JP2858546B2 - Video / Audio Delay Compensation Method and Apparatus for Multipoint Video / Audio Communication System Using Satellite Communication and Terrestrial Communication - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a video / audio delay compensation method and apparatus for a multipoint video / audio communication system using satellite communication and terrestrial communication.

[0002]

In recent years, in a communication system between the multi-point that is being used, for example, remote education and multipoint conferencing, multi-using the TV conference terminal using the broadcast properties and ground communication times lines of communication satellite system that performs communication between the points can be seen many.

[0003] Fig. 3 shows a conventional system of this kind, which uses a TV conference terminal based on the contents described on page 10 of Nikkei New Media magazine, February 22, 1993, for satellite communication and communication. 1 is a configuration diagram of an example of a multipoint video / audio communication system using a terrestrial communication line.

In the figure, the multipoint video communication system includes a center station 56 having a chairman 51 and remote stations 58 and 63 participating in a conference.

The video signal and audio signal of the chairman 51 are generated by a camera 52 and a microphone 53, respectively.
The signal is transmitted to the center station 56, transmitted from the center station 56 as a radio signal through the satellite communication channel 57, and transmitted to the communication satellite 1.
The broadcast is transmitted to all the remote stations including the remote stations 58 and 63 via "0".

The remote station 58 receives the satellite communication channel 57 and outputs the video and audio of the chairman 51 to a video monitor 59 and a speaker 60, respectively.

Here, the conference participant 61 of the remote station 58
Tries to speak, the conference participant 61 inputs a predetermined request to the TV conference terminal 62 and makes a call to the TV conference terminal 55 of the center station via the terrestrial communication network 11.

[0008] The video and audio of the conference participant 61 are
It is generated by the TV conference terminal 62 and transmitted to the TV conference terminal 55 of the center station via the terrestrial communication network 11 via the terrestrial communication network 11. You can see and hear.

When the chairman 51 requests a speech from a conference participant, a call is made from the TV conference terminal 55 of the center station to the TV conference terminal 62 of the remote station 58 via the terrestrial communication network.

The video and audio signals of the conference participant 61 are
It is transmitted to the TV conference terminal 55 of the center station via the terrestrial communication network 11.

The chairman 51 can receive the video signal and the audio signal of the conference participant 61 by the TV conference terminal 55.

[0012] The chairperson 51 is a conference participant 6 who is speaking.
In order to transmit the video and audio signals of the chairman 51 to all the participants, the video and audio signals of the chairman 51, which had been transmitted from the camera 52 and the microphone 53 to the center station 56, are transmitted to the center station via the terrestrial communication network 11. The video / audio being transmitted from the conference participant 61 being transmitted is also output from the TV conference terminal 55 to the center station 56, and all remote stations are transmitted by the center station 56 via the satellite communication channel 57 via the communication satellite 10. Broadcast to.

At this time, the remote station 5 that is speaking
Similarly to the other remote stations, the video signal and the audio signal of the conference participant 61 are transmitted via the satellite communication channel 57, received by the remote station 58, and output to the video monitor 59 and the speaker 60.

At this time, the conference participant 61
Is broadcasted from the center station 56 via satellite communication, and is delayed by a transmission delay time unique to satellite communication, so that its own video signal and audio signal are transmitted. And an audio signal.

Accordingly, the conference participant 61 who is the speaker speaks while watching his own video signal and audio signal with a time delay, and feels a sense of discomfort.

Also, the voice with a time delay of the conference speaker 61 output from the speaker 60 is synthesized in the room with the voice currently being spoken, and is input to the TV conference terminal 62 so that the voice echo and And transmitted to all other stations participating in the conference, significantly degrading the quality of the voice transmitted to the system.

The same phenomenon as described above occurs in the remote station 63 in which the conference participant 66 participates and the TV conference terminal 67 connected to the remote station.

Usually, in such a conventional multipoint video communication system, when performing communication, it is composed of one center station and a plurality of remote stations. The information consisting of voice is broadcasted via a communication satellite, and the transmission of information consisting of video and audio from the remote station to the center station is performed by one of the remote stations which speaks. It is only sent.

