JPWO2020129431A1 - Call system, central control device, terminal station device and call control method - Google Patents

Abstract

In order to enable listening to a terminal station device other than the terminal station device during a call, the present invention provides a call system that eliminates the difficulty of speaking by the call back voice in the terminal station device during a call. The central control device 20 transmits the voice signal received from the command station side to the plurality of terminal station devices 50, transmits the voice signal received from the terminal station side to the command station device 10 and the plurality of terminal station devices 50, and at the same time. Voice return information indicating whether the source of the voice signal is the command station side or the terminal station side is added to the voice signal transmitted to the plurality of terminal station devices 50. When the terminal station device 50 receives a voice signal to which the voice return information indicating that the transmission source is the command station side is received, and the voice return information indicating that the transmission source is the terminal station side is added. When the received voice signal is received and the own station is not in a busy state, the received voice signal is reproduced and output.

Description

The present invention relates to a call system in which a call between a command station device and a terminal station device is controlled by a central control device.

In recent years, a call system has been used that enables a call between a command station device and any of a plurality of terminal station devices and allows the contents of the call to be heard by other terminal station devices. This listening function is realized, for example, by a central control device that controls a call between a command station device and a terminal station device. That is, by controlling the central control device to transmit the received voice from the terminal station side and the received voice from the terminal station side to a plurality of terminal station devices including the terminal station device during a call, the listening function can be performed. It will be realized.

According to the above-mentioned listening function, the voice emitted from the own station is also returned to the terminal station device during the call. Then, when the call back voice is reproduced and output by the terminal station device during the call, there is a problem that it interferes with the call and it is difficult to talk. For this reason, it is necessary to take measures against the folded voice in the listening / speaking function, and various inventions have been proposed from the past. For example, Patent Document 1 discloses an invention in which an on-board station device during a call with a command station device removes a transmitted voice from a received voice by an echo canceller.

Japanese Unexamined Patent Publication No. 2003-18502

However, in the above-mentioned technique of Patent Document 1, it is necessary to delay the transmitted voice in the radio in order to cancel the transmitted voice from the received voice, and reliable echo cancellation cannot be performed unless the delay time is strictly set. In addition, depending on the radio propagation environment, echo cancellation may not be possible.

The present invention has been made in view of the above-mentioned conventional circumstances, and in order to enable listening to a terminal station device other than the terminal station device during a call, the return in the terminal station device during a call is made. The purpose is to eliminate the difficulty of speaking by voice.

In order to achieve the above object, in the present invention, the communication system is configured as follows.
That is, the communication system according to the present invention includes a command station device, a plurality of terminal station devices, and a central control device that controls a call between the command station device and the plurality of terminal station devices. Then, the central control device transmits the voice signal received from the command station side to the plurality of terminal station devices, and the voice signal received from the terminal station side is transmitted to the command station device and the plurality of terminal station devices, and at the same time, the plurality of terminal station devices are transmitted. To the voice signal transmitted to the terminal station device, voice return information indicating whether the source of the voice signal is the command station side or the terminal station side is added, and the terminal station device performs the transmission source on the command station side. When receiving a voice signal to which voice wrapping information indicating that there is, and receiving a voice signal to which voice wrapping information indicating that the source is the terminal station side is received and the own station is in a call It is characterized in that the received audio signal is reproduced and output when it is not in a state.

Here, when the reception of the audio signal from the command station side and the reception of the audio signal from the terminal station side overlap, the central control device outputs the audio signal from the command station side to the audio signal from the terminal station side. It may be configured to transmit to a plurality of terminal station devices with priority over.

Further, the central control device has a first voice detection unit that detects a voice signal from the command station side and a second voice detection unit that detects a voice signal from the terminal station side, and has a first voice. When the voice signal is detected by the detection unit, the voice signal from the command station side is transmitted to a plurality of terminal station devices, and when the voice signal is detected by the second voice detection unit, the first voice detection Only when the audio signal is not detected by the unit, the audio signal from the terminal station side may be transmitted to a plurality of terminal station devices.

Further, the first and second voice detection units may be configured to detect the voice signal when the signal level of the voice signal exceeds a predetermined threshold value, and not detect the voice signal in other cases.

Further, the first and second audio detection units divide the input audio signal into a plurality of frequency bands, measure the signal level for each frequency band, weight each frequency band, and add up the total value of the audio signal. The signal level of may be configured to be compared with a predetermined threshold value.

Further, the central control device has a weighting table for storing weight values for each frequency band, and the first and second voice detection units set the signal level measured for each frequency band to the corresponding frequency in the weighting table. The weighting may be performed by multiplying the weight value of the band.

Further, when the terminal station apparatus receives a voice signal to which voice return information indicating that the transmission source is the terminal station side is added, if the own station is in a state of a call, the received voice signal of the received voice signal. It may be configured to suppress audio reproduction.

