d transfers the detection result in the time slot 1030 "S4", and also transmits a response signal to the fifth fire alarm device 600e.

[0043] The fifth fire alarm device 600e receives the response signal in time slot "S4" 1030. Although omitted in Fig. 12, the fifth fire alarm device 600e transfers the response signal from the fourth fire alarm device 600d to the sixth fire alarm device 600f in time slot 1030 "S5" of the next frame 1020.

[0044] The first relay 700a receives the detection result in time slot 1030 "S4." As before, the first relay 700a transmits a response signal in time slot 1030 "M." The response signal is transferred by the fourth fire alarm device 600d and the fifth fire alarm device 600e, and is received by the sixth fire alarm device 600f.

[0045] When the first relay 700a receives the detection result from the fourth fire alarm 600d, it transmits the detection result to the management device 800. When the management device 800 receives the detection result, it identifies the fire alarm 600 to be activated based on the identification information included in the detection result. The correspondence between the identification information and the information of the fire alarm 600 to be activated is stored in advance in the management device 800. The management device 800 transmits an instruction to activate the fire alarm to the first relay 700a, with the identified fire alarm 600 as the final destination.

[0046] When the fire alarm devices 600 identified by the management device 800 are the third fire alarm device 600c and the sixth fire alarm device 600f, a similar transfer to that shown in FIG. 6 is performed, and the sounding instruction is received by the third fire alarm device 600c and the sixth fire alarm device 600f. Here, the sounding instruction is transmitted instead of the synchronization signal shown in FIG. 6. When the second relay device 700b and the third relay device 700c receive a sounding instruction from the management device 800 via the first relay device 700a, they transfer the sounding instruction to the fire alarms 600. When the communication units 620 of the third fire alarm device 600c and the sixth fire alarm device 600f receive the sounding instruction, the control unit 624 causes the buzzer 632 to sound. The control unit 624 may also cause the light-emitting device to flash.

[0047] (2) Routing Up to now, it has been assumed that a relay route as shown in Fig. 1 has been formed, but here, formation and modification of a relay route will be described using Fig. 8 as well. Fig. 8 shows an overview of routing in the alarm system 1000. Fig. 8 shows the (n+1)th fire alarm 600n+1, the (n+2)th fire alarm 600n+2, the (n+3)th fire alarm 600n+3, and the relay device 700 of the alarm system 1000. The (n+1)th fire alarm 600n+1, the (n+2)th fire alarm 600n+2, and the (n+3)th fire alarm 600n+3 correspond to any of the fire alarms 600 in Fig. 1. There may be a fire alarm 600 other than the (n+1)th fire alarm 600n+1 and the (n+2)th fire alarm 600n+2, for example, the (n+4)th fire alarm 600n+4 (not shown), around the (n+3)th fire alarm 600n+3.

[0048] The following describes (2-1) forming a relay route and (2-2) changing a relay route in that order. (2-1) Formation of relay routes 9 is a sequence diagram showing the routing procedure in the alarm system 1000. Here, the routing process will be explained focusing on the (n+3)th fire alarm device 600n+3. Each fire alarm device 600 broadcasts a HELLO message at regular time intervals. The HELLO message includes route quality information from the fire alarm device 600 to the relay device 700. The communication unit 620 of the (n+3)th fire alarm device 600n+3 receives HELLO messages from the (n+1)th fire alarm 600n+1, the (n+2)th fire alarm 600n+2, and the (n+4)th fire alarm 600n+4 (S10, S12, S14).

[0049] The communication unit 620 of the (n+3)th fire alarm device 600n+3 measures the received power of each received HELLO message, and the processing unit 622 derives the link quality for each fire alarm device 600 based on the measured received power. Link quality varies depending on the received power, and is a value that decreases as the received power increases. The route quality described above is also indicated in the same way as link quality. The control unit 624 derives the tentative route cost as follows by adding the link quality of the (n+1)th fire alarm device 600n+1 and the route quality included in the HELLO message from the (n+1)th fire alarm device 600n+1: Tentative route cost = route quality + Ka × link quality + Kb × C Equation (1) Here, Ka and Kb are coefficients, and C is a predetermined constant. If Kb is set to "0" when forming a relay route, Kb×C is ignored.

[0050] The control unit 624 also derives tentative route costs for the other fire alarm devices 600. The control unit 624 compares multiple tentative route costs and selects several fire alarm devices 600 in descending order of tentative route cost as priority link destinations. Here, for example, the (n+1)th fire alarm 600n+1 and the (n+2)th fire alarm 600n+2 are selected as priority link destinations.

[0051] The communication unit 620 of the (n+3)th fire alarm device 600n+3 transmits the address of the selected fire alarm device 600 and the link quality at the time of reception in a LINK_REQ sub-message of a HELLO message (S16, S18). The (n+1)th fire alarm device 600n+1 and the (n+2)th fire alarm device 600n+2 transmit the link quality in the opposite direction in a LINK_REP sub-message (S20, S22).

[0052] The communication unit 620 of the (n+3)th fire alarm device 600n+3 receives the LINK_REP sub-message. The control unit 624 of the (n+3)th fire alarm device 600n+3 compares the link quality included in the LINK_REP sub-message from the (n+1)th fire alarm device 600n+1 with the link quality derived based on the already measured received power, and selects the larger link quality. The control unit 624 also derives the formal route cost as follows by adding the selected link quality and the route quality for the (n+1)th fire alarm device 600n+1: Formal route cost = route quality + Ka × Max (link quality) + Kb × C Equation (2) Here, Max denotes selecting the maximum link quality.

[0053] The control unit 624 also derives an official route cost for the (n+2)th fire alarm device 600n+2. The control unit 624 compares the official route cost for the (n+1)th fire alarm 600n+1 with the official route cost for the (n+2)th fire alarm 600n+2, and selects the smaller one as the relay route. The relay route that is not selected may be used as an alternative route.

