Sub-station device, disaster prevention wireless system, wireless communication method, and program

Abstract

To provide a slave station device, disaster prevention radio system, radio communication method, and program that can control the direction of an antenna in an appropriate direction according to the radio wave reception status.SOLUTION: A slave station device 1 according to the present disclosure receives disaster prevention information by radio from a master station device, and transmits the received disaster prevention information by a voice output method. The slave station device 1 includes: a measuring unit 2 that measures the reception sensitivity of radio waves received from the master station device by receiving, from the master station device, an antenna adjustment signal for adjusting an antenna of the slave station device; and a determination unit 3 that determines whether to change the direction of the antenna based on the measured reception sensitivity of radio waves.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a slave unit device, a disaster prevention radio system, a wireless communication method, and a program.

Background Art

[0002] In recent years, when opening a floodgate provided in a dam or a weir to discharge water, an alarm system has been established, which includes a slave unit device having sirens, broadcasting facilities, etc. for warning the residents in the basin area, and a monitoring station which is a master unit device for monitoring the slave unit device. The slave unit device may be installed in mountainous areas such as around a dam. Therefore, the slave unit device needs to install an antenna or the like in consideration of the intensity and direction of received radio waves according to the radio wave environment caused by the surrounding environment. Patent Document 1 discloses a technique related to a slave unit device that can optimize the direction of an antenna and substantially maximize the communication speed in communication with a master unit device.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] As described above, for example, a slave unit device installed in a mountainous area may cause problems such as non-starting of broadcasting due to unexpected deterioration of reception sensitivity. This problem is caused by the deterioration of the received electric field and the occurrence of reception failure due to multipath of received radio waves accompanying seasonal changes or changes in trees due to growth in the surrounding environment of the slave unit device compared to when the slave unit device was initially installed. In order to address this problem, it is necessary to adjust the direction of the antenna. However, in mountainous areas, depending on the weather conditions, it may be difficult for workers to go to the site to measure radio waves while adjusting the direction of the antenna or the like.

[0005] The present disclosure has been made to solve such problems, and an object thereof is to provide a slave station device, a disaster prevention radio system, a wireless communication method, and a program that can control the direction of an antenna in an appropriate direction according to the radio wave reception status.

Means for Solving the Problems

[0006] The slave station device according to the present disclosure is a slave station device that receives disaster prevention information by radio from a master station device and transmits the received disaster prevention information by a voice output method, and by receiving an antenna adjustment signal for adjusting the antenna of the slave station device from the master station device, a measurement unit that measures the reception sensitivity of radio waves received from the master station device, and a determination unit that determines whether or not to change the direction of the antenna based on the measured reception sensitivity of the radio waves.

[0007] The disaster prevention radio system according to the present disclosure is a disaster prevention radio system including a master station device and a slave station device belonging to the master station device, wherein the slave station device is a device that receives disaster prevention information by radio from the master station device and transmits the received disaster prevention information by a voice output method, and by receiving an antenna adjustment signal for adjusting the antenna of the slave station device from the master station device, a measurement unit that measures the reception sensitivity of radio waves received from the master station device, and a determination unit that determines whether or not to change the direction of the antenna based on the measured reception sensitivity of the radio waves.

[0008] The wireless communication method according to the present disclosure includes a step of measuring the reception sensitivity of radio waves received from a master station device by a slave station device that receives disaster prevention information by radio from the master station device and transmits the received disaster prevention information by a voice output method by receiving an antenna adjustment signal for adjusting the antenna of the slave station device from the master station device, and a step of the slave station device determining whether or not to change the direction of the antenna based on the measured reception sensitivity of the radio waves.

[0009] The program according to the present disclosure is a program that causes a computer included in a slave station device that receives disaster prevention information wirelessly from a master station device and transmits the received disaster prevention information by voice output to measure the reception sensitivity of radio waves received from the master station device by receiving an antenna adjustment signal for adjusting the antenna of the slave station device from the master station device, and to execute a process of determining whether or not to change the direction of the antenna based on the measured reception sensitivity of the radio waves.

Effect of the Invention

[0010] According to the present disclosure, it is possible to provide a slave station device, a disaster prevention wireless system, a wireless communication method, and a program that can control the direction of an antenna in an appropriate direction according to the reception status of radio waves.

Brief Description of the Drawings

[0011]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Mode for Carrying Out the Invention

[0012] Hereinafter, embodiments will be described with reference to the drawings. Note that since the drawings are simplified, the technical scope of the embodiments should not be narrowly interpreted based on the description of these drawings. Also, the same elements are denoted by the same reference numerals, and duplicate descriptions are omitted.

[0013] <Embodiment 1> One slave station device in this embodiment will be described with reference to FIG. 1. FIG. 1 is a configuration diagram of the slave station device 1 according to this embodiment. The slave station device 1 can communicate with the master station device mutually. The slave station device 1 receives disaster prevention information by radio from the master station device, and notifies the received disaster prevention information by voice output method or character display method. Further, the slave station device 1 includes a measurement unit 2 and a determination unit 3.

[0014] The measurement unit 2 measures the reception sensitivity of the radio wave received from the master station device by receiving an antenna adjustment signal for adjusting the antenna of the slave station device 1 from the master station device. Further, the determination unit 3 determines whether or not to change the direction of the antenna based on the reception sensitivity of the radio wave from the master station device measured by the measurement unit 2.

[0015] According to the slave station device 1 in this embodiment, the direction of the antenna can be controlled in an appropriate direction according to the reception status of the radio wave.

[0016] <Embodiment 2> The wireless communication system 10 in this embodiment will be described with reference to FIG. 2. FIG. 2 is an overall configuration diagram of the wireless communication system 10 in this embodiment. The wireless communication system 10 includes a master station device 20, a relay station device 30, and a slave station device 40. The master station device 20 can communicate with a plurality of slave station devices 40 via the relay station device 30. The slave station device 40 belongs to the master station device 20, receives disaster prevention information wirelessly from the master station device 20, and notifies the received disaster prevention information by means of voice output or character display. Therefore, the wireless communication system 10 in this embodiment has a function as a disaster prevention wireless system.

[0017] Here, the configurations of the master station device 20 and the slave station device 40 in the wireless communication system 10 will be described with reference to FIG. 3. FIG. 3 is a configuration diagram of the master station device 20 and the slave station device 40 of the wireless communication system 10 in this embodiment. The slave station device 40 may be installed outdoors or indoors such as in a station building.

[0018] The master station device 20 includes an antenna 21, a radio unit 22, a control unit 23, an operation unit 24, and a display unit 25. The master station device 20 communicates with the slave station device 40 via the radio unit 22 and the antenna 21. The communication between the master station device 20 and the slave station device 40 can be performed via the relay station device 30, but here the relay station device 30 is omitted.

[0019] The radio unit 22 transmits and receives various signals between the slave station device 40, such as a signal for controlling the start and end of broadcasting in the slave station device 40 and a signal for adjusting the direction of the antenna 41 in the slave station device 40. Hereinafter, the direction of the antenna 41 shall include the elevation angle and azimuth angle of the antenna 41. The control unit 23 outputs a radio signal via the radio unit 22. In addition, the control unit 23 detects the pressing of the broadcast start button and the broadcast end button of the operation unit 24, and controls the start and end of broadcasting by the slave station device 40. In addition, the control unit 23 performs various controls such as detecting the pressing of the antenna adjustment mode button of the operation unit 24 and transmitting a radio signal for adjusting the direction of the antenna 41 in the slave station device 40.

[0020] The operation unit 24 includes a broadcast start button and a broadcast end button for starting and ending the broadcast of the slave unit device 40. Further, the operation unit 24 includes an antenna adjustment mode button for adjusting the direction of the antenna 41 in the slave unit device 40.

[0021] The display unit 25 may use display means such as an LCD (liquid crystal display), an LED (light emitting diode), etc., or may be a touch panel type. Further, the display unit 25 may be configured by a PC (personal computer), a mobile terminal, etc. that can communicate with the master unit device 20. Furthermore, the display unit 25 may be integrally configured with the operation unit 24 and may display a screen for inputting to perform various operations.

[0022] The slave unit device 40 includes an antenna 41, a radio unit 42, a control unit 43, an operation unit 44, a display unit 45, and an antenna adjustment unit 46. The slave unit device 40 communicates with the master unit device 20 via the radio unit 42 and the antenna 41. The communication between the slave unit device 40 and the master unit device 20 can be performed via the relay unit device 30, but here the relay unit device 30 is omitted. Note that the antenna 41 preferably has directivity, and typically, a Yagi antenna can be used.

