Transmitter and Transmitter System

Abstract

To reduce the generation of a collision with a signal transmitted from the other transmission device.SOLUTION: A transmission device 10 comprises: a transmission part 130a; and a determination part 130b. The transmission part 130a transmits a first signal only by Nth times (Nth is two or more integer numbers) by using an abnormal generation such as a depression or the like of an operator 110a as a trigger. The transmission part 130a performs a transmission of a first time at the timing of the abnormal generation, and performs a transmission of a second time and thereafter in a transmission timing determined by the determination part 130b. The determination part 130b determines on time slot from a plurality of time slots set as referring each reference timing of a predetermined transmission period P from the transmission at the first time from the transmission part 130a by using specific information and operation history information in each transmission of the signal.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present disclosure relates to a transmitting device and a transmitting system. Background Art

[0002] A technique for selecting a time slot used for signal transmission using a pseudorandom number is known (e.g., Patent Document 1). Prior Art Documents Patent Documents

[0003] Patent Document 1 Japanese Unexamined Patent Publication No. 11-282975 Summary of the Invention Problem to be Solved by the Invention

[0004] However, in a configuration where time slots are selected using a pseudorandom number like the technique described in Patent Document 1, when the number of time slots is small, the same time slot may be allocated to a plurality of transmitting devices. If the same time slot is allocated to a plurality of transmitting devices, there is a risk that signals transmitted from these transmitting devices will collide.

[0005] The present invention has been made in view of the problems described above, and an object of the present invention is to reduce the occurrence of collisions with signals transmitted from other transmitting devices. Means for Solving the Problem

[0006] In order to solve the above problem, a transmitting device according to a first aspect of the present disclosure includes: a transmitting unit that transmits a radio signal when detection of occurrence of an abnormality is performed; and a determining unit that, after abnormality detection, determines a transmission time slot for transmitting a radio signal by the transmitting unit from among a plurality of time slots set based on transmission timings arriving at a predetermined cycle, using operation history information indicating an operation history of the own device or environment information of the own device. Effect of the Invention

[0007] According to the present disclosure, the occurrence of collisions with signals transmitted from other transmitting devices can be reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] [Figure 1] FIG. 1 is a diagram illustrating a configuration example of a transmission system 1 according to an embodiment of the present disclosure. [Figure 2] FIG. 2 is a diagram illustrating a configuration example of a transmitting device 10. [Figure 3] FIG. 3 is an explanatory diagram for explaining a method of determining transmission timing by a determination unit 130b of the transmitting device 10. [Figure 4] FIG. 4 is a flowchart showing a processing flow in a notification method executed by a control unit 130 of the transmitting device 10 in accordance with a control program. [Figure 5] FIG. 5 is a diagram outlining the operation of the transmitting device 10. [Figure 6] FIG. 6 is a diagram for explaining in detail the second signal transmission operation of the transmitting device 10(1). [Figure 7] FIG. 7 is a diagram for explaining in detail the second signal transmission operation of the transmitting device 10(2). [Figure 8] FIG. 8 is a diagram for explaining in detail the third signal transmission operation of the transmitting device 10(1). [Figure 9] FIG. 9 is a diagram for explaining in detail the third signal transmission operation of the transmitting device 10(2). MODES FOR CARRYING OUT THE INVENTION

[0009] <A. Embodiment> Various technically preferable limitations are added to the embodiments described below. However, the embodiments of the present disclosure are not limited to the forms described below. <A-1. Configuration> Figure 1 shows an example configuration of a transmission system 1 according to one embodiment of the present disclosure. The transmission system 1 is a communication system for notifying an external server installed in a monitoring center or the like of the occurrence of an abnormality in a monitoring area such as a house or store. The external server is not shown in Figure 1. As shown in Figure 1, the transmission system 1 includes a transmission device 10(1), a transmission device 10(2), ... a transmission device 10(M), and a control device 20. M is an integer of 2 or more. Hereinafter, when it is not necessary to distinguish between the transmission devices 10(1), 10(2), ... and 10(M), the transmission devices 10(1), 10(2), ... and 10(M) will be referred to as transmission device 10.