[0054] That is, the (n+3)th fire alarm device 600n+3 exchanges link quality information with the (n+1)th fire alarm device 600n+1, thereby deriving an official route cost (hereinafter referred to as the "first cost") for a relay route (hereinafter referred to as the "first relay route") for communicating with the relay device 700 via the (n+1)th fire alarm device 600n+1. The (n+3)th fire alarm device 600n+3 also exchanges link quality information with the (n+2)th fire alarm device 600n+2, thereby deriving an official route cost (hereinafter referred to as the "second cost") for a relay route (hereinafter referred to as the "second relay route") for communicating with the relay device 700 via the (n+2)th fire alarm 600n+2. Furthermore, the (n+3)th fire alarm 600n+3 compares the first cost with the second cost and selects the relay route which has the smaller cost preferentially. A relay route is formed by performing such processing in each fire alarm device 600. Information about the relay route (alternative route) formed in each fire alarm device 600 is transmitted to the management device 800 via the relay device 700. The management device 800 determines the allocation of time slots 1030 according to the number of hops based on the information about the relay route (alternative route).

[0055] (2-2) Change of relay route When a relay route is formed as described above, the fire alarm device 600 included in the relay route transfers a signal. The signal transfer increases the power consumption of the fire alarm device 600. If the fire alarm 600 is battery-powered, it is preferable that the power consumption be small. In order to suppress the increase in power consumption in the fire alarm device 600, a change of the relay route is executed.

[0056] The control unit 624 of the (n+1)th fire alarm 600n+1 included in the first relay route connecting the (n+3)th fire alarm 600n+3 and the relay device 700 in Figure 8 measures the communication frequency based on the number of communications by the communication unit 620 over a predetermined period. The number of communications includes at least one of the number of transmissions and the number of receptions. The control unit 624 maintains a correspondence relationship between the communication frequency and power consumption, and derives the power consumption based on the communication frequency. In this correspondence relationship, the higher the communication frequency, the greater the power consumption.

[0057] Furthermore, the control unit 624 of the (n+1)th fire alarm 600n+1 may count the number of other fire alarms 600 with which the (n+1)th fire alarm 600n+1 communicates directly. The control unit 624 maintains a correspondence relationship between the number of other fire alarms 600 and power consumption, and derives power consumption based on the number of other fire alarms 600. In this correspondence relationship, the greater the number of other fire alarms 600, the greater the power consumption. Furthermore, the control unit 624 of the (n+1)th fire alarm 600n+1 may measure the remaining battery power of the (n+1)th fire alarm 600n+1. The control unit 624 maintains a correspondence relationship between remaining battery power and power consumption, and derives power consumption based on the remaining battery power. In this correspondence relationship, the smaller the remaining battery power, the greater the power consumption.

[0058] The control unit 624 holds a threshold value for power consumption. Figures 10(a) and 10(b) show the data structure of a table held in the (n+1)th fire alarm 600n+1. Figure 10(a) shows conditions for power consumption and threshold value, and operations according to the conditions. If the power consumption exceeds the threshold value, the control unit 624 decides to send a notification indicating the increase in power consumption. On the other hand, if the power consumption is equal to or less than the threshold value, the control unit 624 decides not to send a notification. Figure 10(b) will be described later, and we will return to Figure 8. If it is decided to send a notification, the communication unit 620 of the (n+1)th fire alarm 600n+1 sends the notification to the (n+3)th fire alarm 600n+3.

[0059] As described above, the control unit 624 of the (n+3)th fire alarm device 600n+3 determines the relay route based on the formal route cost of equation (2). The control unit 624 controls the values ​​of the coefficients Ka and Kb of equation (2) depending on whether or not a notification has been received from the (n+1)th fire alarm device 600n+1. Figures 11(a)-(b) show the data structure of a table stored in the (n+3)th fire alarm device 600n+3. Figure 11(a) shows the values ​​of the coefficients Ka and Kb for when a notification has not been received and when a notification has been received. The coefficients Ka and Kb have a relationship such that when they are added together, they become "1."

[0060] When no notification is received, the coefficient Ka is "A1" and the coefficient Kb is "B1". When no notification is received, this includes the case of forming a relay route in (2-1). For example, "A1" is "1" and "B1" is "0". Therefore, when no notification is received, the three terms on the right side of Equation (2) are ignored.

[0061] When a notification is received, the coefficient Ka is "A2" and the coefficient Kb is "B2". Since "B2" is a value greater than "0", "A2" is a value less than "1". Here, A2 > B2, A2 = B2, or A2 < B2 may hold. Therefore, when a notification is received, the influence of the three terms on the right side of Equation (2) becomes greater, and the formal route cost becomes larger compared to when no notification is received. As a result, it becomes difficult to select the first relay route including the (n + 1)-th fire alarm 600n+1. That is, when the (n + 3)-th fire alarm 600n+3 receives a notification from the (n + 1)-th fire alarm 600n+1, it becomes difficult to select the first relay route including the (n + 1)-th fire alarm 600n+1.

[0062] The two terms on the right side of the formal route cost shown in Equation (2) are "Ka × Max(link quality)", and it can be said that this is an index according to the link quality information with the (n + 1)-th fire alarm 600n+1 (hereinafter referred to as the "first index"). The three terms on the right side of the formal route cost shown in Equation (2) are "Kb × C", and it can be said that this is an index according to the power consumption of the (n + 1)-th fire alarm 600n+1 (hereinafter referred to as the "second index"). When a notification is received, the control unit 624 makes it difficult to select the first relay route by increasing the influence of the second index in the formal route cost. Such processing is also performed with other fire alarms 600.

