JP2023162939A - Alarm system, alarm device, communication method, program - Google Patents

Abstract

To provide a technique capable of switching a relay route smoothly in a multi-hop network.SOLUTION: A fifth fire alarm device 600e receives a signal from a relay device 700 via a third fire alarm device 600c. The fifth fire alarm device 600e is configured so as to, when reception of a signal from the relay device 700 via the third fire alarm device 600c has failed, receive the signal from the relay device 700 via a first fire alarm device 600a. The fifth fire alarm device 600e is also configured so as to, when having switched the relay route that includes the third fire alarm device 600c to the relay route that includes the first fire alarm device 600a, transmit a route switching notification to notify the relay route switching to the relay device 700 to the first fire alarm device 600a.SELECTED DRAWING: Figure 1

Description

The present disclosure relates to alarm technology, and particularly to an alarm system, an alarm, a communication method, and a program using a multihop network.

A base station collects data by installing smart meters in each house and transmitting data between the smart meters using a wireless multi-hop method. In the wireless communication multi-hop method, there is a possibility that a communication abnormality may occur between nodes, making it impossible to send a communication message from a collection node to a destination sensor node. At that time, a node outside the relay route that detects the abnormality autonomously constructs an alternative route and continues communication (for example, see Patent Document 1).

JP2017-50746A

When a communication failure occurs in a multi-hop network, retransmission is performed. In situations where communication failure continues even after retransmission, it is necessary to switch the relay route. It is required to switch relay routes smoothly.

The present disclosure has been made in view of these circumstances, and its purpose is to provide a technique for smoothly switching relay routes in a multi-hop network.

In order to solve the above problems, an alarm system according to an aspect of the present disclosure includes a plurality of alarm devices forming a multi-hop network extending from a relay device. The plurality of alarms include a first alarm, a second alarm, and a third alarm. The first alarm receives a signal from the relay device via the second alarm, and if the first alarm fails to receive the signal from the relay device via the second alarm, the first alarm sends a third alarm. When the first alarm device receives a signal from the relay device via the relay device, and the first alarm device switches the relay route including the second alarm device to the relay route including the third alarm device, the first alarm device transmits the switching of the relay route to the relay device. A route switching notification is sent to the third alarm.

Another aspect of the disclosure is an alarm. This alarm is one of a plurality of alarms configuring a multi-hop network extending from a relay device, and when this alarm is called a first alarm, a plurality of alarms include a second alarm. and a third alarm device, and includes a communication section that receives a signal from the relay device via the second alarm device, and a control section that controls the communication section. If the communication unit fails to receive the signal from the relay device via the second alarm, the communication unit receives the signal from the relay device via the third alarm, and the communication unit receives the signal from the relay device via the third alarm. When the route is switched to a relay route that includes the third alarm, a route switching notification is sent to the third alarm to notify the relay device of the switching of the relay route.

Yet another aspect of the present disclosure is a communication method. This method is a communication method among a plurality of alarm devices that constitute a multi-hop network extending from a relay device, and when this alarm device is called the first alarm device, the plurality of alarm devices include It also includes a second alarm and a third alarm, and includes a step of receiving a signal from the relay device via the second alarm, and a step of receiving the signal from the relay device via the second alarm. a step of receiving a signal from the relay device via the third alarm, and a step of notifying the relay device of the switching of the relay route when the relay route including the second alarm is switched to a relay route including the third alarm. and transmitting a route switching notification to the third alarm device.

Note that arbitrary combinations of the above components and expressions of the present disclosure converted between methods, devices, systems, recording media, computer programs, etc. are also effective as aspects of the present disclosure.

According to the present disclosure, it is possible to smoothly switch relay routes in a multi-hop network.

FIG. 1 is a diagram showing the configuration of an alarm system according to the present embodiment. FIG. 2 is a diagram showing the configuration of the fire alarm shown in FIG. 1. FIG. FIGS. 3(a) to 3(e) are diagrams showing the structure of a superframe used in the alarm system of FIG. 1. 2 is a diagram showing the configuration of the relay device in FIG. 1. FIG. 2 is a diagram showing an overview of communication in the alarm system of FIG. 1. FIG. FIGS. 6(a)-(b) are diagrams showing formats of periodic signals and response signals used in the alarm system of FIG. 1. 7(a)-(b) are diagrams showing another outline of communication in the alarm system of FIG. 1. 2 is a diagram showing an overview of routing in the alarm system of FIG. 1. FIG. 2 is a sequence diagram showing a routing procedure in the alarm system of FIG. 1. FIG. FIGS. 10(a) and 10(b) are diagrams showing a situation when a communication failure occurs in the alarm system of FIG. 1. FIGS. 11(a) and 11(b) are diagrams showing an overview of retransmission in the alarm system of FIG. 1. FIGS. 12(a) and 12(b) are diagrams showing another outline of retransmission in the alarm system of FIG. 1. FIGS. 13(a) and 13(b) are diagrams showing an overview of notifications in the alarm system of FIG. 1. FIGS. 14(a) and 14(b) are diagrams showing an overview of slot switching and aging in the alarm system of FIG. 1. FIGS. 15(a) and 15(b) are diagrams showing an outline of communication after route switching in the alarm system of FIG. 1.

Before specifically explaining the present disclosure, an overview will be given. This embodiment relates to an alarm system installed in facilities such as apartment complexes, single-family houses, offices, and hospitals. In an alarm system, a relay device is connected to a management device, and a plurality of fire alarm devices are connected to the relay device via a wireless multi-hop network. In such a network, the management device corresponds to the upper level side, and the fire alarm device with the largest number of hops from the relay device corresponds to the lower level side. When the fire alarm detects the occurrence of a fire, the fire alarm transmits the detection result to the relay device, and the relay device transmits the detection result to the management device. Upon receiving the detection results, the management device 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 transfer the ringing instruction to the final destination fire alarm, and the final destination fire alarm executes the ringing upon receiving the ringing instruction.

Here, when the line for the signal going from the relay device to the fire alarm with the largest number of hops is called the "downlink," the line for the signal going from the fire alarm to the relay device with the largest number of hops is called the "downlink." The line is called the "uplink". In this embodiment, one frame is formed by arranging a plurality of time slots, and one superframe is formed by arranging a plurality of frames. Additionally, one fire alarm is assigned to one downlink time slot (hereinafter referred to as "downlink communication time slot") and one uplink time slot (hereinafter referred to as "uplink communication time slot"). (referred to as "slot"). Downlink communication time slots are used for downlink transfer, and uplink communication time slots are used for uplink transfer.

On the downlink, in addition to the ringing instruction, a signal (hereinafter referred to as a "periodic signal") for confirming the survival of each fire alarm is periodically transmitted from the relay device. This periodic signal is also used by repeaters and fire alarms in the multihop network to establish and maintain synchronization. On the uplink, in addition to the detection results, response signals to regular signals are transmitted from each fire alarm. In the following description, the periodic signal, response signal, detection result, and ringing instruction may be collectively referred to as "communication signal."

A fire alarm in a multi-hop network must monitor whether detection results are being transmitted in upstream communication time slots assigned to other lower-level fire alarms. In particular, when the number of fire alarms on the lower side increases, the number of uplink communication time slots that must be monitored increases, so the power consumption of the fire alarms increases.

In order to suppress the increase in power consumption of fire alarms, monitoring time slots are introduced. As described above, the frame includes a plurality of downlink communication time slots and a plurality of uplink communication time slots. In addition, the frame is a monitoring time slot (hereinafter referred to as "monitoring signal") in which the fire alarm that is scheduled to transmit a communication signal in the assigned uplink communication time slot transmits a signal (hereinafter referred to as "monitoring signal"). This includes "monitoring time slots"). Each fire alarm waits to receive a monitoring signal in a monitoring time slot. When the fire alarm receives the monitoring signal in the monitoring time slot, the fire alarm waits to receive the communication signal in the uplink communication time slot assigned to itself. On the other hand, if the fire alarm does not receive a monitoring signal in the monitoring time slot, the fire alarm does not wait for reception of a communication signal in the uplink communication time slot assigned to itself.

If the relay device does not receive a response signal from the fire alarm, it retransmits the periodic signal. However, depending on the communication environment, the retransmitted periodic signal may not always reach the fire alarm. This communication environment includes, for example, the presence of fixed shielding objects (iron doors) due to changes in layout, and the presence of constant interference from disturbance waves. Under such circumstances, it is required to smoothly switch relay routes in a multi-hop network.

Below, this example will be explained as (1) basic configuration, (2) routing, (3) occurrence of communication failure, (4) retransmission on new route (part 1), and (5) retransmission on new route (part 1). 2), (6) notification of route change, (7) slot switching/aging, and (8) communication after route switching will be explained in this order.
(1) Basic configuration FIG. 1 shows the configuration of an alarm system 1000. The alarm system 1000 includes first to sixth fire alarms 600a to 600f, which are collectively referred to as fire alarms 600, a relay device 700, and a management device 800. The number of fire alarms 600 is not limited to "6", and the number of relay devices 700 is not limited to "1".

The alarm system 1000 is a system that is applied to facilities such as residences, offices, and commercial facilities, and detects fire and notifies that a fire has occurred. The plurality of fire alarms 600 are, for example, residential fire alarms and include fire detection sensors. The plurality of fire alarms 600 are installed, for example, on the ceiling of a facility, but may also be installed on a wall or the like.

Here, the first fire alarm 600a to the sixth fire alarm 600f constitute a multi-hop network extending from the relay device 700. For example, a relay route connecting the relay device 700 and the first fire alarm 600a, and a relay route connecting the relay device 700, the second fire alarm 600b, the third fire alarm 600c, and the fourth fire alarm 600d are formed. Further, a relay route connecting the relay device 700, the second fire alarm 600b, the third fire alarm 600c, the fifth fire alarm 600e, and the sixth fire alarm 600f is also formed. Such a relay route is determined in each fire alarm device 600 and is also shared by the relay device 700 and the management device 800.