[0010] Each of the M transmitting devices 10 included in the transmitting system 1 is wirelessly connected to the control device 20. The transmitting device 10 has an operator 110a that accepts user input to notify the occurrence of an abnormality. The transmitting device 10 may be a portable device carried by the user, or it may be a stationary device whose installation location in the monitoring area is fixed. In this embodiment, the operator 110a is an emergency call button, and the user's operation to the operator 110a is pressing the operator 110a. When an abnormality occurs in the monitoring area where the transmitting system 1 is installed, the user presses the operator 110a of the transmitting device 10. When the operator 110a is pressed, the transmitting device 10 repeatedly transmits a signal to the control device 20 to notify the control device 20 of the occurrence of an abnormality (hereinafter referred to as the first signal) Nth (Nth is an integer of 2 or more; in this embodiment, Nth=10) times wirelessly to the control device 20. In this embodiment, Nth is 10, but Nth may be any integer of 2 or more, and Nth=5 or Nth=15. Furthermore, the number of transmissions Nth does not have to be a finite value, and the signal may be transmitted repeatedly until a recovery operation is performed. Note that the transmitting device 10 has a transmitting function to transmit signals, but it is not necessary for it to have a receiving function to receive signals transmitted from other devices. In addition, the transmitting device 10 may be configured not to have an operator 110a, and if the transmitting device 10 detects that another device having an operator has been operated by the user, it may repeatedly transmit a signal notifying the occurrence of an abnormality. Note that the signal may continue to be transmitted until an operation is performed by the user (such as a recovery operation indicating that the abnormality has been resolved). When the control device 20 receives the first signal from the transmitting device 10, it transmits a second signal notifying the occurrence of an abnormality to an external server (not shown in Figure 1).

[0011] Other terminals of a different type from the transmitting device 10 may be provided in the space where the transmission system 1 is installed, i.e., the monitoring area. In Figure 1, the illustration of other terminals is omitted. Specific examples of other terminals provided in the monitoring area include fire detectors, gas detectors, and motion sensors. When these terminals detect the occurrence of a predetermined monitoring event such as a fire, they wirelessly transmit a third signal to the control device 20 to notify it of the occurrence of the monitoring event. In the monitoring area, the transmission of the first signal and the transmission of the third signal may occur simultaneously. In this case, if a collision occurs between the first signal and the third signal, the control device 20 may not be able to receive either the first signal or the third signal. Therefore, in this embodiment, in order to avoid a collision between the first signal and the third signal, different transmission periods are predetermined for the other terminals and the transmitting device 10. For example, the transmission period for the first type of terminal is 15 seconds. The transmission period for the second type of terminal is 20 seconds. The transmission period for the transmitting device 10 is 10 seconds, etc.

[0012] Figure 2 shows an example of the configuration of the transmitting device 10. As shown in Figure 2, the transmitting device 10 has an input device 110 including an operator 110a, a communication unit 120, a control unit 130, and a storage unit 140. The input device 110, the communication unit 120, and the storage unit 140 are interconnected with the control unit 130 by a bus that mediates data transmission. The input device 110 is, for example, a push-button switch and has an operator 110a that is pressed by the user when an abnormality occurs. When the operator 110a is pressed, the input device 110 outputs an abnormality detection signal to the control unit 130. By receiving this abnormality detection signal from the input device 110, the control unit 130 detects the occurrence of an abnormality. The communication unit 120 is a wireless communication circuit and communicates wirelessly with the control device 20 under the control of the control unit 130.

[0013] The control unit 130 is, for example, a computer such as a CPU. The storage unit 140 includes, for example, a volatile memory such as RAM and a non-volatile memory such as flash ROM. A control program (not shown in FIG. 2) that causes the control unit 130 to function as the control center of the transmission device 10 is stored in advance in the non-volatile memory. The volatile memory of the storage unit 140 is used by the control unit 130 as a work area when executing the control program. In addition, in the non-volatile memory of the storage unit 140, unique information that uniquely identifies the transmission device 10 including the storage unit 140 (hereinafter referred to as the own device), the number of transmissions Nth of the first signal, period information, and the operation of the own device Operation history information indicating a history is stored.

[0014] Specific examples of the unique information include a serial number (that is, a manufacturing number) corresponding to the manufacturing order of the transmission device 10. The period information indicates a transmission period P (P=10 seconds in the present embodiment) when the first signal is repeatedly transmitted to the control device 20 when an abnormality is detected. In the present embodiment, P=10 seconds, but the transmission period P may be any value such as P=11 seconds or P=12 seconds as long as it is not the same value as the transmission period of other terminals. The transmission period P indicated by the period information is an example of the predetermined period in the present disclosure. A specific example of the operation history information includes information indicating the operating time of the own device, that is, the elapsed time since the own device was powered on.