[0023] The radio unit 42 is a measurement unit that measures the reception sensitivity of the radio wave received from the master unit device 20. The reception sensitivity may use the received radio wave intensity (RSSI: Received Signal Strength Indicator) or the received bit error rate (BER). Further, the radio unit 42 is a communication unit that transmits and receives an antenna adjustment signal in the slave unit device 40, a signal related to the measured received radio wave intensity, and a received bit error rate between the slave unit device 40 and the master unit device 20.

[0024] The control unit 43 analyzes signals such as the antenna adjustment signal via the radio unit 42. Also, based on the measurement results of the received radio wave intensity and the received bit error rate of the received wave from the master station device 20 measured by the radio unit 42, the control unit 43 determines whether to change the direction of the antenna 41. When the results of comparing and determining the received radio wave intensity and the received bit error rate with the threshold values are less than the threshold values, the control unit 43 causes the antenna adjustment unit 46 to change the direction and height of the antenna 41 to a direction different from the current direction and height. The antenna adjustment unit 46 controls the direction of the antenna 41 based on the direction of the antenna 41 determined by the control unit 43. Further, the control unit 43 causes the display unit 45 to display the comparison and determination results between the measurement results of the received radio wave intensity and the received bit error rate and the threshold values.

[0025] The operation unit 44 includes a broadcast start button and a broadcast end button for starting and ending the broadcast of the slave station device 40. Also, the operation unit 24 of the master station device 20 may include an antenna adjustment mode button for adjusting the direction of the antenna 41 in the slave station device 40. Further, the operation unit 44 of the slave station device 40 may include an antenna adjustment mode button for adjusting the direction of the antenna 41. By providing the antenna adjustment mode button in the slave station device 40 in this way, even if the slave station device 40 fails to receive the antenna adjustment signal from the master station device 20, the direction of the antenna 41 can be adjusted.

[0026] The display unit 45 displays the measurement results of the received radio wave intensity and the received bit error rate performed by the radio unit 42 and the results of comparing and determining these with the threshold values. The display unit 45 may use display means such as an LCD (liquid crystal display), an LED (light emitting diode), etc., and may be a touch panel type. Also, the display unit 45 may be configured by a PC (personal computer), a mobile terminal, etc. that can communicate with the slave station device 40. Further, the display unit 45 may be configured integrally with the operation unit 44 and can display a screen for inputting to perform various operations.

[0027] The antenna adjustment unit 46 changes the direction and height of the antenna 41 according to a control signal received from the control unit 43 based on the result of comparing and determining the received radio wave intensity and the received bit error rate performed by the control unit 43 with a threshold value.

[0028] <Explanation of the antenna adjustment process of the wireless communication system 10> The antenna adjustment process performed by the wireless communication system 10 in this embodiment will be described with reference to FIGS. 4 and 5. FIG. 4 is a communication timing diagram of the antenna adjustment process performed by the wireless communication system 10. FIG. 5 is a flowchart showing the antenna adjustment process performed by the wireless communication system 10. The numbers of the steps shown in FIGS. 4 and 5 correspond to each other. The antenna adjustment process shown in FIG. 4 is a process performed when the radio wave environment deteriorates due to the growth of trees or the construction of new buildings around the slave station device 40.

[0029] First, at the operation unit 24 of the master station device 20, an antenna adjustment mode ON button is input (step 101). At this time, the control unit 23 transitions to the antenna adjustment signal transmission process (step 102). The display unit 25 displays that "the antenna of the slave station device is being adjusted". The control unit 23 transmits an antenna adjustment signal to the radio unit 22, and the radio unit 22 transmits the antenna adjustment signal to the slave station device 40 as a radio signal (step 103).

[0030] Next, the radio unit 42 of the slave station device 40 receives the antenna adjustment signal and starts measuring the received radio wave intensity and the received bit error rate in the direction 1 which is the current direction of the antenna 41. In response to this, the control unit 43 transitions to the received bit error rate measurement mode, and causes the display unit 45 to display that "BER measurement in progress (antenna direction 1)" (step 104).

[0031] When the measurement of the received radio wave intensity and the received bit error rate in the wireless unit 42 is completed, the measurement results are notified to the control unit 43. The control unit 43 compares the received radio wave intensity and the received bit error rate measured by the wireless unit 42 with their threshold values (step 105). If the received radio wave intensity and the received bit error rate measured by the wireless unit 42 are less than the threshold values (NO in step 105), the display unit 45 is caused to display that "BER measurement in progress (antenna direction 2)". Further, the control unit 43 designates a direction of the antenna 41 that is different from the current direction at a predetermined direction and height (antenna direction 2) for controlling the antenna 41 (step 106), and transmits the information of the antenna direction 2 to the antenna adjustment unit 46.

[0032] In response to this, the antenna adjustment unit 46 receives the information of the predetermined direction and height (antenna direction 2), and adjusts the antenna 41 to the predetermined direction and height (antenna direction 2) (step 107). Similar to step 104, the wireless unit 42 measures the received radio wave intensity and the received bit error rate, and if the measurement results are equal to or greater than the threshold values (YES in step 105), the adjustment process of the antenna 41 is terminated.

[0033] As a process for determining the position of the antenna 41 of the slave unit device 40, during the required time, the antenna adjustment unit 46 rotates and vertically moves the antenna 41 to a predetermined direction and height, and adjusts the position of the antenna 41 to the direction of the best measurement result based on the measurement results of the received radio wave intensity and the received bit error rate. The measurement of the received radio wave intensity and the received bit error rate may be performed, for example, at four directions at 90° intervals with respect to the azimuth angle of the antenna 41, but is not limited to this.

[0034] The control unit 43 may include a table associating the reception sensitivity of the radio wave measured within a predetermined period with the direction of the antenna, and determine the direction in which the antenna should be directed based on the table. The predetermined period may be each date and time, each month, but is not limited thereto. At this time, the radio unit 42 may measure the received radio wave intensity and the received bit error rate in advance for each predetermined period, and create a table associating the direction, height, and gain of the antenna 41 with the best measurement results. The control unit 43 may be set to optimize the direction and height of the antenna 41 for each month based on the created table.

[0035] Further, the control unit 43 may include a table associating the direction, height, and gain of the antenna 41 within a predetermined period with the received radio wave intensity and the received bit error rate measured at intervals of a predetermined resolution, in relation to the measurement date and time and the weather. At this time, the control unit 43 may cause the antenna adjustment unit 46 to control the direction of the antenna 41 based on the direction, height, and gain of the antenna 41 from which the optimum received radio wave intensity and the received bit error rate can be obtained from the date and time and the weather.

[0036] <Comparison with the related wireless communication system 10> Here, the related wireless communication system 10r will be described with reference to FIGS. 6 and 7. FIG. 6 is a configuration diagram of the master station device 20r and the slave station device 40r in the related wireless communication system 10r. FIG. 7 is a communication timing diagram during broadcasting in the related wireless communication system 10r.

[0037] Also in the related wireless communication system 10r, the master station device 20r and the slave station device 40r can communicate with each other. Here, the description of the configurations of the master station device 20r and the slave station device 40r respectively is omitted. The difference between the wireless communication system 10r and the wireless communication system 10 in the present embodiment is that, as shown in FIG. 6, the slave station device 40r does not include the antenna adjustment unit 46. Therefore, naturally, the control unit 23r of the master station device 20r does not perform transmission control of the antenna adjustment signal unlike the control unit 23, and the control unit 43r of the slave station device 40r does not perform control related to antenna adjustment unlike the control unit 43. Also, although omitted in FIG. 4, the communication timing of the broadcast signal of the wireless communication system 10 can also be as shown in FIG. 7.

[0038] As shown in FIG. 7, around the slave station device 40r, due to the growth of trees or the construction of new buildings, etc., when receiving radio waves from the master station device 20r, it becomes multipath, and the radio wave environment deteriorates. At this time, for example, the received bit error rate becomes less than the threshold value, and the broadcast signal from the master station device 20r cannot be received (step 201). Therefore, there is a problem that necessary broadcasts cannot be performed.