Further, when the terminal station apparatus receives a voice signal to which voice return information indicating that the transmission source is the terminal station side is added, if the own station is in a state of a call, the terminal station apparatus receives the received voice signal. It may be configured to be replaced with a silent code.

Further, when the terminal station apparatus reproduces and outputs the received voice signal, the source of the voice signal is either the command station side or the terminal station side based on the voice return information given to the voice signal. It may be configured to output an output indicating the above.

According to the present invention, in enabling listening to a terminal station device other than the terminal station device during a call, it is possible to eliminate the difficulty of speaking due to the return voice in the terminal station device during a call.

It is a figure which shows the schematic structure of the call system which concerns on one Embodiment of this invention. It is a figure which shows the configuration example of the central control device in the call system of FIG. It is a figure which shows the configuration example of the base station apparatus and the terminal station apparatus in the call system of FIG. It is a figure which shows the structural example of the voice detection part in the central control device of FIG. It is a figure which illustrates the processing sequence when there is a voice input in a command station apparatus. It is a figure which illustrates the processing sequence when there is a voice input in a terminal station apparatus. It is a figure which illustrates the processing sequence when there is a voice input in both a command station apparatus and a terminal office apparatus. It is a figure which illustrates the appearance of the control panel provided in the on-board station apparatus. It is a figure which shows the format example of the control message transmitted to a control panel.

A call system according to an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 shows a schematic configuration of a telephone system according to an embodiment of the present invention. The communication system of this example includes a command station device 10, a central control device 20, a base station device 40, and a terminal station device 50. FIG. 2 shows a configuration example of the central control device 20, and FIG. 3 shows a configuration example of the base station device 40 and the terminal station device 50.

Although only one base station device 40 is shown in FIG. 1, it is common that a plurality of base station devices 40 are installed at a certain interval in a call service providing area. Further, in FIG. 1, only two terminals (50-1, 50-2) are shown as the terminal station apparatus 50, but it goes without saying that the number of the terminal station apparatus 50 may be three or more. The terminal station device 50 may be fixedly installed at an arbitrary base in the area where the call service is provided, may be portable by the user, and may be mounted on an arbitrary mobile body such as a car or a train to move. It may be possible. When the terminal station device 50 is located in the communication area of any of the base station devices 40, the terminal station device 50 can make a call with the command station device 10 via wireless communication with the base station device 40.

The command station device 10 is a device that provides a call with an arbitrary terminal station device 50, and is installed in, for example, a facility that manages a call system. The central control device 20 is a device that controls a call between the command station device 10 and the terminal station device 50, and is installed in the same facility as the command station device 10, for example.

As shown in FIG. 2, the central control device 20 includes a listening function unit 21 for providing a listening function, a codec unit 25 for encoding (encoding) and decoding (decoding) an audio signal, and a terminal station side. A voice switch 26 that switches the voice signal to be transmitted to the terminal station side, a transmission buffer 27 that stores the voice signal transmitted to the terminal station side, a reception buffer 28 that stores the voice signal received from the terminal station side, and a base. It is provided with an IP unit 29 which is a communication interface with the station 40.

First, the configuration of the listening / speaking function unit 21 included in the central control device 20 of this example will be described. The listening function unit 21 has voice detection units 22 and 23 and a determination circuit 24. The voice detection unit 22 is a block that detects a voice signal from the command station side, and the voice detection unit 23 is a block that detects a voice signal from the terminal station side. The voice detection units 22 and 23 output the detection result of the voice signal to the determination circuit 24. A specific configuration of the voice detection units 22 and 23 will be described with reference to a configuration example shown in FIG.

The voice detection units 22 and 23 were measured by a plurality of detection units 31 for detecting the signal level of the voice signal for each frequency band, a weighting table 35 for storing weight values for each frequency band, and each detection unit 31. A plurality of multipliers 36 that multiply the signal level of each frequency band by the weight value of the corresponding frequency band in the weighting table 35, and an integrator 37 that sums the signal levels of each frequency band weighted by each multiplier 36. , A voice detection threshold storage unit 38 that stores a threshold for voice detection, and a comparator 39 that compares the signal level summed by the integrator 37 with the threshold stored in the voice detection threshold storage unit 38. Be prepared.

In this example, the detection unit 31 is provided in units of 10 divisions of the frequency band of 300 to 3300 Hz by 300 Hz. That is, a first detection unit that detects at 300 Hz to 600 Hz, a second detection unit that detects at 600 Hz to 900 Hz, a third detection unit that detects at 900 Hz to 1200 Hz, ..., Detection at 3000 to 3300 Hz. It is provided with a tenth detection unit for performing the above.