[0015] The control unit 130 reads the control program from the non-volatile memory to the volatile memory when the power supply of the transmission device 10 (not shown in FIG. 2) is turned on, and starts executing the control program. The control unit 130 operating in accordance with the control program functions as a transmission unit 130a and a determination unit 130b. That is, the transmission unit 130a and the determination unit 130b shown in FIG. 2 are software modules implemented by operating a computer such as a CPU in accordance with software such as a program. The respective functions of the transmission unit 130a and the determination unit 130b are as follows.

[0016] The transmitter 130a repeatedly transmits the first signal (wireless signal) Nth times upon receiving an abnormality detection signal. Each time the transmitter 130a transmits the first signal, it increments the transmission number corresponding to the number of transmissions by 1. For example, the transmission number for the first wireless transmission is 0, for the second wireless transmission it is 1, for the third wireless transmission it is 2, and for the 101st wireless transmission it is 100. The transmission number may be reset to 0 when the transmission of the first signal is completed on the Nth time.

[0017] Furthermore, the transmission timing for each of the first signals transmitted Nth times triggered by the detection of an anomaly is as follows: The transmission unit 130a first performs the first signal transmission triggered by the receipt of the anomaly detection signal. For the first signal to be transmitted m times (where m is an integer between 2 and Nth), the transmission unit 130a transmits it each time in a time slot determined by the determination unit 130b. In this embodiment, within a predetermined time period (in this embodiment, the period from reference timing - ΔT to reference timing + ΔT) from a reference timing (transmission timing) determined according to the transmission period P (for example, P = 10 seconds), and excluding the reference timing, J (where J is an integer between 2 and Nth) time slots are set, and one of these multiple time slots is determined by the determination unit 130b as the mth transmission timing.

[0018] As the m-th transmission timing of the first signal, the determining unit 130b determines one time slot (transmission time slot) among the aforementioned J time slots at a predetermined timing after completion of the wireless transmission of the (m-1)-th first signal, using the unique information and operation history information. The reason for using the operation history information is that it is unlikely that the operation history information completely matches among a plurality of transmitting devices 10, which makes it difficult for a plurality of transmitting devices 10 to select the same time slot. In addition, by using the unique information in combination with the operation history information, it becomes further more difficult to select the same time slot as that selected by another transmitting device 10. Hereinafter, a method of determining transmission timing by the determining unit 130b when J=32 will be described with reference to FIG. 3.

[0019] FIG. 3 is an explanatory diagram for explaining the method of determining transmission timing by the determining unit 130b when J=32. As described above, the determining unit 130b determines the transmission timing of the first signal to be transmitted for the second time at a predetermined timing after the transmitting unit 130a completes transmitting the first signal for the first time. The determining unit 130b first calculates a basic random number for the transmission number of the first signal to be transmitted next from the unique information, and sets the remainder obtained by dividing the calculated basic random number by J as a basic slot. The basic random number is a pseudo-random number generated according to a well-known algorithm such as the mixed congruential method, using the transmission number and the unique information as parameters. As described above, the transmission number of the first signal for the second time is 1. Here, it is assumed that the unique information of the transmitting device 10(1) is 20442, and 19389 is determined as the basic random number for transmission number=1. Since the remainder of 19389 divided by J (32 in the present embodiment) is 29, the determining unit 130b sets 29 as the basic slot.

[0020] Next, the determination unit 130b extracts the operation history information (operating time) and converts it into an operating count in units of 4 seconds by calculating the quotient obtained by dividing the extracted operation history information by 4. In this embodiment, an example of dividing the operation history information by 4 has been given, but the operation history information may be converted to a number of digits or units that are easy to handle. The determination unit 130b sets the remainder obtained by dividing the operating count by J into the auxiliary slot. For example, if 82729016 is extracted as the operation history information, the determination unit 130b calculates 20682254 as the operating count. Then, the determination unit 130b sets the remainder 14 obtained by dividing the operating count = 20682254 by J (32 in this embodiment) into the auxiliary slot. Note that in Figure 3, only the auxiliary slot when the transmission number is 1 is shown, and the auxiliary slots for transmission numbers 2 and above are not shown. However, in practice, as will be explained later, when the transmission number is 2 or higher, a different auxiliary slot is set up in the same way as when the transmission number is 1.