[0063] Up until now, the values ​​of the coefficients Ka and Kb have been adjusted in two stages. However, the values ​​of the coefficients Ka and Kb may be adjusted in three or more stages. FIG. 10(b) shows conditions for power consumption and thresholds and operations corresponding to the conditions. The control unit 624 of the (n+1)th fire alarm 600n+1 defines a first threshold and a second threshold greater than the first threshold as thresholds for power consumption. When the power consumption is greater than the first threshold and equal to or less than the second threshold, the control unit 624 determines to transmit a first notification indicating an increase in power consumption. When the power consumption exceeds the second threshold, the control unit 624 determines to transmit a second notification indicating a further increase in power consumption. On the other hand, when the power consumption is equal to or less than the first threshold, the control unit 624 determines not to transmit the first notification or the second notification. Return to FIG. 8. When it is determined to transmit the first notification, the communication unit 620 of the (n+1)th fire alarm 600n+1 transmits the first notification to the (n+3)th fire alarm 600n+3. If it is decided to transmit the second notification, the communication unit 620 transmits the second notification to the (n+3)th fire alarm device 600n+3.

[0064] The control unit 624 of the (n+3)th fire alarm 600n+3 controls the values ​​of the coefficients Ka and Kb in equation (2) depending on whether the first or second notification has been received from the (n+1)th fire alarm 600n+1. Figure 11(b) shows the values ​​of the coefficients Ka and Kb for when the first or second notification has not been received and when the first or second notification has been received. Here again, the coefficients Ka and Kb have a relationship such that when they are added together they become "1."

[0065] If the first notification and the second notification have not been received, the coefficient Ka is "A1" and the coefficient Kb is "B1." For example, "A1" is "1" and "B1" is "0." If the first notification has been received, the coefficient Ka is "A2" and the coefficient Kb is "B2." If the second notification has been received, the coefficient Ka is "A3" and the coefficient Kb is "B3." "B3" is a value greater than "B2," and "A3" is a value smaller than "A2." In other words, the control unit 624 increases the influence of the second index on the official route cost when the second notification has been received from the (n+1)th fire alarm device 600n+1 compared to when the first notification has been received.

[0066] (3) Construction Here, a technique for facilitating the construction of a multi-hop network for the alarm system 1000 will be described. In particular, a technique for providing information for determining where to install the fire alarm device 600 will be described. Figures 12(a)-(b) show an overview of the construction of the alarm system 1000. Figure 12(a) shows a first example. The alarm system 1000 includes an external device 900 in addition to the configuration of Figure 8. The external device 900 is, for example, a computer, and is capable of communicating with the management device 800.

[0067] Routing in the multi-hop network is not performed after all fire alarm devices 600 have been installed, but rather after several fire alarm devices 600 have been installed near the relay device 700. After routing for several fire alarm devices 600 has been completed, several more fire alarm devices 600 are installed and then the routing is updated. In this way, the routing is updated in accordance with the stepwise increase in the number of fire alarm devices 600.

[0068] Here, it is assumed that the n+1th fire alarm 600n+1 and the n+2nd fire alarm 600n+2 have been installed before the n+3rd fire alarm 600n+3 is installed. The n+1th fire alarm 600n+1 and the n+2nd fire alarm 600n+2 each derive an official route cost through the above-described process, and then select a relay route based on the official route cost. The communication unit 620 of each of the n+1th fire alarm 600n+1 and the n+2nd fire alarm 600n+2 transmits information regarding the relay route. The information regarding the relay route includes the official route cost. The information regarding the relay route may also include the official route cost for a relay route other than the selected relay route, for example, an alternative route.

[0069] The information regarding the relay route transmitted from the (n+1)th fire alarm device 600n+1 and the (n+2)th fire alarm device 600n+2 is transferred along the relay route and received by the relay device 700. The relay device 700 transmits the information regarding the relay route to the management device 800. The management device 800 receives the information regarding the relay route.

[0070] 13 shows the configuration of external device 900. External device 900 is, for example, a personal computer or a tablet terminal device. External device 900 includes a communication unit 902, a control unit 904, and a display unit 906. The communication unit 902 executes communication processing for communicating with management device 800. An installer operates external device 900 to access management device 800, and communication unit 902 receives information about the relay route from management device 800. The control unit 904 generates a screen based on the information about the relay route, and displays the generated screen on display unit 906.

[0071] 14 shows a screen displayed on the display unit 906. Information about the relay route, such as the identification information and cost of each fire alarm device 600, is displayed. The installer can check the status of the relay route by checking the information about the relay route displayed on the display unit 906.

[0072] The installer adds and installs an (n+3)th fire alarm 600n+3 as a new fire alarm 600 in the multi-hop network. The multiple fire alarms 600, including the (n+1)th fire alarm 600n+1, the (n+2)th fire alarm 600n+2, and the (n+3)th fire alarm 600n+3, update the official route costs with the addition of the new fire alarm 600, and update the relay route based on the updated official route costs. The communication unit 620 of each of the multiple fire alarms 600 transmits information related to the relay route. As before, the management device 800 receives the information related to the relay route, and the external device 900 displays the information related to the updated relay route.

[0073] Fig. 12(b) shows a second example. The alarm system 1000 includes an external device 910 and an information processing device 912 in addition to the configuration of Fig. 8. The external device 910 is a communication device capable of receiving signals transmitted from the fire alarm device 600 and the relay device 700. The information processing device 912 is, for example, a computer, and is connected to the external device 910. In the multi-hop network, the same processing as before is performed. The external device 910 receives information related to the relay route, and the information processing device 912 is, for example, a personal computer or a tablet terminal device. The information processing device 912 displays the information related to the updated relay route.

[0074] The derivation of the formal route cost may be started or ended in response to an instruction from the installer. For example, when the installer operates an operation unit (not shown) provided in the external device 900 or the information processing device 912, the external device 900 or the external device 910 may transmit an instruction to search for a relay route to each fire alarm device 600. In this case, when each of the multiple fire alarm devices 600 receives the instruction to search for a relay route from the external device 900 or the external device 910, it starts deriving the cost.

[0075] When multiple fire alarm devices 600 are searching for a relay route, when the installer operates an operation unit (not shown) provided on the external device 900 or the information processing device 912, the external device 900 or the external device 910 may transmit an instruction to end the relay route search to each fire alarm device 600. At that time, when each of the multiple fire alarm devices 600 receives the instruction to end the relay route search from the external device 900 or the external device 910, it ends the derivation of the cost.