[0019]

In the conventional multipoint video communication system described above, a call from a remote station to a center station and a call from a center station to a remote station are intentions of the calling station to speak. Is performed every time, but in a network with a large number of remote stations, there are many messages from the remote stations, so if the center does not perform call control for the entire remote station, you want to make a statement There is a drawback that a call from a remote station does not easily reach the center.

When the center station broadcasts the video signal and the audio signal transmitted from the remote station that has made a statement and transmitted to the center station via the terrestrial line using satellite communication,
The remote station that is speaking receives its own video signal and audio signal with a time delay as common information via the communication satellite, causing a sense of incongruity in the speech and the time broadcasted via the satellite. It is said that the sound received through the communication satellite is transmitted as an echo to the participant who is speaking because the delayed sound and the sound directly emitted by the participant are superimposed on the sound, which degrades the sound quality of the entire system. Has disadvantages.

[0021]

SUMMARY OF THE INVENTION A video / audio delay compensation method for a multipoint video / audio communication system using satellite communication and terrestrial communication according to the present invention comprises: a communication satellite for relaying communication; A central station that transmits common information to a plurality of remote stations via a satellite, communicates specific information with the remote station via a terrestrial communication network, and transmits common information from the center station to the communication satellite. A plurality of remote stations communicating with the center station via the terrestrial communication network for the specific information received via the terrestrial communication network, wherein the center station comprises a center station comprising video and audio for the remote station. Transmitting information via the communication satellite, transmitting a predetermined inquiry acceptance signal to the center station information to all the remote stations via the terrestrial communication network, When it is possible to receive an inquiry from the remote station via a communication network, and when a predetermined inquiry request signal is transmitted from the remote station to the center station via the terrestrial communication network, the center station Receiving a question request signal, selecting any one of the remote stations that have received the question request signal, and transmitting a predetermined question permission signal to the selected remote station via the terrestrial communication network,
The center station information is transmitted via the terrestrial communication network to the remote station that has transmitted the question permission signal,
The remote station that has received the interrogation permission signal switches and receives the common information received via the communication satellite to the center station information transmitted via the terrestrial communication network, and transmits the common information to the terrestrial communication network. Transmitting the specific information consisting of video and audio about the question from the remote station to the center station, and the center station, upon receiving the specific information transmitted from the remote station, The information is combined with the information and transmitted as common information to the remote station via the communication satellite. When the query is completed, a predetermined query end signal is transmitted from the remote station which has given the query permission to the center via the terrestrial communication network. And the transmission of the specific information is terminated, the output from the center station via the terrestrial communication network is terminated, and the remote Is constituted by a process for displaying the received common information sent via the communication satellite instead of the central station the information sent through the ground communication network at a station.

