Alarm system, control device, assignment method, program

Abstract

To provide a technology for reducing transfer delay time in a multi-hop network.SOLUTION: A first fire alarm 600a is assigned a first time slot of a plurality of time slots arranged on a time axis. A second fire alarm 600b is assigned a second time slot that is a second time slot among the plurality of time slots arranged on the time axis and that is different from the first time slot. According to a first hop number between the first fire alarm 600a and a first relay device 700a and a second hop number between the second fire alarm 600b and the first relay device 700a, an order of the first time slot and the second time slot in the plurality of time slots is determined.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to alarm technology, and particularly to an alarm system, a control device, an allocation method, and a program using a multi-hop network.

Background Art

[0002] When a fire alarm detects a fire, it issues an alarm. By equipping such a fire alarm with a wireless communication function and forming a multi-hop network with a plurality of fire alarms, when one fire alarm detects a fire, other fire alarms can issue an alarm (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] When a multi-hop network is formed by a plurality of fire alarms, it is required to shorten the transfer delay time in the multi-hop network.

[0005] The present disclosure has been made in view of such a situation, and an object thereof is to provide a technique for shortening the transfer delay time in a multi-hop network.

Means for Solving the Problems

[0006] In order to solve the above problems, an alarm system according to an aspect of the present disclosure includes a plurality of alarms constituting a multi-hop network spreading from a relay device. The plurality of alarms include a first alarm and a second alarm, and the first alarm has Of the multiple frames that divide one superframe, divide one frameThe first time slot out of several time slots arranged on the time axis is assigned, and the first alarm transmits a signal in the first time slot, and the second alarm... There are multiple The second time slot, which is different from the first time slot, is assigned to the second alarm, and the second alarm transmits a signal in the second time slot. The order of the first and second time slots in the multiple time slots is determined according to the first hop count between the first alarm and the relay device and the second hop count between the second alarm and the relay device.

[0007] Another aspect of the present disclosure is a control device. This device is a control device for a plurality of alarms constituting a multi-hop network extending from a relay device, wherein the plurality of alarms include a first alarm, a second alarm, and the first alarm includes, Of the multiple frames that divide one superframe, divide one frame Assign the first time slot out of several time slots arranged on the time axis, and the second alarm There are multiple The system includes an allocation unit that allocates a second time slot, which is different from the first time slot, among the time slots, and an output unit that outputs the allocation result from the allocation unit. The allocation unit determines the order of the first time slot and the second time slot in a plurality of time slots according to the first hop count between the first alarm and the relay device and the second hop count between the second alarm and the relay device.

[0008] Another aspect of this disclosure is an assignment method. This method is an assignment method in a control device for a plurality of alarms constituting a multi-hop network extending from a relay device, wherein the plurality of alarms include a first alarm, a second alarm, and the first alarm includes, Of the multiple frames that divide one superframe, divide one frame Assign the first time slot out of several time slots arranged on the time axis, and the second alarm There are multipleThe system includes the steps of assigning a second time slot, which is different from the first time slot, and outputting the assignment result. The assignment step determines the order of the first and second time slots in a plurality of time slots, according to the first hop count between the first alarm and the relay device and the second hop count between the second alarm and the relay device.

[0009] Furthermore, any combination of the above components, as well as any conversion of the expressions of this disclosure between methods, apparatus, systems, recording media, computer programs, etc., are also valid forms of this disclosure. [Effects of the Invention]

[0010] According to this disclosure, it is possible to provide information to help determine where alarm devices should be installed when constructing a multi-hop network. [Brief explanation of the drawing]

[0011] [Figure 1] This figure shows the configuration of the alarm system according to this embodiment. [Figure 2] This diagram shows the configuration of a fire alarm system. [Figure 3] Figures 3(a)-(d) show the configuration of the superframe used in the alarm system shown in Figure 1. [Figure 4] This diagram shows the configuration of the relay device shown in Figure 1. [Figure 5] This figure shows an example of time slot allocation in the alarm system shown in Figure 1. [Figure 6] This figure shows an overview of downlink communication in the alarm system shown in Figure 1. [Figure 7] This figure shows an overview of the uplink communication in the alarm system shown in Figure 1. [Figure 8] This figure shows an overview of the routing in the alarm system shown in Figure 1. [Figure 9] Figure 1 is a sequence diagram showing the routing procedure in the alarm system. [Figure 10] Figures 10(a)-(b) are diagrams showing the data structure of the table held in the first n+1st fire alarm of FIG. 8. [Figure 11] Figures 11(a)-(b) are diagrams showing the data structure of the table held in the first n+3rd fire alarm of FIG. 9. [Figure 12] Figures 12(a)-(b) are diagrams showing an overview of the installation of the alarm system of FIG. 1. [Figure 13] A diagram showing the configuration of external devices in FIG. 12(a). [Figure 14] A diagram showing the screen displayed on the display unit of FIG. 13. [Figure 15] Figures 15(a)-(b) are diagrams showing a partial configuration of the alarm system of FIG. 1. [Figure 16] A diagram showing an overview of downstream communication in the alarm system of FIG. 15(a). [Figure 17] Figures 17(a)-(b) are diagrams showing an overview of downstream communication in the alarm system of FIG. 15(b).

Mode for Carrying Out the Invention

[0012] Before specifically explaining the present disclosure, an overview will be described. This embodiment relates to an alarm system installed in facilities such as apartment houses, single-family houses, offices, hospitals, etc. In the alarm system, a relay device is connected to a management device, and a plurality of fire alarms are connected to the relay device by a wireless multi-hop network. In such a network, the management device corresponds to the upper side, and the fire alarm with the largest number of hops from the relay device corresponds to the lower side. When a fire alarm detects the occurrence of a fire, it transfers the detection result toward the relay device, and the relay device transfers the detection result to the management device. When the management device receives the detection result, it selects one or more fire alarms that will execute the ringing, and transmits an instruction to ring with the selected one or more fire alarms as the final destination. The relay device and the fire alarm transfer the instruction to ring to the fire alarm that is the final destination, and the fire alarm that is the final destination executes the ringing when it receives the instruction to ring.

[0013] Here, the line for signals from the relay device to the fire alarm with the highest number of hops is called the "downlink," and the line for signals from the fire alarm with the highest 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. In addition, one fire alarm is assigned to one downlink time slot (hereinafter referred to as the "downlink communication time slot") and one uplink time slot (hereinafter referred to as the "uplink communication time slot"). The downlink communication time slot is used for downlink transmission, and the uplink communication time slot is used for uplink transmission.