In these relay routes, the first fire alarm 600a and the second fire alarm 600b can communicate with the relay device 700 with the number of hops "1", and the third fire alarm 600c can communicate with the relay device 700 with the number of hops "2". It is possible to communicate with relay device 700. The fourth fire alarm 600d and the fifth fire alarm 600e can communicate with the relay device 700 with a hop number of "3", and the sixth fire alarm 600f can communicate with the relay device 700 with a hop number of "4". It is. Focusing on the fifth fire alarm 600e, the fifth fire alarm 600e receives a signal from the relay device 700 via the third fire alarm 600c, but the first fire alarm 600a or the fourth fire alarm The signal from the relay device 700 can also be received via the relay device 600d. When the fifth fire alarm 600e connects to the first fire alarm 600a or the fourth fire alarm 600d, the number of hops to the relay device 700 changes.

In this way, the relay device 700 performs wireless or wired communication with a plurality of fire alarm devices 600 that constitute a multi-hop network. It can also be said that the relay device 700 relays communication between the plurality of fire alarm devices 600 included in the multi-hop network. Further, the relay device 700 is connected to the management device 800 by a cable, and performs wired communication with the management device 800. Relay device 700 and management device 800 may perform wireless communication.

The management device 800 is, for example, a controller for a HEMS (Home Energy Management System) installed within a facility. The management device 800 is capable of communicating with multiple devices installed in the facility. The plurality of devices include, for example, air conditioners, lighting devices, water heaters, etc. that have communication functions. Furthermore, the management device 800 can communicate with a relay device 700 provided in the facility. Furthermore, the management device 800 can also communicate with each fire alarm device 600 via the relay device 700.

FIG. 2 shows the configuration of the fire alarm 600. The fire alarm 600 includes a communication section 620, a processing section 622, a control section 624, a fire detection sensor 630, and a buzzer 632, and the control section 624 includes a monitoring section 626. The processing section 622 and the control section 624 may be integrated. Any 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, and may detect a fire by detecting smoke during a fire using diffused reflection of light. For example, the fire detection sensor 630 may be a heat detection sensor, and may detect a fire by detecting heat during a fire. For example, the fire detection sensor 630 may be a carbon monoxide detection sensor, and 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, and may detect a fire by detecting infrared rays emitted by combustion during a fire.

The communication unit 620 performs wireless communication with other fire alarm devices 600 or relay devices 700. The communication unit 620 may perform wired communication. 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 operations 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 can emit a buzzer sound. The fire alarm 600 may have a configuration that does not include the buzzer 632 but includes a fire detection sensor 630, that is, a configuration that has a detection function and a communication function. It can be said that such a fire alarm 600 is a sensor capable of issuing an alarm when detecting a fire.

3(a)-(e) show the configuration of a superframe 1010 used in the alarm system 1000. As shown in FIG. 3(a), a certain period is defined as a superframe 1010. Superframe 1010 is arranged repeatedly. Superframe 1010 is divided into multiple frames 1020. As shown in FIG. 3(b), one frame 1020 is divided into multiple time slots 1030. Among the plurality of time slots 1030, one or more time slots 1030 at the beginning are used as "time slots for downlink communication." The plurality of downlink communication time slots are time slots 1030 that should be allocated to each of the plurality of fire alarm devices 600 in order to transmit the signal from the relay device 700, and are arranged on the time axis.

One or more time slots 1030 following the downlink communication time slot are used as "monitoring time slots." One or more time slots 1030 following one or more monitoring time slots are used as "uplink communication time slots." The plurality of uplink communication time slots are time slots 1030 that should be allocated to each of the plurality of fire alarms 600 in order to transmit a signal to the relay device 700, and are arranged on the time axis. One or more time slots 1030 following the uplink communication time slot are used as "empty time slots." The number of downlink communication time slots and the number of uplink communication time slots are the same and are greater than or equal to the number of fire alarms 600 included in the multihop network. The number of monitoring time slots is greater than or equal to the maximum number of hops in the multihop network. There may be no empty slots.

FIG. 3(c) shows a time slot 1030 to be used as a downlink communication time slot or an uplink communication time slot. The length of the time slot 1030 is "A". FIG. 3(d) shows a time slot 1030 to be used as a monitoring time slot. The length of the time slot 1030 is "B". "B" is set to a smaller value than "A".

FIG. 3(e) shows an example of the use of multiple frames 1020 in a superframe 1010. “Regular monitoring” is performed in the first frame 1020 of the superframe 1010. "Regular monitoring" means that the relay device 700 transmits a regular signal, and the fire alarm 600 transmits a response signal in response to the regular signal, so that the relay device 700 becomes the source of the received response signal. This is a process to confirm whether the alarm device 600 is alive. In "two" frames 1020 following "regular monitoring", "same route retransmission" is performed. In the "same route retransmission", if there is a fire alarm 600 whose survival was not confirmed in the "regular monitoring", the same processing is performed on the same relay route as in the "regular monitoring".

In "two" frames 1020 following "same route retransmission", "different route retransmission" is performed. In "Retransmission via another route", if there is a fire alarm 600 whose survival was not confirmed in "Regular monitoring" and "Retransmission on the same route", a relay route other than "Regular monitoring" and "Retransmission on the same route" is used. The same processing is performed in .

A plurality of frames 1020 following the "alternative route retransmission" are "waiting for detection." "Waiting for detection" is a process of waiting for a detection result to be transmitted when at least one fire alarm device 600 detects the occurrence of a fire. When relay device 700 receives a detection result from at least one fire alarm 600, relay device 700 transmits a ringing instruction. When the survival of all fire alarm devices 600 is confirmed in regular monitoring, same route retransmission, and different route retransmission, the remaining same route retransmission or different route retransmission frame 1020 is used for "waiting for detection." Since regular monitoring, same route retransmission, and different route retransmission are performed at predetermined timings, fire alarm 600 and relay device 700 recognize the timing of regular monitoring, same route retransmission, and different route retransmission. Furthermore, in the frames 1020 for "regular monitoring", "same route retransmission", and "same route retransmission", when the fire alarm 600 detects the occurrence of a fire, the detection result is transmitted from the fire alarm 600.

FIG. 4 shows the configuration of relay device 700. It can be said that the relay device 700 is a control device for a plurality of fire alarm devices 600 that constitute a multi-hop network. Relay device 700 includes a communication section 710 and a control section 720 , communication section 710 includes an output section 712 , and control section 720 includes an allocation section 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 the management device 800. Control unit 720 controls the operation of relay device 700.

The communication unit 710 receives the results of the routing performed in each fire alarm device 600 by communicating with the plurality of fire alarm devices 600 that constitute the multi-hop network. The routing performed in each fire alarm device 600 will be described later, but each relay route as shown in FIG. 1 is formed based on the routing results.

The allocation unit 722 allocates the combination of one downlink communication time slot and one uplink communication time slot shown in FIG. 3(b) to one fire alarm 600 based on the routing result. The output unit 712 outputs the allocation result in the allocation unit 722 to the plurality of fire alarm devices 600 as slot information. The slot information indicates the correspondence between the combination of downlink communication time slots and uplink communication time slots and the fire alarm 600.

FIG. 5 shows an overview of communication in the alarm system 1000, particularly an overview of "periodic monitoring." Here, it is assumed that the relay route in the alarm system 1000 is formed as shown in FIG. In FIG. 5, the first fire alarm 600a to the sixth fire alarm 600f are indicated as "C1" to "C6", respectively, and the relay device 700 is indicated as "M".

The downlink communication time slot includes a relay device 700, a first fire alarm 600a, a second fire alarm 600b, a third fire alarm 600c, a fourth fire alarm 600d, a fifth fire alarm 600e, and a sixth fire alarm. The alarm devices 600f are assigned in order from the front side. As mentioned above, the number of hops from the first fire alarm 600a and the second fire alarm 600b to the relay device 700 is "1", and the number of hops from the third fire alarm 600c to the relay device 700 is "2". It is. Further, the number of hops from the fourth fire alarm 600d and the fifth fire alarm 600e to the relay device 700 is "3", and the number of hops from the sixth fire alarm 600f to the relay device 700 is "4". . In other words, the fire alarm device 600 with the smaller number of hops to the relay device 700 is assigned to the front side with respect to the downlink communication time slot.

The uplink communication time slot includes a sixth fire alarm 600f, a fifth fire alarm 600e, a fourth fire alarm 600d, a third fire alarm 600c, a second fire alarm 600b, a first fire alarm 600a, Relay devices 700 are allocated in order from the front side. In other words, the fire alarm device 600 that has a larger number of hops to the relay device 700 is assigned to the front side of the uplink communication time slot.

When focusing on the fifth fire alarm 600e, in the downlink communication time slot, the fifth fire alarm 600e is assigned to the rear side of the fourth fire alarm 600d and the front side of the sixth fire alarm 600f. In the uplink communication time slot, the fifth fire alarm 600e is assigned to the rear side of the sixth fire alarm 600f and the front side of the fourth fire alarm 600d.

Monitoring time slots "N1", "N2", "N3", and "N4" are arranged in front of the downlink communication time slots. The monitoring time slot "N1" is a time slot 1030 in which the fire alarm device 600 with the number of hops of "2" should transmit a monitoring signal to be received by the fire alarm device 600 with the number of hops of "1". The monitoring time slot "N2" is a time slot 1030 in which the fire alarm device 600 with the number of hops of "3" should transmit a monitoring signal to be received by the fire alarm device 600 with the number of hops of "2". The monitoring time slot "N3" is a time slot 1030 in which the fire alarm device 600 with the number of hops of "4" should transmit a monitoring signal to be received by the fire alarm device 600 with the number of hops of "3". The monitoring time slot "N4" is a time slot 1030 in which the fire alarm device 600 with the number of hops of "5" should transmit a monitoring signal to be received by the fire alarm device 600 with the number of hops of "4".

The monitoring time slots are arranged in the order of "N4", "N3", "N2", and "N1". In other words, the fire alarm device 600 having a larger number of hops from the relay device 700 is assigned a monitoring time slot on the earlier side.