[0039] According to the wireless communication system 10 in the present embodiment, even if the radio wave environment deteriorates due to the growth of trees or the construction of new buildings, etc. around the slave station device 40, the slave station device 40 can receive the broadcast signal from the master station device 20. That is, as described above, according to the wireless communication system 10 in the present embodiment, the master station device 20 can grasp the radio wave environment of the slave station device 40, and the slave station device 40 can receive at an appropriate direction of the antenna 41 according to the radio wave environment. Therefore, the slave station device 40 can suppress the problem that it cannot receive information regarding the broadcast content from the master station device 20 when it should perform a broadcast. Therefore, according to the wireless communication system 10 in the present embodiment, the direction of the antenna 41 of the slave station device 40 can be controlled in an appropriate direction according to the radio wave reception situation.

[0040] <Embodiment 3> In the wireless communication system 10 according to Embodiment 2, the communication between the master station device 20 and the slave station device 40 uses radio waves. In the wireless communication system 10 according to the present embodiment, the slave station device 40 may be configured not to have a transmission function and to be connectable to a public network such as a LAN of the master station device 20 by means of short-range communication.

[0041] By adopting such a configuration, the slave station device 40 can simplify its configuration. Further, according to the wireless communication system 10 in the present embodiment, the direction of the antenna of the slave station device 40 can be controlled in an appropriate direction according to the radio wave reception situation.

[0042] <Embodiment 4> Regarding the wireless communication system in the present embodiment, the differences from Embodiment 2 will be mainly described with reference to FIG. 8, and some overlapping descriptions will be omitted. However, various examples described in Embodiments 1 to 3 can also be applied in the present embodiment. FIG. 8 is a configuration diagram of the master station device 20a and the slave station devices 40a, 60a in the wireless communication system 10a according to the present embodiment.

[0043] The wireless communication system 10a includes a master station device 20a and a plurality of slave station devices such as slave station devices 40a and 60a, and may include a relay station device (not shown). The communication between the master station device 20a and each slave station device can be performed via this relay station device, but the relay station device is also omitted here. Similar to the wireless communication system 10 described with reference to FIG. 2, in the wireless communication system 10a, the master station device 20a can communicate with a plurality of slave station devices mutually. Here, the slave station devices 40a and 60a are the 1st and m-th slave station devices respectively, and m is an integer from 2 to n (an integer of 2 or more). That is, the wireless communication system 10a includes n slave station devices. Note that the wireless communication system 10a may also include the slave station device 40 in FIG. 3 as a slave station device.

[0044] The master station device 20a can include the antenna 21, operation unit 24, and display unit 25 described in FIG. 3, and can include a radio unit 22a and a control unit 23a that respectively have the functions of the radio unit 22 and the control unit 23 described in FIG. 3.

[0045] Slave station devices such as the slave station devices 40a and 60a included in the wireless communication system 10a belong to the master station device 20a, receive disaster prevention information wirelessly from the master station device 20a, and notify the received disaster prevention information by voice output or character display. That is, the wireless communication system 10a in this embodiment has a function as a disaster prevention wireless system.

[0046] Therefore, the slave station device 40a can include the antenna 41, radio unit 42, operation unit 44, display unit 45, and antenna adjustment unit 46 described in FIG. 3, and can include a control unit 43a having the function of the control unit 43 described in FIG. 3. Note that although the antenna adjustment unit 46 is shown outside the slave station device 40a for convenience, it goes without saying that it may be built into the main body of the slave station device 40a or provided outside the main body, and the same applies to the antenna adjustment unit 46 in FIG. 3.

[0047] Here, although the description of the display unit 45 is omitted in Embodiment 2, it can also function as a display unit that notifies the received disaster prevention information in a character display manner. However, a display unit for notification can also be provided separately from the display unit 45.

[0048] In addition, the slave station device 40a includes a speaker unit 47 that outputs disaster prevention information by voice as an example of a notification unit that notifies the received disaster prevention information by voice output. The speaker unit 47 can include a speaker and an amplifier that function as a loudspeaker. Note that the speaker unit 47 is a part that was not shown and described in FIG. 3.

[0049] In addition, although the details are omitted, the slave station device 60a can have the same configuration as the slave station device 40a.

[0050] Then, the wireless communication system 10a according to the present embodiment is configured to solve the following problems. As described in Embodiments 1 to 3, when the received electric field deteriorates and a reception failure occurs after the operation of the deployed slave station devices is started, the sensitivity degradation (degradation of the reception state) can be improved by adjusting the antenna element (orientation, etc.) so that the broadcast from the master station device can be received. However, in Embodiments 1 to 3, as a result of the adjustment within the range of the antenna element adjustment, if some of the slave station devices end up with incomplete sensitivity recovery, there may arise a problem that the broadcast does not reach the target area. That is, in Embodiments 1 to 3, improvement of the reception failure can be expected only within the range of the antenna adjustment, and there is a problem that relief for the reception failure beyond the antenna adjustment cannot be provided.

[0051] To solve such problems, the wireless communication system 10a according to the present embodiment executes at least one of adjusting the transmission level of the signal transmitted from the master station device 20a and performing alternative relaying by the surrounding slave station devices, together with the antenna adjustment described in Embodiments 1 to 3. Thereby, the wireless communication system 10a can avoid reception failures. However, by configuring the wireless communication system 10a to execute both the adjustment of the transmission level and the alternative relaying, it is possible to increase the scenarios in which the above-described problems can be solved. Therefore, hereinafter, an example in which the wireless communication system 10a is configured to execute both the adjustment of the transmission level and the alternative relaying will be described.

[0052] First, the master station device 20a will be described centering on the differences from the master station device 20 in FIG. 3. The wireless unit 22a transmits and receives various signals between the slave station devices 40a and 60a, such as signals for controlling the start and end of the broadcast in the slave station devices 40a and 60a and signals for adjusting the direction of the antenna 41 in the slave station devices 40a and 60a. Here too, the direction of the antenna 41 shall include the elevation angle and azimuth angle of the antenna 41. Of course, although the description was omitted in Embodiments 1 to 3, the wireless unit 22a also transmits the broadcast signal broadcast by the slave station devices 40a and 60a.

[0053] In this embodiment, the wireless unit 22a includes a transmission level adjustment unit 22b that adjusts the transmission level for transmitting signals such as broadcasts according to an instruction from the control unit 23a. Further, the wireless unit 22a can be configured to transmit a signal for confirming to the slave unit devices 40a and 60a whether it is necessary to adjust the transmission level by the transmission level adjustment unit 22b according to an instruction from the control unit 23a.

[0054] The control unit 23a outputs a radio signal via the wireless unit 22. Further, the control unit 23a detects the pressing of the broadcast start button and the broadcast end button of the operation unit 24, and controls the start and end of the broadcast by the slave unit devices 40a and 60a. Further, the control unit 23a performs various controls such as controlling the transmission of a radio signal for adjusting the direction of the antenna 41 in the slave unit devices 40a and 60a when detecting the pressing of the antenna adjustment mode button of the operation unit 24.

[0055] The control unit 23a in this embodiment further performs the following control. That is, after the control unit 23a controls the wireless unit 22a to transmit a radio signal for adjusting the direction of the antenna 41, it controls the slave unit devices 40a and 60a to transmit a radio signal for confirming whether it is necessary to adjust the transmission level. Here, the transmission level adjustment is performed to improve the deterioration of the received BER in the slave unit devices 40a and 60a. The radio signal for confirming whether it is necessary to adjust the transmission level is a signal transmitted when it is determined to change the direction of the antenna 41 and the direction of the antenna 41 is changed, and can be referred to as a reception sensitivity adjustment signal for adjusting the reception sensitivity of radio waves in the slave unit device 40a. Then, as a function corresponding to the measurement unit, the radio unit 42 can measure the reception sensitivity of radio waves by receiving this reception sensitivity adjustment signal from the master unit device 20a. The reception sensitivity adjustment signal can be a signal with a higher transmission level than the antenna adjustment signal.

[0056] Note that by configuring the slave unit devices 40a and 60a to return the confirmation result of whether it is necessary to adjust the transmission level by controlling the transmission of the radio signal for adjusting the direction by the control unit 23a, the control of transmitting the radio signal for confirming the necessity can be omitted.

[0057] Further, the control unit 23a controls the transmission level adjustment unit 22b to perform the above-described transmission level adjustment. Further, even when a series of transmission level adjustment operations including communication with the slave units 40a and 60a are completed, if there is a slave unit with a defective reception state, the control unit 23a performs the following control. That is, in this case, the control unit 23a controls the radio unit 22a to notify the nearest relay slave unit that the nearest slave unit of the relay slave unit has a defective reception state. Here, the slave unit with a defective reception state refers to a slave unit in which one or both of the measured BER and RSSI are below the threshold. Also, the nearest relay slave unit of the master unit 20a can refer to a slave unit that is located close to the slave unit with a defective reception state among the slave units that do not have a defective reception state. Whether the slave units are the nearest can be determined by describing the relationship in a storage device inside or outside the control unit 23a, for example, in a table, or by storing the position information of each slave unit and comparing the position information.

