JP2011103041A - Emergency information distribution system and transmitter and receiver to be used for the system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an emergency information distribution system capable of distributing emergency communication information, and to provide a transmitter and a receiver used for the system. <P>SOLUTION: The emergency information distribution system 1 which distributes time information distributed in a wide range transmits emergency communication information distributed by including information for emergency by using a protocol which is different from a protocol for distributing the time information, and by using a frequency band including the frequency of a standard radio wave for distributing the time information. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an emergency information distribution system and a transmitter and a receiver used in the system.

The emergency information distribution system is a system used when urgently and promptly providing information that has a significant effect on a large number of objects. As an application example of an emergency information distribution system, there is a system for predicting the arrival of an earthquake wave and notifying an earthquake early warning that gives a warning before the arrival. In this emergency information distribution system, there is a method of providing using a television or radio, but even when notification is required in a short time, it is difficult to satisfy the required time. For example, emergency earthquake bulletins require information within a few seconds. When providing information within a few seconds, as in the case of emergency earthquake warnings, the problem is that information cannot be provided within the required time.
In addition, since there are people who do not watch television or radio in various situations, the effect of the distribution using television or radio is reduced.

National Institute of Information and Communications Technology (NICT), standard radio wave operation status, (http://www2.nict.go.jp/w/w114/jst/jjy/trans/index. (html, search on October 19, 2009)

By the way, there is a method of distributing common time information to a portable small device using a standard radio wave. Broadcast communication using standard radio waves can be received even with a small device such as a wristwatch, and the portability of the receiving terminal is particularly excellent.
However, provision of time information using standard radio waves requires repeated transmission at predetermined intervals according to a predetermined protocol. In addition, since terminal equipment to be received is based on a standard protocol, it is difficult to change a predetermined protocol.
Thus, there is a problem that emergency communication information cannot be promptly notified in the emergency information distribution system.

  The present invention has been made to solve the above problems, and provides an emergency information distribution system capable of distributing emergency communication information, and a transmitter and a receiver used in the system. It is in.

  In order to solve the above-described problems, the present invention provides an emergency information distribution system that distributes time information distributed over a wide range, the emergency communication information distributed including emergency information, the time information An emergency information distribution system comprising a transmitter for transmitting using a frequency band including a frequency of a standard radio wave for distributing the time information using a protocol different from the protocol for distribution.

  Further, the present invention is the above invention, wherein the transmitter is transmitted prior to the emergency communication information and a standard radio wave transmission unit that transmits the time information using the standard radio wave in a normal time. Add a code indicating the start, add a code for error detection or error correction of the emergency communication information after the emergency communication information, and use a frequency band including the frequency of the standard radio wave for transmitting time information An emergency information transmitting unit for transmitting, and a switching unit for switching between a signal transmitted from the standard radio wave transmitting unit and a signal transmitted from the emergency information transmitting unit.

  Further, according to the present invention, in the above invention, the emergency information transmission unit uses the protocol different from the protocol used when transmitting the time information during the normal time, and the emergency communication information and the error detection code or error correction. It is characterized by repeatedly transmitting a plurality of times by combining codes.

  In the present invention, the protocol used when transmitting the time information in the normal time is an amplitude modulation method, and the protocol used when transmitting the emergency communication information is a frequency shift keying method. It is characterized by being.

  Further, the present invention is characterized in that, in the above-mentioned invention, a receiver is provided that determines whether the communication information is emergency communication information with reference to the transmitted signal.

  Further, the present invention is the above invention, wherein the receiver includes a determination unit that determines that the signal includes the emergency communication information when a signal modulated by a frequency shift keying method is received. Features.

  Further, the present invention provides the information according to the above-mentioned invention, wherein the receiver determines whether or not the emergency communication information has been properly received based on the added code, and corresponds to the received emergency communication information. Is output.

  In the invention described above, the emergency communication information includes information indicating a predetermined type and a target to be applied.

  The present invention is also a transmitter of an emergency information distribution system that distributes emergency information distributed over a wide range, and distributes emergency communication information distributed including the emergency information over a wide range. It is a transmitter characterized by using a protocol different from a protocol for distributing time information and transmitting using a frequency band including a frequency of a standard radio wave for distributing the time information.

  Further, the present invention is a receiver that receives a signal of an emergency information distribution system that distributes emergency information distributed over a wide area, and receives emergency communication information transmitted from the transmitter described above. It is the receiver characterized by this.