Allocation of these time slots 1030 is determined by relay device 700 or management device 800. For example, relay device 700 or management device 800 determines the allocation of time slots 1030 based on relay route information. Relay device 700 or management device 800 notifies each fire alarm device 600 of the determined time slot 1030 assignment. Therefore, each fire alarm device 600 also knows the allocation of these time slots 1030. As a result, the fire alarm device 600 recognizes the time slot 1030 that is to transmit the communication signal and is assigned to itself. The fire alarm 600 also knows the time slot 1030 in which it can receive a communication signal from an adjacent fire alarm 600 or relay device 700 on the relay route.

Along the relay route shown in FIG. 1, periodic signals are transmitted in the downlink communication time slots. Transmission of periodic signals in downlink communication is performed by broadcast transmission (flooding method). Further, along the relay route shown in FIG. 1, a response signal is transmitted in the uplink communication time slot. Transmission of response signals in uplink communication is performed by unicast transmission.

6(a)-(b) show formats of periodic signals and response signals used in alarm system 1000. FIG. 6A shows the format of a periodic signal, that is, a signal periodically transmitted from the relay device 700. As mentioned above, since a flooding method is used, the broadcast address is stored. The synchronization beacon is a flag for TDMA (Time Division Multiple Access) synchronization. The periodic monitoring request flag indicates that the signal is a periodic signal. No data is stored in periodic monitoring requests.

FIG. 6(b) shows the format of the response signal, that is, the signal to be transmitted when each of the plurality of fire alarm devices 600 receives the periodic signal. As described above, since unicast communication is used, the unicast address of another fire alarm device 600 or relay device 700 on the upper side to be transmitted next is stored. A periodic monitoring response flag indicates that the signal is a response signal. 32 bits are assigned to the periodic monitoring response data, and a maximum of 32 fire alarm devices 600 that can be connected to the alarm system 1000 are expressed in 32 bits. Periodic monitoring response data is generated by logically ORing (XOR) its own information with the information included in the response signal received from the other fire alarm device 600 on the lower side. In other words, packet concatenation is performed. Return to FIG. 5.

Triangle marks in FIG. 5 indicate intermittent reception operations performed in the communication section 620 of the fire alarm 600. In the intermittent reception operation in the communication unit 620, the reception operation is executed during a part of the period at the beginning of the time slot 1030, and when a signal (communication signal, monitoring signal) is not received during the part of the period, the reception operation is performed at the beginning of the time slot 1030. The reception operation is stopped during the remaining period. On the other hand, if a signal is received during a partial period at the beginning of time slot 1030, the reception operation continues during the remaining period of time slot 1030. The intermittent reception operation is performed to reduce power consumption.

In downlink communication, the fire alarm device 600 performs intermittent reception only in time slots 1030 assigned to other fire alarm devices 600 on the upper side with which it directly communicates on the relay route. In uplink communication, the fire alarm device 600 performs intermittent reception only in time slots 1030 assigned to other fire alarm devices 600 on the lower side with which it directly communicates on the relay route. Since periodic monitoring is performed at predetermined timing, monitoring time slots are not used in uplink communication.

Relay device 700 transmits a regular signal in time slot 1030 "M" in the downlink communication time slot. As described above, a broadcast address is set in the periodic signal. The first fire alarm 600a and the second fire alarm 600b receive the periodic signal in time slot 1030 "M". The second fire alarm 600b transmits a periodic signal in time slot 1030 "C2". Third fire alarm 600c receives the periodic signal in time slot 1030 "C2". The third fire alarm 600c transmits a periodic signal in time slot 1030 "C3". The fourth fire alarm 600d and the fifth fire alarm 600e receive the periodic signal in time slot 1030 "C3". The fifth fire alarm 600e transmits a periodic signal in time slot 1030 "C5". The sixth fire alarm 600f receives the periodic signal in time slot 1030 "C5".

The sixth fire alarm 600f transmits a response signal in time slot 1030 "C6" in the uplink communication time slot. The fifth fire alarm 600e receives the response signal in time slot 1030 "C6". The fifth fire alarm 600e generates a response signal by concatenating its response with the response signal from the sixth fire alarm 600f, and transmits the response signal in time slot 1030 "C5." Third fire alarm 600c receives the response signal in time slot 1030 "C5".

The fourth fire alarm 600d transmits a response signal in time slot 1030 "C4". Third fire alarm 600c receives the response signal in time slot 1030 "C4". The third fire alarm 600c generates a response signal by combining the response signal from the fifth fire alarm 600e, the response signal from the fourth fire alarm 600d, and its own response, and generates a response signal at time slot 1030 "C3". to send a response signal.

The second fire alarm 600b receives the response signal in time slot 1030 "C3". The second fire alarm 600b generates a response signal by concatenating its response with the response signal from the third fire alarm 600c, and transmits the response signal in time slot 1030 "C2." Relay device 700 receives the response signal in time slot 1030 "C2". The first fire alarm 600a transmits a response signal in time slot 1030 "C1". Relay device 700 receives the response signal in time slot 1030 "C1".

The relay device 700 checks the response signal received from the first fire alarm 600a and the response signal received from the second fire alarm 600b, thereby transmitting the signals from the first fire alarm 600a to the sixth fire alarm 600f. Make sure everything is alive.

When focusing on the fifth fire alarm 600e, the above processing is shown as follows. The third fire alarm 600c transmits a regular signal to the fifth fire alarm 600e in the downlink communication time slot assigned to the third fire alarm 600c. When the fifth fire alarm 600e receives a regular signal by intermittent reception in the downlink communication time slot assigned to the third fire alarm 600c, the fifth fire alarm 600e receives a regular signal in the downlink communication time slot assigned to the fifth fire alarm 600e. A signal is transmitted to the sixth fire alarm 600f. Here, when the fifth fire alarm 600e receives a regular signal from the relay device 700 via the third fire alarm 600c, the fifth fire alarm 600e receives a regular signal from the relay device 700 via the first fire alarm 600a and the fourth fire alarm 600d. does not receive a signal from relay device 700.

The fifth fire alarm 600e receives the response signal by intermittent reception in the uplink communication time slot assigned to the sixth fire alarm 600f. When the fifth fire alarm 600e receives a regular signal from the third fire alarm 600c, the fifth fire alarm 600e sends a response signal to the third fire alarm 600c in the uplink communication time slot assigned to the fifth fire alarm 600e. Send. A response signal from the sixth fire alarm 600f is also connected to this response signal.

After transmitting the periodic signal to the fifth fire alarm 600e, the third fire alarm 600c intermittently receives a response signal in the uplink communication time slot assigned to the fifth fire alarm 600e. Receive from. The third fire alarm 600c transmits a response signal in the uplink communication time slot assigned to the third fire alarm 600c.

Here, when the fifth fire alarm 600e is called a first alarm, the third fire alarm 600c is called a second alarm, the first fire alarm 600a is called a third alarm, and the fourth fire alarm 600a is called a third alarm. The fire alarm 600d is called a fourth alarm.

FIGS. 7(a) and 7(b) show another outline of communication in the alarm system 1000, particularly an outline of "waiting for detection". In FIG. 7A, it is assumed 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 decides to transmit the detection result. The detection result includes identification information of the sixth fire alarm 600f that detected the fire, and also includes information regarding the abnormality. The communication unit 620 of the sixth fire alarm 600f transmits a monitoring signal in the monitoring time slot of time slot 1030 "N3". The fifth fire alarm 600e receives the monitoring signal in the monitoring time slot of time slot 1030 "N3".

The fifth fire alarm 600e transmits a monitoring signal in the monitoring time slot of time slot 1030 "N2". The third fire alarm 600c receives the monitoring signal in the monitoring time slot of time slot 1030 "N2". The third fire alarm 600c transmits a monitoring signal in the monitoring time slot of time slot 1030 "N1". The second fire alarm 600b receives the monitoring signal in the monitoring time slot of time slot 1030 "N1".

As a result, the monitoring signal is transferred within one frame 1020 from the sixth fire alarm device 600f on the lowest side of the multi-hop network to the second fire alarm device 600b with the number of hops of “1”. On the other hand, if the fire detection sensors 630 of all the fire alarms 600 do not detect the occurrence of a fire, the monitoring signal is not transferred.

The sixth fire alarm 600f transmits the detection result in time slot 1030 "C6" in the uplink communication time slot. The fifth fire alarm 600e receives the detection result in time slot 1030 "C6". Here, since the monitoring unit 626 of the fifth fire alarm 600e monitors the reception of the monitoring signal in the monitoring time slot "N3" and detects the reception of the monitoring signal, the fifth fire alarm 600e , performs intermittent reception in time slot 1030 "C6". On the other hand, if the monitoring unit 626 of the fifth fire alarm 600e does not detect reception of the monitoring signal, the fifth fire alarm 600e stops receiving the communication signal in the time slot 1030 "C6".

The fifth fire alarm 600e transfers the detection result in time slot 1030 "C5". The third fire alarm 600c receives the detection result in time slot 1030 "C5". The third fire alarm 600c transfers the detection result in time slot 1030 "C3". The second fire alarm 600b receives the detection result in time slot 1030 "C3". The second fire alarm 600b transfers the detection result in time slot 1030 "C2". Relay device 700 receives the detection result in time slot 1030 “C2”.

When relay device 700 receives the detection result from second fire alarm 600b, relay device 700 transmits the detection result to management device 800. When the management device 800 receives the detection result, it specifies the fire alarm 600 to sound based on the identification information included in the detection result. The correspondence relationship between the identification information and the information on the fire alarm 600 to be sounded is stored in advance in the management device 800. Here, for example, the fifth fire alarm 600e and the sixth fire alarm 600f are specified. The management device 800 transmits a ringing instruction to the relay device 700, with the identified fire alarm 600 as the final destination.

In FIG. 7B, the same process as that in FIG. 6 fire alarms 600f. When the communication units 620 of the fifth fire alarm 600e and the sixth fire alarm 600f receive the instruction to ring, the control unit 624 causes the buzzer 632 to ring. The control unit 624 may cause the light emitting device to blink.

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

FIG. 9 is a sequence diagram showing a 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 includes route quality information from fire alarm 600 to relay device 700. The communication unit 620 of the n+3 fire alarm 600n+3 receives the HELLO message from the n+1 fire alarm 600n+1, the n+2 fire alarm 600n+2, and the n+4 fire alarm 600n+4 (S10, S12, S14).