[0014] On the downlink, in addition to the alarm command, a signal to establish synchronization in the multi-hop network (hereinafter referred to as the "synchronization signal") is periodically transmitted. On the uplink, on the other hand, detection results are primarily transmitted. In the following explanation, the synchronization signal, detection results, and alarm command may be collectively referred to as the "communication signal."

[0015] In the following sections, this embodiment will be described in the following order: (1) basic configuration, (2) routing, (3) construction, and (4) modification of time slot allocation. (1) Basic configuration Figure 1 shows the configuration of the alarm system 1000. The alarm system 1000 includes the first fire alarms 600a to the ninth fire alarms 600i, collectively referred to as fire alarms 600, the first relay devices 700a to the third relay devices 700c, collectively referred to as relay devices 700, and a control 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 a system applied to facilities such as residences, offices, and commercial buildings, which detects fires and notifies the public that a fire has occurred. 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 walls.

[0017] Here, the first fire alarm 600a to the sixth fire alarm 600f constitute 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 600a, and the second fire alarm 600b, and a relay route is formed connecting the first relay device 700a, the fourth fire alarm 600d, the fifth fire alarm 600e, and the third fire alarm 600c. In addition, a relay route is formed connecting the first relay device 700a, the fourth fire alarm 600d, the fifth fire alarm 600e, and the sixth fire alarm 600f, and a relay route is formed connecting the first relay device 700a and the seventh fire alarm 600g. Such relay routes are determined at each fire alarm 600 and are also shared with the first relay device 700a and the control 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 device 700a in 1 hop. The second fire alarm 600b and the fifth fire alarm 600e can communicate with the first relay device 700a in 2 hops. The third fire alarm 600c and the sixth fire alarm 600f can communicate with the first relay device 700a in 3 hops.

[0019] The second relay device 700b, the third relay device 700c, the eighth fire alarm 600h, and the ninth fire alarm 600i are configured in the same way as the first relay device 700a, the first fire alarm 600a, etc. For example, a multi-hop network originating from the first relay device 700a is installed on the first floor of the facility, a multi-hop network originating from the second relay device 700b is installed on the second floor of the facility, and a multi-hop network originating from the third relay device 700c is installed on the third floor of the facility. Different frequencies are used for the multi-hop network originating from the first relay device 700a, the multi-hop network originating from the second relay device 700b, and the multi-hop network originating from the third relay device 700c. In addition, the first relay device 700a, the second relay device 700b, and the third relay device 700c communicate with each other wirelessly or via wired communication.

[0020] In this way, the relay device 700 performs wireless communication with multiple fire alarms 600 that constitute 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 multiple fire alarms 600 included in the multi-hop network. Furthermore, the first relay device 700a is connected to the management device 800 by cable and performs wired communication with the management device 800.

[0021] The management device 800 is, for example, a controller for a HEMS (Home Energy Management System) installed within the facility. The management device 800 can communicate with multiple devices installed in the facility. These multiple devices include, for example, air conditioning equipment, lighting equipment, water heaters, etc., that have communication functions. The management device 800 can also communicate with a first relay device 700a installed in the facility. Furthermore, the management device 800 can communicate with a second relay device 700b, a third relay device 700c, and each of the fire alarms 600 via the first relay device 700a.

[0022] Figure 2 shows the configuration of the 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. Known technology may be used for the fire detection sensor 630. For example, the fire detection sensor 630 may be an optical smoke detection sensor, which may detect a fire by detecting smoke during a fire using the diffuse reflection of light. For example, the fire detection sensor 630 may be a heat detection sensor, which may detect a fire by detecting heat during a fire. For example, the fire detection sensor 630 may be a carbon monoxide detection sensor, which may detect a fire by detecting the concentration of carbon monoxide generated by combustion during a fire. For example, the fire detection sensor 630 may be an infrared detection sensor, which may detect a fire by detecting infrared radiation emitted by combustion during a fire.

[0023] The communication unit 620 performs wireless communication with other fire alarms 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 of the control unit 624 will be described later. The buzzer 632 can emit a buzzer sound. The fire alarm 600 may also be configured to include a fire detection sensor 630 without the buzzer 632, that is, a configuration having detection and communication functions. Such a fire alarm 600 can also be said to be a detector capable of warning of fire detection.

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

[0025] Figure 3(d) shows the usage of the multiple time slots 1030 included in frame 1020 shown in Figure 3(b). Of the multiple time slots 1030, the first one or more time slots 1030 are used as "downlink communication time slots". One time slot 1030 following the downlink communication time slot is used as an "uplink communication time slot". One or more time slots 1030 following the uplink communication time slot are used as "reserves". The number of downlink communication time slots and the number of uplink communication time slots are the same and must be greater than or equal to the number of fire alarms 600 included in the multi-hop network. Reserves are not required.

[0026] Figure 4 shows the configuration of the relay device 700. The relay device 700 can also be described as a control device for multiple fire alarms 600 that constitute a multi-hop network. The relay device 700 includes a communication unit 710 and a control unit 720. The communication unit 710 includes an output unit 712, and the control unit 720 includes an allocation unit 722. The communication unit 710 has a communication function for communicating with multiple relay devices 700, as well as a communication function for communicating with the management device 800. The control unit 720 controls the operation of the relay device 700.

[0027] The communication unit 710 receives the routing results from each of the multiple fire alarms 600 that constitute the multi-hop network by communicating with them. The routing performed at each fire alarm 600 will be described later, but the routing results indicate the various relay routes shown in Figure 1.

[0028] Based on the routing results, the allocation unit 722 assigns a combination of one downlink time slot and one uplink time slot, as shown in Figure 3(d), to one fire alarm 600. The allocation in the allocation unit 722 will be described later, but the combination of downlink and uplink time slots is changed for each fire alarm 600. The output unit 712 outputs the allocation results from the allocation unit 722 to multiple fire alarms 600. The allocation results show the correspondence between the combination of downlink and uplink time slots and the fire alarms 600.

[0029] Figure 5 shows an example of time slot allocation in the alarm system 1000, and is shown in the same way as Figure 3(d). This shows the allocation of multiple time slots 1030 to the first relay device 700a and the first to seventh fire alarms 600a to 600g in Figure 1. In Figure 5, "M" represents the first relay device 700a, and "S1" to "S7" represent the first to seventh fire alarms 600a to 600g, respectively. The time slots for downlink communication are allocated from front to back to the first relay device 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. As mentioned 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 device 700a is "1". The number of hops from the second fire alarm 600b and the fifth fire alarm 600e to the first relay device 700a is "2", and the number of hops from the third fire alarm 600c and the sixth fire alarm 600f to the first relay device 700a is "3". In other words, for the downlink communication time slot, the fire alarms 600 with the smallest number of hops to the first relay device 700a are allocated further forward.