[0076] An operation unit (not shown) that receives instructions from the installer may be provided in each fire alarm device 600. When each of the multiple fire alarm devices 600 receives an instruction to search for a relay route, it starts deriving the cost. Furthermore, when each of the multiple fire alarm devices 600 receives an instruction to end the search for a relay route, it ends deriving the cost.

[0077] (4) Correction of time slot allocation As described above, time slots 1030 should be allocated to each fire alarm device 600 according to the number of hops between the relay device 700 and the fire alarm device 600. However, when the alarm system 1000 is installed, allocation may not be made according to the number of hops. Allocating time slots 1030 in this manner may result in large transfer delays in communication signals. Here, we will explain the process of correcting allocation when allocation is not made according to the number of hops during operation of the alarm system 1000 after installation of the alarm system 1000.

[0078] Figures 15(a)-(b) show the configuration of part of the alarm system 1000. Figure 15(a) shows the first stage configuration of the alarm system 1000. A multi-hop network is formed by connecting the (m+1)th fire alarm 600m+1 to the relay device 700 and connecting the (m+2)th fire alarm 600m+2 to the (m+1)th fire alarm 600m+1. The number of hops between the relay device 700 and the (m+1)th fire alarm 600m+1 is "1", and the number of hops between the relay device 700 and the (m+2)th fire alarm 600m+2 is "2".

[0079] 16 shows an overview of downstream communications in the alarm system 1000. "M" indicates the time slot 1030 assigned to the relay device 700, "S1" indicates the time slot 1030 assigned to the (m+1)th fire alarm 600m+1, and "S2" indicates the time slot 1030 assigned to the (m+2)th fire alarm 600m+2. As before, the fire alarm 600 with the smaller number of hops is assigned the earlier time slot 1030.

[0080] The relay device 700 transmits a communication signal in time slot 1030 "M", and the (m+1)th fire alarm 600m+1 receives the communication signal in time slot 1030 "M". The (m+1)th fire alarm 600m+1 transmits a communication signal in time slot 1030 "S1", and the (m+2)th fire alarm 600m+2 receives the communication signal in time slot 1030 "S1". The (m+2)th fire alarm 600m+2 transmits a communication signal in time slot 1030 "S2". In the above explanation, the transmission and reception of response signals will not be described.

[0081] Figure 15(b) shows the second stage configuration of the alarm system 1000. This configuration adds an (m+3)th fire alarm 600m+3 to the configuration in Figure 15(b). A multi-hop network is formed by connecting the (m+3)th fire alarm 600m+3 to the relay device 700, connecting the (m+1)th fire alarm 600m+1 to the (m+3)th fire alarm 600m+3, and connecting the (m+2)th fire alarm 600m+2 to the (m+1)th fire alarm 600m+1.

[0082] Figures 17(a)-(b) show an overview of downstream communication in the alarm system 1000. In Figure 17(a), time slot 1030 "S3" is placed after time slot 1030 "S2." Furthermore, the newly added (m+3)th fire alarm 600m+3 is assigned to time slot 1030 "S3."

[0083] The relay device 700 transmits a communication signal in time slot 1030 "M", and the (m+3)-th fire alarm 600m+3 receives the communication signal in time slot 1030 "M". The (m+3)-th fire alarm 600m+3 transmits a communication signal in time slot 1030 "S3", and the (m+1)-th fire alarm 600m+1 receives the communication signal in time slot 1030 "S3". The (m+1)-th fire alarm 600m+1 transmits a communication signal in time slot 1030 "S1" in the next frame 1020, and the (m+2)-th fire alarm 600m+2 receives the communication signal in time slot 1030 "S1". The (m+2)-th fire alarm 600m+2 transmits a communication signal in time slot 1030 "S2".

[0084] In other words, the (m+3)th fire alarm device 600m+3, which has a hop count of "1" to the relay device 700, is assigned the time slot 1030 "S3" that comes after the time slot 1030 "S1" assigned to the (m+1)th fire alarm device 600m+1, which has a hop count of "2", causing a delay in transfer. In the above explanation, the transmission and reception of the response signal will not be described.

[0085] In order to suppress such a delay in transfer, after the (m+3)th fire alarm device 600m+3 is added, a change in allocation is made in the relay device 700 or the management device 800. For example, in downstream communication, if the time slot 1030 "S1" and the time slot 1030 "S2" are arranged before the time slot 1030 "S3," the allocation unit 722 of the relay device 700 changes the allocation so that the time slot 1030 "S1" and the time slot 1030 "S2" are arranged after the time slot 1030 "S3." Downstream communication is communication on a downlink, and signals are transferred in a direction away from the relay device 700 in a multi-hop network.

[0086] Furthermore, in upstream communication, if time slot 1030 "S1" and time slot 1030 "S2" are arranged after time slot 1030 "S3," allocation unit 722 changes the allocation so that time slot 1030 "S1" and time slot 1030 "S2" are arranged before time slot 1030 "S3." Upstream communication is communication on the uplink, and signals are transferred in a direction approaching relay device 700 in the multi-hop network.

[0087] Each fire alarm 600 is assigned an identification number to identify the fire alarm 600. The identification numbers are assigned, for example, in the order in which they were installed. Therefore, in FIG. 15(b), the (m+3)th fire alarm 600m+3 with identification number "3", the (m+1)th fire alarm 600m+1 with identification number "1", and the (m+2)th fire alarm 600m+2 with identification number "2" are arranged in that order. When managing multiple fire alarms 600, it is preferable to arrange the identification numbers in the order in which the fire alarms 600 are arranged along the relay route. The relay device 700 or management device 800 determines the identification number of each fire alarm 600 according to the number of hops. In Figure 15(b), the (m+3)th fire alarm 600m+3 is assigned the identification number "1", the (m+1)th fire alarm 600m+1 is assigned the identification number "2", and the (m+2)th fire alarm 600m+2 is assigned the identification number "3".

[0088] 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.