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. Link quality is a value that changes depending on received power and decreases as received power increases. The aforementioned route quality is also indicated in the same way as the link quality. The control unit 624 derives a tentative 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.
Temporary route cost = route quality + Ka x link quality + Kb x C Formula (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.

The control unit 624 also derives provisional route costs for other fire alarms 600. The control unit 624 compares a plurality of temporary route costs and selects several fire alarm devices 600 as priority link destinations in descending order of temporary route costs. 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.

The communication unit 620 of the n+3 fire alarm device 600n+3 includes the address of the selected fire alarm device 600 and the link quality at the time of reception in the LINK_REQ sub-message of the HELLO message and transmits it (S16, S18). The (n+1)-th fire alarm 600n+1 and the (n+2)-th fire alarm 600n+2 transmit the LINK_REP sub-message including the link quality in the reverse direction (S20, 22).

The communication unit 620 of the n+3 fire alarm device 600n+3 receives the LINK_REP sub-message. The control unit 624 of the n+3 fire alarm device 600n+3 compares the link quality included in the LINK_REP sub-message from the n+1 fire alarm device 600n+1 with the link quality derived based on the already measured received power, Select the higher link quality. Furthermore, the control unit 624 derives the formal route cost as follows by adding the selected link quality and the route quality for the (n+1)th fire alarm 600n+1.
Formal route cost = route quality + Ka x Max (link quality) + Kb x C Formula (2)
Here, Max indicates selecting the maximum link quality.

The control unit 624 also derives the formal route cost for the n+2 fire alarm 600n+2. The control unit 624 compares the official route cost for the (n+1)th fire alarm 600n+1 and the official route cost for the (n+2)th fire alarm 600n+2, and selects the smaller one as the relay route. The unselected relay route may be used as an alternative route.

In other words, the (n+3)th fire alarm 600n+3 establishes a relay route ( The official route cost (hereinafter referred to as "first cost") for the "first relay route" (hereinafter referred to as "first relay route") is derived. In addition, the n+3 fire alarm 600n+3 exchanges link quality information with the n+2 fire alarm 600n+2, thereby establishing a relay route ( The official route cost (hereinafter referred to as "second cost") for the "second relay route" (hereinafter referred to as "second relay route") is derived. Furthermore, the (n+3)th fire alarm 600n+3 preferentially selects the relay route with the smaller cost compared to the first cost and the second cost. By performing such processing in each fire alarm device 600, a relay route is formed. Information regarding the relay route (alternative route) formed in each fire alarm device 600 is transmitted to the management device 800 via the relay device 700. Management device 800 determines the allocation of time slots 1030 according to the number of hops based on information regarding relay routes (alternative routes).

(3) Occurrence of communication failure FIGS. 10(a) and 10(b) show the situation when a communication failure occurs in the alarm system 1000. In FIG. 10A, a situation is assumed in which an obstacle (not shown) such as an iron door exists between the third fire alarm 600c and the fifth fire alarm 600e in the alarm system 1000 of FIG. The presence of such an obstacle deteriorates the communication environment between the third fire alarm 600c and the fifth fire alarm 600e.

FIG. 10(b) shows an overview of communication in the situation of FIG. 10(a), particularly an overview of "regular monitoring". Relay device 700 transmits a regular signal in time slot 1030 "M" in the downlink communication time slot. The first fire alarm 600a and the second fire alarm 600b receive the periodic signal in time slot 1030 "M". The second fire alarm 600b transmits a periodic signal in time slot 1030 "C2". Third fire alarm 600c receives the periodic signal in time slot 1030 "C2". The third fire alarm 600c transmits a periodic signal in time slot 1030 "C3". The fourth fire alarm 600d and the fifth fire alarm 600e perform intermittent reception in time slot 1030 "C3". The fourth fire alarm 600d receives the regular signal, but the fifth fire alarm 600e fails to receive the regular signal. As a result, the regular signal is not received by the sixth fire alarm 600f either.

The fourth fire alarm 600d transmits a response signal in time slot 1030 "C4" in the uplink communication time slot. Third fire alarm 600c receives the response signal in time slot 1030 "C4". The third fire alarm 600c generates a response signal by concatenating its response with the response signal from the fourth fire alarm 600d, and transmits the response signal in time slot 1030 "C3."

The second fire alarm 600b receives the response signal in time slot 1030 "C3". The second fire alarm 600b generates a response signal by concatenating its response with the response signal from the third fire alarm 600c, and transmits the response signal in time slot 1030 "C2." Relay device 700 receives the response signal in time slot 1030 "C2". The first fire alarm 600a transmits a response signal in time slot 1030 "C1". Relay device 700 receives the response signal in time slot 1030 "C1".

The relay device 700 confirms the response signal received from the first fire alarm 600a and the response signal received from the second fire alarm 600b, so that the first fire alarm 600a to the fourth fire alarm 600d are activated. Make sure you're alive. The relay device 700 also confirms that there is no response from the fifth fire alarm 600e and the sixth fire alarm 600f. Following this, the relay device 700 retransmits the periodic signal in the next frame 1020, as shown in FIG. 3(e). At that time, the relay route (FIG. 1) through which the first periodic signal was transmitted is used. In addition, a monitoring time slot is also used in uplink communication. If there is no response from any of the fire alarm devices 600 even after such retransmission of the periodic signal, the relay device 700 repeats retransmission of the periodic signal using the same relay route. On the other hand, if the relay device 700 confirms that all the fire alarm devices 600 are alive, "wait for detection" is executed from the next frame 1020.

(4) Retransmission on new route (Part 1)
If there is a fire alarm 600 that does not respond even after transmitting the regular signal multiple times through the same relay route, it is necessary to switch the relay route. In this embodiment, (4) retransmission on a new route (part 1) or (5) retransmission on a new route (part 2) is executed. Here, (4) retransmission on a new route (Part 1) will be explained.

FIGS. 11(a) and 11(b) show an overview of retransmission in the alarm system 1000. FIG. 11(a) shows the situation following FIG. 10(a). Until now, the fifth fire alarm 600e has used a relay route via the third fire alarm 600c as a relay route toward the relay device 700. However, in the situation of FIG. 10(a), the fifth fire alarm 600e fails to receive the regular signal from the relay device 700 via the third fire alarm 600c. In the frame 1020 shown as another route retransmission in FIG. (excluding the time slot 1030 assigned to the fire alarm 600e). As a result, the communication unit 620 receives the regular signal from the first fire alarm 600a and the regular signal from the fourth fire alarm 600d. The control unit 624 transmits a periodic signal to the sixth fire alarm 600f in the time slot 1030 assigned to the fifth fire alarm 600e.

The control unit 624 compares the communication quality of the regular signal received from the first fire alarm 600a and the communication quality of the regular signal received from the fourth fire alarm 600d. An example of communication quality is RSSI (Received Signal Strength Indicator). The control unit 624 selects the fire alarm 600 that has transmitted the periodic signal with the larger RSSI, that is, the one with better communication quality. This corresponds to selecting the fire alarm device 600 that transmitted the periodic signal with the lower link quality. In FIG. 11(a), for example, the first fire alarm 600a is selected. The control unit 624 determines switching to a relay route via the first fire alarm 600a as the relay route toward the relay device 700. The relay route that is switched can be said to be an alternative route. The communication unit 620 transmits a response signal to the relay device 700 to the first fire alarm 600a.

FIG. 11(b) shows an outline of communication in the situation of FIG. 11(a), particularly an outline of "alternative route retransmission". Relay device 700 transmits a regular signal in time slot 1030 "M" in the downlink communication time slot. The first fire alarm 600a and the second fire alarm 600b receive the periodic signal in time slot 1030 "M". The first fire alarm 600a transmits a periodic signal in time slot 1030 "C1". The fifth fire alarm 600e receives the periodic signal in time slot 1030 "C1". The second fire alarm 600b transmits a periodic signal in time slot 1030 "C2". Third fire alarm 600c receives the periodic signal in time slot 1030 "C2". The third fire alarm 600c transmits a periodic signal in time slot 1030 "C3".

The fourth fire alarm 600d and the fifth fire alarm 600e perform intermittent reception in time slot 1030 "C3". The fourth fire alarm 600d receives the regular signal, but the fifth fire alarm 600e fails to receive the regular signal. The fourth fire alarm 600d transmits a periodic signal in time slot 1030 "C4". The fifth fire alarm 600e receives the periodic signal in time slot 1030 "C4".

As a result of the processing so far, the fifth fire alarm 600e receives the periodic signal from the first fire alarm 600a and the fourth fire alarm by performing intermittent reception in time slots 1030 "C1" to "C4". The regular signal from the device 600d is being received. As described above, the fifth fire alarm 600e selects the relay route via the first fire alarm 600a as an alternative route to the relay device 700. The fifth fire alarm 600e transmits a periodic signal in time slot 1030 "C5". The sixth fire alarm 600f receives the periodic signal in time slot 1030 "C5".

The sixth fire alarm 600f transmits a monitoring signal in the monitoring time slot of time slot 1030 "N3". The fifth fire alarm 600e receives the monitoring signal in the monitoring time slot of time slot 1030 "N3". The fourth fire alarm 600d transmits a monitoring signal in the monitoring time slot of time slot 1030 "N2". The third fire alarm 600c receives the monitoring signal in the monitoring time slot of time slot 1030 "N2".

The third fire alarm 600c transmits a monitoring signal in the monitoring time slot of time slot 1030 "N1". The fifth fire alarm 600e transmits a monitoring signal in the monitoring time slot of time slot 1030 "N1". The first fire alarm device 600a and the second fire alarm device 600b receive the monitoring signal in the monitoring time slot of time slot 1030 “N1”. As a result, a monitoring signal is transferred within one frame 1020 from the sixth fire alarm 600f on the lowest side of the multi-hop network to the first fire alarm 600a and second fire alarm 600b with a hop count of "1". Ru.