The first to tenth detection units are configured by using a filter 32, a full-wave rectification unit 33, and a smoothing unit 34, respectively. As the filter 32, a band-passing filter that passes through the band to be detected by the detection unit (for example, 300 Hz to 600 Hz in the case of the first detection unit) while blocking the passage of other bands is used. The audio signal that has passed through the filter 32 is full-wave rectified and smoothed by the full-wave rectifying unit 33 and the smoothing unit 34, and the signal level is detected. With such a configuration, the signal level of the audio signal can be measured for each frequency band.

The weighting table 35 stores the weight value to be multiplied by the signal level measured in the frequency band for each frequency band corresponding to each of the plurality of detection units 31. Preferably, the weight value is set so that the signal level in the frequency band of the audible range is emphasized. That is, the weight value to be multiplied by the signal level of the frequency band in the audible range is set to a value larger than the weight value to be multiplied by the signal level of the other frequency band. The weight value of each frequency band held by the weighting table 35 is output to the multiplier 36 corresponding to the frequency band.

Each multiplier 36 multiplies the measured value of the signal level by the corresponding detection unit 31 with the weight value of the corresponding frequency band given from the weighting table 35. The integrator 37 inputs the signal levels for each frequency band after being weighted by each multiplier 36, sums them up to calculate the integrated value of the signal level, and outputs the integrated value to the comparator 39.

The comparator 39 compares the integrated value of the signal level output from the integrator 37 with the threshold value stored in the voice detection threshold value storage unit 38, and outputs a detection flag indicating the comparison result to the subsequent determination circuit 24. Specifically, when the integrated value of the signal level exceeds the threshold value, a detection flag indicating the detection of the audio signal is output, and when the integrated value of the signal level is below the threshold value, the audio signal is not detected. Outputs the indicated detection flag.

The determination circuit 24 determines a voice signal to be transmitted to the terminal station side based on the detection flag input from the voice detection unit 22 and the detection flag input from the voice detection unit 23, and voice according to the result. Controls the switch 26. Specifically, when the detection flag indicating the detection of the voice signal is input from the voice detection unit 22, and the detection flag indicating the non-detection of the voice signal is input from the voice detection unit 23, the voice signal from the command station side is input. Since only is detected, the voice switch 26 is controlled so that the voice signal from the command station side is transmitted to the terminal station side. Further, when the detection flag indicating the non-detection of the voice signal is input from the voice detection unit 22 and the detection flag indicating the detection of the voice signal is input from the voice detection unit 23, only the voice signal from the terminal station side is detected. Therefore, the voice switching device 26 is controlled so that the voice signal from the terminal station side is returned to the terminal station side and transmitted. Further, when the detection flag indicating the detection of the voice signal is input from the voice detection unit 22, and the detection flag indicating the detection of the voice signal is input from the voice detection unit 23, the voice signal from the command station side and the terminal station side are input. Both of the voice signals from are detected, and in this case, the voice switch 26 is controlled so that the voice signal from the command station side is transmitted to the terminal station side.

Here, the voice spoken by a person has some silence between words. Therefore, the detection result of the voice signal of the voice detection unit 23 may be switched for each syllable. As a result, the determination circuit 24 switches the voice switch 26 each time, and there is a possibility that the call voice will be interrupted if it is muffled. Therefore, when the determination circuit 24 switches the voice switch 26 so that the voice signal is detected by the voice detection unit 22 and the voice signal from the command station side is transmitted to the terminal station side, the determination circuit 24 takes a predetermined time (about 150 to about 150 to). For 500 msec, preferably 200 msec), it is preferable to maintain the state of the voice switch 26 regardless of the detection result of the voice signal of the voice detection unit 23.

That is, once the determination circuit 24 switches the voice switch 26 to the “0” side so that the voice signal from the command station side is transmitted to the terminal station side, the voice signal is not detected by the voice detection unit 22 thereafter. Even so, switching of the voice switch 26 to the "1" side is suppressed for a predetermined time. Then, if the voice detection unit 22 continues not detecting the voice signal until after a predetermined time elapses, the determination circuit 24 sets the voice switch 26 to "1" if the voice detection unit 23 detects the voice signal. If the voice detection unit 23 does not detect the voice signal, the voice switch 26 is left on the “0” side. On the other hand, when the voice detection unit 22 detects the voice signal and then detects the voice signal again within a predetermined time, the determination circuit 24 resets the count for the predetermined time and restarts the measurement. As a result, it is possible to prevent the voice switching device 26 from being unnecessarily switched in the silent section during the talk and the call voice being muffled and interrupted.

