Transmitter

Abstract

To reduce occurrences of collision with signals transmitted from other transmitters.SOLUTION: A transmission part 130a executes first signal transmission triggered by reception of an abnormality detection signal. A transmission part 130a transmits, at and after a second time, the first radio signal at transmission timing determined by a determination part 130b each time it is transmitted. The determination part 130b determines arrival timing as transmission timing of the first radio signal each time a fixed transmission period T arrives after transmission completion of the first radio signal of the first time executed triggered by reception of the abnormality detection signal as an opportunity. Further, the determination part 130b also determines a prescribed number of timing undergoing time dispersion within each fixed transmission period T as transmission timing of the first radio signal. The timing undergoing time dispersion is determined by using unique information unique to each transmitter 10 and operation history information showing an operation history of the transmitter 10.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to a transmitting device. [Background technology]

[0002] A technique is known in which a time slot used for transmitting a signal is selected using pseudo-random numbers (for example, Patent Document 1). [Prior art documents] [Patent documents]

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

[0004] However, in a configuration that uses pseudorandom numbers to select time slots, as in the technology described in Patent Document 1, if the number of time slots is small, the same time slot may be assigned to multiple transmitting devices. If the same time slot is assigned to multiple transmitting devices, there is a risk of collision between signals transmitted from these transmitting devices.

[0005] The present invention has been made in view of the above-described problems, and has as its object 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 determination unit that determines a transmission timing within a predetermined period using at least operation history information indicating the operation history of the transmitting device, and a transmitting unit that transmits the wireless signal at the predetermined period and the determined transmission timing when an abnormality occurs.

[0007] In addition, in order to solve the above problem, a transmitting device according to a second aspect of the present disclosure includes a determination unit that determines variable transmission timings, which are transmission timings that are varied using at least operation history information that indicates the operation history of the transmitting device, for some of the multiple transmission timings that are determined at a predetermined cycle, and a transmitting unit that, when an abnormality occurs, transmits a wireless signal at fixed transmission timings that are not varied by the variation unit and at variable transmission timings that are varied by the variation unit, among the multiple transmission timings that are determined at the predetermined cycle. [Effects of the Invention]

[0008] According to the present disclosure, it is possible to reduce the occurrence of collisions with signals transmitted from other transmitting devices through simple processing. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a diagram illustrating an example of the configuration of a transmission system 1 according to an embodiment of the present disclosure. [Figure 2] 1 is a diagram illustrating an example of the configuration of a transmitting device 10. FIG. [Figure 3] 10 is an explanatory diagram for explaining a first method for determining the transmission timing by a determination unit 130b of the transmitting device 10. FIG. [Figure 4] 10 is an explanatory diagram illustrating a second method for determining the transmission timing by a determination unit 130b of the transmitting device 10. FIG. [Figure 5] 10 is an explanatory diagram illustrating a third method for determining the transmission timing by determination unit 130b of transmitting device 10. FIG. [Figure 6] FIG. 10 is a diagram illustrating a specific example of the transmission timing of the first radio signal. [Figure 7] 10 is a flowchart showing the flow of processing in a notification method executed by control unit 130 of transmitting device 10 according to a control program. [Figure 8] FIG. 10 is a diagram showing a specific example of transmission timing of a radio signal in a modified example. DETAILED DESCRIPTION OF THE INVENTION

[0010] <A. Embodiment> The embodiments described below are subject to various technically preferable limitations. However, the embodiments of the present disclosure are not limited to the forms described below.

[0011] <A-1. Configuration> FIG. 1 is a diagram showing a configuration example of a transmission system 1 according to an embodiment of the present disclosure. The transmission system 1 is a communication system for notifying the occurrence of an abnormality in a monitoring area such as a house or a store to an external server installed in a monitoring center or the like. In FIG. 1, the illustration of the external server is omitted. As shown in FIG. 1, the transmission system 1 includes transmission devices 10(1), 10(2),..., 10(M), and a control device 20. M is an integer of 2 or more. Hereinafter, when it is not necessary to distinguish each of the transmission devices 10(1), 10(2),..., and 10(M), the transmission devices 10(1), 10(2),..., and 10(M) are denoted as transmission device 10.