The sixth fire alarm 600f transmits a response signal in time slot 1030 "C6" in the uplink communication time slot. The fifth fire alarm 600e receives the response signal at time slot 1030 "C6". The fifth fire alarm 600e transmits a response signal in time slot 1030 "C5". Since the response signal is the same as before, the explanation will be omitted here. The first fire alarm 600a receives the response signal at time slot 1030 "C5".

The fourth fire alarm 600d transmits a response signal in time slot 1030 "C4" in the uplink communication time slot. Third fire alarm 600c receives the response signal at time slot 1030 "C4". The third fire alarm 600c transmits a response signal in time slot 1030 "C3". The second fire alarm 600b receives the response signal at time slot 1030 "C3". The second fire alarm 600b transmits a response signal in time slot 1030 "C2." Relay device 700 receives the response signal in time slot 1030 "C2". The first fire alarm 600a transmits a response signal in time slot 1030 "C1". Relay device 700 receives the response signal in time slot 1030 "C1".

The relay device 700 checks the response signal received from the first fire alarm 600a and the response signal received from the second fire alarm 600b, thereby transmitting the signals from the first fire alarm 600a to the sixth fire alarm 600f. Make sure everything is alive. Through such processing, the route information stored in the relay device 700 and each fire alarm 600, that is, the routing information, corresponds to the relay route (hereinafter referred to as "main route") in FIG. The notification and response signals are sent along an alternative route by using the auxiliary signal. That is, if the notification signal is sent along the alternative route, the response signal is also sent along the alternative route. Since the alternative route is a relay route with the best communication quality in the fifth fire alarm 600e, it can be said that it is a highly reliable relay route.

(5) Retransmission on new route (Part 2)
12(a)-(b) show another overview of retransmission in alarm system 1000. FIG. 12(a) shows a situation following FIG. 10(a). Until now, the fifth fire alarm 600e has used a relay route via the third fire alarm 600c as a relay route toward the relay device 700. However, in the situation of FIG. 10(a), the fifth fire alarm 600e fails to receive the regular signal from the relay device 700 via the third fire alarm 600c. On the other hand, the control unit 624 of the fifth fire alarm 600e derives the link quality for other surrounding fire alarms 600 when executing the above-described routing process. The link quality may be periodically derived even after the routing process is completed. For example, the link quality for the first fire alarm 600a, the third fire alarm 600c, and the fourth fire alarm 600d is derived.

In the frame 1020 shown as another route retransmission in FIG. 3(e), the control unit 624 of the fifth fire alarm 600e compares the link quality for each fire alarm 600, and , selects another fire alarm 600 with the lowest link quality. This corresponds to selecting another fire alarm 600 with the highest communication quality, excluding the third fire alarm 600c. Here, the first fire alarm 600a is selected as an example. The control unit 624 causes the communication unit 620 to perform intermittent reception in the time slot 1030 assigned to the first fire alarm 600a in the downlink communication time slot. As a result, the communication unit 620 receives the regular signal from the first fire alarm 600a. In other words, when the fifth fire alarm 600e fails to receive the regular signal from the third fire alarm 600c, the link quality with the first fire alarm 600a is higher than the link quality with the fourth fire alarm 600d. If it is OK, a regular signal is received via the first fire alarm 600a. The fifth fire alarm 600e does not receive the regular signal from the fourth fire alarm 600d. The control unit 624 transmits a periodic signal to the sixth fire alarm 600f in the time slot 1030 assigned to the fifth fire alarm 600e.

The control unit 624 determines a relay route via the first fire alarm 600a as an alternative route to the relay device 700. The communication unit 620 transmits a response signal to the relay device 700 to the first fire alarm 600a. That is, the fifth fire alarm 600e transmits a response signal to the first fire alarm 600a when receiving a regular signal from the first fire alarm 600a.

FIG. 12(b) shows an outline of communication in the situation of FIG. 12(a), particularly an outline of "retransmission via another route". The fifth fire alarm 600e in FIG. 11(b) performs intermittent reception in time slots 1030 "C1" to "C4" and "C6" in the downlink communication time slot. On the other hand, the fifth fire alarm 600e in FIG. 12(b) performs intermittent reception in time slot 1030 "C1" in the downlink communication time slot, but in time slots 1030 "C2" to "C4" and "C6". Do not perform intermittent reception. The rest is the same as in FIG. 11(b), so the explanation will be omitted here.

(6) Notification of route change Even if communication via the main route fails due to processing in (4) Retransmission on the new route (Part 1) or (5) Retransmission on the new route (Part 2), communication via the alternative route becomes possible. Following this, in the alarm system 1000, the alternative route is changed to the main route.

13(a)-(b) show an overview of notifications in the alarm system 1000. FIG. 13(a) shows a situation following FIG. 11(a) or FIG. 12(a). When the fifth fire alarm 600e switches the relay route including the third fire alarm 600c to the relay route including the first fire alarm 600a, the fifth fire alarm 600e provides a route switching notification to notify the relay device 700 of the switching of the relay route. is transmitted to the first fire alarm 600a. The route switching notification indicates, for example, that the third fire alarm 600c has been switched to the first fire alarm 600a. The route switching notification is received by the relay device 700 via the first fire alarm 600a.

FIG. 13(b) shows an overview of communication in the situation of FIG. 13(a). The fifth fire alarm device 600e that has generated the route switching notification transmits a monitoring signal in the monitoring time slot of time slot 1030 "N1". The first fire alarm 600a receives the monitoring signal in the monitoring time slot of time slot 1030 "N1". The fifth fire alarm 600e transmits a route switching notification in time slot 1030 "C5". The first fire alarm device 600a, which received the route switching notification in time slot 1030 "C5", transmits the route switching notification in time slot 1030 "C1". Relay device 700 receives the route switching notification in time slot 1030 "C1".

Control unit 720 of relay device 700 updates the relay route of alarm system 1000 based on the route switching notification received from first fire alarm 600a. As a result, the relay route managed by the relay device 700 is updated from FIG. 1 to FIG. 12(a). By updating the relay route in this way, the number of hops from the fifth fire alarm 600e to the relay device 700 is changed from "3" to "2", and the number of hops from the sixth fire alarm 600f to the relay device 700 is changed from "3" to "2". Changed from "4" to "3".

(7) Slot Switching/Aging If there is a fire alarm device 600 whose number of hops to the relay device 700 is changed by updating the relay route, it is necessary to change the allocation of communication time slots. The allocation unit 722 of the relay device 700 determines a change in the allocation of the fire alarm 600 to the downlink communication time slot and the uplink communication time slot according to the number of hops. When a change in the allocation of the fire alarm 600 to the downlink communication time slot and the uplink communication time slot is determined, the control unit 720 generates slot information indicating the changed allocation. The output unit 712 outputs slot information to the plurality of fire alarm devices 600. For example, the slot information is transmitted using the downlink communication time slot before the allocation is changed. Each fire alarm device 600 that has received the slot information recognizes the downlink communication time slot and uplink communication time slot assigned to itself. After that, the assignment of the fire alarm 600 to the downlink communication time slot and the uplink communication time slot is actually changed.

Each fire alarm 600 recognizes the change in the downlink communication time slot and uplink communication time slot, but does not recognize the changed relay route. Therefore, each fire alarm 600 has a time slot assigned to another fire alarm 600 that was connected on the relay route before the change and is not connected on the relay route after the change. 1030 also performs intermittent reception. Since such intermittent reception is a wasteful process, it is desirable to update the relay route. Each fire alarm device 600 performs aging processing in order to forget the relay route before the change and remember the relay route after the change.

FIGS. 14(a) and 14(b) show an overview of slot switching and aging in the alarm system 1000. FIG. 14(a) shows a situation following FIG. 13(a). Although the allocation of the fire alarm 600 to the downlink communication time slots and uplink communication time slots has been changed, the relay route is shown in the same manner as in FIG. 13(a). In such a relay route, the fire alarm 600 that has decided to change the relay route is the fifth fire alarm 600e. Furthermore, in the changed relay route, the higher-order fire alarm 600 that is newly connected to the fifth fire alarm 600e is the first fire alarm 600a. Furthermore, in the changed relay route, the third fire alarm 600c is the fire alarm 600 that is disconnected from the fifth fire alarm 600e.

Aging processing is performed in "periodic monitoring." The fifth fire alarm 600e receives the regular signal in the downlink communication time slot assigned to the first fire alarm 600a. Furthermore, upon receiving the periodic signal, the fifth fire alarm 600e transmits a response signal to the first fire alarm 600a in the uplink communication time slot assigned to the fifth fire alarm 600e. At that time, the next destination of the response signal is set to the first fire alarm 600a. After transmitting the response signal to the first fire alarm 600a, if the fifth fire alarm 600e does not receive the retransmission of the periodic signal from the relay device 700, the fifth fire alarm 600e transmits the upper side from the third fire alarm 600c to the first fire alarm. Switch to the container 600a. This corresponds to switching the reception of the regular signal in the downlink communication time slot assigned to the third fire alarm 600c to the reception of the regular signal in the downlink communication time slot assigned to the first fire alarm 600a. do.

The third fire alarm 600c transmits a periodic signal to the fifth fire alarm 600e. If the third fire alarm 600c does not receive a response signal from the fifth fire alarm 600e in the uplink communication time slot assigned to the fifth fire alarm 600e after transmitting the periodic signal, the third fire alarm 600c receives If the retransmission of the regular signal is not received, the fifth fire alarm 600e on the lower side is deleted. This means that the periodic signal is not transmitted to the fifth fire alarm 600e in the downlink communication time slot assigned to the third fire alarm 600c, and in the uplink communication time slot assigned to the fifth fire alarm 600e. This corresponds to not receiving a response signal.

The first fire alarm 600a is assigned to the fifth fire alarm 600e in a situation where the response signal is not received from the fifth fire alarm 600e in the uplink communication time slot assigned to the fifth fire alarm 600e. When the response signal is received from the fifth fire alarm 600e in the assigned uplink communication time slot, the response signal is transmitted in the uplink communication time slot assigned to the first fire alarm 600a. Subsequently, if the first fire alarm 600a does not receive the retransmission of the periodic signal from the relay device 700, the first fire alarm 600a adds the fifth fire alarm 600e to the lower side. This corresponds to transmitting a regular signal to the fifth fire alarm 600e in the downlink communication time slot assigned to the first fire alarm 600a.