[0021] Next, the determination unit 130b uses the remainder obtained by adding the basic slot and the auxiliary slot and dividing the result by the number of slots as the value indicating the transmission slot. As mentioned above, if the basic slot = 29 and the auxiliary slot = 14, the determination unit 130b determines the 11th time slot from the beginning of the 32 time slots, which is set with the point in time when the transmission period P has elapsed since the first transmission of the first signal as the reference timing, as the transmission timing for the second first signal. Subsequently, in the case of the third transmission of the first signal, the transmission number changes from 1 to 2, so even though the unique information is the same, the basic random number changes from 19389 to, for example, 15853, and the basic slot is set to 13. Furthermore, the operating time of the transmitter 10 also changes by approximately +10 seconds from 82729016. As a result, the number of auxiliary slots changes by approximately 2 or 3, and the value indicating the transmission slot becomes a different value from 11 (for example, 29) depending on the changes in the basic slot and auxiliary slots.

[0022] Furthermore, when the control unit 130, which operates according to the control program, receives an abnormality detection signal output from the input device 110, it executes a notification method that prominently displays the features of this disclosure. Figure 4 is a flowchart showing the processing flow in this notification method. As shown in Figure 4, this notification method includes initialization processing SA110, first transmission processing SA120, first determination processing SA130, decision processing SA140, second determination processing SA150, second transmission processing SA160, and count-up processing SA170. The processing contents of each of the initialization processing SA110, first transmission processing SA120, first determination processing SA130, decision processing SA140, second determination processing SA150, second transmission processing SA160, and count-up processing SA170 are as follows.

[0023] In initialization process SA110, the control unit 130 initializes the variables K, T, and t used for controlling the transmission of Nth first signals. Variable K is used to manage which signal transmission it is. In initialization process SA110, the control unit 130 sets variable K to 1. Variable T is used to manage the transmission timing of the second and subsequent first signals. In initialization process SA110, variable T is set to 0. Variable t is used to manage the elapsed time since the most recent first signal transmission. In initialization process SA110, variable t is set to 0.

[0024] In the first transmission process SA120, the control unit 130 functions as a transmission unit 130a. In the first transmission process SA120, the control unit 130 transmits the first signal for the first time and adds 1 to the variable K.

[0025] The first determination process SA130 determines whether the variable K is less than or equal to Nth. If the variable K is less than or equal to Nth, the result of the first determination process SA130 is "Yes". If the result of the first determination process SA130 is "Yes", the control unit 130 executes the processes from the decision process SA140 onward. If the variable K is greater than Nth, the result of the first determination process SA130 is "No". If the result of the first determination process SA130 is "No", the control unit 130 terminates this notification method.

[0026] In the determination process SA140, the control unit 130 functions as the determination unit 130b. In the determination process SA140, the control unit 130 determines one time slot among the aforementioned J time slots as the transmission timing of the next first signal by using the unique information and the operation history information, and sets the time from the time point when the latest first signal was transmitted to the determined time slot to the variable T.

[0027] In the second determination process SA150, the control unit 130 determines whether the transmission timing of the next first signal has come based on the variable t and the variable T. When the variable t is less than the variable T, the determination result of the second determination process SA150 is "No". When the determination result of the second determination process SA150 is "No", the control unit 130 executes the count-up process SA170 and executes the second determination process SA150 again. When the variable t reaches the variable T, the determination result of the second determination process SA150 is "Yes". When the determination result of the second determination process SA150 is "Yes", the control unit 130 executes the second transmission process SA160 and executes the first determination process SA130 again.

[0028] In the second transmission process SA160, the control unit 130 functions as the transmission unit 130a and transmits the first signal. Further, in the second transmission process SA160, the control unit 130 adds 1 to the variable K and resets the variable t to 0. In the count-up process SA170, the control unit 130 counts up the variable t in accordance with the elapsed time from the previous transmission of the first signal. The above is the configuration of the transmitting device 10.

[0029] <A-2:Operation> Next, the operations of the transmitting device 10(1) and the transmitting device 10(2) will be described by taking, as an example, a case where the operator 110a of the transmitting device 10(1) and the operator 110a of the transmitting device 10(2) are pressed simultaneously at time t1 in FIG. 5. Note that time t2 in FIG. 5 is a time after a time corresponding to the transmission period P has elapsed from time t1, time t3 is a time after a time corresponding to the transmission period P has elapsed from time t2, and time t4 is a time after a time corresponding to the transmission period P has elapsed from time t3. That is, in this operation example, each of time t2, time t3, and time t4 in FIG. 5 serves as a reference timing.