[0012] Each of the M transmitting devices 10 included in the transmission system 1 is wirelessly connected to the control device 20. The transmitting device 10 has an operator 110a that accepts a user operation to notify the control device 20 of the occurrence of an abnormality. The transmitting device 10 may be a portable device carried by the user or a stationary device that is installed at a fixed location in the monitoring area. In this embodiment, the operator 110a is an emergency call button, and a user operation on the operator 110a is pressing the operator 110a. When an abnormality occurs in the monitoring area where the transmission 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 wirelessly transmits a signal (hereinafter referred to as a first wireless signal) notifying the control device 20 of the occurrence of the abnormality to the control device 20 Nth times (Nth is an integer equal to or greater than 2; in this embodiment, Nth=12). In this embodiment, Nth is 12, but N may be any integer equal to or greater than 2, such as Nth=5 or Nth=15. Furthermore, the number of transmissions Nth does not have to be a finite value, and a signal may be repeatedly transmitted until a recovery operation is performed. Note that the transmitting device 10 has a transmitting function for transmitting a signal, but may or may not have a receiving function for receiving signals transmitted from other devices. Also, the transmitting device 10 may be configured without an operator 110a, and when the transmitting device 10 detects that another device having an operator has been operated by a user, the transmitting device 10 may repeatedly transmit a signal notifying the occurrence of an abnormality. Note that the signal may continue to be transmitted until a user operation (such as a recovery operation indicating that the abnormality has been resolved) is performed. When the control device 20 receives the first wireless signal from the transmitting device 10, it transmits a second signal notifying the occurrence of an abnormality to an external server (not shown in FIG. 1).

[0013] Other terminals of different types than the transmitting device 10 may be installed in the space where the transmission system 1 is installed, i.e., the monitored area. The illustration of the other terminals is omitted in FIG. 1 . Specific examples of other terminals installed in the monitored area include fire detectors, gas detectors, and motion sensors. When these terminals detect the occurrence of a predetermined monitored event, such as a fire, they wirelessly transmit a third wireless signal to the control device 20 to notify the occurrence of the monitored event. Transmission of the first wireless signal and the third wireless signal may occur simultaneously in the monitored area. In this case, if the first wireless signal and the third wireless signal collide, the control device 20 may not be able to receive either the first wireless signal or the third wireless signal. Therefore, in this embodiment, to avoid collision between the first wireless signal and the third wireless signal, different transmission periods are predefined 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, and the transmission period for the transmitting device 10 is 45 seconds. However, these are just a few examples.

[0014] The transmitting device 10 mixes transmission of a wireless signal at a fixed transmission cycle T, which is a predetermined transmission cycle, with transmission at a cycle other than the fixed transmission cycle T. For example, in addition to repeatedly transmitting a first wireless signal at the fixed transmission cycle T, the transmitting device 10 transmits the first wireless signal a predetermined number of times in a time-distributed manner between the transmission timings of each fixed transmission cycle T. The reason why the transmitting device 10 mixes transmission at the fixed transmission cycle T with transmission at a cycle other than the fixed transmission cycle T is to minimize collision of the first wireless signal transmitted from the transmitting device 10 with the first wireless signal transmitted from another transmitting device 10 or the third wireless signal transmitted from the other terminal described above. In other words, as will be described later, by transmitting at a cycle other than the fixed transmission cycle T at a transmission timing determined by each transmitting device 10 using different operation history information, signal collision with other transmitting devices 10 can be reduced. Furthermore, by also transmitting at the fixed transmission cycle T, signal collision with other terminals having different periodicity of the fixed transmission cycle can be reduced.

[0015] FIG. 2 is a diagram illustrating an example configuration of the transmitting device 10. As illustrated in FIG. 2, the transmitting device 10 includes 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 each connected to the control unit 130 via a bus that mediates data transmission and reception. The input device 110 is, for example, a push button switch and includes an operator 110a that is pressed by a 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.

[0016] 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 a RAM and a non-volatile memory such as a flash ROM. A control program (not shown in FIG. 2) that causes the control unit 130 to function as a control center of the transmitting 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. The non-volatile memory of the storage unit 140 also stores unique information that uniquely identifies the transmitting device 10 including the storage unit 140 (hereinafter, the transmitting device), the number of transmissions Nth of the first wireless signal, periodic information, operation history information, and the like.

[0017] Specific examples of the unique information include a model code corresponding to the type of transmitting device 10 and a serial number corresponding to the order of manufacture (i.e., a manufacturing number). As described above, the number of transmissions Nth is, for example, 12. The period information is information indicating a fixed transmission period T (T=45 seconds in this embodiment) when repeatedly transmitting a first wireless signal to the control device 20 when an abnormality is detected. A specific example of the operation history information is information indicating a transmission number assigned to the first wireless signal transmitted to the control device 20.

[0018] When the transmitting device 10 is powered on (not shown in FIG. 2), the control unit 130 reads the control program from the non-volatile memory to the volatile memory and starts executing the control program. The control unit 130, operating in accordance with the control program, functions as the transmitting unit 130a and the determining unit 130b. In other words, the transmitting unit 130a and the determining unit 130b shown in FIG. 2 are software modules realized by operating a computer such as a CTU in accordance with software such as a program. The functions of the transmitting unit 130a and the determining unit 130b are as follows:

[0019] Upon receiving the abnormality detection signal, the transmitter 130a repeatedly transmits the first wireless signal (wireless signal) Nth times. The transmitter 130a assigns a transmission number to each transmission of the first wireless signal according to the number of transmissions. The transmission number may be reset to 0 when the Nth transmission of the first wireless signal is completed.