[0030] For the uplink communication time slot, the 6th fire alarm 600f, 3rd fire alarm 600c, 5th fire alarm 600e, 2nd fire alarm 600b, 7th fire alarm 600g, 4th fire alarm 600d, 1st fire alarm 600a, and 1st relay device 700a are assigned in order from the front. In other words, for the uplink communication time slot, fire alarms 600 that have a larger number of hops to the 1st relay device 700a are assigned further forward.

[0031] Focusing on the fifth fire alarm 600e, which has a hop count of "2," the fifth fire alarm 600e is allocated a downlink communication time slot that is ahead of the sixth fire alarm 600f, which has a hop count of "3." Downlink communication time slots are used when signals (communication signals) are transferred away from the first relay device 700a in a multi-hop network. In addition, the fifth fire alarm 600e is allocated an uplink communication time slot that is behind the sixth fire alarm 600f. Uplink communication time slots are used when signals (communication signals) are transferred towards the first relay device 700a in a multi-hop network. In other words, the relay device 700 determines which time slot 1030 to assign to each fire alarm 600 from among multiple time slots 1030, depending on the hop count between each fire alarm 600 and the relay device 700.

[0032] The fifth fire alarm 600e is assigned a downlink communication time slot "S5" and an uplink communication time slot "S5", and transmits a signal (communication signal) using either the downlink communication time slot "S5" or the uplink communication time slot "S5". The sixth fire alarm 600f is assigned a downlink communication time slot "S6" and an uplink communication time slot "S6", and transmits a signal (communication signal) using either the downlink communication time slot "S6" or the uplink communication time slot "S6".

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

[0034] In such circumstances, the communication unit 620 of the fire alarm 600 may perform intermittent reception operation to reduce power consumption. In the intermittent reception operation of the communication unit 620, reception operation is performed for a portion of the beginning of the time slot 1030, and if no signal (communication signal) is received during that portion, reception operation is stopped for the remainder of the time slot 1030. On the other hand, if a signal is received during a portion of the beginning of the time slot 1030, reception operation continues for the remainder of the time slot 1030.

[0035] Figure 6 shows an overview of downlink communication in the alarm system 1000. This shows the downlink communication time slots in Figure 5. The first relay device 700a periodically transmits a synchronization signal to the multiple fire alarms 600 that constitute 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 Figure 3(a), and not in the remaining frames 1020. The first relay device 700a transmits the synchronization signal in time slot 1030 "M" of the first frame 1020 of the superframe 1010. When the fourth fire alarm 600d receives the synchronization signal in time slot 1030 "M", it forwards the synchronization signal in time slot 1030 "S4". The fourth fire alarm 600d also transmits a response signal to the first relay device 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 device 700a receives the response signal in time slot 1030 "S4". When the fifth fire alarm 600e receives the synchronization signal in time slot 1030 "S4", it forwards the synchronization signal in time slot 1030 "S5" and also transmits a response signal to the fourth fire alarm 600d. The fourth fire alarm 600d receives the response signal in time slot 1030 "S5". Although omitted in Figure 11, the fourth fire alarm 600d forwards the response signal from the fifth fire alarm 600e to the first relay device 700a in time slot 1030 "S4" of the next frame.

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

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

[0039] Thus, the synchronization signal is transferred in frame 1020 when the first relay device 700a transmits the synchronization signal. Furthermore, each fire alarm 600 that receives the synchronization signal from the first relay device 700a establishes timing synchronization with the first relay device 700a based on the synchronization signal. Since known techniques can be used for timing synchronization, a detailed explanation is omitted here.

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

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

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

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

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

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

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

[0047] (2) Routing Up to this point, it has been assumed that a relay route as shown in Figure 1 has been formed, but here, the formation and modification of the relay route will be explained using Figure 8 as well. Figure 8 shows an overview of the routing in the alarm system 1000. In Figure 8, 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 are shown. 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 Figure 1. Around the (n+3)th fire alarm 600n+3, there may be other fire alarms 600 besides 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).

[0048] The following sections will explain (2-1) the formation of relay routes and (2-2) the modification of relay routes in that order. (2-1) Formation of relay routes Figure 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 600n+3. Each fire alarm 600 broadcasts a HELLO message at regular intervals. The HELLO message contains route quality information from the fire alarm 600 to the relay device 700. The communication unit 620 of the (n+3)th fire alarm 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) fire alarm 600n+3 measures the received power of each received HELLO message, and the processing unit 622 derives the link quality for each fire alarm 600 based on the measured received power. The link quality is a value that changes according to the received power and decreases as the received power increases. The aforementioned route quality is expressed in the same way as the link quality. The control unit 624 derives the provisional route cost as follows by adding the link quality of the (n+1) fire alarm 600n+1 and the route quality included in the HELLO message from the (n+1) fire alarm 600n+1. Provisional route cost = Route quality + Ka × Link quality + Kb × C Equation (1) Here, Ka and Kb are coefficients, and C is a predetermined constant. When forming a relay route, if Kb is set to "0", Kb × C is ignored.

[0050] The control unit 624 also derives a provisional route cost for the other fire alarms 600. The control unit 624 compares the multiple provisional route costs and selects several fire alarms 600 as priority link destinations in order of lowest provisional route cost. In this case, 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) fire alarm 600n+3 transmits the address of the selected fire alarm 600 and the link quality at the time of reception in the LINK_REQ submessage of the HELLO message (S16, S18). The (n+1) fire alarm 600n+1 and the (n+2) fire alarm 600n+2 transmit the link quality in the reverse direction in the LINK_REP submessage (S20, 22).

[0052] The communication unit 620 of the (n+3) fire alarm 600n+3 receives the LINK_REP submessage. The control unit 624 of the (n+3) fire alarm 600n+3 compares the link quality included in the LINK_REP submessage from the (n+1) fire alarm 600n+1 with the link quality derived from the received power already measured, and selects the larger link quality. The control unit 624 also derives the formal route cost by adding the selected link quality with the route quality for the (n+1) fire alarm 600n+1, as follows. Official route cost = Route quality + Ka × Max (link quality) + Kb × C Equation (2) Here, Max indicates that he will select the highest link quality.