Further, the determination circuit 24 operates in the same manner as described above when the voice detection unit 22 does not detect the voice signal and only the voice detection unit 23 detects the voice signal. That is, when the voice detection unit 23 detects the voice signal, the determination circuit 24 switches the voice switching device 26 to the “1” side and maintains the voice switching unit 26 for a predetermined time regardless of the detection result of the voice detection unit 23. Then, if the voice detection unit 23 detects the voice signal by the time when the predetermined time elapses, the determination circuit 24 resets the count for the predetermined time and restarts the measurement. Further, when the predetermined time elapses, the determination circuit 24 switches the voice switch 26 to the “0” side. When the voice detection unit 22 detects a voice signal while the voice switch 26 is switched to the “1” side, the determination circuit 24 immediately switches the voice switch 26 to the “0” side to the command station side. Controls so that the voice signal from is transmitted to the terminal station side.

When the determination circuit 24 does not detect the voice signal in both the voice detection units 22 and 23, it is preferable to control the voice switch 26 so that the voice of the command station 10 is passed. As a result, the voice of the command station having a high priority can be reliably transmitted to the base station 40 without a head break.

Further, a delay circuit or buffer for delaying the received voice from the terminal station for a predetermined time may be provided between the receiving buffer 28 and the voice switching device 26 at a location that does not affect the input to the codec unit 25. As a result, it is possible to eliminate the head break of the voice of the terminal station due to the time until the voice detection unit 23 detects the voice signal and the voice switching unit 26 is switched by the determination circuit 24.

The voice switch 26 switches to selectively output either the voice signal received from the command station side or the voice signal received from the terminal station side to the transmission buffer 27 according to the control by the determination circuit 24. Further, the determination circuit 24 returns the voice signal (voice signal transmitted to the terminal station side) in the transmission buffer 27 to indicate whether the source of the voice signal is the command station side or the terminal station side. Add information (eg, flag). The voice signal stored in the transmission buffer 27 is output to the base station 40 via the IP unit 29 together with the voice return information, and is transmitted to the terminal station device 50.

As shown in FIG. 3, the base station device 40 includes an IP unit 41 which is a communication interface with the central control device 20, a codec unit 42 which performs coding and decoding for wireless communication, and an RF unit which performs wireless processing. 43 and. When the base station device 40 receives the voice signal and the voice return information to be transmitted to the terminal station side from the central control device 20, the SACCH (Slow Associated Control Channel) of the wireless frame used for wireless transmission of the voice signal is used. The voice return information is stored in the terminal station device 50 and wirelessly transmitted to the terminal station device 50. The voice loop information may be stored in a channel other than the SACCH, and can be added to the voice signal and transmitted by various methods.

As shown in FIG. 3, the terminal station apparatus 50 includes an RF unit 51 that performs wireless processing, a codec unit 52 that performs coding and decoding for wireless communication, and a silent code output unit 53 that outputs a silent code. A comparison unit 54 that determines whether or not the source of the received audio signal is the own station, an audio switch 55 that switches the audio signal to be played back and output, and a codec unit 56 that encodes and decodes the audio signal. And prepare. Although not shown, it also has a speaker for reproducing voice and a microphone for voice input.

When the terminal station apparatus 50 receives the audio signal wirelessly transmitted from the base station apparatus 40, the terminal station apparatus 50 determines whether or not to reproduce and output the received audio signal based on the audio loopback information accompanying the audio signal. Specifically, when a voice signal to which voice loop information indicating that the transmission source is on the command station side is added is received, the received voice signal is reproduced and output. Further, when the voice signal to which the voice return information indicating that the transmission source is the terminal station side is received is received, the received voice signal is reproduced and output only when the own station is not in the state of being in a call. In other words, when a voice signal with voice loop information indicating that the source is the terminal station side is received, if the own station is in a busy state, the reproduction output of the received voice signal is suppressed. do.

Such control is realized by the silent code output unit 53, the comparison unit 54, and the voice switch 55 as follows. First, the comparator 54 compares the voice return information accompanying the received voice signal with the in-call flag indicating whether or not the own station is in a call. Here, the voice loop information of this example is "0" when the source of the voice signal is the command station side, and "1" when the source of the voice signal is the terminal station side. .. Further, the in-call flag in this example is "0" when the own station is not in a call, and is "1" when the own station is in a call. The comparator 54 takes a logical product (AND) of the voice call back information and the busy flag and outputs it to the voice switch 55. As a result, "1" is output to the voice switch 55 only when the source of the voice signal is the terminal station side and the own station is in a call, and "0" is output to the voice switch 55 in other cases. It will be output.

The voice switching device 55 switches to selectively output either the received voice signal or the silent code to the codec unit 56 according to the input from the comparator 54. That is, when "0" is input from the comparator 54 to the voice switch 55, the voice signal transmitted by the own station is not folded back, so that the received voice signal is output to the codec unit 56. Switch to. On the other hand, when "1" is input from the comparator 54 to the voice switch 55, since the voice signal transmitted by the own station is folded back, the silent code is switched so as to be output to the codec unit 56. Therefore, if the received audio signal is transmitted from the own station, the audio signal is not reproduced and output.