According to the present invention, a transmitter of an emergency information distribution system that distributes time information distributed over a wide range uses a protocol different from a protocol for distributing time information for emergency communication information distributed including emergency information. It uses and transmits using the frequency band containing the frequency of the standard radio wave which distributes time information.
Thereby, it is possible to share and configure the radio equipment using the standard radio wave, and to simplify the radio equipment. That is, in a standard radio wave transmission facility, an existing transmission antenna can be used as a large transmission antenna required for communication using a long wavelength radio wave.
Furthermore, by using a frequency band that includes the same frequency as the standard radio wave, the receiver's receiving circuit can be shared, the circuit scale can be reduced, and the receiving function can be easily realized without compromising portability. can do.

It is a schematic block diagram which shows the structure of the emergency information delivery system by one Embodiment of this invention. It is a figure which shows an example of the frame structure of the digital code used with the emergency information delivery system by this embodiment. It is a flowchart which shows the process of the discrimination function of the receiver by this embodiment. It is a block diagram which shows schematic structure of the transmitter of the emergency information output system by this embodiment. It is a flowchart which shows operation | movement when the receiver which does not detect emergency communication information by this embodiment receives emergency communication information.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

(First embodiment)
FIG. 1 is a schematic block diagram showing a configuration of an emergency information distribution system according to an embodiment of the present invention.
The emergency information distribution system 1 shown in this figure includes a transmitter 10 and a receiver 20.
The receiver 30 shown together receives the time information transmitted by the transmitter 10 without detecting the emergency communication information by the emergency information distribution system 1. The receiver 30 functions independently of the receiver 20.

The transmitter 10 includes a standard time transmission device 11, an emergency information transmission device 12, a switching device 13, and an antenna 14.
The standard time transmitter 11 transmits the standard time and the standard frequency using a signal using a predetermined frequency. For example, the radio wave format is a format defined as an A1B type of amplitude modulation system.
The emergency information transmission device 12 generates and transmits a signal to be notified using radio waves based on emergency communication information provided from other connected equipment. The generated signal forms a frame having a predetermined structure and is transmitted together with a code for performing error correction or error detection. The emergency information transmission device 12 transmits emergency communication information using a radio wave modulated by the frequency shift keying method.
In addition, the emergency information transmission device 12 outputs a control signal for transmitting emergency communication information to the switching device 13 and outputs it via the antenna 14 when notification is required. The emergency communication information includes information of a type determined according to the type of content to be notified, and information of an applicable range determined according to the region and purpose.
The switching device 13 selects a signal provided from the standard time transmission device 11 and the emergency information transmission device 12 and supplies the selected signal to the antenna 14.
The antenna 14 emits a radio wave of electric power corresponding to the signal supplied from the switching device 13.

The receiver 20 includes a determination unit 21, an error control unit 22, an analysis unit 23, an output unit 24, an antenna 25, and a calibration unit 29, and includes the determination unit 21, the error control unit 22, the analysis unit 23, and the output unit 24. The receiving unit 26 is formed.
The determination unit 21 detects a reception signal in which the power of the received radio wave is converted by the antenna 25, and determines information included in the received signal. The discriminating unit 21 discriminates time information included in the received signal received in normal times, and supplies the discriminated time information to the calibration unit 29. When receiving the emergency communication information, the determination unit 21 extracts the emergency communication information transmitted using a predetermined frame from the received information. When the emergency communication information is extracted, the determination unit 21 also extracts a code for error correction or error detection transmitted together using the same transmission frame.
The error control unit 22 performs error correction or error detection using the code for error correction or error detection extracted by the determination unit 21.
The analysis unit 23 analyzes emergency communication information included in the received signal. The analysis unit 23 detects that the received information includes emergency communication information based on the result of error correction or error detection by the error control unit 22. The emergency communication information is detected by a comparison process based on a predetermined information pattern.
The output unit 24 outputs emergency communication information detected by the analysis unit 23.
The antenna 25 converts the received radio wave into a received signal and supplies it.
The receiving unit 26 formed including the above configuration detects and outputs the received signal converted by the antenna 25.
Note that the calibration unit 29 calibrates the time information held in a time measuring unit (not shown) based on the time information supplied from the determination unit 21.