[0058] Hereinafter, for the sake of convenience, on the premise that the slave unit with a defective reception state after the completion of a series of transmission level adjustment operations is the slave unit 60a, and the slave unit that is in a normal reception state and is located close to the slave unit 60a and serves as a relay is the slave unit 40a, an explanation will be given. However, the combination of these slave units is not limited to this example, and there may be a case where there is no slave unit with a defective reception state after the completion of a series of transmission level adjustment operations. Of course, there may also be a case where there is no slave unit with a defective reception state after the completion of a series of transmission level adjustment operations.

[0059] Next, the differences between the slave unit 40a and the slave unit 40 in FIG. 3 will be mainly described. Although the description is omitted, as described above, the slave unit 60a can also have the same configuration as the slave unit 40a. The slave unit 40a communicates with the master unit 20a via the radio unit 42.

[0060] The control unit 43a can perform the same control as the control unit 43. That is, the control unit 43a analyzes signals such as antenna adjustment signals via the radio unit 42. Further, based on the measurement results of the RSSI and the received BER of the received wave from the master station device 20a measured by the radio unit 42, the control unit 43a determines whether to change the direction of the antenna 41. When the results of comparing and determining the RSSI and the received BER with the threshold value are less than the threshold value, the control unit 43a causes the antenna adjustment unit 46 to change the direction and height of the antenna 41 to a direction different from the current direction and height. The antenna adjustment unit 46 controls the direction and height of the antenna 41 based on the direction and height of the antenna 41 determined by the control unit 43a. By repeating such control, the direction and height of the antenna 41 can be optimized. Further, the control unit 43a causes the display unit 45 to display the comparison and determination results between the measurement results of the RSSI and the received BER and the threshold value. Also, the control unit 43a controls the speaker unit 47. The speaker unit 47 broadcasts the voice of the broadcast content and the like through a speaker according to an instruction from the control unit 43a.

[0061] The control unit 43a in the present embodiment further performs the following control. That is, after changing the direction of the antenna 41, the control unit 43a performs the above-described comparison and determination. When the result is less than the threshold value, the control unit 43a performs control to transmit the adjustment result as incomplete together with the BER value and the RSSI value to the master station device 20a via the radio unit 42. Further, when the control unit 43a receives a notification of reception state incompleteness of the nearest slave station device 60a from the master station device 20a, the control unit 43a records the broadcast content during subsequent broadcast reception and controls to rebroadcast the recorded content at a predetermined time.

[0062] Here, if information such as the ID related to the slave station device 60a closest to this notification is included, the control unit 43a can specify the rebroadcast destination and can also generate a broadcast signal with the specified rebroadcast destination. Also, the relationship of the position with other slave station devices such as the slave station device 60a is described, for example, in a table in a storage device inside or outside the control unit 43a, read it, determine whether the slave station device 60a indicated by the above notification is the closest, and if it is the closest, rebroadcast can also be executed. Instead of this determination, position information of the slave station device 40a and other slave station devices can be stored, for example, as a table in a storage device inside or outside the control unit 43a, the position information of both can be compared, and it can also be determined whether the slave station device 60a indicated by the above notification is the closest.

[0063] Also, recording is executed by the recording unit 43b of the control unit 43a. The recording unit 43b stores data of the broadcast content, that is, data of the broadcast content, in a storage device inside or outside the control unit 43a. In this way, the recording unit 43b records the disaster prevention information received from the master station device 20a on behalf of other slave station devices (in this example, the slave station device 60a) according to the instruction from the master station device 20a. This instruction can be a wirelessly transmitted instruction when the value obtained by measuring the radio wave reception sensitivity by receiving a reception sensitivity adjustment signal or an antenna adjustment signal at the slave station device 40a is equal to or greater than a predetermined threshold value and the value measured in the same way at the slave station device 60a is less than the above predetermined threshold value. In this case, this instruction is an instruction wirelessly transmitted from the master station device 20a to the slave station device 40a.

[0064] Also, rebroadcast is executed by the rebroadcast unit 43c of the control unit 43a. The rebroadcast unit 43c reads out the stored data of the broadcast content and rebroadcasts by transmitting the signal indicated by the data to the slave station device 60a with BER failure via the wireless unit 42. Therefore, the wireless unit 42 includes a wireless transmission unit that transmits information wirelessly. This wireless transmission unit can also be used for transmitting information such as measurement values to the master station device 20a. Note that the rebroadcast unit 43c and the wireless unit 42 can also be defined as a wireless transmission unit that wirelessly transmits the recorded disaster prevention information to other slave station devices (in this example, the slave station device 60a) instructed by the master station device 20a.

[0065] Here, the antenna 41 of the slave unit device 40a does not need to be separately provided for communication with the master unit and for communication between slave units. Although such an example is given, it may be separately provided. Also, although the antenna 41 is basically optimized for receiving radio waves from the master unit device 20a, no special adjustment is required when rebroadcasting to the nearest slave unit device (for example, the slave unit device 60a). The slave unit device (here, the slave unit device 60a) to which rebroadcasting is performed is arranged at a position closer to the installation position of the slave unit device (here, the slave unit device 40a) that performs rebroadcasting than the installation position of the master unit device 20a, because there is no problem with communication for rebroadcasting between the two.

[0066] Also, examples of the communication method used in the present embodiment and Embodiments 1 to 3 include communication methods used in current municipal disaster prevention systems, such as the SCPC method and the TDMA method, but it is not limited to this. Here, SCPC is an abbreviation for Single Channel Per Carrier, and TDMA is an abbreviation for Time Division Multiple Access. Examples of the TDMA method include, but are not limited to, the TDMA-TDD (Time Division Duplex) method.

[0067] <Explanation of the BER adjustment process of the wireless communication system 10a> In the wireless communication system 10a in the present embodiment, a process for adjusting the reception state (hereinafter, the BER adjustment process) is performed, and this BER adjustment process can include the antenna adjustment process described in Embodiment 2. An example of this BER adjustment process will be described with reference to FIGS. 9 to 13. FIG. 9 is a communication timing diagram for the BER adjustment process performed by the wireless communication system 10a, FIG. 10 is a timing diagram following FIG. 9, and FIG. 11 is a partial timing diagram following FIG. 10. FIG. 12 is a flowchart showing the BER adjustment process performed by the wireless communication system 10a, and FIG. 13 is a flowchart following FIG. 12. Note that the step numbers shown in FIGS. 9 to 11 and the step numbers shown in FIGS. 12 and 13 correspond to each other.

[0068] The BER adjustment process exemplified here is a process performed when the radio wave environment deteriorates due to the growth of trees or the construction of new buildings, etc., around some or all of the slave station devices belonging to the master station device 20a. Further, the BER adjustment process exemplified here can be implemented using the free time of the line, etc., while the slave station device is waiting for or during a broadcast, and can also be implemented periodically. This is the same for the antenna adjustment process of Embodiment 2 in this regard.

[0069] First, at the operation unit 24 of the master station device 20a, an input of the BER adjustment mode ON button is received (step 201). Here, the BER adjustment mode is a mode including the antenna adjustment mode described in Embodiment 2, and is a mode for executing the BER adjustment process including the antenna adjustment process.

[0070] Receiving the input in step 201, the same processing as in steps 102 to 107 is performed (steps 202 to 207). Here, the antenna adjustment signal transmitted in step 203 is described as having a transmission level of transmission level A. The transmission level A can be the transmission level at which a broadcast signal was transmitted before the antenna adjustment process. Regarding step 205, the threshold values are illustrated by a one-dot chain line in FIGS. 9 to 11, and the description thereof is omitted, but the same is illustrated in FIGS. 4 and 7 as well.

[0071] If it becomes YES in step 205, the adjustment process of the antenna 41 is temporarily terminated (step 208). Also, after step 207, the adjustment process of the antenna 41 is temporarily terminated (step 208). Alternatively, after step 207, for example, it may be determined whether the number of changes of the antenna 41 is equal to or greater than a threshold value (for example, 3 times, etc.), and if it is equal to or greater than the threshold value, the adjustment process of the antenna 41 may be temporarily terminated.