FIG. 14(b) shows an overview of communication in the situation of FIG. 14(a), particularly an overview of communication during aging processing. Due to the change in the relay route, the number of hops to the fifth fire alarm 600e and the sixth fire alarm 600f has been changed. Therefore, the downlink communication time slot includes the relay device 700, the first fire alarm 600a, the second fire alarm 600b, the third fire alarm 600c, the fifth fire alarm 600e, the fourth fire alarm 600d, and the third fire alarm 600c. 6 fire alarms 600f are assigned in order from the front side. Also, in the uplink communication time slot, the sixth fire alarm 600f, the fourth fire alarm 600d, the fifth fire alarm 600e, the third fire alarm 600c, the second fire alarm 600b, and the first fire alarm 600a and relay devices 700 are allocated in order from the front side.

Relay device 700 transmits a regular signal in time slot 1030 "M" in the downlink communication time slot. The first fire alarm 600a and the second fire alarm 600b receive the periodic signal in time slot 1030 "M". The first fire alarm 600a transmits a periodic signal in time slot 1030 "C1". The fifth fire alarm 600e receives the periodic signal in time slot 1030 "C1". The second fire alarm 600b transmits a periodic signal in time slot 1030 "C2". Third fire alarm 600c receives the periodic signal in time slot 1030 "C2". The third fire alarm 600c transmits a periodic signal in time slot 1030 "C3".

The fourth fire alarm 600d and the fifth fire alarm 600e perform intermittent reception in time slot 1030 "C3". The fourth fire alarm 600d receives the regular signal, but the fifth fire alarm 600e fails to receive the regular signal. The fifth fire alarm 600e transmits a periodic signal in time slot 1030 "C5". The sixth fire alarm 600f receives the periodic signal in time slot 1030 "C5".

The fourth fire alarm 600d and the sixth fire alarm 600f transmit monitoring signals in the monitoring time slot of time slot 1030 "N2". The third fire alarm 600c and the fifth fire alarm 600e receive the monitoring signal in the monitoring time slot of time slot 1030 "N2". The third fire alarm 600c and the fifth fire alarm 600e transmit monitoring signals in the monitoring time slot of time slot 1030 "N1". The first fire alarm device 600a and the second fire alarm device 600b receive the monitoring signal in the monitoring time slot of time slot 1030 “N2”.

The sixth fire alarm 600f transmits a response signal in time slot 1030 "C6" in the uplink communication time slot. The fifth fire alarm 600e receives the response signal at time slot 1030 "C6". The fourth fire alarm 600d transmits a response signal in time slot 1030 "C4" in the uplink communication time slot. Third fire alarm 600c receives the response signal at time slot 1030 "C4".

The fifth fire alarm 600e transmits a response signal in time slot 1030 "C5". Since the response signal is the same as before, the explanation will be omitted here. The first fire alarm 600a receives the response signal at time slot 1030 "C5". The third fire alarm 600c transmits a response signal in time slot 1030 "C3". The second fire alarm 600b receives the response signal at time slot 1030 "C3". The second fire alarm 600b transmits a response signal in time slot 1030 "C2". Relay device 700 receives the response signal in time slot 1030 "C2". The first fire alarm 600a transmits a response signal in time slot 1030 "C1". Relay device 700 receives the response signal in time slot 1030 "C1".

The relay device 700 checks the response signal received from the first fire alarm 600a and the response signal received from the second fire alarm 600b, thereby transmitting the signals from the first fire alarm 600a to the sixth fire alarm 600f. Make sure everything is alive. As a result, relay device 700 does not retransmit the periodic signal. Through such processing, the aging condition is satisfied in each fire alarm device 600, and the relay route before the change is deleted.

(8) Communication after route switching After aging, the alternative route becomes the main route. FIGS. 15(a) and 15(b) show an overview of communication after route switching in the alarm system 1000. FIG. 15(a) shows a situation following FIG. 14(a). This corresponds to after the aging process. FIG. 15(b) shows an overview of communication in the situation of FIG. 15(a), particularly an overview of "regular monitoring". Relay device 700 transmits a regular signal in time slot 1030 "M" in the downlink communication time slot. The first fire alarm 600a and the second fire alarm 600b receive the periodic signal in time slot 1030 "M". The first fire alarm 600a transmits a periodic signal in time slot 1030 "C1". The fifth fire alarm 600e receives the periodic signal in time slot 1030 "C1". The second fire alarm 600b transmits a periodic signal in time slot 1030 "C2". Third fire alarm 600c receives the periodic signal in time slot 1030 "C2". The third fire alarm 600c transmits a periodic signal in time slot 1030 "C3". The fourth fire alarm 600d receives the periodic signal in time slot 1030 "C3". The fifth fire alarm 600e transmits a periodic signal in time slot 1030 "C5". The sixth fire alarm 600f receives the periodic signal in time slot 1030 "C5".

The sixth fire alarm 600f transmits a response signal in time slot 1030 "C6" in the uplink communication time slot. The fifth fire alarm 600e receives the response signal at time slot 1030 "C6". The fourth fire alarm 600d transmits a response signal in time slot 1030 "C4" in the uplink communication time slot. Third fire alarm 600c receives the response signal at time slot 1030 "C4". The fifth fire alarm 600e transmits a response signal in time slot 1030 "C5". Since the response signal is the same as before, the explanation will be omitted here. The first fire alarm 600a receives the response signal at time slot 1030 "C5".

The third fire alarm 600c transmits a response signal in time slot 1030 "C3". The second fire alarm 600b receives the response signal at time slot 1030 "C3". The second fire alarm 600b transmits a response signal in time slot 1030 "C2". Relay device 700 receives the response signal in time slot 1030 "C2". The first fire alarm 600a transmits a response signal in time slot 1030 "C1". Relay device 700 receives the response signal in time slot 1030 "C1". Since the relay route is switched and regular monitoring is performed at predetermined timing, monitoring time slots are not used in uplink communication.

The main body of the device, system, or method in the present disclosure includes a computer. When this computer executes the program, the main functions of the device, system, or method of the present disclosure are realized. A computer includes, as its main hardware configuration, a processor that operates according to a program. The type of processor does not matter as long as it can implement a function by executing a program. A processor is composed of one or more electronic circuits including a semiconductor integrated circuit (IC) or a large scale integration (LSI). A plurality of electronic circuits may be integrated on one chip or may be provided on a plurality of chips. A plurality of chips may be integrated into one device, or may be provided in a plurality of devices. The program is recorded on a computer-readable non-transitory storage medium such as a ROM, optical disk, or hard disk drive. The program may be stored in the recording medium in advance, or may be supplied to the recording medium via a wide area communication network including the Internet.

According to this embodiment, since it is possible to receive signals from each of a plurality of alarm devices, a plurality of relay routes can be secured. Furthermore, since multiple relay routes are secured, communication reliability can be improved even in the event of constant communication failure. Furthermore, since a plurality of relay routes are secured, it is possible to smoothly switch between relay routes in a multi-hop network. Furthermore, when a signal is being received from the connected fire alarm device 600, signals from other fire alarm devices 600 are not received, so an increase in power consumption can be suppressed. Moreover, if the reception of a signal from the connected fire alarm device 600 fails, the signal from another fire alarm device 600 is received, so that the relay route can be smoothly switched in the multi-hop network.

Further, since it is possible to receive signals from two or more other fire alarm devices 600 that are not connected, communication reliability can be further improved even in the event of a constant communication failure. Further, since it is possible to receive signals from two or more other fire alarm devices 600 that are not connected, relay routes can be smoothly switched in a multi-hop network. In addition, it is possible to receive signals from two or more other fire alarm devices 600 that are not connected, and if reception of a signal from the connected fire alarm device 600 fails, the other fire alarm device 600 with better link quality can receive signals. Since the signal from the fire alarm 600 is received, the relay route can be smoothly switched in the multi-hop network. In addition, it is possible to receive signals from two or more other fire alarm devices 600 that are not connected, and if reception of a signal from the connected fire alarm device 600 fails, the other fire alarm device 600 with better link quality can receive signals. Since the signal from the fire alarm 600 is received, switching of the relay route can be performed efficiently. Further, since the upstream signal is transmitted to the fire alarm device 600 that has received the downstream signal, the upstream communication reliability can be improved.

Furthermore, when the relay route is switched, a route switch notification is sent to inform the relay device 700 of the switching of the relay route, so that the relay route can be switched smoothly in a multi-hop network. In addition, if the retransmission of the periodic signal from the relay device 700 is not received after transmitting the response signal to the new fire alarm 600, the periodic signal in the downlink communication time slot assigned to the original fire alarm 600 is Since the reception is switched to the reception of the regular signal in the downlink communication time slot assigned to the third new fire alarm 600, unnecessary reception processing can be stopped. Further, since unnecessary reception processing is stopped, an increase in power consumption can be suppressed.

Furthermore, after transmitting the periodic signal to the fire alarm 600, if a response signal is not received in the uplink communication time slot assigned to the fire alarm 600, the retransmission of the periodic signal from the relay device 700 must be received. Since communication is not performed in the downlink communication time slot and the uplink communication time slot assigned to the fire alarm 600, unnecessary communication processing can be stopped. Further, since unnecessary communication processing is stopped, an increase in power consumption can be suppressed. Further, when a response signal is received from a fire alarm device 600 that has not received a response signal, the response signal is transmitted, and if the retransmission of the periodic signal from the relay device 700 is not received, the periodic signal is sent to the fire alarm device 600 concerned. Since the information is transmitted, relay routes can be switched smoothly in a multi-hop network.

Further, since the fire alarm device 600 with a smaller number of hops to the relay device 700 is assigned a forward downlink communication time slot, the transfer can be completed within the frame 1020. Further, since the fire alarm device 600 with a larger number of hops to the relay device 700 is assigned an earlier uplink communication time slot, the transfer can be completed within the frame 1020. Further, when a route switching notification is received, slot information is transmitted when the allocation of the fire alarm device 600 to the downlink communication time slot and the uplink communication time slot is changed, so that the change in allocation can be notified.