A video / audio delay compensating device for a multipoint video / audio communication system using satellite communication and terrestrial communication according to the second invention comprises: a communication satellite for relaying communication; A video / audio delay compensation device for a multipoint video / audio communication system using satellite communication and terrestrial communication for performing communication between a center station and one or more remote stations using the communication satellite, The center station combines a camera that generates a video within the local station, a microphone that generates a voice within the local station, a center station information including the video and the voice generated within the local station, and specific information to generate common information. A video / audio synthesizing device that outputs the same, a satellite communication device that converts the common information into a radio signal and sends it to the communication satellite,
When a predetermined question reception instruction is received, a predetermined question reception signal is generated and output. When a predetermined question request signal is received, a predetermined reception display indicating that this signal has been received is performed, and a predetermined selection designation is received in the own station. An answer control device that generates and outputs a predetermined question permission signal to the remote station that has transmitted the received question request signal, and transmits the question reception signal from the answer control device via the terrestrial communication network when receiving the question reception signal from the answer control device. When the question request signal is received through the terrestrial communication network, the question request signal is output to the answer control device, and when the question permission signal is received from the answer control device, the question permission signal and the center station information are transmitted through the terrestrial communication network. the query request signal sent was transmitted to the remote station said particular information receiving and the output to video and speech synthesizer of a predetermined through the ground communication network And a wired communication device for terminating transmission of the center station information to the terrestrial communication network upon receipt of a query end signal, wherein the remote station receives the radio signal via the communication satellite and converts it to the common information. And a satellite receiving device that outputs and outputs the inquiry request signal and the inquiry permission signal and the video signal and the audio signal to the own station when received via the terrestrial communication network and receives the interrogation request signal within the own station. When receiving the video signal and the audio signal output through the terrestrial communication network and generated in the own station, when receiving the question permission signal, the specific information is transmitted to the terrestrial communication network as the specific information , and the question end signal is transmitted. And a transmission / reception device for transmitting the specific information to the terrestrial communication network upon transmitting the specific information to the terrestrial communication network when receiving from the own station, When a question acceptance signal is received from the transmitting / receiving device, a questionable display is performed, and when a predetermined question request designation is received, the question request signal is generated and output to the transmitting / receiving device, and when the question permission signal is received from the transmitting / receiving device, switching control is performed. An interrogation control device that outputs a signal and interrupts the output of the switching control signal when a predetermined end signal is input, and while the switching control signal is being input, within its own station output from the transmitting and receiving device. If the video signal generated video signal and audio signal received via the terrestrial network to together and outputs to the terrestrial communications network and the audio signal output to the local station the switching control signal is not the the video and audio switching device common information is output as video and audio signals, turtle to be output to the transceiver generates a video signal of the local station to the satellite receiver output When is configured to include a microphone to be output to the transceiver generates a sound signal of the local station.

[0023]

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 shows a video / audio system for a multipoint video / audio communication system using satellite communication and terrestrial communication according to the present invention.
1 is a block diagram illustrating a configuration of a multipoint video / audio communication device to which an audio delay compensation method is applied.

As shown in FIG. 1, the multipoint video / audio communication apparatus according to the present embodiment comprises a center station 1, a communication satellite 10 for relaying a radio signal transmitted from the center station 1, and a plurality of remote stations 16. And 25.

The center station 1 and the remote station 16
And 25 are also connected by a terrestrial communication network 11.

In the configuration shown in FIG. 1, there are only two remote stations, 16 and 25. However, any number of remote stations having the same configuration as the above-mentioned remote stations can be provided.

The center station 1 receives common information including center station information including video and audio generated in the center station 1, converts the common information into a predetermined radio signal, and transmits the radio signal to the communication satellite 10. A communication device 9, a camera 3 for generating and outputting the video signal of the lecturer 2, a microphone 4 for outputting the voice of the lecturer 2 as an audio signal, and the above-described video signal and audio signal generated by the own station as center station information. receive Rutotomoni, and a question reception signals defined and questions permission signal is input and outputs to the terrestrial communications network 11 described above, the query request signal is sent through the ground communication network 11 itself When output to the station and receiving a predetermined question permission signal from within the station,
Question and output to ground communication network 11 is permitted destined remote station, the identification information sent from a remote station to be described later and a wired communication device 7 for input to the local station.

The center station 1 synthesizes the center station information described above and specific information described later sent from a remote station, and outputs a video / audio synthesizing device 8 to the satellite communication device 9 described above. When receiving a predetermined input instructing designation, it sends the above-mentioned question reception signal to the above-mentioned wired communication device 7, and further, when receiving a question request signal from the above-mentioned wire communication device 7, performs a predetermined reception process, Is performed, and when the designation of a predetermined question permission is input in the own station, a predetermined question permission signal addressed to the specified remote station is generated, and the above-described wired communication device 7 is used.
An answer control device 36 for outputting the answer is provided.

Further, the center station 1 includes a video monitor 5 for displaying a video of specific information sent from the remote station that has permitted the inquiry, and a speaker 6 for outputting audio of the specific information. Have.

The remote station 16 shown in FIG. 1 receives a radio signal transmitted via the communication satellite 10, converts it into the above-mentioned common information and outputs the same, and a video of the speaker 24. 21 for generating a video signal and outputting it as a video signal
And a microphone 22 for outputting a speech of the speaker 24 as an audio signal, a video monitor 19 for displaying a video signal as an image, and a speaker 20 for outputting an audio signal.