The receiver 30 includes a determination unit 31, an antenna 35, and a calibration unit 39.
The determination unit 31 detects a reception signal in which the power of the received radio wave is converted by the antenna 35, determines time information included in the received signal, and supplies the determined time information to the calibration unit 39. When receiving the emergency communication information, the determination unit 21 provides time information for requesting the calibration unit 39 to perform calibration to a timer unit (not shown).
The calibration unit 39 calibrates the time information held in a clock unit (not shown) based on the time information supplied from the determination unit 31.

The basic operation in the emergency information transmission system 1 is organized.
In the transmitter 10, the standard time transmitter 11 is normally connected to the antenna 14 and time information is transmitted by a standard frequency protocol. If the transmitter 10 determines that it is necessary to transmit emergency communication information based on the detected request signal, the emergency information transmission device 12 is connected to the antenna 14 via the switching device 13 and emergency communication information is transmitted. Send information.

  The receiver 20 receives standard radio waves in normal times. When the emergency communication information is received, the determination unit 21 determines that it is emergency communication information, error control is performed by the error determination unit 22, and the analysis unit 23 determines the content. When the receiver 20 has a corresponding content, the output by the output unit 24 is performed. In the receiver 20, while emergency communication is not being performed, the determination unit 21 of the emergency information transmission system determines that it is not emergency communication information, interrupts the subsequent processing until the information output, and performs repeated detection. Therefore, no output is performed. Also, the fact that the emergency communication information has been received is not output even when a communication error occurs in the received reception information or when the reception information indicating a type that the receiver 20 does not support is received.

A frame configuration of information for transmitting emergency communication information used in the emergency information transmission system 1 formed by combining the above-described components will be described.
FIG. 2 is a diagram illustrating an example of a digital code frame configuration used in the emergency information distribution system according to the present embodiment. The code transmitted based on this frame configuration is subjected to frequency shift keying, whereby emergency communication information is transmitted. The minimum unit of the frame configuration shown in this figure is composed of a frame FL1 composed of three parts: a communication start information area FL1_h, an emergency communication information area FL1_m, and an error detection code area FL1_crc. The purpose of this frame FL1 is to detect or correct errors in emergency communication information by 10 bits (bits) in the communication start information area FL1_h for transmitting a code indicating the start of emergency communication information, 16 bits in the emergency communication information area FL1_m. 16 bits are used for an error detection code area FL1_crc for transmitting an error detection (correction) code. Further, by repeating the frame FL2 to FL6 having the same configuration as the frame FL1 shown as the minimum unit 6 times, one transmission is performed with a total of 252 bits. If communication is performed at 45 bps (bits per second), it takes 0.9 seconds to transmit one frame (minimum unit), and approximately 5.5 seconds to transmit the entire frame. A system using the communication speed of 45 bps (bits per second) has a radio teletype (RTTY: Radiooteletype) that performs communication at a frequency shift of 110 Hz (Hertz), and is easy to realize.
This ensures a sufficient communication speed to deliver emergency communication information, and at the same time, even if a communication error occurs, a process to send a retransmission request after the error occurs by receiving the next information that is repeatedly transmitted It is possible to take the necessary measures without doing. A communication delay of about 1 second due to this is a range that can be allowed as a time delay for notifying emergency communication information.

FIG. 3 is a flowchart showing processing of the determination function of the receiver in this embodiment.
The receiver 20 (FIG. 1) always detects whether or not communication start information is included in the received signal. The receiver 20 detects the start code from the signal received by the determination unit 21 (step Sa1). The determination unit 21 determines whether a start code is detected. As a result of the determination, the process of step Sa1 is repeated until a start code is detected (step Sa2).

  When the start code is detected as a result of the determination in step Sa2, the error determination unit 22 extracts the emergency communication information and the error detection code from the frame based on the start code determined by the determination unit 21, and detects the error. Processing is performed (step Sa3). The error determination unit 22 determines whether or not the emergency communication information has been received without error as a result of the error determination using the emergency communication information and the error detection code. As a result of the determination, when it is determined that there is an error on the way, the process returns to the detection of the start code indicating the start of communication from step Sa1, and this is repeated (step Sa4). If it is determined in step Sa4 that the emergency communication information has been received without error, the analysis unit 23 analyzes the emergency communication information and determines whether the received emergency communication information is relevant information. Whether or not the received emergency communication information is applicable is determined based on the setting information stored in the storage area in advance. For example, the location information indicating the location where the receiver 20 is disposed, The identification information indicating the type is a determination target. As a result of the determination, if it is determined that there is an error on the way, the process returns to the detection of the start code indicating the start of communication from step Sa1, and this is repeated (step Sa6).