[0072] In step 208, if the measurement result in step 204 indicates that recovery has occurred when compared with these threshold values, the antenna adjustment result is regarded as a good reception state. If recovery has not occurred, the antenna adjustment result is regarded as an incomplete reception state. This adjustment result may be stored at least in the internal memory of the control unit 43a until transmission to the master station device 20a. Note that instead of the measurement result in step 204, the RSSI and BER may be measured again in the same manner as in step 204, and based on the measurement result, the good / incomplete state of the reception state may be determined to obtain an adjustment result.

[0073] Also, in step 208, when the predetermined BER measurement waiting time has elapsed, the control unit 23a transitions to the state of inquiring about the adjustment result and inquires about the adjustment result. In response to this, the control unit 23a causes the display unit 25 to display that "inquiring about the adjustment result". Then, the control unit 43a of the slave station device 40a controls the radio unit 42 to transmit the adjustment result to the master station device 20a in response to the inquiry about the adjustment result from the master station device 20a or spontaneously (step 209), and the radio unit 42 executes the transmission (step 210). Also, in step 209, during the response to the inquiry, the control unit 43a causes the display unit 45 to display that "responding to the adjustment result". The transmission of the adjustment result is similarly executed for the slave station device 60a.

[0074] The radio unit 22a receives the adjustment results transmitted from the slave station devices 40a and 60a (step 211). The control unit 23a receives the received adjustment results from the radio unit 22a. When the adjustment results indicate a good reception state, the BER adjustment mode is terminated. When the adjustment results indicate an incomplete reception state, the control unit 23a transitions to the state of in the middle of slave station BER adjustment (step 212), and the following processing is executed.

[0075] When transitioning to the state of adjusting the BER of the slave station, the control unit 23a designates a predetermined transmission level (transmission level B) to the transmission level adjustment unit 22b, and sets the transmission level of the BER adjustment signal for adjusting the reception states of the slave stations 40a and 60a to transmission level B. Here, the transmission level B may be any transmission level higher than the transmission level A. Then, the control unit 23a controls the radio unit 22a to transmit the BER adjustment signal, and the radio unit 22a transmits the BER adjustment signal at the transmission level B. Also, when transitioning to the state of adjusting the BER of the slave station, the control unit 23a causes the display unit 25 to display that "the BER of the slave station is being adjusted (during the transmission of the BER adjustment signal)".

[0076] In the slave stations 40a and 60a, when the radio unit 42 receives the BER adjustment signal (step 213), the radio unit 42 performs the measurement processes of RSSI and BER in the same manner as in step 204 (step 214). Also, in step 213, in response to the reception of the BER adjustment signal, the control unit 43a causes the display unit 45 to display that "the BER is being measured". However, FIGS. 9 to 10 only illustrate the processing in the slave station 40a.

[0077] In the slave stations 40a and 60a, when the measurement result in step 214 is equal to or greater than the threshold value, the control unit 43a controls the radio unit 42 to transmit, as a response to the master station 20a, an adjustment result indicating that the reception state is good to the master station 20a (step 215). Also, in step 215, in response to the start of this transmission control, the control unit 43a causes the display unit 45 to display that "responding with the adjustment result", and can further display the measured values such as BER and the fact that the measured values are good. Next to step 215, the radio unit 42 executes the transmission (step 216).

[0078] In the master station device 20a, the control unit 23a receives adjustment results from all the slave station devices 40a and 60a via the radio unit 22a (step 217). When adjustment results indicating that the reception state is good are received from all the slave station devices 40a and 60a, the slave station BER adjustment operation is terminated (step 218). Then, the transmission level to be specified during subsequent broadcasts is specified as transmission level B (step 219). Note that the adjustment results indicating that the reception state is good may include or be attached with the measured values of BER and RSSI.

[0079] On the other hand, regarding steps 215 to 217, when the measurement result in step 214 is less than the threshold value in any one of the slave station devices 40a and 60a (here, exemplified by the slave station device 60a), the slave station device 60a performs the following processing. That is, the control unit 43a of the slave station device 60a controls the radio unit 42 of the slave station device 60a to transmit, as a response to the master station device 20a, an adjustment result indicating that the reception state is defective to the master station device 20a, and the radio unit 42 executes the transmission.

[0080] In this case, in the master station device 20a, in step 217, an adjustment result indicating that the reception state is defective is received from the slave station device 60a. When an adjustment result indicating that the reception state is defective is received, in the master station device 20a, the transmission level that is the next candidate within a predetermined adjustment range is specified, and steps 212 to 217 are performed in the same manner. Then, the master station device 20a repeats a series of operations until an adjustment result indicating that the reception state is good is responded from the slave station device 60a with a defective reception state (or all the slave station devices). At this time, in order to increase the possibility of success, antenna direction adjustment can also be combined to measure BER and the like.

[0081] Here, transmission levels A, B, etc. are held in advance by the control unit 23a of the master station device 20a in terms of the number of resolutions within the adjustable range of the transmission level, and the system can be configured so that the correlation with the measured values of the reception states at the slave station devices 40a and 60a can be derived in advance. Then, when the control unit 23a receives an adjustment result indicating that the reception state is defective, it may determine the next candidate transmission level corresponding to the notified measured value from the above-mentioned correlation.

[0082] Here, the slave station devices 40a and 60a are exemplified as the slave station devices belonging to the master station device 20a. However, the same processing can be similarly performed for n (an integer of 1 or more) slave station devices to which they belong. The reception states of the n slave station devices are similarly measured. When the measurement result of a certain slave station device i (an integer from 1 to n) is poor (below the threshold), the transmission level designation may be changed to the next candidate and the measurement of the slave station device i may be performed. Then, the adjustment is repeated within the transmission level adjustment range until the measurement result of the slave station device i becomes good (reaches the threshold). Also at this time, in order to increase the possibility of success, the antenna direction adjustment may be combined and measured. As a result of executing all of a series of transmission level adjustments, for example, if the reception state at the slave station device i is defective, in other words, if the transmission level adjustment fails, the following processing may be performed. That is, in this case, the nearest slave station device j (an integer from 1 to n other than i) to the slave station device i may act as a relay and record on behalf, and the broadcast content may be rebroadcast only to the slave station device 60a. Thereby, the slave station device i can receive the content rebroadcast by the slave station device j and can sound, and the reception failure is remedied.

[0083] If the reception state does not become good even when measured at the transmission levels of all candidates within a predetermined adjustment range, the control unit 23a regards the slave station device with poor reception (slave station device 60a in this example) as having a defective reception state, and performs the following control at the next broadcast. That is, the control unit 23a notifies the slave station device 40a, which is the slave station device with the best reception state closest to the slave station device 60a, that the slave station device 60a has a defective reception state (step 219). In step 219, the control unit 23a can control the radio unit 22a to transmit this notification included in the broadcast signal. Although the following example is given, the radio unit 22a may be controlled to transmit the signal of this notification before the start of the broadcast. Further, the measured values of BER and RSSI can be included in this notification as part of the adjustment result or together with the adjustment result.

[0084] Also, if the reception state does not become good even when measured at the transmission levels of all candidates within a predetermined adjustment range, the control unit 23a can set the transmission level of the broadcast signal to the transmission level B that was good for the slave station device 40a. However, the transmission level in this case is not limited to the transmission level B. When adjusting the slave station device 60a, the slave station device 40a, which was good at the transmission level B, can also be adjusted, and it can be set to the transmission level at which the reception state of the slave station device 40a is the best.

[0085] In the slave station device 40a, the control unit 43a receives, as part of the broadcast signal, the above-mentioned notification, that is, the notification of the reception state failure of the nearest slave station device 60a, via the wireless unit 42 (step 220). When this notification is received, the control unit 43a of the slave station device 40a causes the recording unit 43b to record the broadcast content in parallel with the broadcast operation in step 220. Also, in step 220, in response to the reception of this notification, the control unit 43a causes the display unit 45 to display that "the broadcast signal is being received". Further, when the reception state of the nearest slave station device 60a for this broadcast signal is incomplete, the control unit 43a can also cause the display unit 45 to display that "recording is in progress". Note that in the slave station device 40a, as shown in FIG. 11, the reception state may or may not be measured even when the broadcast signal is being received.