[0030] <A-2-1:First transmission> When the operator 110a is pressed in each of the transmitting device 10(1) and the transmitting device 10(2) at time t1, each of the transmitting device 10(1) and the transmitting device 10(2) wirelessly transmits a first signal for the first transmission. Since the first signal transmitted for the first time from the transmitting device 10(1) and the first signal transmitted for the first time from the transmitting device 10(2) are transmitted substantially simultaneously, collision of both signals may occur.

[0031] <A-2-2:Second transmission> In the transmitting device 10, when the first transmission of the first signal is completed, the determining unit 130b determines the transmission timing of the second first signal based on the unique information and the operation history information. Here, the unique information of the transmitting device 10(1) and the unique information of the transmitting device 10(2) are different from each other, and the operation history information of the transmitting device 10(1) and the operation history information of the transmitting device 10(2) are different from each other. Therefore, for the transmitting device 10(1) and the transmitting device 10(2), different time slots are determined as the transmission timing of the second first signal. For example, in the transmitting device 10(1), as shown in FIG. 6, the 11th time slot among 32 time slots centered on time t2 is determined as the transmission timing of the second first signal. On the other hand, in the transmitting device 10(2), as shown in FIG. 7, the 32nd time slot among 32 time slots centered on time t2 is determined as the transmission timing of the second first signal. The transmitting device 10(1) wirelessly transmits the second first signal in the 11th time slot, and the transmitting device 10(2) wirelessly transmits the second first signal in the 32nd time slot. Accordingly, the first signal transmitted the second time from the transmitting device 10(1) does not collide with the first signal transmitted the second time from the transmitting device 10(2).

[0032] <A-2-3:Third Transmission> When the transmission of the second first signal is completed in the transmitting device 10, the determination unit 130b determines the transmission timing of the third first signal based on the unique information and the operation history information. For example, in the transmitting device 10(1), as shown in FIG. 8, the 29th time slot among 32 time slots centered on time t3 is determined as the transmission timing of the third first signal. On the other hand, in the transmitting device 10(2), as shown in FIG. 9, the 1st time slot among 32 time slots centered on time t3 is determined as the transmission timing of the third first signal. The transmitting device 10(1) wirelessly transmits the third first signal in the 29th time slot described above, and the transmitting device 10(2) wirelessly transmits the third first signal in the 1st time slot described above. Therefore, the first signal transmitted for the third time from the transmitting device 10(1) does not collide with the first signal transmitted for the third time from the transmitting device 10(2). Thereafter, the transmitting device 10 repeats the operation of transmitting the first signal at the transmission timing determined based on the unique information and the operation history information, as in the second transmission and the third transmission, until the first signal is transmitted Nth times. The above is the operation of the transmitting device 10.

[0033] According to the embodiment described above, even when the operators 110a of a plurality of transmitting devices 10 are pressed at the same time, the possibility that the same time slot is determined for those transmitting devices 10 is reduced, and the occurrence of collision of signals wirelessly transmitted from those transmitting devices 10 can be reduced. Further, if the transmitting device 10 transmits a signal at random timing, a difference occurs in the total number of transmissions among the transmitting devices 10, and a difference in battery life occurs particularly in the case of battery driving. Such a problem can be avoided by transmitting a signal based on a reference timing of a predetermined period as in the above embodiment.

[0034] <B.Modified Example> The above embodiment may be modified as follows. (1) In the above embodiment, the auxiliary slots were calculated by dividing the operating count obtained by dividing the operating time indicated in the operation history information by 4 by the number of time slots. However, the auxiliary slots may also be calculated by dividing the operating time indicated in the operation history information by the number of time slots.

[0035] (2) Operation history information is not limited to operating time, and can be any information other than unique information that changes for each device or each time a signal is transmitted, such as the elapsed time since the last press of the operator 110a or the power-on date and time. Also, if the transmitter 10 is a device used for a limited period, such as rental equipment, and is repeatedly shipped and returned, information such as the factory shipment date and time can also be applied as operation history information. Furthermore, operation history information may be obtained by processing calculations between these parameters.

[0036] (3) In the above embodiment, the transmission timing (transmission slot) of the first signal transmitted from the second time onward was determined based on unique information and operation history information, but it may also be determined based on operation history information alone. Specifically, the auxiliary slot in the above embodiment may be used as the transmission slot. Since the possibility of operation history information being perfectly identical among multiple transmitters 10 is low, determining the transmission slot based on operation history information is less efficient than combining unique information and operation history information, but it makes it difficult for the same time slot to be determined among multiple transmitters 10.