The remote station 16 is connected to the terrestrial communication network 11 described above.
When the center station 1 receives the center station information, the question acceptance signal and the question permission signal transmitted from the center station 1 via its own terminal and outputs it to its own station, and receives the question request signal from its own station, the center station 1 1, a transmission / reception device 23 which receives a video signal output from the camera 21 and an audio signal output from the microphone 22 and outputs the received information as specific information to its own station and to the above-mentioned terrestrial communication network 11.

Further, upon receiving the question acceptance signal from the transmission / reception device 23, the remote station 16 performs a predetermined display indicating that the question request can be made, and a specific designation for requesting the question is made within the station itself. When it is input, it generates a predetermined question request signal and outputs it to the transmitting / receiving device 23, and the transmitting / receiving
3 receives a question permission signal from the terminal 3, outputs a switching control signal, and receives a question control device 34 which cuts off the switching control signal when a predetermined designation to end the question is input from the own station, and a switching control signal. During this time, the video signal in the center station information output from the transmitting / receiving device 23 is output to the video monitor 19,
The audio signal in the center station information is output to the speaker 20 respectively, and when there is no switching control signal, the satellite receiver 1
7 outputs a video signal among the common signals output from the video monitor 19.
The audio signal of the common signal is transmitted to the speaker 20.
And a video / audio switching device 18 for outputting to

The remote station 25 shown in FIG.
Is the same as the configuration of the remote station 16.

That is, the satellite receiving device 26 has the same configuration as the satellite receiving device 17, the video monitor 28 has the same configuration as the video monitor 19, the speaker 29 has the same configuration as the speaker 20, and the video / audio switching device 27 has the same configuration as 18. Configuration.

Similarly, the transmitting / receiving device 32 is
, The camera 30 has the same configuration as 21, the microphone 31 has the same configuration as 22, and the interrogation control device 35 has the same configuration as the interrogation control device 34.

FIG. 3 is a flowchart showing the operation of one embodiment of the delay compensation method of the multipoint video / audio communication system using the satellite communication and the terrestrial communication according to the present invention.

The operation of the delay compensation method for the multipoint video / audio communication system using the satellite communication and the terrestrial communication shown in FIG. 1 will be described below with reference to the flowchart of FIG.

The video signal and the audio signal of the lecturer 2 are generated by the camera 3 and the microphone 4, respectively, and added to the video / audio synthesizing device 8 as center station information.

At the same time, the center station signal is also applied to the wired communication device 7.

The video / audio synthesizing device 8 outputs the center station information to the satellite communication device 9.

The satellite communication device 9 converts the input center station information into a predetermined radio signal and sends it to the communication satellite 10.

At this time, the remote stations 16 and 25 receive radio signals relayed by the communication satellite 10 by the satellite receivers 17 and 26, respectively.

In the remote stations 16 and 25, the received radio signals are converted into center station information composed of video signals and audio signals, and instructed by the video monitors 19 and 28 via the video / audio switching devices 18 and 27. 2 are displayed, and the voice of the instructor 2 is output from the speakers 20 and 29, respectively.

In the remote station 16, the video of the participant 24 is converted by the camera 21 into a video signal as a video signal.
3 is output to the microphone 22
, And is output to the transmitting / receiving device 23.

Similarly, in the remote station 25, the participants 33
The video signal about
Is output to the transmitting / receiving device 32 by the microphone 31.

Here, when the lecturer 2 inputs a predetermined question acceptance specification to the answer control device 36 (step S1), the answer control device 36 identifies this specification and
A predetermined question reception signal is output to the wired communication device 7.

Upon receiving the question acceptance signal, the wired communication device 7 receives all the target remote stations (in the case of FIG. 1,
A question acceptance signal is transmitted to the remote stations 16 and 25) via the terrestrial communication network 11 (step S2).

Each of the remote stations 16 and 25 receives a question acceptance signal via the transmission / reception devices 23 and 32, respectively.
A question acceptance signal is output to question controllers 34 and 35, respectively.

When the question control devices 34 and 35 receive the question acceptance signal, each of the stations performs a predetermined display indicating that a question is possible (step S3).