[0089] According to this embodiment, a relay route with a lower cost is selected preferentially. However, if the power consumption of a fire alarm device 600 included in the relay route increases, the relay route becomes less likely to be selected. This suppresses an increase in power consumption in the fire alarm device 600 included in the multi-hop network. Furthermore, the cost is derived based on a first index corresponding to link quality information and a second index corresponding to the power consumption of other fire alarm devices 600. When a notification is received from another fire alarm device 600, the influence of the second index on the cost is increased, making it less likely to be selected as a relay route including other fire alarm devices 600. Furthermore, since the cost is changed simply by increasing the influence of the second index, processing can be simplified. Furthermore, a first threshold and a second threshold are defined as thresholds for power consumption. The influence of the second index on the cost is changed depending on the magnitude of power consumption relative to the first and second thresholds. This allows for detailed configuration of relay route selection. Furthermore, since power consumption is derived based on communication frequency, power consumption can be easily estimated. Furthermore, since power consumption is derived based on the number of other fire alarm devices 600 that directly communicate, power consumption can be easily estimated. Furthermore, since the power consumption is derived based on the remaining battery power of the fire alarm 600, the power consumption can be easily estimated.

[0090] Furthermore, each of the multiple fire alarm devices 600 transmits information about the relay route to the external device 900 or the external device 910, which provides information for determining where the fire alarm device 600 should be installed when building a multi-hop network. Furthermore, providing information for determining where the fire alarm device 600 should be installed makes it easy to build a multi-hop network. Furthermore, when a new fire alarm 600 is added, each of the multiple fire alarm devices 600 updates the information about the relay route and transmits the updated information to the external device 900 or the external device 910, which provides information for determining where the new fire alarm 600 should be installed. Furthermore, since the information about the relay route includes costs, it is easy to understand the routing status. Furthermore, since the information about the relay route is displayed on the external device 900, it is easy to check the information about the relay route.

[0091] Furthermore, when each of the multiple fire alarm devices 600 receives an instruction to search for a relay route from the external device 900 or the external device 910, it starts deriving a cost, and therefore a trigger can be given to start the cost derivation. When each of the multiple fire alarm devices 600 receives an instruction to end the relay route search from the external device 900 or the external device 910, it ends the cost derivation, and therefore a trigger can be given to end the cost derivation. When each of the multiple fire alarm devices 600 receives an instruction to search for a relay route via its operation unit, it starts deriving a cost, and therefore a trigger can be given to start the cost derivation. When each of the multiple fire alarm devices 600 receives an instruction to end the relay route search via its operation unit, it ends the cost derivation, and therefore a trigger can be given to end the cost derivation.

[0092] Furthermore, the order of the time slots 1030 assigned to each fire alarm device 600 is determined according to the number of hops between the fire alarm device 600 and the relay device 700, thereby reducing the delay time of transfer in the multi-hop network. Furthermore, in downstream communication, the greater the number of hops of the fire alarm device 600, the later the time slots 1030 are assigned, thereby reducing the delay time of transfer in the multi-hop network. Furthermore, in upstream communication, the greater the number of hops of the fire alarm device 600, the earlier the time slots 1030 are assigned, thereby reducing the delay time of transfer in the multi-hop network.

[0093] Furthermore, in downstream communications, if a fire alarm device 600 with a large number of hops is assigned to an earlier time slot 1030, the time slot is changed so that the fire alarm device 600 is assigned to a later time slot 1030, thereby reducing the delay time in transfer. Furthermore, in upstream communications, if a fire alarm device 600 with a large number of hops is assigned to a later time slot 1030, the time slot is changed so that the fire alarm device 600 is assigned to an earlier time slot 1030, thereby reducing the delay time in transfer.

[0094] Furthermore, because allocation changes are made after the installation of the alarm system 1000, the number of allocation changes can be reduced. Furthermore, because the identification number of the fire alarm 600 is determined according to the number of hops, management of the fire alarm 600 can be made easier. Since allocation is performed in the relay device 700, the relay device 700 can manage the allocation. Furthermore, since allocation is performed in the management device 800, the management device 800 can manage the allocation.

[0095] An overview of one aspect of the present disclosure may be summarized as follows. (Item 1-1) The system comprises a plurality of alarm devices (600) that form a multi-hop network extending from a relay device (700), The plurality of alarm devices (600) include a first alarm device (600), a second alarm device (600), and a third alarm device (600), the third alarm device (600) is capable of communicating with the first alarm device (600) and the second alarm device (600); The third alarm device (600) exchanges link quality information with the first alarm device (600), thereby deriving a first cost for a first relay route for communicating with the relay device (700) via the first alarm device (600), and also exchanges link quality information with the second alarm device (600), thereby deriving a second cost for a second relay route for communicating with the relay device (700) via the second alarm device (600); The third alarm device (600) selects the first relay route with priority when the first cost is smaller than the second cost, When the power consumption in the first alarm device (600) becomes greater than a threshold value, the first alarm device (600) sends a notification indicating an increase in power consumption to the third alarm device (600), When the third alarm device (600) receives the notification from the first alarm device (600), it makes it more difficult to select the first relay route. Alarm system (1000).

[0096] (Item 1-2) the third alarm device (600) derives a first cost based on a first index corresponding to link quality information between it and the first alarm device (600), and a second index corresponding to the power consumption of the first alarm device (600); When the third alarm device (600) receives the notification from the first alarm device (600), it increases the influence of the second index on the first cost, thereby making it more difficult to select the first relay route (an alarm system (1000) as described in item 1-1).

[0097] (Item 1-3) The first alarm (600) defines a first threshold value and a second threshold value greater than the first threshold value as threshold values ​​for power consumption, When the power consumption in the first alarm device (600) becomes greater than the first threshold value, the first alarm device (600) sends a first notification to the third alarm device (600), When the power consumption of the first alarm device (600) becomes greater than the second threshold value, the first alarm device (600) transmits a second notification to the third alarm device (600), The alarm system (1000) described in (item 1-2) above, wherein the third alarm device (600) increases the influence of the second index on the first cost when the second notification is received from the first alarm device (600) more than when the first notification is received.