Next, the flow of listening and speaking in the call system of this example will be described with reference to FIGS. 5 to 7. In the following, a case where the command station device 10 and the terminal station device 50-1 make a call and the terminal station device 50-2 listens to the contents of the call will be described as an example. The "wrapping flag" in the figure corresponds to voice wrapping information.

FIG. 5 illustrates a processing sequence when there is a voice input to the command station device 10.
When the command station device 10 has a voice input in the state of a call with the terminal station device 50-1 (step S11), the command station device 10 transmits the voice signal to the central control device 20.
Upon receiving the audio signal, the central control device 20 determines the source thereof (step S12). Then, the voice return information according to the determination result is set (step S13). In the case of this example, since the voice signal is received from the command station side, "0" indicating that the source of the voice signal is the command station side is set in the voice return information. After that, the voice signal received from the command station side is transmitted to the terminal station device 50-1 during the call and the other terminal station devices 50-2 together with the voice return information.

Upon receiving the voice signal and the voice return information, the terminal station apparatus 50-1 determines whether or not to reproduce the voice signal (step S14). In the case of this example, since the voice return information in which "0" is set indicating that the transmission source of the voice signal is the command station side is received, the voice signal is reproduced and output (step S15).
Similarly, when the terminal station apparatus 50-2 receives the voice signal and the voice return information, it determines whether or not to reproduce the voice signal (step S16). In the case of this example, since the voice return information in which "0" is set indicating that the transmission source of the voice signal is the command station side is received, the voice signal is reproduced and output (step S17).

FIG. 6 illustrates a processing sequence when there is a voice input to the terminal station apparatus 50-1.
When there is a voice input in the state of a call with the command station device 10 (step S21), the terminal station device 50-1 transmits the voice signal to the central control device 20.
Upon receiving the audio signal, the central control device 20 determines the source thereof (step S22). Then, the voice return information according to the determination result is set (step S23). In the case of this example, since the voice signal is received from the terminal station side, "1" indicating that the source of the voice signal is the terminal station side is set in the voice return information. After that, the audio signal received from the terminal station side is transmitted to the command station device 10. Further, the voice signal received from the terminal station side is transmitted to the terminal station device 50-1 during a call and the other terminal station devices 50-2 together with the voice return information.

When the command station device 10 receives the audio signal, it reproduces and outputs the audio signal (step S24).
Further, when the terminal station apparatus 50-1 receives the voice signal and the voice return information, it determines whether or not to reproduce the voice signal (step S25). In the case of this example, since the voice return information in which "1" indicating that the source of the voice signal is set is set to the terminal station side is received and the own station is in a call with the command station device 10. The audio signal is not reproduced and output (step S26).
Similarly, when the terminal station apparatus 50-2 receives the voice signal and the voice return information, it determines whether or not to reproduce the voice signal (step S27). In the case of this example, since the voice return information in which "1" indicating that the source of the voice signal is set is set to the command station side is received and the own station is not in a call with the command station device 10. The audio signal is reproduced and output (step S28).

FIG. 7 illustrates a processing sequence when there is a voice input to both the command station device 10 and the terminal station device 50-1.
When the command station device 10 has a voice input in the state of a call with the terminal station device 50-1 (step S31), the command station device 10 transmits the voice signal to the central control device 20. Further, when the terminal station device 50-1 has a voice input in the state of a call with the command station device 10 (step S32), the terminal station device 50-1 transmits the voice signal to the central control device 20.

Upon receiving the audio signal, the central control device 20 determines the source thereof (step S33). Then, the voice return information according to the determination result is set (step S34). In the case of this example, the audio signal is received from both the command station side and the terminal station side, but since the audio signal on the command station side is preferentially transmitted to the terminal station side, the source of the audio signal is the command. "0" indicating that it is the station side is set in the voice return information. After that, the voice signal received from the command station side is transmitted to the terminal station device 50-1 during the call and the other terminal station devices 50-2 together with the voice return information. Further, the audio signal received from the terminal station side is transmitted to the command station device 10.

When the command station device 10 receives the audio signal, it reproduces and outputs the audio signal (step S35).
Further, when the terminal station apparatus 50-1 receives the voice signal and the voice return information, it determines whether or not to reproduce the voice signal (step S36). In the case of this example, since the voice return information in which "0" is set indicating that the transmission source of the voice signal is the command station side is received, the voice signal is reproduced and output (step S37).
Similarly, when the terminal station apparatus 50-2 receives the voice signal and the voice return information, it determines whether or not to reproduce the voice signal (step S38). In the case of this example, since the voice return information in which "0" is set indicating that the transmission source of the voice signal is the command station side is received, the voice signal is reproduced and output (step S39).