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

[0054] In other words, the (n+3)th fire alarm 600n+3 derives the formal route cost (hereinafter referred to as the "first cost") for a relay route (hereinafter referred to as the "first relay route") to communicate with the relay device 700 via the (n+1)th fire alarm 600n+1 by exchanging link quality information with the (n+1)th fire alarm 600n+1. The (n+3)th fire alarm 600n+3 also derives the formal route cost (hereinafter referred to as the "second cost") for a relay route (hereinafter referred to as the "second relay route") to communicate with the relay device 700 via the (n+2)th fire alarm 600n+2 by exchanging link quality information with the (n+2)th fire alarm 600n+2. Furthermore, the (n+3)th fire alarm 600n+3 prioritizes selecting the relay route with the smaller cost compared to the first cost and the second cost. A relay route is formed by performing this process at each fire alarm 600. Information regarding the relay route (alternative route) formed at each fire alarm 600 is transmitted to the management device 800 via the relay device 700. Based on the relay route (alternative route) information, the management device 800 determines the allocation of time slots 1030 according to the number of hops.

[0055] (2-2) Change of relay route As described above, once a relay route is formed, the fire alarms 600 included in the relay route perform signal forwarding. Signal forwarding increases the power consumption of the fire alarms 600. If the fire alarms 600 are battery-powered, it is preferable to have low power consumption. To suppress the increase in power consumption of the fire alarms 600, the relay route is modified.

[0056] The control unit 624 of the (n+1) fire alarm 600n+1, which is included in the first relay route connecting the (n+3) 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 between the communication frequency and power consumption, and derives the power consumption based on the communication frequency. In this correspondence, the power consumption increases as the communication frequency increases.

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

[0058] The control unit 624 maintains a threshold value for power consumption. Figures 10(a)-(b) show the data structure of the table maintained in the (n+1)th fire alarm 600n+1. Figure 10(a) shows the conditions for power consumption and the threshold value, and the operation corresponding to those conditions. When the power consumption exceeds the threshold value, the control unit 624 decides to send a notification indicating an increase in power consumption. On the other hand, when the power consumption is below 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 the communication unit 620 of the (n+1)th fire alarm 600n+1 decides to send a notification, it sends the notification to the (n+3)th fire alarm 600n+3.

[0059] The control unit 624 of the (n+3) fire alarm 600n+3 determines the relay route based on the formal route cost of equation (2), as described above. The control unit 624 controls the values ​​of the coefficients Ka and Kb in equation (2) depending on whether or not it has received a notification from the (n+1) fire alarm 600n+1. Figures 11(a)-(b) show the data structure of the table held in the 1 (n+3) fire alarm 600n+3. Figure 11(a) shows the values ​​of the coefficients Ka and Kb for when no notification is received and when a notification is received. The coefficients Ka and Kb have a relationship where their sum equals "1".

[0060] When no notification is received, the coefficient Ka is "A1" and the coefficient Kb is "B1". When no notification is received, it 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, the (n + 3)-th fire alarm 600n+3 makes it difficult to select the first relay route including the (n + 1)-th fire alarm 600n+1 when receiving a notification from 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 they are indicators (hereinafter referred to as "the first indicator") according to the link quality information with the (n + 1)-th fire alarm 600n+1. 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 they are indicators (hereinafter referred to as "the second indicator") according to the power consumption of the (n + 1)-th fire alarm 600n+1. When receiving a notification, the control unit 624 makes it difficult to select the first relay route by increasing the influence of the second indicator in the formal route cost. Such processing is also performed with other fire alarms 600.

[0063] Previously, the values ​​of the coefficients Ka and Kb were adjusted in two stages. However, the values ​​of the coefficients Ka and Kb may be adjusted in three or more stages. Figure 10(b) shows the conditions for power consumption and thresholds, and the operation according to those conditions. The control unit 624 of the (n+1)th fire alarm 600n+1 defines a first threshold and a second threshold that is greater than the first threshold as thresholds for power consumption. The control unit 624 decides to send a first notification indicating an increase in power consumption if the power consumption is greater than the first threshold and less than or equal to the second threshold. The control unit 624 decides to send a second notification indicating a further increase in power consumption if the power consumption exceeds the second threshold. On the other hand, the control unit 624 decides not to send the first or second notification if the power consumption is less than or equal to the first threshold. Returning to Figure 8, the communication unit 620 of the (n+1)th fire alarm 600n+1 sends the first notification to the (n+3)th fire alarm 600n+3 if it has decided to send the first notification. If the communication unit 620 decides to send the second notification, it sends the second notification to the n+3 fire alarm 600n+3.

[0064] The control unit 624 of the (n+3) fire alarm 600n+3 controls the values ​​of the coefficients Ka and Kb in equation (2) depending on whether or not it has received a first or second notification from the (n+1) fire alarm 600n+1. Figure 11(b) shows the values ​​of the coefficients Ka and Kb for the case where neither the first nor the second notification has been received, and for the case where either the first or second notification has been received. Here again, the coefficients Ka and Kb have a relationship where their sum equals "1".

[0065] If neither the first nor the second notification is 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 is received, the coefficient Ka is "A2" and the coefficient Kb is "B2". If the second notification is received, the coefficient Ka is "A3" and the coefficient Kb is "B3". "B3" is a value greater than "B2", and "A3" is a value less than "A2". In other words, the control unit 624 increases the influence of the second indicator in the formal route cost when the second notification is received compared with when the first notification is received from the (n+1)th fire alarm 600n+1.

[0066] (3) Construction This section describes techniques for facilitating the installation of a multi-hop network for the alarm system 1000. In particular, it describes techniques for providing information to help determine where the fire alarms 600 should be installed. Figures 12(a) and 12(b) show an overview of the installation 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 shown in Figure 8. The external device 900 is, for example, a computer and is able to communicate with the control device 800.

[0067] Routing in a multi-hop network is not performed after all fire alarms 600 have been installed, but rather after several fire alarms 600 have been installed near the relay device 700. After routing for several fire alarms 600 has been completed, the routing is updated once several more fire alarms 600 are added and installed. In this way, the routing is updated in stages as the number of fire alarms 600 increases.

[0068] Here, we assume that the (n+1)th fire alarm 600n+1 and the (n+2)th fire alarm 600n+2 are installed before the (n+3)th fire alarm 600n+3 is installed. The (n+1)th fire alarm 600n+1 and the (n+2)th fire alarm 600n+2 each derive their official route costs through the process described above, and then select a relay route based on the official route costs. The communication units 620 of the (n+1)th fire alarm 600n+1 and the (n+2)th fire alarm 600n+2 each transmit information regarding the relay route. This information regarding the relay route includes the official route costs. The information regarding the relay route may also include the official route costs for relay routes other than the selected relay route, such as alternative routes.