An overview of one aspect of the present disclosure may be provided by the following items.
(Item 1-1)
Equipped with a plurality of alarm devices (600) forming a multi-hop network extending from a relay device (700),
The plurality of alarm devices (600) include a first alarm device (600e), a second alarm device (600c), and a third alarm device (600a),
The first alarm device (600e) receives a signal from the relay device (700) via the second alarm device (600c),
The first alarm device (600e) can also receive a signal from the relay device (700) via the third alarm device (600a).
Alarm system (1000).

(Item 1-2)
When the first alarm device (600e) receives a signal from the relay device (700) via the second alarm device (600c), the first alarm device (600e) receives the signal from the relay device (700) via the third alarm device (600a). No signal is received from the relay device (700),
When the first alarm device (600e) fails to receive a signal from the relay device (700) via the second alarm device (600c), the first alarm device (600e) receives the signal from the relay device via the third alarm device (600a). The alarm system (1000) according to item 1-1, which receives a signal from the device (700).

(Item 1-3)
The plurality of alarm devices (600) also include a fourth alarm device (600d),
The first alarm device (600e) can also receive a signal from the relay device (700) via the fourth alarm device (600d),
When the first alarm device (600e) receives a signal from the relay device (700) via the second alarm device (600c), the first alarm device (600e) receives the signal from the relay device (700) via the fourth alarm device (600d). No signal is received from the relay device (700),
When the first alarm device (600e) fails to receive a signal from the relay device (700) via the second alarm device (600c), the first alarm device (600e) receives the signal from the relay device via the third alarm device (600a). The alarm system (1000) according to item 1-2, which receives a signal from the device (700) and also receives a signal from the relay device (700) via the fourth alarm device (600d).

(Item 1-4)
The plurality of alarm devices (600) also include a fourth alarm device (600d),
The first alarm device (600e) can also receive a signal from the relay device (700) via the fourth alarm device (600d),
When the first alarm device (600e) receives a signal from the relay device (700) via the second alarm device (600c), the first alarm device (600e) receives the signal from the relay device (700) via the fourth alarm device (600d). No signal is received from the relay device (700),
When the first alarm device (600e) fails to receive a signal from the relay device (700) via the second alarm device (600c), the link quality with the third alarm device (600a) is determined. If the link quality with the fourth alarm device (600d) is better, the signal from the relay device (700) is received via the third alarm device (600a), and the fourth alarm device (600d) is connected to the fourth alarm device (600d). The alarm system (1000) according to item 1-2, which does not receive a signal from the relay device (700) via the relay device (700).

(Item 1-5)
When the first alarm device (600e) is receiving a signal from the relay device (700) via the second alarm device (600c), the first alarm device (600e) transmits a signal to the relay device (700) to the second alarm device (600c). Send to 2 alarm (600c),
When the first alarm device (600e) receives a signal from the relay device (700) via the third alarm device (600a), the first alarm device (600e) transmits a signal to the relay device (700) to the third alarm device (600a). 3. The alarm system (1000) according to any one of (item 1-1) to (item 1-3).

(Item 1-6)
An alarm device (600) among a plurality of alarm devices (600) forming a multi-hop network extending from a relay device (700),
When this alarm (600) is called a first alarm (600e), the plurality of alarms (600) also include a second alarm (600c) and a third alarm (600a),
It is possible to receive a signal from the relay device (700) via the second alarm device (600c) and also receive a signal from the relay device (700) via the third alarm device (600a). A communication department (620) and
a control unit (624) that controls the communication unit (620);
An alarm device (600) comprising:

(Item 1-7)
A communication method in an alarm device (600) among a plurality of alarm devices (600) forming a multi-hop network extending from a relay device (700),
When this alarm (600) is called a first alarm (600e), the plurality of alarms (600) also include a second alarm (600c) and a third alarm (600a),
receiving a signal from the relay device (700) via the second alarm (600c);
a step of being able to receive a signal from the relay device (700) also via the third alarm device (600a);
A communication method comprising:

(Item 1-8)
A program to be executed by an alarm device (600) among a plurality of alarm devices (600) forming a multi-hop network extending from a relay device (700),
When this alarm (600) is called a first alarm (600e), the plurality of alarms (600) also include a second alarm (600c) and a third alarm (600a),
receiving a signal from the relay device (700) via the second alarm (600c);
A program for causing a computer to execute a step of being able to receive a signal from the relay device (700) also via the third alarm device (600a).

(Item 2-1)
Equipped with a plurality of alarm devices (600) forming a multi-hop network extending from a relay device (700),
The plurality of alarm devices (600) include a first alarm device (600e), a second alarm device (600c), and a third alarm device (600a),
The first alarm device (600e) receives a signal from the relay device (700) via the second alarm device (600c),
When the first alarm device (600e) fails to receive a signal from the relay device (700) via the second alarm device (600c), the first alarm device (600e) receives the signal from the relay device via the third alarm device (600a). receiving a signal from the device (700);
When the first alarm device (600e) switches a relay route including the second alarm device (600c) to a relay route including the third alarm device (600a), the first alarm device (600e) switches the relay route to the relay device (600e). transmitting a route switching notification to the third alarm (600a) to notify the third alarm (600a);
Alarm system (1000).

(Item 2-2)
In order to transmit the signal from the relay device (700), a plurality of downlink communication time slots to be allocated to each of the plurality of alarm devices (600) are arranged on a time axis,
In order to transmit a signal to the relay device (700), a plurality of uplink communication time slots to be allocated to each of the plurality of alarm devices (600) are arranged on a time axis,
The signal from the relay device (700) is a regular signal periodically transmitted from the relay device (700),
The signal to the relay device (700) is a response signal to be transmitted when each of the plurality of alarm devices (600) receives the periodic signal,
When the first alarm device (600e) receives the regular signal in the downlink communication time slot assigned to the second alarm device (600c), the first alarm device (600e) receives the periodic signal from the periodic signal assigned to the first alarm device (600e). transmitting the response signal to the second alarm (600c) in an uplink communication time slot;
If the first alarm device (600e) fails to receive the periodic signal in the downlink communication time slot assigned to the second alarm device (600c), the first alarm device (600e) is assigned to the third alarm device (600a). receiving the periodic signal in the downlink communication time slot;
When the first alarm device (600e) receives the periodic signal in the downlink communication time slot assigned to the third alarm device (600a), the first alarm device (600e) transmitting the response signal to the third alarm (600a) in an uplink communication time slot;
If the first alarm device (600e) does not receive the retransmission of the periodic signal from the relay device (700) after transmitting the response signal to the third alarm device (600a), the second alarm device (600e) transmits the response signal to the third alarm device (600a). (600c) switches the reception of the periodic signal in the downlink communication time slot assigned to the third alarm (600a) to the reception of the periodic signal in the downlink communication time slot assigned to the third alarm (600a) (Item 2 The alarm system (1000) described in -1).

(Item 2-3)
In order to transmit the signal from the relay device (700), a plurality of downlink communication time slots to be allocated to each of the plurality of alarm devices (600) are arranged on a time axis,
In order to transmit a signal to the relay device (700), a plurality of uplink communication time slots to be allocated to each of the plurality of alarm devices (600) are arranged on a time axis,
The signal from the relay device (700) is a regular signal periodically transmitted from the relay device (700),
The signal to the relay device (700) is a response signal to be transmitted when each of the plurality of alarm devices (600) receives the periodic signal,
The second alarm (600c) transmits the periodic signal to the first alarm (600e) in the downlink communication time slot assigned to the second alarm (600c),
After transmitting the periodic signal to the first alarm (600e), the second alarm (600c) transmits the response signal in the uplink communication time slot assigned to the first alarm (600e). When received from the first alarm device (600e), transmitting the response signal in the uplink communication time slot assigned to the second alarm device (600e);
After transmitting the periodic signal to the first alarm (600e), the second alarm (600c) transmits the response signal in the uplink communication time slot assigned to the first alarm (600e). If the periodic signal is not received from the first alarm (600e) and the periodic signal is not retransmitted from the relay device (700), the downlink communication time slot assigned to the second alarm (600c) The periodic signal is not transmitted to the first alarm device (600e), and the response signal is not received in the uplink communication time slot assigned to the first alarm device (600e) (Item 2- The alarm system (1000) described in 1).

(Item 2-4)
In order to transmit the signal from the relay device (700), a plurality of downlink communication time slots to be allocated to each of the plurality of alarm devices (600) are arranged on a time axis,
In order to transmit a signal to the relay device (700), a plurality of uplink communication time slots to be allocated to each of the plurality of alarm devices (600) are arranged on a time axis,
The signal from the relay device (700) is a regular signal periodically transmitted from the relay device (700),
The signal to the relay device (700) is a response signal to be transmitted when each of the plurality of alarm devices (600) receives the periodic signal,
In a situation where the third alarm device (600a) does not receive the response signal from the first alarm device (600e) in the uplink communication time slot assigned to the first alarm device (600e), the third alarm device (600a) When the response signal is received from the first alarm device (600e) in the uplink communication time slot assigned to the first alarm device (600e), the uplink communication time slot assigned to the third alarm device (600a) transmitting the response signal in a time slot;
If the third alarm device (600a) does not receive retransmission of the periodic signal from the relay device (700), the third alarm device (600a) transmits the periodic signal in the downlink communication time slot assigned to the third alarm device (600a). The alarm system (1000) according to item 2-1, transmitting a signal to the first alarm device (600e).

(Item 2-5)
The lower the number of hops to the relay device (700) of the alarm device (600), the earlier the downlink communication time slot is assigned,
The alarm device (600) with a larger number of hops to the relay device (700) is assigned the uplink communication time slot on the earlier side,
When the relay device (700) receives the route switching notification and the allocation of the alarm device (600) to the downlink communication time slot and the uplink communication time slot is changed, the relay device (700) updates the changed allocation to the downlink communication time slot and the uplink communication time slot. The alarm system (1000) according to any one of (item 2-2) to (item 2-4), wherein the indicated slot information is transmitted to each of the plurality of alarm devices (600).