[0020] The transmission timing of each of the first wireless signals transmitted Nth times in response to the detection of an abnormality is as follows: First, the transmitter 130a executes the first signal transmission in response to the reception of the abnormality detection signal. For the second and subsequent first wireless signals, the transmitter 130a transmits each of the first wireless signals at the transmission timing determined by the determiner 130b.

[0021] There are three methods for determining the transmission timing by the determination unit 130b, as described below: Fig. 3 is an explanatory diagram for explaining the first method for determining the transmission timing.

[0022] <First method for determining transmission timing> In this first determination method, each time transmitting unit 130a transmits the first wireless signal, it adds 1 to the transmission number corresponding to the number of transmissions. For example, the transmission number for the first wireless transmission is 0, the transmission number for the second wireless transmission is 1, the transmission number for the third wireless transmission is 2, and the transmission number for the 101st wireless transmission in total is 100.

[0023] After the first transmission of the first wireless signal, which is triggered by receiving an anomaly detection signal, is completed, the determiner 130b determines the timing of the arrival of the fixed transmission period T as the transmission timing of the first wireless signal. In FIG. 3, if the transmission time of the first wireless signal is 0, the timings corresponding to multiples of "45," such as 45 seconds, 90 seconds, and so on, when the fixed transmission period T (=45 seconds) has elapsed become the transmission timings of the first wireless signal. In other words, when an anomaly occurs, the first wireless signal is transmitted at least at predetermined intervals. For example, in the example of FIG. 6, the first wireless signal is transmitted at times t0, t1, and t2, which correspond to the fixed transmission period T, which is the predetermined period.

[0024] Furthermore, the determination unit 130b also determines a predetermined number of times (four times in this example) dispersed over time between each fixed transmission period T as the transmission timing of the first wireless signal. Specifically, the determination unit 130b calculates a basic random number corresponding to the transmission number of the most recent first wireless signal that has already been transmitted from the unique information, calculates a quotient by dividing the calculated basic random number by a certain constant J, and sets the quotient value as the transmission interval until the transmission timing of the next first wireless signal. However, the method for determining the transmission timing of the first wireless signal is not limited to this example. For example, if the remainder when the basic constant is divided by the constant J is a value that falls within a predetermined range, the remainder may be set as the transmission interval until the transmission timing of the next first wireless signal. The basic random number is a pseudorandom number generated according to a well-known algorithm, such as a mixed congruential algorithm, using the transmission number and unique information as parameters. Since the transmission number corresponds to operation history information of the transmitting device 10, the pseudorandom number is generated using unique information unique to each transmitting device 10 and operation history information indicating the operation history of the transmitting device 10. Although the pseudo-random numbers are generated using the unique information and the operation history information here, the pseudo-random numbers may be generated using only at least one of the unique information and the operation history information.Furthermore, the pseudo-random numbers may be generated using at least the operation history information.

[0025] Furthermore, instead of or in addition to the above-described operation history information, the determination unit 130b may determine the transmission timing using different usage environment information for each transmitting device 10. The usage environment information is information corresponding to the environment when the transmitting device 10 is being used, such as the temperature and humidity when the transmitting device 10 is being used, but may be other information. In this case, the transmitting device 10 is equipped with a thermometer or hygrometer, and measurements taken by the thermometer or hygrometer are used as usage environment information to generate pseudo-random numbers and determine the transmission timing. Furthermore, instead of using the measurements taken by the thermometer or hygrometer directly as usage environment information, the measurements may be converted using a predetermined conversion formula to generate pseudo-random numbers and determine the transmission timing.

[0026] An example will be described with reference to Fig. 3. In Fig. 3, the transmission number of the first wireless signal after the occurrence of an abnormality is 0. Here, it is assumed that 17852 is determined as the basic random number for transmission number = 0 according to the unique information of transmitting device 10(1). Since the quotient obtained by dividing this basic random number 17852 by J (which is set to 2000, for example, in this embodiment) is 8.9, the determination unit 130b determines the point in time when 8.9 seconds have elapsed since the first transmission timing (transmission number = 0) of the first wireless signal as the second transmission timing (transmission number = 1). Note that it is assumed that the decimal point to which the quotient obtained by dividing the basic random number by J is rounded up, down, or rounded up is determined in advance.

[0027] Furthermore, for the third transmission timing (transmission number = 2), if 17409 is determined as the basic random number for transmission number = 1, the quotient obtained by dividing the basic random number 17409 by J = 2000 is 8.7 seconds. Therefore, the transmission interval from the second transmission timing (transmission number = 1) to the third transmission timing (transmission number = 2) of the first wireless signal is 8.7 seconds.