As a result of the determination by the analysis unit 23, when it is determined that the received emergency communication information is the corresponding information, the output unit 24 performs output based on the emergency communication information (step Sa7).
In addition, the receiver 20 corresponding to emergency communication does not necessarily need to output emergency communication information outside by detecting the first emergency communication information. The receiver 20 may perform output to the outside when the emergency communication information repeated a plurality of times is repeatedly detected a predetermined number of times. This emergency communication information detection process is easily realized by adding a state transition determination process that repeats the process of step Sa7 in the figure a predetermined number of times, and replacing it with a process of outputting after multiple detections. Is possible. As described above, the emergency communication information detection process can be selected to be appropriately incorporated in the corresponding receiver 20 according to the degree of influence when the emergency communication information is output.

FIG. 4 is a block diagram showing a schematic configuration of the transmitter of the emergency information output system in the present embodiment.
The emergency information transmitting device 12 in the transmitter 10 shown in this figure is connected to the switching device 13. The same components as those shown in FIG.
The emergency information transmission device 12 includes a transmission request input unit 12a, a signal creation unit 12b, a frequency shift modulation unit 12c, an amplification unit 12d, and a transmission switching request unit 12e.
The oscillation request input unit 12a receives a request to transmit emergency communication information and the information, sends a control signal to the transmission switching request unit 12e, and switches from transmission of standard radio waves to transmission of emergency communication information. Switch the antenna connection. At the same time, the oscillation request input unit 12a supplies the emergency communication information to be transmitted to the signal creation unit 12b to create a signal for transmission. The signal creation unit 12b creates an error detection code and the like based on the emergency communication information supplied from the oscillation request input unit 12a, creates a communication signal having the frame structure shown in FIG. 2, and the frequency shift modulation unit 12c. To supply. The frequency shift modulation unit 12c performs frequency shift modulation at the frequency of the standard radio wave based on the communication signal supplied from the signal creation unit 12b, and the amplification unit 12d amplifies and outputs the modulation signal. The transmission switching request unit 12e performs the emergency communication with the antenna 14 connected to the standard time transmission apparatus 11 (FIG. 1) that outputs a standard radio wave in a normal time according to the control signal instruction supplied from the oscillation request input unit 12a. When the information is transmitted, the switching device 13 is controlled to switch to the connection with the emergency information transmitting device 12.

FIG. 5 is a flowchart showing an operation when a receiver that does not detect emergency communication information shown in the present embodiment receives emergency communication information.
It is known that standard radio waves are mainly used to calibrate time information held by devices such as clocks that have timekeeping functions, and are transmitted in combination with 20%, 50%, and 80% duty pulses, respectively. ing. That is, the received electric field intensity changes according to the duty of the pulse (see Non-Patent Document 1).
Here, the receiver 30 (FIG. 1) that does not detect emergency communication information detects the received pulse received by the determination unit 31 (step Sb1). The discriminating unit 31 discriminates whether or not the duty indicated by the received pulse is defined in a predetermined protocol in order to discriminate whether or not the received information is time information. The determination of the duty of the pulse is performed by detecting the pulse width using a timekeeping function provided inside (step Sb2).
If the determination unit 31 determines that the received pulse is stipulated in the predetermined protocol, the determination unit 31 converts the received pulse into a digital value according to the information indicated by the extracted pulse (step Sb3).
On the other hand, if it is determined in step Sb2 that the specified protocol is not specified, or if the duty is erroneously detected due to the influence of noise or the like, the receiver 30 discards (resets) the detected pulse. Then, the reception process is performed again (step Sb4).

The discriminating unit 31 detects a feature of a pulse whose emergency communication information is not included in the standard radio wave. In other words, since the emergency communication information is modulated by frequency shift keying, when the receiver 30 receives the emergency communication information, the receiver 30 has a pulse train (for example, a duty cycle different from the duty (20%, 50%, 80%) indicated by the standard radio wave (for example, , A pulse train including a duty exceeding 80%), and a pulse train whose amplitude shows a constant value. Since such a pulse train that is not transmitted including a marker (duty 20%) indicates information that is not defined in the standard radio wave, the receiver 30 discards the pulse. In other words, the receiver 30 determines that the detected emergency communication information is equivalent to that in which noise has occurred for a few seconds. Then, the receiver 30 repeatedly performs an operation of discarding the pulse and newly starting reception until the standard radio wave is received again.
In the receiver 30, the calibration unit 39 does not calibrate the time information held in the time measuring unit (not shown) when the standard radio wave is not detected. Thereby, the receiver 30 does not calibrate the wrong time due to the reception of the emergency communication information. During this time, the receiver 30 updates and displays the time information based on the time information held by the timing unit, and after the emergency information distribution for several seconds is completed, receives the standard radio wave again and calibrates it to the correct time. Or it is good also as notifying a user that time calibration failed.