As described above, the communication system of this example is a central system that controls a call between the command station device 10, the plurality of terminal station devices 50, and any of the command station device 10 and the plurality of terminal station devices 50. It is provided with a control device 20. The central control device 20 transmits the voice signal received from the command station side to the plurality of terminal station devices 50, transmits the voice signal received from the terminal station side to the command station device 10 and the plurality of terminal station devices 50, and at the same time. To the voice signal transmitted to the plurality of terminal station devices 50, voice return information indicating whether the source of the voice signal is the command station side or the terminal station side is added. When the terminal station device 50 receives a voice signal to which the voice return information indicating that the transmission source is the command station side is received, and the voice return information indicating that the transmission source is the terminal station side is added. When the received voice signal is received and the own station is not in a busy state, the received voice signal is reproduced and output.

With such a configuration, a call between the command station device 10 and one of the terminal station devices 50 (for example, the terminal station device 50-1) can be made to another terminal station device 50 (for example, the terminal station device 50-2). In addition to being able to hear and speak, the terminal station device 50 (for example, the terminal station device 50-1) during a call does not reproduce and output the audio signal emitted and returned by the own station. In addition, this function of suppressing the reproduction of the return voice can also be applied to a call system using a codec without an echo cancel function.

Further, in the communication system of this example, when the reception of the audio signal from the command station side and the reception of the audio signal from the terminal station side overlap, the central control device 20 receives the audio signal from the command station side. It is transmitted to a plurality of terminal station devices 50 with priority over the audio signal from the terminal station side. Therefore, the terminal station device 50 during a call with the command station device 10 reproduces and outputs the voice signal from the command station device 10 even when the voice is input to the command station device 10 at a timing overlapping with the voice input at the own station. can do.

Further, in the call system of this example, the central control device 20 has a voice detection unit 22 for detecting a voice signal from the command station side and a voice detection unit 23 for detecting the voice signal from the terminal station side. When the voice signal is detected by the voice detection unit 22, the voice signal from the command station side is transmitted to the plurality of terminal station devices 50, and when the voice signal is detected by the voice detection unit 23, the voice detection unit 22 is used. Only when the voice signal is not detected, the voice signal from the terminal station side is transmitted to the plurality of terminal station devices 50. Therefore, when the voice input to the command station device 10 and the voice signal to the terminal station device 50 overlap, the voice signal from the command station side can be preferentially transmitted to the terminal station side.

Further, in the call system of this example, the voice detection units 22 and 23 detect the voice signal when the signal level of the voice signal exceeds a predetermined threshold value, and do not detect the voice signal in other cases. It has become. Therefore, if an audio signal with a signal level lower than that of a general call audio is received (for example, if the microphone is on but the speaker is not speaking), there is no need to listen. It is possible to suppress the transmission of the voice signal to the terminal station side.

Further, in the call system of this example, the voice detection units 22 and 23 divide the input voice signal into a plurality of frequency bands, measure the signal level for each frequency band, weight each frequency band, and add up the total values. Is used as the signal level of the voice signal, and is compared with a predetermined threshold value. Therefore, for example, by weighting the signal level in the frequency band of the audible range so as to be emphasized, the presence or absence of voice input can be accurately detected.

Further, in the call system of this example, the central control device 20 has a weighting table 35 for storing weight values for each frequency band, and the voice detection units 22 and 23 weight the signal levels measured for each frequency band. Weighting is performed by multiplying the weight values of the corresponding frequency bands in the table 35. Therefore, it is possible to easily realize the weighting of the signal level measured for each frequency band.

Further, in the call system of this example, when the terminal station device 50 receives a voice signal to which voice return information indicating that the transmission source is the terminal station side is added, the terminal station apparatus 50 is in a state of being in a call. Is configured to replace the received audio signal with a silent code. Therefore, it is possible to easily prevent the return voice from being reproduced and output by the terminal station device 50 during a call. Needless to say, instead of replacing the received audio signal with a silent code, it is possible to suppress the reproduction output of the folded voice by another method such as discarding the received audio signal.

Further, the present invention can also be grasped as an invention of the central control device 10 and the terminal station device 50 constituting the above-mentioned communication system. It can also be grasped as an invention of a call control method implemented by the above call system.

Although the present invention has been described in detail based on the above examples, it is needless to say that the present invention is not limited to the call system described here and can be widely applied to call systems other than the above.

In the above-described embodiment, the case where the voice return information is a flag has been described, but the device ID of the transmission source may be used, and information capable of determining whether the transmission source of the voice signal is the command station side or the terminal station side. It should be.