[0028] Furthermore, for the fourth transmission timing (transmission number = 3), if 20544 is determined as the basic random number for transmission number = 2, the quotient obtained by dividing the basic random number 20544 by J = 2000 is 10.3 seconds. Therefore, the transmission interval from the third transmission timing (transmission number = 2) to the fourth transmission timing (transmission number = 3) of the first wireless signal is 10.3 seconds.

[0029] Furthermore, for the fifth transmission timing (transmission number=4), if 17211 is determined as the basic random number for transmission number=3, the quotient obtained by dividing the basic random number 17211 by J=2000 is 8.6 seconds, and therefore the transmission interval from the fourth transmission timing (transmission number=3) to the fifth transmission timing (transmission number=4) of the first wireless signal is 8.6 seconds. For example, in the example of Fig. 6, during the fixed transmission period T starting from time t0, the first wireless signal is transmitted at times t01, t02, t03, and t04, which correspond to a predetermined number of times (four times).

[0030] The fifth transmission timing means that the predetermined number (four) of transmission timings has been reached during one fixed transmission period T. Therefore, the next sixth transmission timing (transmission number = 5) occurs when the fixed transmission period T = 45 seconds has elapsed. In this case, the transmission interval from the fifth transmission timing (transmission number = 4) of the first wireless signal to the sixth transmission timing (transmission number = 5) is 8.5 seconds, which is the time from the fifth transmission timing (transmission number = 4) of the first wireless signal to the time when the fixed transmission period T = 45 seconds has elapsed. Thereafter, each transmission timing is determined in a similar manner until the number of transmissions of the first wireless signal reaches Nth.

[0031] As described above, the determination unit 130b determines the arrival timing of the fixed transmission cycle T as the transmission timing of the first wireless signal. Furthermore, during each fixed transmission cycle T, the determination unit 130b determines the timing, which is the transmission interval from the transmission timing of transmission number = m-1 to the transmission timing of transmission number = m, obtained by dividing the basic random number for transmission number = m-1 (m is an integer greater than or equal to 2 and less than or equal to J) by J, as the transmission timing of the first wireless signal. Therefore, the transmitter 130a transmits the first wireless signal at the transmission timing corresponding to the fixed transmission cycle, which is a predetermined cycle, and at the transmission timings determined in a time-distributed manner within the fixed transmission cycle. In this first determination method, the timing of transmitting the next first wireless signal is determined each time a first wireless signal is transmitted.

[0032] <Second method for determining transmission timing> In the first determination method described above, the transmission number is incremented by 1 each time the first wireless signal is transmitted. In contrast, in the second determination method illustrated in Fig. 4, the transmission number is not incremented for the first wireless signal transmitted at a fixed transmission cycle T. Details of this method will be explained below.

[0033] In this second determination method, as in the first determination method, after the completion of the first transmission of the first wireless signal, which is executed in response to the reception of an anomaly detection signal, the determiner 130b determines the arrival timing of the fixed transmission period T as the transmission timing of the first wireless signal. In Fig. 4, if the transmission time of the first first wireless signal is 0, the timings corresponding to multiples of "45", such as 45 seconds, 90 seconds, ..., at which the fixed transmission period T = 45 seconds has elapsed become the transmission timings of the first wireless signal.

[0034] Furthermore, the determination unit 130b determines, as the transmission timing of the first wireless signal, a predetermined number of times (four times) that are time-distributed between each fixed transmission period T. Specifically, the determination unit 130b calculates a basic random number for the transmission number of the first wireless signal to be transmitted next from the unique information, calculates a quotient by dividing the calculated basic random number by a constant J, and sets this value as the transmission interval from the immediately preceding transmission timing to the next transmission timing.

[0035] 4, the transmission number of the first wireless signal is not an integer value but information indicating "fixed." Here, it is assumed that 19389 is determined as the basic random number for the transmission number=1 of the first wireless signal to be transmitted next according to the unique information of transmitting device 10(1). Since the quotient obtained by dividing this basic random number 19389 by J=2000 is 9.7, determination unit 130b determines the second transmission timing (transmission number=1) to be the point in time when 9.7 seconds have elapsed since the first transmission timing (transmission number=fixed) of the first wireless signal.

[0036] Furthermore, if 15852 is determined as the basic random number for the third transmission timing (transmission number = 2), the quotient obtained by dividing the basic random number 15852 by J = 2000 is 7.9 seconds. Therefore, the transmission interval from the second transmission timing (transmission number = 1) to the third transmission timing (transmission number = 2) of the first wireless signal is 7.9 seconds.

[0037] If 19095 is determined as the basic random number for the fourth transmission timing (transmission number = 3), the quotient obtained by dividing the basic random number 19095 by J = 2000 is 9.5 seconds. Therefore, the transmission interval from the third transmission timing (transmission number = 2) to the fourth transmission timing (transmission number = 3) of the first wireless signal is 9.5 seconds.