[0037] (4) In the above embodiment, the transmission slot was determined by taking the sum of the basic slot and the auxiliary slot. Alternatively, a transmission slot table may be used in which the rows represent the basic slots and the columns represent the auxiliary slots, and the transmission slot can be selected from the cell where the two intersect.

[0038] (5) The operator 110a is not limited to a push-button switch. The operator 110a may be a slide switch or a software button displayed on a display. In addition, although both the transmitter 130a and the determination unit 130b in the above embodiment were software modules, either one or both of the transmitter 130a and the determination unit 130b may be hardware modules such as electronic circuits. Even if either one or both of the transmitter 130a and the determination unit 130b are hardware modules, the same effects as in the above embodiment will be achieved.

[0039] (6) The transmitting device 10 is not limited to an emergency call button. The transmitting device 10 may be a sensor that detects abnormalities such as fire, gas leak, or intrusion by a suspicious person (fire detection sensor, gas detection sensor, motion sensor), and when these sensors detect an abnormality, they may output an abnormality detection signal to the control unit 130. Upon receiving this abnormality detection signal, the control unit 130 detects the occurrence of an abnormality and repeatedly transmits the first signal Nth times. Note that if the transmitting device 10 is an abnormality detection sensor, the transmitting device 10 does not necessarily have to be equipped with an operator 110a.

[0040] (7) In the above embodiment, a transmission system 1 including a plurality of transmission devices 10 has been described, but the transmission devices 10 may be manufactured or sold individually. Also, in the above embodiment, a control program that causes the control unit 130 to execute a notification method that prominently displays the features of this disclosure was pre-stored in the storage unit 140, but this control program may be manufactured or provided individually. Specific ways of providing this control program include distribution by download via a telecommunications line such as the Internet, or distribution by writing the control program to a computer-readable recording medium such as flash ROM.

[0041] (8) In the above embodiment, the time slot was determined using operation history information, but environmental information of the transmitter 10 may be used instead of or in addition to the operation history information. Environmental information is information that indicates the installation environment of the transmitter 10. For example, if the transmitter 10 has a function to detect interference waves, this information includes the frequency of interference wave detection and the intensity of the interference waves. Specific examples of interference waves include the carrier wave of the third signal mentioned above, and electromagnetic noise radiated from other electronic equipment installed in the monitoring area. Furthermore, if the transmitter has a function to detect physical quantities such as a voltage detection function or a temperature detection function, the detected values ​​may be used as environmental information. Since it is unlikely that the environmental information will perfectly match among multiple transmitters 10, even when environmental information is used, it will be difficult to determine the same time slot among multiple transmitters 10.

[0042] (9) The determination unit 130b does not necessarily have to determine a time slot for each signal transmission, and may determine multiple time slots at once. For example, a time slot determined by the determination unit 130b as the transmission timing for the mth first signal may also be used as the transmission timing for the m+1th and subsequent first signals. [Explanation of Symbols]

[0043] 1...Transmission system, 10, 10(1)~10(M)...Transmission device, 110...Input device, 110a...Operator, 120...Communication unit, 130...Control unit, 130a...Transmission unit, 130b...Decision unit, 140...Storage unit, 20...Control device.

Claims

1. A transmitting unit that transmits a wireless signal when it detects the occurrence of an abnormality, The system includes a determination unit that, after detecting an anomaly, determines a transmission time slot from a plurality of time slots set based on transmission timings that occur at predetermined intervals, using operation history information indicating the operation history of the device itself, to determine a transmission time slot from which the transmission unit transmits a wireless signal, The aforementioned operation history information represents the operating time of the device. Transmitter.

2. The aforementioned operation history information shows the history of operations that change with each transmission of a wireless signal. The transmitting device according to claim 1.

3. The aforementioned determination unit, The transmission time slot is determined using a value generated using unique information specific to each transmitting device and which differs for each transmission of a wireless signal, along with the operation history information. The transmitting device according to claim 1.

4. The value is a pseudorandom number generated from the unique information. The transmitting device according to claim 3.

5. Equipped with multiple transmitting devices, Each of the aforementioned plurality of transmitting devices is A transmitting unit that transmits a wireless signal when it detects the occurrence of an abnormality, The system includes a determination unit that, after detecting an anomaly, determines a transmission time slot from a plurality of time slots set based on transmission timings that occur at predetermined intervals, using operation history information indicating the operation history of the device itself, to determine a transmission time slot from which the transmission unit transmits a wireless signal, The aforementioned operation history information represents the operating time of the device. Transmission system.

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