The question control unit 34 monitors that a predetermined question request specification is input in the own station, and waits for the question request specification to be input by the participant 24 or 33.

When the question request specified by the participant 24 is input to the question control device 34, the question control device 34 detects this (step S4) and transmits a predetermined question request signal to the transmission / reception device 23. Output to

When receiving the inquiry request signal, the transmission / reception device 23 sends the inquiry request signal to the center station 1 via the terrestrial communication network 11 (step S5).

When receiving the inquiry request signal via the terrestrial communication network 11, the wired communication device 7 outputs the received inquiry request signal to the answer control device 36.

Upon receiving the question request signal, the answer control device 36 displays a predetermined request source indicating which remote station has made the question request (step S6).

The instructor 2 selects one of the remote stations requesting the question and inputs a predetermined question permission designation to the answer control device 36, and the answer control device 36 identifies this. (Step S7), and outputs a predetermined question permission signal addressed to the selected and designated remote station (here, the remote station 16) to the wired communication device 7.

When the wire communication device 7 receives the question permission signal from the answer control device 36,
The data is transmitted to the selected remote station (step S8).

At this time, the wired communication device 7 sends the center station information via the terrestrial communication network 11 to the remote station to which the inquiry has been permitted (step S9).

The interrogation control device 34 of the remote station (remote station 16) to which the inquiry permission has been given is transmitted to the transmission / reception device 23.
Via receives this inquiry permission signal, identifies (step S10), and outputs a predetermined switching control signal to the video and audio switching device 18 (step S11).

When the transmitting / receiving device 23 receives center station information from the center station 1 via the terrestrial communication network 11, the transmitting / receiving device 23 outputs the center station information to the video / audio switching device 18.

While receiving the switching control signal, the video / audio switching device 18 outputs the video signal of the center station information output from the transmitting / receiving device 23 to the video monitor 19, and outputs the center station information. The audio signal inside the speaker 20
Output to

That is, the center station information is transmitted to the video monitor 19.
Is displayed and output by the speaker 20 (step S12).

Further, upon receiving the question permission signal, the transmission / reception device 23 transmits the video signal output from the camera 21 and the audio signal output from the microphone 22 to the center station 1 via the terrestrial communication network 11 as specific information. (Step S1
3).

Upon receiving this specific information, the wired communication device 7 outputs the received specific information to the video / audio synthesizing device 8.

The video / audio synthesizing device 8 synthesizes the center station information and the specific information in a predetermined format, outputs the information to the satellite communication device 9 as common information, and converts the information into a radio signal by the satellite communication device 9 for communication. The data is transmitted to the satellite 10 (step S14).

The remote station (in this case, the remote station 25) which is not subject to question permission receives the radio signal transmitted from the communication satellite 10 by the satellite receiver 26, converts the radio signal into common information, and converts the radio signal into video / video data. Output to the audio switching device 27.

When the switching control signal is not received, the video / audio switching device 27 outputs the video signal of the common information to the video monitor 28 and outputs the audio signal of the common information to the speaker 29. That is, in the remote stations that are not subject to question permission, the common information is displayed and output (step S15).

At this time, also in the remote station 16, the common information is output from the satellite receiver 17, but the video / audio switching device 18 sends the video monitor 19 and the speaker 20.
Is not output to

When the participant 24 of the remote station to which the question is permitted by the question permission signal inputs a predetermined question end designation indicating the end of the question to the question control device 34 (step S16), the question control device 34 Turns off the output of the switching control signal (step S17).

At this time, the question control device 34 outputs a predetermined question end signal to the transmitting / receiving device 23,
Is transmitted to the center station via the ground communication network 11 (step S18).

When receiving the inquiry end signal, the wired communication device 7 ends the output of the center station information output to the remote station 16 via the terrestrial communication network (step S1).
9).

When receiving the inquiry end signal, the transmission / reception device 23 ends transmission of the specific information.

Accordingly, the output of the specific information from the wired communication device 7 to the video / audio synthesizing device 8 is also terminated, and only the center station information is output from the video / audio synthesizing device 8 to the satellite communication device 9 as a common signal. (Step S20).