Further, in the above-described embodiment, the voice detection unit 22 is configured to detect the voice level by the circuit of FIG. 4 to detect the presence or absence of the voice signal of the command station 10. However, the method for detecting an audio signal of the present invention is not limited to this. For example, the microphone of the command station 10 may be provided with a press button or a switch (hereinafter, simply referred to as a button), and when the speaker speaks, the button is pressed and a signal indicating the button press is transmitted to the central control device 20. good. Then, the voice detection unit 22 may be configured to detect that there is a voice signal of the command station 10 when it detects a signal indicating that the button is pressed.

Further, in the above-described embodiment, the terminal station device 50 outputs a silent code to the codec unit 56 by switching the voice switching device (switch) 55, and suppresses the voice output. However, the method of suppressing the audio output is not limited in the present invention, and the codec is stopped without the audio switch 55, the connection to the speaker is disconnected, and the power supply to the decoder and the speaker is stopped. You may do it.

Next, a configuration in which the above-described embodiment is extended will be described by exemplifying a case where the present invention is applied to a train radio system. Here, the "on-board station device" in the following description is mounted on a train which is an example of a mobile body, and corresponds to the terminal station device 50 in the above-described embodiment.

FIG. 8 illustrates the appearance of the control panel 60 provided in the on-board station device. The control panel 60 has a listening display for identifiable the source of the audio signal (listening voice) being heard, in addition to the display unit / operation unit related to functions such as protective alarm / emergency alarm and train radio. It has a part 61. The hearing display unit 61 in the figure is provided with a command identification unit 62, an on-vehicle identification unit 63, and an organization number identification unit 64.

The command identification unit 62 is configured by using an LED (Light Emitting Diode) as an example, and lights up when the source of the heard voice is a command station device. The on-vehicle identification unit 63 is configured by using LE as an example, and lights up when the source of the heard voice is an on-vehicle station device. The train number identification unit 64 is configured by using a 7-segment LED as an example, and displays a train number that identifies a train equipped with the on-board station device when the source of the heard voice is an on-board station device. ..

The on-board station device controls the display of the hearing display unit 61 by transmitting a control telegram to the control panel 60. FIG. 9 shows an example of the format of the control message transmitted to the control panel 60. The control message in the figure is composed of a total of 48 bits of Bit0 to Bit47, of which Bit22 to Bit31 are used for controlling the display unit 61.

The on-board station device that has received the voice signal from the central control device 20 performs the following processing when reproducing and outputting the voice signal.
When the voice return information indicating that the transmission source is the command station side is added to the voice signal, the on-board station device reproduces and outputs the voice signal. At this time, the command identification unit 62 is turned on by setting "1" (lighting instruction of the command identification unit 62) in Bit 22 of the control telegram and transmitting it to the control panel 60.

In addition, when the voice return information indicating that the transmission source is the on-board station side is added to the voice signal, the on-board station device has the voice signal only when the own station is not in a busy state. Is played back and output. At this time, by setting "1" (lighting instruction of the on-vehicle identification unit 63) in Bit 23 of the control telegram and transmitting it to the control panel 60, the on-vehicle identification unit 63 is turned on. Further, by setting the organization number of the on-board station during a call transmitted from the central control device 20 in Bits 24 to 31 of the control message and transmitting it to the control panel 60, the organization number of the on-board station during a call can be identified. Displayed in unit 64.

As described above, in the above-mentioned extended example, when the on-board station device reproduces the voice signal received from the central control device 20, the voice signal is based on the voice return information given to the voice signal. It is configured to output to indicate whether the source is the command station side or the on-board station side. Therefore, the user of the on-board station device (eg, a train driver or crew member) identifies whether the audio being heard is from the command station device or from another on-board station device. be able to. In addition, when the source of the voice is the on-board station side, the information for identifying the on-board station device (organization number in this example) is also displayed, so the voice is from any on-board station device. Can also be identified.

The present invention can also be provided, for example, as a method or method for executing the process according to the present invention, a program for realizing such a method or method, a storage medium for storing the program, or the like.

The present invention can be used in various communication systems in which a call between a command station device and a terminal station device is controlled by a central control device.

10: Command station device, 20: Central control device, 22: Hearing function unit, 23, 24: Voice detection unit, 24: Judgment circuit, 25: Code code unit, 26: Voice switch, 27: Transmission buffer, 28: Receive buffer, 29: IP section, 31: Detection section, 32: Filter, 33: Full-wave rectifier section, 34: Smooth section, 35: Weighting table, 36: Multiplier,
37: Integrator, 38: Voice detection threshold storage unit, 39: Comparator, 40: Base station equipment, 41: IP unit, 42: Codec unit, 43: RF unit, 50-1, 50-2: Terminal station equipment, 51: RF unit, 52: Codec unit, 53: Silence code output unit, 54: Comparison unit, 55: Voice switch, 56: Codec unit, 60: Control panel, 61: Listening display unit, 62: Command identification unit, 63: On-board identification unit, 64: Organization number identification unit