[0038] Furthermore, if 17070 is determined as the basic random number for the fifth transmission timing (transmission number = 4), the quotient obtained by dividing the basic random number 17070 by J = 2000 is 8.5 seconds, so the transmission interval from the fourth transmission timing (transmission number = 3) to the fifth transmission timing (transmission number = 4) of the first wireless signal is 8.5 seconds.

[0039] The fifth transmission timing means that the predetermined number (four) of transmission timings has been reached during one fixed transmission cycle. Therefore, the next sixth transmission timing (transmission number = 5) occurs when the fixed transmission cycle T = 45 seconds has elapsed. Thereafter, each transmission timing is determined in the same manner until the number of transmissions of the first wireless signal reaches Nth.

[0040] As described above, the determination unit 130b determines the arrival timing of the fixed transmission cycle T as the transmission timing of the first wireless signal. Furthermore, the determination unit 130b determines the timing of transmission of the first wireless signal as the transmission interval from the transmission timing of transmission number = m-1 to the transmission timing of transmission number = m (m is an integer greater than or equal to 2 and less than or equal to J) during each fixed transmission cycle, obtained by dividing the basic random number for transmission number = m (m is an integer greater than or equal to 2 and less than or equal to J), by J. Therefore, the transmitter 130a transmits the first wireless signal at the transmission timing corresponding to the fixed transmission cycle, which is a predetermined cycle, and at the transmission timings determined in a time-distributed manner within the fixed transmission cycle. In this second determination method, the timing of transmitting the next first wireless signal is determined each time a first wireless signal is transmitted.

[0041] <Third method for determining transmission timing> In the third determination method illustrated in Fig. 5, the transmission number of the first wireless signal transmitted in the fixed transmission cycle T is not incremented, and all transmission timings to be time-distributed during the fixed transmission cycle T are determined using a basic random number calculated for the transmission immediately following the timing at which the fixed transmission cycle T arrives. Details of this method will be described below.

[0042] In this third determination method, as in the first determination method, after the completion of the first transmission of the first wireless signal, which is executed in response to the reception of the anomaly detection signal, the determiner 130b determines the arrival timing of the fixed transmission period T as the transmission timing of the first wireless signal. In Fig. 5, if the transmission time of the first first wireless signal is 0, the timings corresponding to multiples of "45", such as 45 seconds, 90 seconds, ..., at which the fixed transmission period T = 45 seconds has elapsed become the transmission timing of the first wireless signal.

[0043] Furthermore, the determination unit 130b determines, as the transmission timing of the first wireless signal, a predetermined number of timings (four times in this example) that are time-distributed within each fixed transmission cycle T. Specifically, the determination unit 130b calculates a basic random number for the transmission number of the first wireless signal to be transmitted next from the unique information, calculates a quotient by dividing the calculated basic random number by a certain constant J, and sets this value as the transmission interval from the immediately preceding transmission timing to the next transmission timing.

[0044] 5, the transmission number of the first wireless signal is "fixed." Next, assume that 19389 is determined as the basic random number for transmission number=1 according to the unique information of transmitting device 10(1). Since the quotient obtained by dividing this basic random number 19389 by J=2000 is 9.7, determination unit 130b determines the second transmission timing (transmission number=1) to be the point in time when 9.7 seconds have elapsed since the first transmission timing (transmission number=fixed) of the first wireless signal.

[0045] Next, the determination unit 130b calculates the remaining time from the second transmission timing (transmission number = 1) to the timing when the next fixed transmission cycle T arrives, and sets the quotient obtained by dividing the remaining time by a certain constant K (2 in this case) as the transmission interval from the second transmission timing (transmission number = 1) to the third transmission timing (transmission number = 2) of the first wireless signal. In the example of Fig. 5, the timing when the next fixed transmission cycle T arrives is when 45 seconds have elapsed, so (45 - 9.7) / 2 = 17.7, and therefore the transmission interval from the second transmission timing to the third transmission timing is 17.7 seconds.

[0046] Next, the determination unit 130b calculates the remaining time from the third transmission timing (transmission number = 2) until the timing when the next fixed transmission cycle T arrives, and sets the quotient obtained by dividing the remaining time by a constant K = 2 as the transmission interval from the third transmission timing (transmission number = 2) to the fourth transmission timing (transmission number = 3) of the first wireless signal. In the example of Fig. 5, (45 - 9.7 - 17.7) / 2 = 8.8, so the transmission interval from the third transmission timing to the fourth transmission timing is 8.8 seconds.

[0047] Next, the determination unit 130b calculates the remaining time from the fourth transmission timing (transmission number = 3) to the timing when the next fixed transmission cycle T arrives, and sets the quotient obtained by dividing the remaining time by a constant K = 2 as the transmission interval from the fourth transmission timing (transmission number = 3) to the fifth transmission timing (transmission number = 4) of the first wireless signal. In the example of Fig. 5, (45 - 9.7 - 17.7 - 8.8) / 2 = 4.4, so the transmission interval from the fourth transmission timing to the fifth transmission timing is 4.4 seconds.