[0086] After the slave station device 40a completes the recording of the broadcast content, after a predetermined waiting time has elapsed, the rebroadcast unit 43c transmits, via the wireless unit 42, a broadcast signal indicating the above-mentioned recorded content to the nearest slave station device 60a with an incomplete reception state, and the slave station device 60a performs a loudspeaker broadcast (step 221). This transmission by the slave station device 40a corresponds to the retransmission of the broadcast content, that is, the rebroadcast. In this way, the slave station device 40a functions as a relay for the broadcast content. By this rebroadcast, it is possible to remedy the case where the nearest slave station device 60a with an incomplete reception state suffers from a broadcast transmission failure due to the incomplete reception state. Note that in the slave station device 60a, as shown in FIG. 11, the reception state may or may not be measured while the rebroadcast signal is being received.

[0087] In step 221, the control unit 43a of the slave station device 40a causes the display unit 45 to display that "rebroadcasting is in progress". Here, the control unit 43a can also cause the display unit 45 to display that "rebroadcasting is in progress for the slave station device 60a". Also, on the side of the slave station device 60a that receives the rebroadcast signal, mainly as shown in FIG. 11, in step 221, the control unit 43a receives the rebroadcast signal via the radio unit 42, and the speaker unit 47 performs amplified broadcasting. At this time, the control unit 43a causes the display unit 45 to display that "rebroadcasting is in progress". Here, the control unit 43a of the slave station device 60a can also cause the display unit 45 to display that "broadcasting the rebroadcast from the slave station device 40a is in progress".

[0088] Also, in step 221, when the slave station device 40a executes transmission of a rebroadcast signal to transfer the broadcast content, by including the ID of the slave station device in the transmission signal that is the rebroadcast signal, it is possible to distinguish that it is a retransmission for itself at the retransmission destination. Therefore, the slave station device 40a can transmit the rebroadcast signal only to the slave station device it wants to transmit to (in this example, the slave station device 60a), and other slave station devices will not receive this rebroadcast signal.

[0089] Also, in step 221, rebroadcasting is executed after a predetermined waiting time has elapsed. This is because if transfer is performed in real time, the broadcast signal transmitted from the master station device 20a and the broadcast signal (rebroadcast signal) transmitted from the slave station device 40a will overlap. In order to prevent such signal overlap, the above-mentioned predetermined waiting period, that is, the time difference in transmission, is provided to enable transmission in the same frequency band. For example, in the TDMA system, it is also possible for the slave station device 40a to transmit the rebroadcast signal, that is, transfer the broadcast content, with a small time difference in the next slot of the received signal, generally in real time.

[0090] In this way, after the series of slave station BER adjustment operations in steps 201 to 218 are completed, finally, the master station device 20a receives the adjustment results (good / bad reception status) notified as responses from all the slave station devices under its jurisdiction, and compares the measured values of BER and RSSI included in the adjustment results with their respective threshold values. Then, when all the results reach the threshold values, the master station device 20a considers that the interference corresponding to the transmission level is minimized, and in other cases, it considers that the slave station device with the adjustment result (bad reception status) may have some possibility of reception failure including interference. Then, the master station device 20a will perform relief for non-received broadcasts in the operations of steps 220 to 221.

[0091] As described above, in this embodiment, the same effects as those in Embodiment 2 are achieved. The specific effects will be supplemented and explained. In this embodiment, similar to Embodiment 2, even in a system for disaster prevention radio in municipalities where the slave station is a fixed station and may be affected by sensitivity degradation due to environmental changes, such sensitivity degradation can be detected in advance or immediately, and the reception failure of the slave station can be notified or avoided.

[0092] In addition to such effects, in this embodiment, by the process of adjusting the transmission level of the signal transmitted from the master station, the master station side can grasp the reception status of the slave station side, and the slave station side can receive with an appropriate antenna direction and appropriate RSSI according to the reception status. That is, in this embodiment, by adjusting the transmission level at the master station, the interference to the surrounding slave stations can be minimized while improving the sensitivity of the slave station. Furthermore, in this embodiment, even if the sensitivity recovery is incomplete due to such improvement and as a result, the broadcast transmission of a slave station becomes incomplete, the nearest slave station to that slave station will act as a relay and rebroadcast. Therefore, in this embodiment, it is possible to prevent the slave station from being unable to receive broadcasts during broadcasting, and even if there is a transmission failure of the broadcast content due to the instability of broadcast reception, it is possible to support the transmission of the broadcast content.

[0093] Although an example of the BER adjustment process of the wireless communication system 10a has been described, if the reception condition is still poor after the above series of operations, the user who has confirmed the content of the notification displayed on either the master station device 20a or the slave station devices 40a and 60a may improve the installation of the antenna or the like according to the surrounding environment.

[0094] As described above, in this embodiment, the BER adjustment process executed in the BER adjustment mode has been described as a process including the antenna adjustment process described in Embodiment 2. However, it can also be a process that does not include the antenna adjustment process described in Embodiment 2.

[0095] In the case of this example, the slave station device is provided with a wireless transmission unit that transmits information wirelessly, a measurement unit, a recording unit, and a rebroadcast unit. This measurement unit measures the reception sensitivity of the radio wave received from the master station device by receiving a reception sensitivity adjustment signal for adjusting the reception sensitivity of the slave station device from the master station device, and wirelessly transmits the measured value to the master station device via the wireless transmission unit. The above recording unit, as exemplified by the recording unit 43b, records the disaster prevention information received from the master station device on behalf of other slave station devices according to an instruction from the master station device. This instruction is an instruction wirelessly transmitted from the master station device to the slave station device when the value measured by the slave station device is equal to or greater than a predetermined threshold and the value measured by other slave station devices is less than the predetermined threshold. The above rebroadcast unit, as exemplified by the rebroadcast unit 43c, wirelessly transmits the recorded disaster prevention information to other slave station devices instructed by the master station device via the wireless transmission unit.

[0096] Also, in this embodiment, it can be configured to be capable of executing both the antenna adjustment process and the BER adjustment process that does not include the antenna adjustment process. In that case, the user can be configured to be able to select, for example, which process to execute.

[0097] In addition, the wireless communication system 10a according to this embodiment has been described by way of an example in which it executes transmission level adjustment processing as BER adjustment processing and proxy rebroadcast processing in the case of sensitivity recovery failure. However, it can be configured to execute only one of them, or it can be configured to execute both. When the wireless communication system 10a is configured to be able to execute both adjustment processing and proxy rebroadcast processing, the operator can be configured to be able to select, for example, which processing to execute.

[0098] <Other Embodiments> The slave unit device 1 in the present disclosure includes, for example, an embodiment as a wireless communication method. That is, the wireless communication method includes a step of measuring the reception sensitivity of radio waves received from the master unit device by receiving an antenna adjustment signal for adjusting the antenna of the slave unit device from the master unit device in a slave unit device that receives disaster prevention information wirelessly from the master unit device and transmits the received disaster prevention information by a voice output method, and a step of determining whether or not to change the direction of the antenna based on the measured reception sensitivity of the radio waves.

[0099] In addition, the slave unit device 1 in the present disclosure includes, for example, an embodiment as a program. The above program is a wireless communication program that causes a computer to execute a process of measuring the reception sensitivity of radio waves received from the master unit device by receiving an antenna adjustment signal for adjusting the antenna of the slave unit device from the master unit device in a slave unit device that receives disaster prevention information wirelessly from the master unit device and transmits the received disaster prevention information by a voice output method, and a process of determining whether or not to change the direction of the antenna based on the measured reception sensitivity of the radio waves.

[0100] In the above example, the program can be stored using various types of non-transitory computer readable media and supplied to a computer. Non-transitory computer readable media include various types of tangible storage media. Non-transitory computer readable media include, for example, magnetic recording media, magneto-optical recording media, CD-ROM (Read Only Memory), CD-R, CD-R / W, and semiconductor memories. Semiconductor memories include, for example, mask ROM, PROM (Programmable ROM), EPROM (Erasable PROM), flash ROM, RAM (Random Access Memory), etc. Also, the program may be supplied to the computer by various types of transitory computer readable media. Examples of transitory computer readable media include electrical signals, optical signals, and electromagnetic waves. The transitory computer readable media can supply the program to the computer via wired communication paths such as electric wires and optical fibers, or wireless communication paths.

[0101] Some or all of the above embodiments can also be described as follows, but are not limited thereto.