[0098] (Items 1-4) The first alarm device (600) derives the power consumption based on the communication frequency of the first alarm device (600), The alarm system (1000) according to any one of (item 1-1) to (item 1-3), wherein the first alarm device (600) increases the power consumption as the communication frequency increases.

[0099] (Items 1-5) The first alarm device (600) derives the power consumption based on the number of other alarm devices (600) with which the first alarm device (600) directly communicates, An alarm system (1000) according to any one of (item 1-1) to (item 1-3), wherein the power consumption of the first alarm device (600) increases as the number of other alarm devices (600) increases.

[0100] (Items 1-6) The first alarm device (600) derives the power consumption based on the remaining battery charge of the first alarm device (600), The alarm system (1000) according to any one of (item 1-1) to (item 1-3), wherein the first alarm device (600) increases the power consumption as the remaining battery charge decreases.

[0101] (Items 1-7) The alarm system (1000) according to any one of (item 1-1) to (item 1-6), wherein the third alarm device (600) makes it difficult to select the first relay route when a user operation is received.

[0102] (Items 1-8) An alarm device (600) among a plurality of alarm devices (600) that make up a multi-hop network extending from a relay device (700), a communication section (620) capable of communicating with a first alarm device (600) and a second alarm device (600) of the plurality of alarm devices (600); a control unit (624) which derives a first cost for a first relay route for communicating with the relay device (700) via the first alarm device (600) by exchanging link quality information with the first alarm device (600) using the communication unit (620), and which derives a second cost for a second relay route for communicating with the relay device (700) via the second alarm device (600) by exchanging link quality information with the second alarm device (600) using the communication unit (620), and then preferentially selects the first relay route if the first cost is smaller than the second cost; When the power consumption in the first alarm device (600) exceeds a threshold value, the communication section (620) receives a notification from the first alarm device (600) indicating an increase in power consumption, The control unit (624) makes it difficult to select the first relay route when the communication unit (620) receives the notification from the first alarm device (600). Alarm (600).

[0103] (Items 1-9) A method for setting a relay route in an alarm device (600) out of multiple alarm devices (600) that make up a multi-hop network extending from a relay device (700), comprising: the alarm device (600) is capable of communicating with a first alarm device (600) and a second alarm device (600) of the plurality of alarm devices (600); a step of exchanging link quality information with the first alarm device (600) to derive a first cost for a first relay route for communicating with the relay device (700) via the first alarm device (600), and exchanging link quality information with the second alarm device (600) to derive a second cost for a second relay route for communicating with the relay device (700) via the second alarm device (600); a step of preferentially selecting the first relay route when the first cost is smaller than the second cost; a step of receiving a notification from the first alarm device (600) indicating an increase in power consumption when the power consumption in the first alarm device (600) exceeds a threshold value; a step of making it difficult to select the first relay route when the notification is received from the first alarm device (600); A relay route setting method comprising:

[0104] (Items 1-10) A program to be executed by an alarm device (600) out of multiple alarm devices (600) that make up a multi-hop network extending from a relay device (700), the alarm device (600) is capable of communicating with a first alarm device (600) and a second alarm device (600) of the plurality of alarm devices (600); a step of exchanging link quality information with the first alarm device (600) to derive a first cost for a first relay route for communicating with the relay device (700) via the first alarm device (600), and exchanging link quality information with the second alarm device (600) to derive a second cost for a second relay route for communicating with the relay device (700) via the second alarm device (600); a step of preferentially selecting the first relay route when the first cost is smaller than the second cost; a step of receiving a notification from the first alarm device (600) indicating an increase in power consumption when the power consumption in the first alarm device (600) exceeds a threshold value; and a step of making it difficult to select the first relay route when the notification is received from the first alarm device (600).

[0105] (Item 2-1) The system comprises a plurality of alarm devices (600) that form a multi-hop network extending from a relay device (700), Each of the multiple alarm devices (600) exchanges link quality information with other surrounding alarm devices (600) to derive a cost for a relay route for communicating with the relay device (700) via the other surrounding alarm devices (600), and then selects a relay route based on this cost; Each of the plurality of alarm devices (600) transmits information about the relay route to an external device. Alarm system (1000).

[0106] (Item 2-2) In the multi-hop network, a new alarm device (600) is added to the plurality of alarm devices (600), The multiple alarm devices (600) update their costs due to the addition of the new alarm device (600), and update their relay routes based on the updated costs; The alarm system (1000) according to (item 2-1), wherein each of the plurality of alarm devices (600) transmits information relating to updated relay routes to the external device.

[0107] (Item 2-3) The alarm system (1000) according to (Item 2-1) or (Item 2-2), wherein the information about the relay route includes a cost.

[0108] (Item 2-4) An alarm system (1000) according to any one of (item 2-1) to (item 2-3), wherein the information relating to the relay route transmitted from each of the plurality of alarm devices (600) is displayed on the external device.

[0109] (Item 2-5) An alarm system (1000) according to any one of (item 2-1) to (item 2-4), wherein each of the plurality of alarm devices (600) begins deriving a cost when it receives an instruction to search for a relay route from the external device.

[0110] (Item 2-6) An alarm system (1000) according to any one of (item 2-1) to (item 2-4), wherein each of the plurality of alarm devices (600) terminates deriving the cost when it receives an instruction to terminate the search for a relay route from the external device.

[0111] (Item 2-7) The alarm system (1000) according to any one of (item 2-1) to (item 2-4), wherein each of the plurality of alarm devices (600) begins deriving a cost when it receives an instruction to search for a relay route.

[0112] (Item 2-8) The alarm system (1000) according to any one of (item 2-1) to (item 2-4), wherein each of the plurality of alarm devices (600) terminates deriving the cost when it receives an instruction to terminate the search for a relay route.