[0048] The fifth transmission timing means that the predetermined number (four) of transmission timings has been reached during one fixed transmission cycle T. Therefore, the next sixth transmission timing (transmission number = 5) occurs when the fixed transmission cycle T = 45 seconds has elapsed. Thereafter, each transmission timing is determined in the same manner until the number of transmissions of the first wireless signal reaches Nth.

[0049] As described above, the determination unit 130b determines the arrival timing of the fixed transmission period T as the transmission timing of the first radio signal. Also, the determination unit 130b uses, as the transmission interval from the timing of the immediately preceding fixed transmission period T, the quotient obtained by dividing the basic random number for the transmission number that arrives first during each fixed transmission period T by J. Further, the determination unit 130b uses, as the transmission interval from the immediately preceding transmission timing, the quotient obtained by dividing the time until the next fixed transmission period T arrives by a constant K. In this third determination method, when the transmission unit 130a transmits the first radio signal at a fixed transmission period T which is a predetermined period, the transmission timings during that fixed transmission period T are collectively determined.

[0050] <A-2: Operation> When the control unit 130 operating according to the control program receives the abnormality detection signal output from the input device 110, it executes a notification method that prominently shows the features of the present disclosure. FIG. 7 is a flowchart showing the flow of processing in this notification method.

[0051] In step SA110 of FIG. 7, the control unit 130 initializes variables (such as the transmission number) used for the transmission control of the Nth first radio signal.

[0052] In step SA120, the transmission unit 120a first transmits the first radio signal for the first time, and thereafter, transmits the first radio signal for the second and subsequent times at the transmission timings determined by the determination unit 130b according to the determination method described above. The processing of this step SA120 is repeated until it is determined that the number of transmissions of the first radio signal has reached Nth (step SA130; YES).

[0053] According to the embodiment described above, by transmitting the first radio signal by mixing the transmission timing at the fixed transmission period T and the transmission timing other than the fixed transmission period T, it is possible to reduce the collision with the radio signals transmitted from other transmitting devices 10 and other terminals. That is, even if the operators 110a of a plurality of transmitting devices 10 are pressed simultaneously, even if there is a possibility that the first radio signals transmitted from these transmitting devices 10 for the first time collide, the occurrence of collision of the first radio signals transmitted after the second time can be reduced. Further, similarly for the first radio signals transmitted from the transmitting device 10 and other terminals, the occurrence of the collision can be reduced. And since the transmission timing during a predetermined period is determined using the unique information of each transmitting device 10 and the operation history information of the transmitting device 10, for example, compared with a mechanism for determining the transmission time slot for transmitting the first radio signal through a complicated process from a plurality of time slots set based on the transmission timing that arrives at a predetermined period after abnormal detection, the process can be simplified.

[0054] <B. Modified Example> The above embodiment may be modified as follows. (1) In the above embodiment, although "4" is exemplified as the predetermined number of times for transmitting the first radio signal during one fixed transmission period T, this predetermined number of times (hereinafter referred to as the transmission number N) may be set based on the transmission time of the first radio signal by a plurality of transmitting devices 10 per fixed transmission period.

[0055] First, the variables used for this setting of N are defined as follows. Tb: The basic period defined in the transmitting device 10 M: The number of transmitting devices 10 belonging to the transmission system 1 N: The number of times of transmitting the first radio signal during one fixed transmission period T T: Fixed transmission period Ttx: The transmission required time required for transmitting the first radio signal once Drf: The average occupancy rate (time ratio) of the first wireless signal, which is the ratio of the total time during which wireless transmission is performed to the average transmission time when the transmitting device 10 transmits the first wireless signal once. Tave: the average transmission interval per transmission of the first wireless signal by the transmitting device 10 belonging to the transmission system 1, and has the relationship Tave=T / (N+1). Tdiff: Transmission interval from the previous transmission to the next transmission of the first radio signal

[0056] First, the fixed transmission period T is set to one of the following values. (1) The maximum delay time allowed in the control device 20 that receives the first wireless signal (2) The least common multiple of the fundamental periods Tb between the transmitters 10 with different fundamental periods Tb For example, if the fundamental periods of the two transmitters 10 are 9 seconds and 15 seconds, respectively, the lowest common multiple is 45 seconds. (3) The time when the relationship Tdiff>1.5×Tb is within three times For example, if the basic period Tb = 10 seconds and Tdiff is 13, 16, 7, 10, 18, 17, 9, etc., then there will be three times in the sixth (N = 6) transmission of the first wireless signal where the time exceeds 15 seconds. Therefore, in order to keep the relationship Tdiff > 1.5 × Tb within three times, the basic period Tb = 10 seconds × (N-1) = 10 × 5 = 50.