[0069] Information regarding the relay route transmitted from the (n+1)th fire alarm 600n+1 and the (n+2)th fire alarm 600n+2 is forwarded 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] Figure 13 shows the configuration of the external device 900. The external device 900 is, for example, a personal computer or a tablet terminal device. The external device 900 includes a communication unit 902, a control unit 904, and a display unit 906. The communication unit 902 performs communication processing to communicate with the management device 800. The installer operates the external device 900 to access the management device 800, and the communication unit 902 receives information about the relay route from the management device 800. The control unit 904 generates a screen based on the information about the relay route and displays the generated screen on the display unit 906.

[0071] Figure 14 shows the screen displayed on the display unit 906. Information regarding the relay route is displayed, including the identification information and cost of each fire alarm 600. The installer checks the status of the relay route by looking at the relay route information displayed on the display unit 906.

[0072] The installer installs a new fire alarm 600, specifically the n+3rd fire alarm 600n+3, in the multi-hop network. The multiple fire alarms 600, including the n+1st fire alarm 600n+1, the n+2nd fire alarm 600n+2, and the n+3rd fire alarm 600n+3, update their official route costs with the addition of the new fire alarm 600, and update the relay routes based on the updated official route costs. The communication unit 620 of each of the multiple fire alarms 600 transmits information about the relay routes. As before, the management device 800 receives the information about the relay routes, and the external device 900 displays the updated information about the relay routes.

[0073] Figure 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 in Figure 8. The external device 910 is a communication device capable of receiving signals transmitted from the fire alarm 600 and the relay device 700. The information processing device 912 is, for example, a computer and is connected to the external device 910. The same processing is performed in the multi-hop network as before. The external device 910 receives information about 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 updated information about the relay route.

[0074] The derivation of the formal route cost may be started or stopped by instructions from the contractor. For example, when the contractor operates an operating unit (not shown) provided on an external device 900 or an information processing device 912, the external device 900 or external device 910 may transmit an instruction to each fire alarm 600 to search for a relay route. In this case, each of the multiple fire alarms 600, upon receiving the instruction to search for a relay route from the external device 900 or external device 910, will start deriving the cost.

[0075] If multiple fire alarms 600 are searching for a relay route, the installer may operate an operating unit (not shown) provided on an external device 900 or an information processing device 912, and the external device 900 or external device 910 may transmit an instruction to each fire alarm 600 to terminate the relay route search. In this case, each of the multiple fire alarms 600 will terminate cost derivation when it receives the instruction to terminate the relay route search from the external device 900 or external device 910.

[0076] An operating unit (not shown) for receiving instructions from the installer may be provided in each fire alarm 600. When each of the multiple fire alarms 600 receives an instruction to search for a relay route, it starts deriving the cost. Also, when each of the multiple fire alarms 600 receives an instruction to end the search for a relay route, it stops deriving the cost.

[0077] (4) Correction of time slot allocation As mentioned above, each fire alarm 600 should be assigned a time slot 1030 according to the number of hops between the relay device 700 and the fire alarm 600. However, during the installation of the alarm system 1000, the assignment may not be made according to the number of hops. Such an assignment of time slots 1030 can lead to a large delay in the transmission of communication signals. This section describes the process for correcting the assignment when the assignment is not made according to the number of hops after the installation of the alarm system 1000 and during its operation.

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

[0079] Figure 16 shows an overview of the downlink communication 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 fire alarm 600m+1, and "S2" indicates the time slot 1030 assigned to the m+2 fire alarm 600m+2. As before, the time slot 1030 is assigned to the fire alarm 600 that has a smaller hop count and is further forward.

[0080] The relay device 700 transmits a communication signal in time slot 1030 "M", and the m+1 fire alarm 600m+1 receives the communication signal in time slot 1030 "M". The m+1 fire alarm 600m+1 transmits a communication signal in time slot 1030 "S1", and the m+2 fire alarm 600m+2 receives the communication signal in time slot 1030 "S1". The m+2 fire alarm 600m+2 transmits a communication signal in time slot 1030 "S2". The transmission and reception of response signals are omitted from the above explanation.

[0081] Figure 15(b) shows the configuration of the second stage of the alarm system 1000. This configuration is the same as in Figure 15(b) but with the addition of the m+3 fire alarm 600m+3. The m+3 fire alarm 600m+3 is connected to the relay device 700, the m+1 fire alarm 600m+1 is connected to the m+3 fire alarm 600m+3, and the m+2 fire alarm 600m+2 is connected to the m+1 fire alarm 600m+1, thereby forming a multi-hop network.

[0082] Figures 17(a)-(b) show an overview of the downlink communication in the alarm system 1000. In Figure 17(a), time slot 1030 "S3" is located after time slot 1030 "S2". In addition, the newly added m+3 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 fire alarm 600m+3 receives the communication signal in time slot 1030 "M". The m+3 fire alarm 600m+3 transmits a communication signal in time slot 1030 "S3", and the m+1 fire alarm 600m+1 receives the communication signal in time slot 1030 "S3". The m+1 fire alarm 600m+1 transmits a communication signal in time slot 1030 "S1" in the next frame 1020, and the m+2 fire alarm 600m+2 receives the communication signal in time slot 1030 "S1". The m+2 fire alarm 600m+2 transmits a communication signal in time slot 1030 "S2".

[0084] In other words, for the m+3rd fire alarm 600m+3, which has a hop count of "1" to relay device 700, a time slot 1030 "S3" is assigned, which is later than the time slot 1030 "S1" assigned to the m+1st fire alarm 600m+1, which has a hop count of "2". Therefore, a delay occurs in transmission. The transmission and reception of response signals are omitted from the above explanation.

[0085] To suppress such transmission delays, after the addition of the m+3 fire alarm 600m+3, the assignment is changed in the relay device 700 or the management device 800. For example, in downlink communication, if time slots 1030 "S1" and 1030 "S2" are placed before time slot 1030 "S3", the assignment unit 722 of the relay device 700 changes the assignment so that time slots 1030 "S1" and 1030 "S2" are placed after time slot 1030 "S3". Downlink communication is communication on a downlink line, and in a multi-hop network, signals are transmitted away from the relay device 700.

[0086] Furthermore, in uplink communication, if time slots 1030 "S1" and 1030 "S2" are located behind time slot 1030 "S3", the allocation unit 722 changes the allocation so that time slots 1030 "S1" and 1030 "S2" are located in front of time slot 1030 "S3". Uplink communication is communication on the uplink line, and in a multi-hop network, the signal is transferred in the direction approaching the relay device 700.