[0113] (Item 2-9) An external device (900, 910) capable of communicating with a plurality of alarm devices (600) that form a multi-hop network extending from a relay device (700), each of the multiple alarm devices (600) exchanges link quality information with other surrounding alarm devices (600) to derive a cost for the relay route for communicating with the relay device (700) via the other surrounding alarm devices (600), and then selects a relay route based on this cost; and a communication unit (902) that receives information related to the relay route from each of the multiple alarm devices (600); a display unit (906) that displays information about the relay route received by the communication unit (902); and an external device (900, 910).

[0114] (Item 2-10) A display method in external devices (900, 910) that are capable of communicating with multiple alarm devices (600) that form a multi-hop network extending from a relay device (700), comprising: each of the multiple alarm devices (600) derives a cost for a relay route for communicating with the relay device (700) via other surrounding alarm devices (600) by exchanging link quality information with other surrounding alarm devices (600), and then selects a relay route based on this cost, receiving information relating to the relay route from each of the multiple alarm devices (600); displaying the received information about the relay route; A display method comprising:

[0115] (Item 2-11) A program to be executed by external devices (900, 910) that are capable of communicating with multiple alarm devices (600) that make up a multi-hop network extending from a relay device (700), each of the multiple alarm devices (600) derives a cost for a relay route for communicating with the relay device (700) via other surrounding alarm devices (600) by exchanging link quality information with other surrounding alarm devices (600), and then selects a relay route based on this cost, receiving information relating to the relay route from each of the multiple alarm devices (600); and displaying the received information about the relay route.

[0116] (Item 3-1) The system comprises a plurality of alarm devices (600) that form a multi-hop network extending from a relay device (700), The plurality of alarm devices (600) include a first alarm device (600) and a second alarm device (600), A first time slot out of a plurality of time slots arranged on a time axis is allocated to the first alarm device (600), and the first alarm device (600) transmits a signal in the first time slot; The second alarm device (600) is assigned a second time slot out of a plurality of time slots arranged on a time axis, which second time slot is different from the first time slot, and the second alarm device (600) transmits a signal in the second time slot; The order of the first time slots and the second time slots in the plurality of time slots is determined according to the first number of hops between the first alarm device (600) and the relay device (700), and the second number of hops between the second alarm device (600) and the relay device (700). Alarm system (1000).

[0117] (Item 3-2) An alarm system (1000) described in item 3-1, wherein when a signal is transferred in a direction away from the relay device (700) in the multi-hop network, if the second hop number is greater than the first hop number, the second time slot is placed after the first time slot.

[0118] (Item 3-3) An alarm system (1000) described in item 3-1, wherein when a signal is transferred in the multi-hop network in a direction approaching the relay device (700), if the second hop number is greater than the first hop number, the second time slot is placed before the first time slot.

[0119] (Item 3-4) An alarm system (1000) described in (item 3-2) in which, if the second time slot is positioned before the first time slot, the allocation is changed so that the second time slot is positioned after the first time slot.

[0120] (Item 3-5) An alarm system (1000) described in (item 3-3) in which, if the second time slot is positioned after the first time slot, the allocation is changed so that the second time slot is positioned before the first time slot.

[0121] (Item 3-6) The alarm system (1000) according to (item 3-4) or (item 3-5), wherein the change of the allocation is made after the installation of the alarm system (1000).

[0122] (Item 3-7) An alarm system (1000) according to any one of (item 3-1) to (item 3-6), wherein the identification numbers of the first alarm device (600) and the second alarm device (600) are determined according to the first hop count and the second hop count.

[0123] (Item 3-8) The relay device (700) executes the allocation in the alarm system (1000) described in any one of (item 3-1) to (item 3-7).

[0124] (Item 3-9) Further comprising a management device connected to the relay device (700), The management device executes the allocation in the alarm system (1000) described in any one of (item 3-1) to (item 3-7).

[0125] (Item 3-10) A control device for a plurality of alarm devices (600) that make up a multi-hop network extending from a relay device (700), an allocation section where the multiple alarm devices (600) include a first alarm device (600) and a second alarm device (600), which allocates a first time slot of multiple time slots aligned on a time axis to the first alarm device (600), and allocates a second time slot of multiple time slots aligned on the time axis to the second alarm device (600), which second time slot is different from the first time slot; an output unit that outputs an allocation result in the allocation unit; the allocation unit determines the order of the first time slots and the second time slots in the plurality of time slots according to the first hop count between the first alarm device (600) and the relay device (700), and the second hop count between the second alarm device (600) and the relay device (700). Control device.

[0126] (Item 3-11) A method of allocation in a control device to a plurality of alarm devices (600) that make up a multi-hop network extending from a relay device (700), comprising: the multiple alarm devices (600) include a first alarm device (600) and a second alarm device (600), allocating a first time slot of multiple time slots aligned on a time axis to the first alarm device (600), and allocating a second time slot of multiple time slots aligned on the time axis to the second alarm device (600), which second time slot is different from the first time slot; and outputting the allocation result, The allocating step determines the order of the first time slots and the second time slots in the plurality of time slots according to the first hop count between the first alarm device (600) and the relay device (700), and the second hop count between the second alarm device (600) and the relay device (700). Allocation method.

[0127] (Item 3-12) A program to be executed by a control device for multiple alarm devices (600) that make up a multi-hop network extending from a relay device (700), the multiple alarm devices (600) include a first alarm device (600) and a second alarm device (600), allocating a first time slot of multiple time slots aligned on a time axis to the first alarm device (600), and allocating a second time slot of multiple time slots aligned on the time axis to the second alarm device (600), which second time slot is different from the first time slot; and outputting the allocation result, A program for causing a computer to execute the allocating step to determine the order of the first time slots and second time slots within the plurality of time slots in accordance with the first number of hops between the first alarm device (600) and the relay device (700), and the second number of hops between the second alarm device (600) and the relay device (700).

[0128] 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.

[0129] In this embodiment, when the (n+3)th fire alarm 600n+3 receives a notification from the (n+1)th fire alarm 600n+1, it makes it difficult to select the first relay route that includes the (n+1)th fire alarm 600n+1. However, this is not limiting, and for example, the (n+3)th fire alarm 600n+3 makes it difficult to select the first relay route when it receives a user operation. The user operation is received by, for example, the management device 800, the external device 900, the external device 910, or the fire alarm 600. According to this modification, the relay route can be changed according to the user's intention.