(Item 2-6)
The alarm system according to item 2-1, wherein the relay device, when receiving the route switching notification, transmits route information indicating the switched relay route to each of the plurality of alarm devices.

(Item 2-7)
An alarm device (600) among a plurality of alarm devices (600) forming a multi-hop network extending from a relay device (700),
When the main alarm (600) is called a first alarm (600e), the plurality of alarms also include a second alarm (600c) and a third alarm (600a),
a communication unit (620) that receives a signal from the relay device (700) via the second alarm (600c);
A control unit (624) that controls the communication unit (620),
When the communication unit (620) fails to receive a signal from the relay device (700) via the second alarm device (600c), the communication unit (620) transmits the signal from the relay device (700) via the third alarm device (600a). 700),
When switching a relay route including the second alarm device (600c) to a relay route including the third alarm device (600a), the communication unit (620) switches the relay route to the relay device (700). transmitting a route switching notification to the third alarm (600a) to notify the third alarm (600a);
Alarm (600).

(Item 2-8)
A communication method in an alarm device (600) among a plurality of alarm devices (600) forming a multi-hop network extending from a relay device (700),
When this alarm (600) is called a first alarm (600e), the plurality of alarms (600) also include a second alarm (600c) and a third alarm (600a),
receiving a signal from the relay device (700) via the second alarm (600c);
If reception of the signal from the relay device (700) via the second alarm device (600c) fails, a signal from the relay device (700) is received via the third alarm device (600a). step and
When the relay route including the second alarm device (600c) is switched to the relay route including the third alarm device (600a), a route switching notification is sent to notify the relay device (700) of the switching of the relay route. transmitting to the third alarm (600a);
A communication method comprising:

(Item 2-9)
A program to be executed by an alarm device (600) among a plurality of alarm devices (600) forming a multi-hop network extending from a relay device (700),
When this alarm (600) is called a first alarm (600e), the plurality of alarms (600) also include a second alarm (600c) and a third alarm (600a),
receiving a signal from the relay device (700) via the second alarm (600c);
If reception of the signal from the relay device (700) via the second alarm device (600c) fails, a signal from the relay device (700) is received via the third alarm device (600a). step and
When the relay route including the second alarm device (600c) is switched to the relay route including the third alarm device (600a), a route switching notification is sent to notify the relay device (700) of the switching of the relay route. A program for causing a computer to execute the step of transmitting data to the third alarm device (600a).

The present disclosure has been described above based on examples. It will be understood by those skilled in the art that this example is merely an example, and that various modifications can be made to the combinations of these components or processing processes, and that such modifications are also within the scope of the present disclosure. .

In this embodiment, the relay device 700 is connected to a fire alarm device 600 that has both a fire detection function and an alarm sounding function. However, the present invention is not limited to this, and for example, the fire alarm 600 may have only a fire detection function. Furthermore, instead of the fire alarm 600, a sensor that detects not only fire but also water damage, earthquakes, gas leaks, and generation of CO (carbon monoxide) due to incomplete combustion may be used. According to this modification, the degree of freedom in configuration can be improved.

In this embodiment, when a route switching notification is sent from the fire alarm 600 to the relay device 700 and the relay route is updated in the relay device 700, when the allocation of communication time slots is changed, the relay device 700 Slot information is transmitted to multiple fire alarms 600. However, the present invention is not limited thereto, and for example, the relay device 700 may transmit not only slot information but also route information indicating an updated (switched) relay route to each fire alarm device 600. Each fire alarm 600 recognizes the updated relay route based on the received route information. For example, if the number of hops of each fire alarm device 600 does not change even if the relay route is updated, the above-described aging is performed. On the other hand, if the relay route is updated and the number of hops of each fire alarm device 600 changes, route information is transmitted. According to the modification, it is possible to reliably switch the relay route.

600 fire alarm (alarm), 620 communication unit, 622 processing unit, 624 control unit, 626 monitoring 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, 1000 alarm system, 1010 superframe, 1020 frame, 1030 time slot.

Claims (9)

Equipped with multiple alarm devices that form a multi-hop network extending from relay devices,
The plurality of alarms include a first alarm, a second alarm, and a third alarm,
The first alarm receives a signal from the relay device via the second alarm,
The first alarm receives a signal from the relay device via the third alarm if reception of the signal from the relay device via the second alarm fails,
When the first alarm device switches a relay route including the second alarm device to a relay route including the third alarm device, the first alarm device sends a route switching notification to the relay device to notify the switching of the relay route to the third alarm device. 3 Send to alarm,
alarm system. In order to transmit the signal from the relay device, a plurality of downlink communication time slots to be allocated to each of the plurality of alarm devices are arranged on a time axis,
In order to transmit a signal to the relay device, a plurality of uplink communication time slots to be assigned to each of the plurality of alarm devices are arranged on a time axis,
The signal from the relay device is a regular signal periodically transmitted from the relay device,
The signal to the relay device is a response signal to be transmitted when each of the plurality of alarm devices receives the periodic signal,
When the first alarm receives the periodic signal in the downlink communication time slot assigned to the second alarm, the first alarm transmits the response signal in the uplink communication time slot assigned to the first alarm. to the second alarm,
If the first alarm device fails to receive the periodic signal in the downlink communication time slot assigned to the second alarm device, the first alarm device receives the periodic signal in the downlink communication time slot assigned to the third alarm device. receive periodic signals,
When the first alarm receives the periodic signal in the downlink communication time slot assigned to the third alarm, the first alarm transmits the response signal in the uplink communication time slot assigned to the first alarm. to the third alarm,
If the first alarm device does not receive the retransmission of the periodic signal from the relay device after transmitting the response signal to the third alarm device, the first alarm device transmits the downlink communication time allocated to the second alarm device. The alarm system according to claim 1, wherein reception of the periodic signal in a slot is switched to reception of the periodic signal in the downlink communication time slot assigned to the third alarm device. In order to transmit the signal from the relay device, a plurality of downlink communication time slots to be allocated to each of the plurality of alarm devices are arranged on a time axis,
In order to transmit a signal to the relay device, a plurality of uplink communication time slots to be assigned to each of the plurality of alarm devices are arranged on a time axis,
The signal from the relay device is a regular signal periodically transmitted from the relay device,
The signal to the relay device is a response signal to be transmitted when each of the plurality of alarm devices receives the periodic signal,
The second alarm transmits the periodic signal to the first alarm in the downlink communication time slot assigned to the second alarm,
When the second alarm receives the response signal from the first alarm in the uplink communication time slot assigned to the first alarm after transmitting the periodic signal to the first alarm, transmitting the response signal in the uplink communication time slot assigned to the second alarm;
If the second alarm does not receive the response signal from the first alarm in the uplink communication time slot assigned to the first alarm after transmitting the periodic signal to the first alarm , if retransmission of the periodic signal is not received from the relay device, the periodic signal is not transmitted to the first alarm in the downlink communication time slot assigned to the second alarm, and 2. The alarm system according to claim 1, wherein the response signal is not received in the uplink communication time slot assigned to one alarm device. In order to transmit the signal from the relay device, a plurality of downlink communication time slots to be allocated to each of the plurality of alarm devices are arranged on a time axis,
A plurality of uplink communication time slots to be assigned to each of the plurality of alarm devices are arranged on a time axis in order to transmit a signal to the relay device,
The signal from the relay device is a regular signal periodically transmitted from the relay device,
The signal to the relay device is a response signal to be transmitted when each of the plurality of alarm devices receives the periodic signal,
In a situation where the third alarm device does not receive the response signal from the first alarm device in the uplink communication time slot assigned to the first alarm device, the third alarm device receives the response signal from the first alarm device. Upon receiving the response signal from the first alarm in the uplink communication time slot, transmitting the response signal in the uplink communication time slot assigned to the third alarm;
If the third alarm does not receive retransmission of the periodic signal from the relay device, the third alarm transmits the periodic signal to the first alarm in the downlink communication time slot assigned to the third alarm. The alarm system according to claim 1. The lower the number of hops to the relay device, the earlier the downlink communication time slot is assigned to the alarm device,
The higher the number of hops to the relay device, the earlier the uplink communication time slot is assigned to the alarm device,
When the relay device receives the route switching notification and the allocation of alarm devices to the downlink communication time slot and the uplink communication time slot is changed, the relay device transmits slot information indicating the changed allocation. The alarm system according to any one of claims 2 to 4, wherein the alarm is transmitted to each of the plurality of alarm devices. The alarm system according to claim 1, wherein the relay device, when receiving the route switching notification, transmits route information indicating the switched relay route to each of the plurality of alarm devices. An alarm device among multiple alarm devices configuring a multi-hop network extending from a relay device,
When this alarm device is called a first alarm device, the plurality of alarm devices also include a second alarm device and a third alarm device,
a communication unit that receives a signal from the relay device via the second alarm;
and a control unit that controls the communication unit,
The communication unit receives a signal from the relay device via the third alarm when receiving the signal from the relay device via the second alarm,
When the relay route including the second alarm device is switched to the relay route including the third alarm device, the communication unit sends a route switching notification to the relay device to notify the switching of the relay route to the third alarm device. transmit to the device,
alarm. A communication method in an alarm device among a plurality of alarm devices constituting a multi-hop network extending from a relay device,
When this alarm device is called a first alarm device, the plurality of alarm devices also include a second alarm device and a third alarm device,
receiving a signal from the relay device via the second alarm;
If reception of the signal from the relay device via the second alarm device fails, receiving a signal from the relay device via the third alarm device;
When the relay route including the second alarm device is switched to the relay route including the third alarm device, transmitting a route switching notification to the third alarm device to notify the relay device of the switch of the relay route. and,
A communication method comprising: A program to be executed by an alarm device among a plurality of alarm devices forming a multi-hop network extending from a relay device,
When this alarm device is called a first alarm device, the plurality of alarm devices also include a second alarm device and a third alarm device,
receiving a signal from the relay device via the second alarm;
If reception of the signal from the relay device via the second alarm device fails, receiving a signal from the relay device via the third alarm device;
When the relay route including the second alarm device is switched to the relay route including the third alarm device, transmitting a route switching notification to the third alarm device to notify the relay device of the switch of the relay route. A program that causes a computer to execute

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