[0087] Each fire alarm 600 is assigned an identification number to identify it. The identification numbers are assigned, for example, in the order in which they were installed. Therefore, in Figure 15(b), the m+3 fire alarm 600m+3 with identification number "3", the m+1 fire alarm 600m+1 with identification number "1", and the m+2 fire alarm 600m+2 with identification number "2" are arranged in that order. When managing multiple fire alarms 600, it is preferable that the identification numbers be arranged in the order in which the fire alarms 600 are lined up 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+3rd fire alarm 600m+3 is assigned identification number "1", the m+1st fire alarm 600m+1 is assigned identification number "2", and the m+2nd fire alarm 600m+2 is assigned identification number "3".

[0088] The subject of the apparatus, system, or method in this disclosure comprises a computer. The functions of the subject of the apparatus, system, or method in this disclosure are realized by the computer executing a program. The computer comprises a processor as its main hardware component, which operates according to the program. The processor is of any type as long as it can realize its functions by executing the program. The processor consists of one or more electronic circuits, including semiconductor integrated circuits (ICs) or LSIs (Large Scale Integrations). Multiple electronic circuits may be integrated on one chip or provided on multiple chips. Multiple chips may be aggregated in one device or provided on multiple devices. The program is recorded on a non-temporary recording medium such as a ROM, optical disc, or hard disk drive that is readable by the computer. The program may be pre-stored on the recording medium or supplied to the recording medium via a wide-area communication network, including the Internet.

[0089] According to this embodiment, the relay route with the lower cost is prioritized for selection. However, if the power consumption of the fire alarm 600 included in that relay route increases, it becomes difficult to select that relay route, thereby suppressing the increase in power consumption of fire alarms 600 included in the multi-hop network. Furthermore, the cost is derived based on a first indicator corresponding to link quality information and a second indicator corresponding to the power consumption of other fire alarms 600. When a notification is received from another fire alarm 600, the influence of the second indicator on the cost is increased, making it difficult to select a relay route that includes other fire alarms 600. Also, since the cost is changed only by increasing the influence of the second indicator, the processing can be simplified. In addition, a first threshold and a second threshold are defined as thresholds for power consumption, and the influence of the second indicator on the cost is changed according to the magnitude of power consumption relative to the first and second thresholds, so the selection of relay routes can be set in detail. Furthermore, since power consumption is derived based on the communication frequency, power consumption can be easily estimated. Furthermore, since power consumption is derived based on the number of other fire alarms 600 that communicate directly, power consumption can be easily estimated. Furthermore, since power consumption is derived based on the remaining battery level of the fire alarm 600, power consumption can be easily estimated.

[0090] Furthermore, each of the multiple fire alarms 600 transmits information about the relay route to the external device 900 or external device 910, providing information to help determine where to install the fire alarms 600 when building a multi-hop network. This also facilitates the construction of a multi-hop network. Additionally, when a new fire alarm 600 is added, each of the multiple fire alarms 600 updates the information about the relay route and transmits the updated information to the external device 900 or external device 910, providing information to help determine where to install the new fire alarm 600. The relay route information also includes costs, making it easier to understand the routing situation. Furthermore, the relay route information is displayed on the external device 900, making it easy to check the relay route information.

[0091] Furthermore, each of the multiple fire alarms 600 can start deriving costs when it receives an instruction from external device 900 or external device 910 to search for a relay route, thus providing a trigger to start cost derivation. Also, each of the multiple fire alarms 600 can stop deriving costs when it receives an instruction from external device 900 or external device 910 to end the search for a relay route, thus providing a trigger to end cost derivation. Furthermore, each of the multiple fire alarms 600 can start deriving costs when it receives an instruction from the control unit to search for a relay route, thus providing a trigger to start cost derivation. Also, each of the multiple fire alarms 600 can stop deriving costs when it receives an instruction from the control unit to end the search for a relay route, thus providing a trigger to end cost derivation.

[0092] Furthermore, the order of the time slots 1030 assigned to each fire alarm 600 is determined according to the number of hops between the fire alarm 600 and the relay device 700, thereby reducing the transmission delay time in a multi-hop network. Also, in downlink communication, the larger the number of hops for the fire alarm 600, the more late the time slot 1030 is assigned, thus reducing the transmission delay time in a multi-hop network. Also, in uplink communication, the larger the number of hops for the fire alarm 600, the more early the time slot 1030 is assigned, thus reducing the transmission delay time in a multi-hop network.

[0093] Furthermore, in downlink communication, if a fire alarm 600 with a high hop count is assigned to the front time slot 1030, the system will change to assign the rear time slot 1030 to that fire alarm 600, thereby reducing the transmission delay time. Similarly, in uplink communication, if a fire alarm 600 with a high hop count is assigned to the rear time slot 1030, the system will change to assign the front time slot 1030 to that fire alarm 600, thereby reducing the transmission delay time.

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

[0095] An overview of one aspect of this disclosure may be provided by the following items: (Item 1-1) Equipped with multiple alarm devices (600) that constitute 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 (600) exchanges link quality information with the first alarm (600) to derive a first cost for a first relay route to communicate with the relay device (700) via the first alarm (600), and exchanges link quality information with the second alarm (600) to derive a second cost for a second relay route to communicate with the relay device (700) via the second alarm (600). The third alarm (600) prioritizes selecting the first relay route when the first cost is less than the second cost. When the power consumption of the first alarm (600) exceeds a threshold, the first alarm (600) sends a notification to the third alarm (600) indicating an increase in power consumption. The third alarm device (600), upon receiving the notification from the first alarm device (600), makes it difficult to select the first relay route. Alarm system (1000).

[0096] (Item 1-2) The third alarm (600) derives a first cost based on a first index corresponding to link quality information between it and the first alarm (600) and a second index corresponding to the power consumption of the first alarm (600). The alarm system (1000) described in item 1-1, wherein the third alarm (600), upon receiving the notification from the first alarm (600), makes it more difficult to select the first relay route by increasing the influence of the second indicator on the first cost.

[0097] (Item 1-3) The first alarm device (600) defines a first threshold value and a second threshold value that is greater than the first threshold value as threshold values ​​for power consumption. When the power consumption of the first alarm device (600) exceeds the first threshold, the first alarm device (600) transmits a first notification to the third alarm device (600). When the power consumption of the first alarm device (600) exceeds the second threshold, the first alarm device (600) transmits a second notification to the third alarm device (600). Alarm system (1000) as described in item 1-2, wherein the third alarm (600) increases the impact of the second indicator on the first cost when it receives the second notification compared to when it receives the first notification from the first alarm (600).