[0102] (Appendix 1) A slave station device that receives disaster prevention information wirelessly from a master station device and transmits the received disaster prevention information in a voice output manner, a measurement unit that measures the reception sensitivity of radio waves received from the master station device by receiving an antenna adjustment signal for adjusting the antenna of the slave station device from the master station device; a determination unit that determines whether to change the direction of the antenna based on the measured reception sensitivity of the radio waves; A slave station device comprising: (Appendix 2) When the direction of the antenna is the current direction, the determination unit determines to change the direction of the antenna to a direction different from the current direction as a direction for newly measuring the reception sensitivity of the radio wave when the reception sensitivity of the radio wave is less than a threshold value. The slave station device according to Supplementary Note 1. (Supplementary Note 3) The antenna is a directional antenna. The slave station device according to Supplementary Note 1 or 2. (Supplementary Note 4) The determination unit includes a table associating the reception sensitivity of the radio wave measured within a predetermined period with the direction of the antenna, and determines the direction in which the antenna should be directed based on the table. The slave station device according to any one of Supplementary Notes 1 to 3. (Supplementary Note 5) The slave station device controls the direction of the antenna based on the direction determined by the determination unit. The slave station device according to any one of Supplementary Notes 1 to 4. (Supplementary Note 6) The slave station device further includes a recording unit that records the received disaster prevention information from the master station device on behalf of other slave station devices according to an instruction from the master station device, and a wireless transmission unit that wirelessly transmits the recorded disaster prevention information to the other slave station devices instructed by the master station device. The slave station device according to any one of Supplementary Notes 1 to 5. (Supplementary Note 7) When the measurement unit is determined by the determination unit to change the direction of the antenna, and when the direction of the antenna is changed, the measurement unit measures the reception sensitivity of the radio wave by receiving from the master station device a reception sensitivity adjustment signal that has a transmission level higher than that of the antenna adjustment signal and that adjusts the reception sensitivity of the radio wave in the slave station device. The slave station device according to any one of Supplementary Notes 1 to 6. (Supplementary Note 8) A wireless transmission unit that transmits information wirelessly, a recording unit that records the received disaster prevention information from the master station device on behalf of other slave station devices according to an instruction from the master station device, and a rebroadcast unit that causes the wireless transmission unit to transmit the recorded disaster prevention information to the other slave station devices instructed by the master station device. When the measurement unit is determined by the determination unit to change the direction of the antenna, and when the direction of the antenna is changed, the reception sensitivity adjustment signal, which has a transmission level higher than that of the antenna adjustment signal and adjusts the reception sensitivity of the radio wave at the slave station device, is received from the master station device, thereby measuring the reception sensitivity of the radio wave, and wirelessly transmitting the measured value to the master station device via the wireless transmission unit. The instruction from the master station device is an instruction wirelessly transmitted from the master station device to the slave station device when the value of the reception sensitivity of the radio wave measured by receiving the reception sensitivity adjustment signal or the antenna adjustment signal at the slave station device is equal to or greater than a predetermined threshold value and the value of the reception sensitivity of the radio wave measured by receiving the reception sensitivity adjustment signal or the antenna adjustment signal at the other slave station device is less than the predetermined threshold value. The slave station device according to any one of Appendices 1 to 5. (Appendix 9) A slave station device that receives disaster prevention information wirelessly from a master station device and transmits the received disaster prevention information by a voice output method. A wireless transmission unit that transmits information wirelessly. A measurement unit that measures the reception sensitivity of the radio wave received from the master station device by receiving a reception sensitivity adjustment signal for adjusting the reception sensitivity of the slave station device from the master station device, and wirelessly transmits the measured value to the master station device via the wireless transmission unit. A recording unit that records the received disaster prevention information from the master station device on behalf of other slave station devices according to an instruction from the master station device. A rebroadcast unit that wirelessly transmits the recorded disaster prevention information to the other slave station devices instructed by the master station device via the wireless transmission unit. Comprising. The instruction from the master station device is an instruction wirelessly transmitted from the master station device to the slave station device when the measured value at the slave station device is equal to or greater than a predetermined threshold value and the measured value at the other slave station device is less than the predetermined threshold value. Slave station device. (Appendix 10) In a disaster prevention wireless system including a master station device and a slave station device belonging to the master station device, The slave station device is a device that receives disaster prevention information wirelessly from the master station device and transmits the received disaster prevention information by voice output, a measurement unit that measures the reception sensitivity of radio waves received from the master station device by receiving an antenna adjustment signal for adjusting the antenna of the slave station device from the master station device; a determination unit that determines whether or not to change the direction of the antenna based on the measured reception sensitivity of the radio wave, Disaster prevention wireless system. (Appendix 11) The slave station device further includes a recording unit that records the received disaster prevention information from the master station device on behalf of other slave station devices according to an instruction from the master station device, and a wireless transmission unit that wirelessly transmits the recorded disaster prevention information to the other slave station devices instructed by the master station device. The disaster prevention wireless system according to Appendix 10. (Appendix 12) When the determination unit determines to change the direction of the antenna and the direction of the antenna is changed, the measurement unit measures the reception sensitivity of the radio wave by receiving from the master station device a reception sensitivity adjustment signal that is a reception sensitivity adjustment signal having a higher transmission level than the antenna adjustment signal and that adjusts the reception sensitivity of the radio wave at the slave station device. The disaster prevention wireless system according to Appendix 10 or 11. (Appendix 13) The slave station device further includes a wireless transmission unit that transmits information wirelessly, a recording unit that records the received disaster prevention information from the master station device on behalf of other slave station devices according to an instruction from the master station device, and a rebroadcast unit that causes the wireless transmission unit to transmit the recorded disaster prevention information to the other slave station devices instructed by the master station device. When the determination unit determines to change the direction of the antenna and the direction of the antenna is changed, the measurement unit measures the reception sensitivity of the radio wave by receiving, from the master station device, a reception sensitivity adjustment signal that is higher in transmission level than the antenna adjustment signal and that adjusts the reception sensitivity of the radio wave at the slave station device, and wirelessly transmits the measured value to the master station device via the wireless transmission unit. When a value obtained by measuring the reception sensitivity of the radio wave by receiving the reception sensitivity adjustment signal or the antenna adjustment signal at the slave station device is equal to or greater than a predetermined threshold and a value obtained by measuring the reception sensitivity of the radio wave by receiving the reception sensitivity adjustment signal or the antenna adjustment signal at the other slave station device is less than the predetermined threshold, the master station device wirelessly transmits the instruction to the slave station device. The disaster prevention wireless system according to Supplementary Note 11. (Supplementary Note 14) In a disaster prevention wireless system including a master station device and a slave station device belonging to the master station device, The slave station device is a device that receives disaster prevention information wirelessly from the master station device and transmits the received disaster prevention information by a voice output method, and includes a wireless transmission unit that transmits information wirelessly, a measurement unit that measures the reception sensitivity of the radio wave received from the master station device by receiving a reception sensitivity adjustment signal for adjusting the reception sensitivity of the slave station device from the master station device, and wirelessly transmits the measured value to the master station device via the wireless transmission unit, a recording unit that records the received disaster prevention information from the master station device on behalf of other slave station devices according to an instruction from the master station device, and a rebroadcast unit that wirelessly transmits the recorded disaster prevention information to the other slave station devices instructed by the master station device via the wireless transmission unit. The slave station device is provided with When the value of the radio wave reception sensitivity measured in the slave station device is equal to or higher than a predetermined threshold value and the value of the radio wave reception sensitivity measured in the other slave station device is less than the predetermined threshold value, the master station device wirelessly transmits the instruction to the slave station device. Disaster prevention radio system. (Appendix 15) A slave station device that receives disaster prevention information wirelessly from a master station device and transmits the received disaster prevention information by a voice output method measures the reception sensitivity of radio waves received from the master station device by receiving an antenna adjustment signal for adjusting the antenna of the slave station device from the master station device, The slave station device determines whether to change the direction of the antenna based on the measured reception sensitivity of the radio wave. A wireless communication method comprising the steps. (Appendix 16) A slave station device that receives disaster prevention information wirelessly from a master station device and transmits the received disaster prevention information by a voice output method measures the reception sensitivity of radio waves received from the master station device by receiving a reception sensitivity adjustment signal for adjusting the reception sensitivity of the slave station device from the master station device, and wirelessly transmits the measured value to the master station device, The slave station device records the received disaster prevention information from the master station device on behalf of other slave station devices according to an instruction from the master station device, The slave station device wirelessly transmits the recorded disaster prevention information to the other slave station devices instructed by the master station device, Comprising The instruction from the master station device is an instruction wirelessly transmitted from the master station device to the slave station device when the measured value at the slave station device is equal to or higher than a predetermined threshold value and the measured value at the other slave station device is less than the predetermined threshold value. Wireless communication method. (Appendix 17) In a computer included in a slave station device that receives disaster prevention information wirelessly from a master station device and transmits the received disaster prevention information by a voice output method, By receiving an antenna adjustment signal for adjusting the antenna of the slave station device from the master station device, a process of measuring the reception sensitivity of radio waves received from the master station device, a process of determining whether to change the direction of the antenna based on the measured reception sensitivity of the radio waves, and A program for executing the above. (Appendix 18) In a computer included in a slave station device that receives disaster prevention information wirelessly from a master station device and transmits the received disaster prevention information by voice output, by receiving a reception sensitivity adjustment signal for adjusting the reception sensitivity of the slave station device from the master station device, measuring the reception sensitivity of radio waves received from the master station device, and wirelessly transmitting the measured value to the master station device, when the instruction from the master station device is such that the measured value at the slave station device is equal to or greater than a predetermined threshold value and the measured value at another slave station device is less than the predetermined threshold value, taking the instruction wirelessly transmitted from the master station device to the slave station device as the instruction, and recording the received disaster prevention information from the master station device on behalf of the other slave station device according to the instruction from the master station device, a process of wirelessly transmitting the recorded disaster prevention information to the other slave station device instructed by the master station device, and A program for executing the above.