[0057] Next, Drf1 is defined as follows: Drf1=(M×Ttx) / Tave 0 <Drf1<1 In other words, Drf1 is the ratio of the transmission time required for each transmission of the first wireless signal by each transmission device 10 belonging to the transmission system 1 to the average transmission interval per transmission of the first wireless signal by each transmission device 10, and is 0 <Drf1<1である。

[0058] Next, Drf2 is defined as follows: Drf2=(N×M×Ttx) / T 0 <Drf2<1

[0059] Then, a desired average occupancy rate (for example, 0.5) is substituted into Drf2 to determine the number N of transmissions of the first wireless signal during one fixed transmission period T. For example, if the transmission time required for one transmission of the first wireless signal is Ttx=0.5 seconds, the number M of transmitting devices 10 belonging to the transmission system 1 is 5, and the fixed transmission period T=30 seconds, then the number N of transmissions of the first wireless signal during the fixed transmission period T to achieve Drf2=0.5 is N=6, and the number N of transmissions to achieve Drf2=0.2 is N=2.4.

[0060] In contrast, if the number of times N of transmissions of the first wireless signal during a fixed transmission period T is fixed at, for example, N=5, the number M of transmitting devices 10 required to achieve Drf2=0.5 becomes M=6, and the number M of transmitting devices 10 required to achieve Drf2=0.2 becomes M=2.4.

[0061] In this way, by setting N based on the transmission time of wireless signals by a plurality of transmitting devices 10 per fixed transmission period, it is possible to achieve a desired average occupancy rate of wireless signals.

[0062] (2) The operation history information used to generate the pseudorandom number is not limited to the transmission number disclosed in the above embodiment, and may be any operation history information that has a different value each time the first wireless signal is transmitted. For example, the count of the fixed transmission period T (the elapsed time within the fixed transmission period T) or the operating time of the transmitting device 10 (the time elapsed since the power was turned on) may be considered.

[0063] (3) In the above embodiment, the transmission timing of the first radio signal during the transmission timing of the fixed transmission cycle T was determined arbitrarily using pseudo-random numbers. However, this method may result in an extreme imbalance in the transmission timing of the first radio signal during the transmission timing of the fixed transmission cycle T. To avoid this, the following may be adopted. The determination unit 130b first determines a predetermined cycle for transmitting the first radio signal as a fixed value, and sequentially identifies the transmission timing for each predetermined cycle on the time axis, starting from the transmission timing of the initial first radio signal. As a result, times t2 to t12... corresponding to predetermined cycles starting from time t1 of the transmission timing of the initial first radio signal are identified, as illustrated in FIG. 8.

[0064] Next, the determination unit 130b determines, from the sequentially identified transmission timings, the transmission timings in a predetermined order on the time axis (for example, the 6th, 11th, ..., 1+K×Nth transmission timings: here, K=5, N is a positive integer, the same applies hereinafter) as fixed transmission timings. In the example of FIG. 8, times t6, t11, ... correspond to the fixed transmission timings. The transmitter 130a transmits the first wireless signal when the fixed transmission timing arrives.

[0065] On the other hand, between the above-mentioned fixed transmission timings (between the 1+K×(N-1)th transmission timing and the 1+K×Nth transmission timing), the first wireless signal is transmitted at transmission timings that are shifted back and forth on the time axis based on the above-mentioned transmission cycle. This transmission timing is called shifted transmission timing. In the example of FIG. 8, the transmission timings corresponding to times t2, t3, t4, t5, t7, t8, t9, t10, t12... shift back and forth on the time axis.

[0066] (3-1) A possible method is to use a value calculated from the operation history information of the transmitting device 10 as the fluctuation range of the variable transmission timing. For example, the determination unit 130b may use the time calculated by dividing the last two digits of the number representing the operating time, which is the operation history information of the transmitting device 10, by 100 as the fluctuation range. Since the operation history information is unlikely to match between transmitting devices 10 and the values extracted as the operation history information themselves vary between transmitting devices 10, even if the value is applied as is to the fluctuation range, the effect of being able to vary the transmission timing on the time axis can be obtained.

[0067] In addition to determining the fluctuation range by time, the fluctuation range may be determined by using the transmission order (time slot number) of the first wireless signal. For example, the determination unit 130b may divide a pseudo-random number generated from the operation history information by a constant and round down the decimal point to determine the transmission timing of the transmission order (time slot number) that matches the value obtained, as the variable transmission timing.

[0068] (3-2) Furthermore, the decision unit 130b may vary the transmission period between fixed transmission timings back and forth on the time axis (for example, ±2 seconds) using a random number or the like according to the operation history information of the transmitting device 10, and may transmit the first wireless signal at a variable transmission timing that is further varied back and forth on the time axis based on the varied transmission period.