[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 first alarm device (600) is an alarm system (1000) according to any one of items (1-1) to (1-3), wherein the power consumption increases 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) communicates directly. The alarm system (1000) described in any one of items (1-1) to (1-3) wherein the first alarm (600) increases in power consumption as the number of other alarms (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 first alarm device (600) is an alarm system (1000) according to any one of items (1-1) to (1-3) which increases the power consumption as the remaining battery level decreases.

[0101] (Items 1-7) The third alarm device (600) is an alarm system (1000) described in any one of items (1-1) to (1-6) that makes it difficult to select the first relay route when it receives user input.

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

[0103] (Items 1-9) A method for setting relay routes in an alarm device (600) among multiple alarm devices (600) that constitute a multi-hop network extending from a relay device (700), The alarm device (600) is capable of communicating with the first alarm device (600) and the second alarm device (600) among the plurality of alarm devices (600). The steps include: deriving a first cost for a first relay route to communicate with the relay device (700) via the first alarm device (600) by exchanging link quality information with the first alarm device (600); and deriving a second cost for a second relay route to communicate with the relay device (700) via the second alarm device (600) by exchanging link quality information with the second alarm device (600); A step of prioritizing the selection of the first relay route when the first cost is smaller than the second cost, When the power consumption of the first alarm (600) exceeds a threshold, the first alarm (600) receives a notification indicating an increase in power consumption. When the notification from the first alarm device (600) is received, the step of making it difficult to select the first relay route, A relay route setting method that includes the following features.

[0104] (Items 1-10) A program to be executed by an alarm device (600) among multiple alarm devices (600) that constitute a multi-hop network extending from a relay device (700), The alarm device (600) is capable of communicating with the first alarm device (600) and the second alarm device (600) among the plurality of alarm devices (600). The steps include: deriving a first cost for a first relay route to communicate with the relay device (700) via the first alarm device (600) by exchanging link quality information with the first alarm device (600); and deriving a second cost for a second relay route to communicate with the relay device (700) via the second alarm device (600) by exchanging link quality information with the second alarm device (600); A step of prioritizing the selection of the first relay route when the first cost is smaller than the second cost, When the power consumption of the first alarm (600) exceeds a threshold, the first alarm (600) receives a notification indicating an increase in power consumption. A program that causes a computer to perform the steps of making it difficult to select the first relay route when it receives the notification from the first alarm device (600).

[0105] (Item 2-1) Equipped with multiple alarm devices (600) that constitute a multi-hop network extending from a relay device (700), Each of the plurality of alarm devices (600) exchanges link quality information with other alarm devices (600) in the vicinity to derive the cost of a relay route for communicating with the relay device (700) via the other alarm devices (600) in the vicinity, and then selects a relay route based on the cost. Each of the aforementioned plurality of alarm devices (600) transmits information regarding 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 aforementioned multiple alarm devices (600) update the cost by adding the new alarm device (600), and update the relay route based on the updated cost. Each of the plurality of alarm devices (600) transmits information regarding the updated relay route to the external device (the alarm system (1000) as described in item 2-1).

[0107] (Item 2-3) Information regarding the aforementioned relay route, including costs, is provided to the alarm system (1000) as described in (item 2-1) or (item 2-2).

[0108] (Item 2-4) Information regarding the relay route transmitted from each of the plurality of alarm devices (600) is displayed in the external device as an alarm system (1000) as described in any one of items (2-1) to (2-3).

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

[0110] (Item 2-6) Each of the plurality of alarm devices (600) terminates cost derivation when it receives an instruction from the external device to end the search for a relay route, according to the alarm system (1000) described in any one of items (2-1) to (2-4).

[0111] (Item 2-7) Each of the plurality of alarm devices (600) starts deriving the cost when it receives an instruction to search for a relay route, according to the alarm system (1000) described in any one of items (2-1) to (2-4).

[0112] (Item 2-8) Each of the plurality of alarm devices (600) terminates cost derivation when it receives an instruction to end the search for a relay route, as described in any one of items (2-1) to (2-4).

[0113] (Item 2-9) External devices (900, 910) capable of communicating with multiple alarm devices (600) that constitute a multi-hop network extending from a relay device (700), Each of the plurality of alarm devices (600) exchanges link quality information with other alarm devices (600) in the vicinity to derive the cost of a relay route for communicating with the relay device (700) via the other alarm devices (600) in the vicinity, and then selects a relay route based on the cost. A communication unit (902) receives information regarding the relay route from each of the plurality of alarm devices (600). A display unit (906) that displays information about the relay route received in the communication unit (902), External devices (900, 910) equipped with these features.

[0114] (Item 2-10) A display method for external devices (900, 910) that can communicate with multiple alarm devices (600) constituting a multi-hop network extending from a relay device (700), Each of the plurality of alarm devices (600) exchanges link quality information with other alarm devices (600) in the vicinity to derive the cost of a relay route for communicating with the relay device (700) via the other alarm devices (600) in the vicinity, and then selects a relay route based on the cost, and receives information regarding the relay route from each of the plurality of alarm devices (600), The steps include displaying the received information regarding the relay route, A display method that includes the following features.

[0115] (Item 2-11) A program to be executed by multiple alarm devices (600) that constitute a multi-hop network extending from a relay device (700), and external devices (900, 910) that can communicate with them, Each of the plurality of alarm devices (600) exchanges link quality information with other alarm devices (600) in the vicinity to derive the cost of a relay route for communicating with the relay device (700) via the other alarm devices (600) in the vicinity, and then selects a relay route based on the cost, and receives information regarding the relay route from each of the plurality of alarm devices (600), A program that causes a computer to perform the steps of displaying information about the relay route that it has received.

[0116] (Item 3-1) Equipped with multiple alarm devices (600) that constitute 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), The first alarm device (600) is assigned a first time slot from among a plurality of time slots arranged on the time axis, 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 from among a plurality of time slots arranged on the time axis, and is a second time slot 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 slot and the second time slot in the plurality of time slots is determined according to the first hop number between the first alarm (600) and the relay device (700) and the second hop number between the second alarm (600) and the relay device (700). Alarm system (1000).

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

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

[0119] (Item 3-4) If the second time slot is located in front of the first time slot, the assignment is changed so that the second time slot is located behind the first time slot (the alarm system (1000) as described in item 3-2).

[0120] (Item 3-5) If the second time slot is located behind the first time slot, the assignment is changed so that the second time slot is located in front of the first time slot (the alarm system (1000) as described in item 3-3).

[0121] (Item 3-6) The aforementioned change in assignment is made after the installation of the alarm system (1000) as described in (item 3-4) or (item 3-5).