[0130] In this embodiment, each fire alarm device 600 exchanges link quality to determine a relay route. However, this is not limiting, and for example, each fire alarm device 600 may exchange a power consumption value. The power consumption value is reflected in C, the third term on the right side of equations (1) and (2). For example, the larger the power consumption value, the larger "C" is made. According to this modification, the influence of power consumption can be reflected in the tentative route cost or the official route cost. [Explanation of symbols]

[0131] 600 fire alarm, 620 communication unit, 622 processing unit, 624 control unit, 630 fire detection sensor, 632 buzzer, 700 relay device, 710 communication unit, 712 output unit, 720 control unit, 722 allocation unit, 800 management device, 900 external device, 902 communication unit, 904 control unit, 906 display unit, 910 external device, 912 information processing device, 1000 alarm system.

Claims

1. It is equipped with multiple alarm devices that form a multi-hop network that spreads from the relay device, the plurality of alarm devices include a first alarm device, a second alarm device, and a third alarm device; the third alarm device is capable of communicating with the first alarm device and the second alarm device, the third alarm device derives a first cost for a first relay route for communicating with the relay device via the first alarm device by exchanging link quality information with the first alarm device, and derives a second cost for a second relay route for communicating with the relay device via the second alarm device by exchanging link quality information with the second alarm device; the third alarm device preferentially selects the first relay route when the first cost is smaller than the second cost; When the power consumption in the first alarm device becomes greater than a threshold value, the first alarm device sends a notification indicating an increase in power consumption to the third alarm device, the third alarm device derives a first cost based on a first index corresponding to link quality information between the third alarm device and the first alarm device, and a second index corresponding to the power consumption of the first alarm device, When the third alarm device receives the notification from the first alarm device, it increases the influence of the second index on the first cost, thereby making it less likely that the first relay route will be selected. Alarm system.

2. the first alarm device defines a first threshold value and a second threshold value greater than the first threshold value as threshold values ​​for power consumption, When power consumption in the first alarm device becomes greater than the first threshold, the first alarm device sends a first notification to the third alarm device, When power consumption in the first alarm device becomes greater than the second threshold, the first alarm device sends a second notification to the third alarm device, The alarm system according to claim 1 , wherein the third alarm device increases the influence of the second index on the first cost when it receives the second notification more than when it receives the first notification from the first alarm device.

3. the first alarm device derives the power consumption based on the communication frequency of the first alarm device; The alarm system according to claim 1 or 2, wherein the first alarm device increases the power consumption as the communication frequency increases.

4. the first alarm device derives the power consumption based on the number of other alarm devices with which the first alarm device directly communicates, The alarm system according to claim 1 or 2, wherein the first alarm device increases its power consumption as the number of other alarm devices increases.

5. the first alarm device derives the power consumption based on the remaining battery charge of the first alarm device; The alarm system according to claim 1 or 2, wherein the first alarm device increases the power consumption as the remaining battery charge decreases.

6. The alarm system according to any one of claims 1 to 5, wherein the third alarm device makes it difficult to select the first relay route when a user operation is received.

7. An alarm device among multiple alarm devices that make up a multi-hop network extending from a relay device, a communication section that is capable of communicating with a first alarm device and a second alarm device of the plurality of alarm devices; a control unit that derives a first cost for a first relay route for communicating with the relay device via the first alarm device by exchanging link quality information with the first alarm device using the communication unit, and that derives a second cost for a second relay route for communicating with the relay device via the second alarm device by exchanging link quality information with the second alarm device using the communication unit, and then preferentially selects the first relay route if the first cost is smaller than the second cost; When the power consumption in the first alarm device becomes greater than a threshold value, the communication unit receives a notification from the first alarm device indicating an increase in power consumption, the control unit derives a first cost based on a first index corresponding to link quality information with the first alarm device, and a second index corresponding to the power consumption of the first alarm device, when the notification is received from the first alarm device, the control unit increases the influence of the second index on the first cost, thereby making it more difficult to select the first relay route. alarm.

8. A method for setting a relay route in an alarm device among multiple alarm devices that make up a multi-hop network extending from a relay device, comprising: the alarm device is capable of communicating with a first alarm device and a second alarm device of the plurality of alarm devices, a step of exchanging link quality information with the first alarm device, thereby deriving a first cost for a first relay route for communicating with the relay device via the first alarm device, and exchanging link quality information with the second alarm device, thereby deriving a second cost for a second relay route for communicating with the relay device via the second alarm device; a step of preferentially selecting the first relay route when the first cost is smaller than the second cost; a step of receiving a notification from the first alarm device indicating an increase in power consumption when the power consumption in the first alarm device becomes greater than a threshold value; a step of deriving a first cost based on a first index corresponding to link quality information with the first alarm device and a second index corresponding to the power consumption of the first alarm device; when the notification is received from the first alarm device, making it less likely that the first relay route will be selected by increasing the influence of the second index on the first cost; A relay route setting method comprising:

9. A program to be executed by an alarm device among multiple alarm devices that make up a multi-hop network extending from a relay device, the alarm device is capable of communicating with a first alarm device and a second alarm device of the plurality of alarm devices, a step of exchanging link quality information with the first alarm device, thereby deriving a first cost for a first relay route for communicating with the relay device via the first alarm device, and exchanging link quality information with the second alarm device, thereby deriving a second cost for a second relay route for communicating with the relay device via the second alarm device; a step of preferentially selecting the first relay route when the first cost is smaller than the second cost; a step of receiving a notification from the first alarm device indicating an increase in power consumption when the power consumption in the first alarm device becomes greater than a threshold value; a step of deriving a first cost based on a first index corresponding to link quality information with the first alarm device and a second index corresponding to the power consumption of the first alarm device; and when the notification is received from the first alarm device, making it more difficult to select the first relay route by increasing the influence of the second index on the first cost.

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