Claims (12)

In a communication system including a command station device, a plurality of terminal station devices, and a central control device for controlling a call between the command station device and any of the plurality of terminal station devices.
The central control device transmits a voice signal received from the command station side to the plurality of terminal station devices, and transmits a voice signal received from the terminal station side to the command station device and the plurality of terminal station devices. To the voice signal transmitted to the plurality of terminal station devices, voice return information indicating whether the source of the voice signal is the command station side or the terminal station side is added.
When the terminal station device receives a voice signal to which voice return information indicating that the transmission source is on the command station side is received, and voice return information indicating that the transmission source is on the terminal station side is added. A call system characterized in that a received voice signal is received and the received voice signal is reproduced and output when the own station is not in a state of being in a call. In the calling system according to claim 1,
When the reception of the audio signal from the command station side and the reception of the audio signal from the terminal station side overlap, the central control device makes the audio signal from the command station side more than the audio signal from the terminal station side. A call system characterized in that it is preferentially transmitted to the plurality of terminal station devices. In the calling system according to claim 2,
The central control device has a first voice detection unit that detects a voice signal from the command station side and a second voice detection unit that detects a voice signal from the terminal station side, and the first voice. When the voice signal is detected by the detection unit, the voice signal from the command station side is transmitted to the plurality of terminal station devices, and when the voice signal is detected by the second voice detection unit, the first A call system characterized in that a voice signal from the terminal station side is transmitted to the plurality of terminal station devices only when the voice signal is not detected by the voice detection unit of the above. In the calling system according to claim 3,
The first and second voice detection units detect a voice signal when the signal level of the voice signal exceeds a predetermined threshold value, and do not detect the voice signal in other cases. system. In the calling system according to claim 4,
The first and second voice detection units divide the input voice signal into a plurality of frequency bands, measure the signal level for each frequency band, weight each frequency band, and add up the total value of the voice signal. A communication system characterized in that the signal level is compared with the predetermined threshold value. In the calling system according to claim 5,
The central control device has a weighting table that stores weight values for each frequency band.
The first and second voice detection units are a call system characterized in that weighting is performed by multiplying the signal level measured for each frequency band by the weight value of the corresponding frequency band in the weighting table. In the calling system according to any one of claims 1 to 6.
When the terminal station device receives a voice signal to which voice return information indicating that the transmission source is the terminal station side is added, if the own station is in a state of a call, the terminal station apparatus reproduces the received voice signal. A calling system characterized by suppressing output. In the calling system according to any one of claims 1 to 7.
When the terminal station device receives a voice signal to which voice return information indicating that the transmission source is the terminal station side is added, if the own station is in a state of a call, the received voice signal is silenced. A calling system characterized by replacing it with a code. In the calling system according to any one of claims 1 to 8.
When the terminal station device reproduces and outputs the received voice signal, whether the source of the voice signal is the command station side or the terminal station side based on the voice return information given to the voice signal. A calling system characterized by producing an output indicating. In a central control device that controls a call between a command station device and any of a plurality of terminal station devices.
The voice signal received from the command station side is transmitted to the plurality of terminal station devices, the voice signal received from the terminal station side is transmitted to the command station device and the plurality of terminal station devices, and the voice signal is received. In the voice signal transmitted to the plurality of terminal station devices, the source of the voice signal is the command station side or the terminal station so that it can be determined whether or not each of the plurality of terminal station devices reproduces and outputs the voice signal. A central control device characterized by giving voice wrapping information indicating which side it is. In a terminal station device that talks to a command station device under the control of a central controller
The voice signal transmitted from the central control device is provided with voice loop information indicating whether the source of the voice signal is the command station side or the terminal station side.
When receiving a voice signal to which voice return information indicating that the transmission source is on the command station side is received, and when receiving a voice signal to which voice return information indicating that the transmission source is on the terminal station side is added. A terminal station device characterized in that the received voice signal is reproduced and output when the own station is not in a state of being on a call. A call control method implemented by a call system comprising a command station device, a plurality of terminal station devices, and a central control device for controlling a call between the command station device and any of the plurality of terminal station devices. In
The central control device transmits a voice signal received from the command station side to the plurality of terminal station devices, and a voice signal received from the terminal station side is transmitted to the command station device and the plurality of terminal station devices. A step of adding voice loop information indicating whether the source of the voice signal is the command station side or the terminal station side to the voice signal transmitted to the plurality of terminal station devices, and
When the terminal station device receives a voice signal to which the voice return information indicating that the transmission source is the command station side is received, and the voice return information indicating that the transmission source is the terminal station side is added. A call control method comprising a step of playing back and outputting a received voice signal when the voice signal is received and the own station is not in a state of being in a call.

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