As shown in the present embodiment, in the emergency information distribution system 1, the emergency communication information can be received by the receiver 20 having excellent portability. Even if the receiver 30 does not have a function for receiving emergency communication information, it is possible to perform time correction using a standard radio wave without substantial influence even if an interrupt broadcast that distributes emergency communication information is performed. It becomes.
Thus, in the emergency information distribution system 1 using the same frequency as the standard radio wave, the following effects can also be realized. By constantly receiving a standard radio wave as a communication state between the transmitter 10 and the receiver 20, the receiver 20 is located in an area where the radio wave cannot be sufficiently received by the determination unit 21, or a failure has occurred in the equipment. The situation can be monitored.
That is, the above-described monitoring information can be used to avoid a serious problem that may occur when emergency communication information cannot be detected or is transmitted in error. In the case of communication using radio waves, erroneous information may be received due to the influence of noise, propagation state changes, etc., but in such a state, the receiver 20 displays that a communication failure has occurred. Therefore, the communication state can be specified.
If it is possible to identify the receiver 20 in which a communication failure has occurred, the majority of receivers may simultaneously receive errors in one range, causing confusion, or some receivers may be in emergency communication. It is possible to provide information for avoiding problems such as when confusion occurs due to a sudden change in behavior in a group having other receivers that have not received and received information in error.

  If noise such as static electricity occurs in a normal radio clock, etc., it is sufficient to hold the decision and calibrate the clock with the information from the next time onward, assuming that it takes several minutes to calibrate the clock. There is no particular problem. However, in the case of emergency communication, it is important to avoid erroneous reception and confusion accompanying it due to the influence of noise and the like, and the emergency information distribution system 1 shown in the present embodiment avoids these problems. Is possible.

In the emergency information distribution system 1 shown in the present embodiment, the transmitter 10 converts the emergency communication information distributed including emergency information into a time information using a protocol different from the protocol for distributing the time information. Transmit using a frequency band that includes the frequency of the standard radio wave to be distributed.
As a result, the transmitter 10 can be configured by sharing wireless equipment using standard radio waves, and the wireless equipment can be simplified. That is, the transmitter 10 can share a large antenna 14 required for communication using a long-wavelength radio wave used for distributing standard radio waves.
The receiver 20 can receive the emergency communication information, and can distribute the emergency communication information in which a delay of several seconds is a problem over a wide range.
Furthermore, by using a frequency band that includes the same frequency as that of the standard radio wave, the receiving circuit of the receiver 20 can be shared, the circuit scale can be reduced, and the receiving function can be easily performed without impairing portability. Can be realized.

Further, in the present embodiment, in the transmitter 10, the standard radio wave transmission device 11 transmits time information using the standard radio wave at normal times. The emergency information transmitting device 12 is transmitted before the emergency communication information transmitted including emergency information, adds a code indicating the start of the emergency communication information, and detects the error of the emergency communication information after the emergency communication information or A code for error correction is added and transmitted using a frequency band including the frequency of a standard radio wave for transmitting time information. The switching device 13 switches between a signal transmitted from the standard radio wave transmitter 11 and a signal transmitted from the emergency information transmitter 12.
As a result, even in a standard radio wave propagation environment in which noise is present, emergency communication information can be transmitted without false alarms, and the reliability of the emergency information distribution system 1 can be improved over that of the prior art.

Further, in the present embodiment, the emergency information transmitting apparatus 11 repeats a plurality of times by combining emergency communication information and an error detection code or error correction code using a protocol different from the protocol used when transmitting time information during normal times. To send.
Thereby, the receiver 20 can easily detect that the received signal is a protocol different from the protocol used when transmitting time information.

In this embodiment, the protocol used when transmitting time information during normal time is an amplitude modulation method, and the protocol used when transmitting emergency communication information is a frequency shift keying method.
Thereby, emergency communication information can be transmitted using a modulation method different from the modulation method of the standard radio wave transmitted at the normal time.