[0103] Note that the present disclosure is not limited to the above-described embodiments, and can be appropriately changed without departing from the gist.

Explanation of Reference Numerals

[0104] 1, 40, 40a, 60a Slave station device 2 Measurement unit 3 Determination unit 10, 10a Wireless communication system 20, 20a Master station device 30 Relay station device

Claims

1. A slave station device that receives disaster prevention information wirelessly from a master station device and transmits the received disaster prevention information in an audio output manner, comprising: a measurement unit that measures the reception sensitivity of radio waves received from the master station device by receiving an antenna adjustment signal for adjusting the antenna of the slave station device from the master station device; a determination unit that determines whether to change the direction of the antenna based on the measured reception sensitivity of the radio waves; a recording unit that records the received disaster prevention information from the master station device on behalf of another slave station device designated by the master station device according to an instruction designating the other slave station device; a wireless transmission unit that wirelessly transmits the recorded disaster prevention information to the other slave station device instructed by the master station device; The slave station device further comprises: The determination unit includes a table associating the reception sensitivity of the radio waves measured within a predetermined period with the direction of the antenna, and determines the direction in which the antenna should be directed based on the table. Slave station device.

2. When the direction of the antenna is the current direction, the determination unit determines to change the direction of the antenna to a direction different from the current direction as a direction for newly measuring the reception sensitivity of the radio waves when the reception sensitivity of the radio waves is less than a threshold value. The slave station device according to Claim 1.

3. The antenna is a directional antenna. The slave station device according to Claim 1 or 2.

4. The slave station device controls the direction of the antenna based on the direction determined by the determination unit. The slave station device according to Claim 1 or 2.

5. When the determination unit determines to change the direction of the antenna and the direction of the antenna is changed, the measurement unit measures the reception sensitivity of the radio waves by receiving from the master station device a reception sensitivity adjustment signal having a transmission level higher than that of the antenna adjustment signal and for adjusting the reception sensitivity of the radio waves at the slave station device. The slave station device according to Claim 1 or 2.

6. A slave station device that receives disaster prevention information wirelessly from a master station device and transmits the received disaster prevention information in an audio output manner, comprising: a wireless transmission unit that transmits information wirelessly; a measurement unit that measures the reception sensitivity of radio waves received from the master station device by receiving a reception sensitivity adjustment signal for adjusting the reception sensitivity of the slave station device from the master station device, and wirelessly transmits the measured value to the master station device via the wireless transmission unit. A determination unit that determines whether to change the direction of the antenna of the slave station device based on the received sensitivity of the radio wave measured; A recording unit that records the received disaster prevention information from the master station device on behalf of other slave station devices according to an instruction designating the other slave station devices from the master station device; A rebroadcasting unit that causes the wireless transmission unit to wirelessly transmit the recorded disaster prevention information to the other slave station devices instructed by the master station device; Comprising; The instruction from the master station device is an instruction wirelessly transmitted from the master station device to the slave station device when the measured value at the slave station device is equal to or greater than a predetermined threshold value and the measured value at the other slave station device is less than the predetermined threshold value; The determination unit includes a table associating the received sensitivity of the radio wave measured within a predetermined period with the direction of the antenna, and determines the direction in which the antenna should be directed based on the table; Slave station device.

7. In a disaster prevention wireless system including a master station device and a slave station device belonging to the master station device, The slave station device is a device that receives disaster prevention information wirelessly from the master station device and transmits the received disaster prevention information by a voice output method, A measurement unit that measures the received sensitivity of the radio wave received from the master station device by receiving an antenna adjustment signal for adjusting the antenna of the slave station device from the master station device; A determination unit that determines whether to change the direction of the antenna based on the received sensitivity of the radio wave measured; A recording unit that records the received disaster prevention information from the master station device on behalf of other slave station devices according to an instruction designating the other slave station devices from the master station device; A wireless transmission unit that wirelessly transmits the recorded disaster prevention information to the other slave station devices instructed by the master station device; Comprising; The determination unit includes a table associating the received sensitivity of the radio wave measured within a predetermined period with the direction of the antenna, and determines the direction in which the antenna should be directed based on the table; Disaster prevention wireless system.

8. In a disaster prevention wireless system including a master station device and a slave station device belonging to the master station device, The slave station device is a device that receives disaster prevention information wirelessly from the master station device and transmits the received disaster prevention information by a voice output method, A wireless transmission unit that transmits information wirelessly; By receiving a reception sensitivity adjustment signal for adjusting the reception sensitivity of the slave unit device from the master unit device, measuring the reception sensitivity of the radio wave received from the master unit device, and wirelessly transmitting the measured value to the master unit device via the wireless transmission unit, a measurement unit; A determination unit that determines whether to change the direction of the antenna of the slave unit device based on the measured reception sensitivity of the radio wave; A recording unit that records the received disaster prevention information from the master unit device on behalf of other slave unit devices designated by the master unit device according to an instruction; A rebroadcast unit that wirelessly transmits the recorded disaster prevention information to the other slave unit devices instructed by the master unit device via the wireless transmission unit; Comprising; When the value of the reception sensitivity of the radio wave measured in the slave unit device is equal to or greater than a predetermined threshold and the value of the reception sensitivity of the radio wave measured in the other slave unit devices is less than the predetermined threshold, the master unit device wirelessly transmits the instruction to the slave unit device; The determination unit includes a table associating the reception sensitivity of the radio wave measured within a predetermined period with the direction of the antenna, and determines the direction in which the antenna should be directed based on the table; Disaster prevention wireless system.

9. A slave unit device that receives disaster prevention information wirelessly from a master unit device and transmits the received disaster prevention information in an audio output manner, by receiving an antenna adjustment signal for adjusting the antenna of the slave unit device from the master unit device, measuring the reception sensitivity of the radio wave received from the master unit device; A determination step in which the slave unit device determines whether to change the direction of the antenna based on the measured reception sensitivity of the radio wave; A step of recording the received disaster prevention information from the master unit device on behalf of other slave unit devices designated by the master unit device according to an instruction; A step of wirelessly transmitting the recorded disaster prevention information to the other slave unit devices instructed by the master unit device; Comprising; In the determination step, based on a table associating the reception sensitivity of the radio wave measured within a predetermined period with the direction of the antenna, the direction in which the antenna should be directed is determined; Wireless communication method.

10. In a computer included in a slave unit device that receives disaster prevention information wirelessly from a master unit device and transmits the received disaster prevention information in an audio output manner; By receiving an antenna adjustment signal for adjusting the antenna of the slave unit from the master unit, a process of measuring the reception sensitivity of radio waves received from the master unit; A determination process of determining whether or not to change the direction of the antenna based on the measured reception sensitivity of the radio waves; A process of proxy-recording the received disaster prevention information from the master unit for another slave unit according to an instruction designating the other slave unit from the master unit; A process of wirelessly transmitting the recorded disaster prevention information to the other slave unit instructed by the master unit; A program for executing the above; In the determination process, based on a table associating the reception sensitivity of the radio waves measured within a predetermined period with the direction of the antenna, the direction in which the antenna should be directed is determined. Program.

Images