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

[0123] (Item 3-8) The relay device (700) is an alarm system (1000) described in any one of items (3-1) to (3-7) that performs the assignment.

[0124] (Item 3-9) The relay device (700) is further connected to a management device, The management device is an alarm system (1000) described in any one of items (3-1) to (3-7) that performs the assignment.

[0125] (Item 3-10) A control device for multiple alarm devices (600) that constitute 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), the first alarm device (600) being assigned a first time slot from among a plurality of time slots arranged on a time axis, and the second alarm device (600) being assigned a second time slot from among a plurality of time slots arranged on a time axis, which is different from the first time slot, The system includes an output unit that outputs the allocation results from the allocation unit, The allocation unit determines the order of the first time slot and the second time slot in the plurality of time slots according to the first hop count between the first alarm (600) and the relay device (700) and the second hop count between the second alarm (600) and the relay device (700). Control device.

[0126] (Item 3-11) A method for assigning to multiple alarm devices (600) that constitute a multi-hop network extending from a relay device (700), in a control device, The plurality of alarm devices (600) include a first alarm device (600) and a second alarm device (600), and the first alarm device (600) is assigned a first time slot from among a plurality of time slots arranged on a time axis, and the second alarm device (600) is assigned a second time slot from among a plurality of time slots arranged on a time axis, which is different from the first time slot. The step includes outputting the assignment result, The aforementioned assignment step determines the order of the first time slot and the second time slot in the plurality of time slots according to the first hop number between the first alarm (600) and the relay device (700) and the second hop number between the second alarm (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 constitute 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), and the first alarm device (600) is assigned a first time slot from among a plurality of time slots arranged on a time axis, and the second alarm device (600) is assigned a second time slot from among a plurality of time slots arranged on a time axis, which is different from the first time slot. The step includes outputting the assignment result, The aforementioned assignment step is a program that causes a computer to perform the action of determining the order of the first time slot and the second time slot in the plurality of time slots, according to the first hop number between the first alarm (600) and the relay device (700) and the second hop number between the second alarm (600) and the relay device (700).

[0128] The present disclosure has been described above based on examples. These examples are illustrative, and it will be understood by those skilled in the art that various modifications are possible for each component or combination of processing steps, and that such modifications are also within the scope of the present disclosure.

[0129] In this embodiment, the (n+3) fire alarm 600n+3 makes it difficult to select the first relay route including the (n+1) fire alarm 600n+1 when it receives a notification from the (n+1) fire alarm 600n+1. However, this is not the only example; for instance, the (n+3) fire alarm 600n+3 also makes it difficult to select the first relay route when it receives user input. User input is received, for example, by the management device 800, external device 900, external device 910, and fire alarm 600. According to this modified example, the relay route can be changed according to the user's wishes.

[0130] In this embodiment, each fire alarm 600 exchanges link quality to determine the relay route. However, it is not limited to this; for example, each fire alarm 600 may also exchange power consumption values. The power consumption value is reflected in C, the third term on the right-hand side of equations (1) and (2). For example, the larger the power consumption value, the larger "C" becomes. According to this modification, the effect of power consumption can be reflected in the provisional 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. Equipped with multiple alarms that constitute a multi-hop network extending from a relay device, The aforementioned plurality of alarm devices include a first alarm device, a second alarm device, The first alarm device is assigned a first time slot from among a plurality of time slots arranged on the time axis by dividing one of the plurality of frames that divide a single superframe, and the first alarm device transmits a signal in the first time slot. The second alarm device is assigned the second time slot from the plurality of time slots, which is different from the first time slot, and the second alarm device transmits a signal in the second time slot. The order of the first time slot and the second time slot in the plurality of time slots is determined according to the first hop number between the first alarm and the relay device and the second hop number between the second alarm and the relay device. Alarm system.

2. In the multi-hop network, when a signal is transferred away from the relay device, if the second hop number is greater than the first hop number, the second time slot is positioned behind the first time slot, according to claim 1.

3. In the multi-hop network, when a signal is transferred in the direction approaching the relay device, if the second hop number is greater than the first hop number, the second time slot is positioned before the first time slot, according to claim 1.

4. The alarm system according to claim 2, wherein if the second time slot is located in front of the first time slot, the allocation is changed so that the second time slot is located behind the first time slot.

5. The alarm system according to claim 3, wherein if the second time slot is located behind the first time slot, the allocation is changed so that the second time slot is located in front of the first time slot.

6. The alarm system according to claim 4 or 5, wherein the change in the assignment is made after the installation of the alarm system.

7. The alarm system according to any one of claims 1 to 6, wherein the identification numbers of the first alarm and the second alarm are determined according to the first hop count and the second hop count.

8. The relay device performs the assignment.

9. The relay device further comprises a management device connected to the relay device, The alarm system according to any one of claims 1 to 7, wherein the management device performs the assignment.

10. A control device for multiple alarm devices that constitute a multi-hop network extending from a relay device, The plurality of alarms include a first alarm and a second alarm, the first alarm is assigned a first time slot from among a plurality of time slots arranged on a time axis by dividing one of the plurality of frames that divide one superframe, and the second alarm is assigned a second time slot from among the plurality of time slots, which is different from the first time slot, The system includes an output unit that outputs the allocation results from the allocation unit, The allocation unit determines the order of the first time slot and the second time slot in the plurality of time slots according to the first hop count between the first alarm and the relay device and the second hop count between the second alarm and the relay device. Control device.

11. A method for assigning multiple alarm devices in a control device to a multi-hop network extending from a relay device, The plurality of alarms include a first alarm and a second alarm, and the first alarm is assigned a first time slot from among a plurality of time slots arranged on a time axis by dividing one of the plurality of frames that divide one superframe, and the second alarm is assigned a second time slot from among the plurality of time slots, which is different from the first time slot. The step includes outputting the assignment result, The aforementioned assignment step determines the order of the first time slot and the second time slot in the plurality of time slots according to the first hop number between the first alarm and the relay device and the second hop number between the second alarm and the relay device. Allocation method.

12. A program to be executed by a control device for multiple alarm devices that constitute a multi-hop network extending from a relay device, The plurality of alarms include a first alarm and a second alarm, and the first alarm is assigned a first time slot from among a plurality of time slots arranged on a time axis by dividing one of the plurality of frames that divide one superframe, and the second alarm is assigned a second time slot from among the plurality of time slots, which is different from the first time slot. The step includes outputting the assignment result, The aforementioned assignment step is a program that causes a computer to perform the action of determining the order of the first time slot and the second time slot in the plurality of time slots, according to the first hop number between the first alarm and the relay device and the second hop number between the second alarm and the relay device.

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