[0069] The fluctuation range may be determined when determining the variable transmission timing, or multiple times of variable transmission timing may be determined together when determining the fixed transmission timing.

[0070] (3-3) Instead of varying all of the transmission timings that exist at predetermined intervals between fixed transmission timings to obtain variable transmission timings, the determination unit 130b may vary some of the transmission timings that exist at predetermined intervals between fixed transmission timings to obtain variable transmission timings. For example, the determination unit 130b may not vary the first predetermined number of transmission timings between fixed transmission timings, but may vary the remaining transmission timings.

[0071] As described above, in Modification 3, determiner 130b determines variable transmission timings by varying some of the multiple transmission timings that arrive at a predetermined cycle, using at least operation history information that indicates the operation history of transmitting device 10. Then, when an abnormality occurs, transmitter 130a transmits a wireless signal at the fixed transmission timings that have not been varied by determiner 130b and the variable transmission timings that have been varied by determiner 130b, among the multiple transmission timings that arrive at a predetermined cycle.

[0072] In each of the above modified examples, as described in the above embodiment, the transmission timing may be determined using the usage environment information described in the above embodiment instead of or in addition to the operation history information.

[0073] (4) 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 the transmission unit 130a and the determination unit 130b in the above embodiment are both software modules, either or both of the transmission unit 130a and the determination unit 130b may be hardware modules such as electronic circuits. Even if either or both of the transmission unit 130a and the determination unit 130b are hardware modules, the same effects as those of the above embodiment can be achieved.

[0074] (5) Transmitting device 10 is not limited to an emergency call button. Transmitting device 10 may be a sensor (fire detection sensor, gas detection sensor, human presence sensor) that detects abnormalities such as fire, gas leak, or intrusion by a suspicious person, and may output an abnormality detection signal to control unit 130 when these sensors detect an abnormality. By receiving this abnormality detection signal, control unit 130 detects the occurrence of an abnormality and repeatedly transmits the first wireless signal Nth times. Note that if transmitting device 10 is a sensor that detects an abnormality, transmitting device 10 does not necessarily have to include operation button 110a.

[0075] (6) In the above embodiment, the transmitting system 1 including multiple transmitting devices 10 has been described, but the transmitting device 10 may be manufactured or sold as a standalone device. Also, in the above embodiment, a control program that causes the control unit 130 to execute a notification method that prominently exhibits the features of the present disclosure is pre-stored in the storage unit 140, but this control program may be manufactured or provided as a standalone device. Specific ways of providing this control program include distributing it by downloading it via a telecommunications line such as the Internet, or distributing it by writing it to a computer-readable recording medium such as a flash ROM. [Explanation of symbols]

[0076] 1...transmission system, 10, 10(1) to 10(M)...transmission device, 110...input device, 110a...operator, 120...communication unit, 130...control unit, 130a...transmission unit, 130b...determination unit, 140...storage unit, 20...control device.

Claims

1. a determination unit that determines a transmission timing of a wireless signal between transmission timings of a predetermined cycle by using at least operation history information indicating an operation history of the transmitting device; a transmitter that transmits the wireless signal at the predetermined period and at the determined transmission timing when an abnormality occurs; A transmitting device comprising:

2. a determination unit that determines a variable transmission timing by varying some of a plurality of transmission timings that arrive at a predetermined cycle, using at least operation history information that indicates an operation history of the transmitting device; a transmitter that, when an abnormality occurs, transmits a wireless signal at a fixed transmission timing that has not been changed by the determination unit and a variable transmission timing that has been changed by the determination unit among a plurality of transmission timings that arrive at the predetermined cycle; A transmitting device comprising:

3. The determination unit generates a pseudo-random number using at least the operation history information, and determines the transmission timing using the generated pseudo-random number.

3. The transmitting device according to claim 1 or 2.

4. 3. The transmitting device according to claim 1, wherein the determination unit determines the transmission timing of the next radio signal every time the transmission unit transmits a radio signal.

5. The transmitting device according to claim 1 , wherein the determination unit determines all transmission timings between transmission timings of the predetermined period when the transmission unit transmits the radio signal at the predetermined period.

6. The determination unit determining a first transmission timing during the predetermined cycle of transmission timings using the operation history information; 2. The transmitting device according to claim 1, wherein the next transmission timing is determined to be the timing at which a quotient obtained by dividing the remaining time of a predetermined period from the immediately preceding transmission timing by a constant has elapsed.

7. the transmitter transmits a wireless signal N times (N is a positive integer) during the predetermined period of transmission timing; 2. The transmitting device according to claim 1, wherein said N is set based on the transmission time of the radio signals from said plurality of transmitting devices per predetermined period.

8. The transmitting device according to claim 1 or 2, wherein the determination unit determines the transmission timing using information specific to the transmitting device in addition to the operation history information.

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