Moreover, in this embodiment, the receiver 20 determines whether it is emergency communication information with reference to the transmitted signal.
Thereby, the emergency communication information transmitted using the modulated wave of the same frequency as the standard radio wave can be received.

In the present embodiment, when the determination unit 21 receives a signal modulated by the frequency shift keying method, the receiver 20 determines that the signal includes emergency communication information.
Thereby, the distinction from the standard radio wave can be facilitated by adopting a modulation method with a feature different from the standard radio wave. It is possible to simply handle an error as a timepiece without adversely affecting the time of the time, such as a radio timepiece, that uses a standard radio wave only for time calibration. Coexistence with the system becomes easy. Moreover, the emergency communication information determined to be an error due to noise is continuously transmitted, so that the certainty of communication delivery is increased as compared with information transmission only once.
Alternatively, the determination unit 21 may determine that the signal includes emergency communication information when the amplitude of the signal modulated by the frequency shift keying method is constant.
Thereby, the characteristic different from the standard radio wave is characterized in that the amplitude of the modulation signal is constant, so that the discrimination from the standard radio wave can be facilitated.

In the present embodiment, the receiver 20 determines whether or not the emergency communication information is properly received based on the added code, and outputs information corresponding to the received emergency communication information. And
As a result, there is a probability that an emergency communication false alarm due to noise can be virtually ignored. In addition, it is possible to make emergency call communication more reliable and quicker than in the prior art.

In the present embodiment, the emergency communication information includes information indicating a predetermined type and a target to be applied.
Thereby, it becomes possible to distribute a plurality of emergency communications to targets classified by a plurality of places and a plurality of types, and the emergency information distribution system 1 can be used for various types of emergency information distribution. Furthermore, reliable and quick emergency communication information communication of emergency communication can be enabled, and the usefulness of emergency communication can be greatly increased during a disaster.
The target for providing information by the emergency information distribution system 1 uses a common transmission facility by defining information that classifies places (regions), systems, and information types that require emergency communication information. Thus, it is possible to distribute emergency communication information according to multiple purposes.

1 Emergency Information Distribution System 10 Transmitter 20, 30 Receiver

Claims (10)

An emergency information distribution system that distributes time information distributed widely,
Transmitter for transmitting emergency communication information distributed including emergency information using a frequency band including a frequency of a standard radio wave for distributing the time information using a protocol different from the protocol for distributing the time information An emergency information distribution system comprising: The transmitter is
A standard radio wave transmitter that transmits the time information using the standard radio wave at normal times;
A time code that is transmitted prior to the emergency communication information, indicating a start of the emergency communication information, and adding a code for error detection or error correction of the emergency communication information after the emergency communication information; An emergency information transmitter that transmits using a frequency band that includes the frequency of a standard radio wave that transmits information;
A switching unit that switches between a signal transmitted from the standard radio wave transmission unit and a signal transmitted from the emergency information transmission unit;
The emergency information distribution system according to claim 1, further comprising: The emergency information transmitter
The emergency communication information and the error detection code or error correction code are combined and transmitted repeatedly a plurality of times using a protocol different from the protocol used when transmitting the time information during the normal time. The emergency information delivery system according to claim 1 or claim 2. The protocol used when transmitting the time information in the normal time is an amplitude modulation method, and the protocol used when transmitting the emergency communication information is a frequency shift keying method. The emergency information distribution system according to claim 3. The emergency information distribution system according to any one of claims 1 to 4, further comprising: a receiver that determines whether the communication information is emergency communication information with reference to the transmitted signal. The receiver
6. The determination unit according to claim 1, further comprising: a determination unit configured to determine that the signal includes the emergency communication information when a signal modulated by a frequency shift keying method is received. Emergency information distribution system. The receiver
Determine whether the emergency communication information has been properly received based on the added code,
The emergency information distribution system according to any one of claims 1 to 6, wherein information corresponding to the received emergency communication information is output. The emergency information distribution system according to any one of claims 1 to 7, wherein the emergency communication information includes information indicating a predetermined type and a target to be applied. A transmitter of an emergency information distribution system that distributes emergency information distributed over a wide area,
The emergency communication information distributed including the emergency information uses a frequency band including the standard radio wave frequency for distributing the time information using a protocol different from the protocol for distributing the time information distributed over a wide range. Transmitter characterized by transmitting. A receiver that receives signals of an emergency information distribution system that distributes emergency information distributed over a wide area,
A receiver that receives emergency communication information transmitted from the transmitter according to claim 9.

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