The video signal of only the center station information is output to the video monitor 19 of the remote station 16, and the audio signal of only the center station information is output to the speaker 20 (step S21). .

The above is a description of the multi-point communication using the satellite communication and the terrestrial communication from the transmission of the inquiry reception signal from the center station 1 to the completion of the inquiry by the remote station authorized for the inquiry transmitting the inquiry end signal. 5 is an operation description of a video / audio delay compensation method for an inter-video / audio communication system.

In the above description, the operation when the inquiry to the remote station 16 is permitted has been described.

If the object of question permission is the remote station 25, the question control device 35 receives the question permission signal via the transmission / reception device 32, detects this signal, and
A switching control signal is output to the audio switching device 27. Subsequent processes are the same as those of the remote station 16 in the components of the remote station 25 shown in FIG. I do.

As can be seen from the above description, the remote station permitted to make a question and making a comment outputs center station information from a video monitor and a speaker via a terrestrial communication network. Table of self-operation with time delay on the video monitor , such as when receiving via
Self-time delay from the speaker without watching
Without hearing the comments of the
You can speak while checking the response of the other party.

In the above description of the embodiment, the number of remote stations is two, but it is clear that similar communication can be performed using an arbitrary number of remote stations.

[0080]

As described above, the video / audio delay compensation method and apparatus for the multipoint video / audio communication system using the satellite communication and the terrestrial communication according to the present invention are provided via the terrestrial communication network. In order to communicate control signals such as requesting questions and permitting, a wired communication device is installed in the center station,
By providing a transceiver to the remote station, the control
Using the control signal , it is possible to promptly perform a series of processes such as requesting, accepting, and permitting a question between the center station and the remote station.

Further, a video / audio switching device is provided in the remote station, and the center station information is transmitted from the center station to the corresponding remote station via the terrestrial communication network from the center station with respect to the remote station making a speech. To the station's transceiver,
Since the center station information is output by the video monitor and speaker in the remote station that is speaking, the video / audio switching device in the remote station that is speaking makes the speaker delay.
See and hear your own video and audio, which you cannot ignore
Without reacting and watching the other party's video and audio
Remote station speaker who can speak naturally without feeling uncomfortable
This has the effect of improving the remark environment.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a multipoint video / audio communication apparatus to which a video / audio delay compensation method is applied to a multipoint video / audio communication system using satellite communication and terrestrial communication according to the present invention. is there.

FIG. 2 is a flowchart illustrating an example of an operation of a video / audio delay compensation method in a multipoint video / audio system using satellite communication and terrestrial communication according to the present embodiment.

FIG. 3 is a configuration diagram showing an example of a conventional multipoint video / audio communication system using this type of satellite communication and terrestrial communication.

[Explanation of symbols]

 Reference Signs List 1 center station 2 lecturer 3 camera 4 microphone 5 video monitor 6 speaker 7 wired communication device 8 video / sound synthesis device 9 satellite communication device 10 communication satellite 11 terrestrial communication network 16 remote station 17 satellite receiving device 18 video / voice switching device 19 video Monitor 20 Speaker 21 Camera 22 Microphone 23 Transceiver 24 Participant 25 Remote station 26 Satellite receiver 27 Video / audio switching device 28 Video monitor 29 Speaker 30 Camera 31 Microphone 32 Transceiver 34-35 Question control device 36 Answer control device

Continuation of the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) H04M 3/56 H04M 3/00 H04N 7/15

Claims (2)

(57) [Claims] 1. A communication satellite for relaying communication, and a center for transmitting common information to a plurality of remote stations via the communication satellite and communicating specific information with the remote station via a terrestrial communication network. And a plurality of remote stations that receive common information from the center station via the communication satellite and communicate with the center station via the terrestrial communication network for the specific information. The station transmits center station information composed of video and audio to the remote station via the communication satellite, and transmits a predetermined inquiry reception signal to the center station information to all the remote stations in the ground communication. Transmitting via a network, enabling reception of an inquiry from the remote station via the terrestrial communication network, and a predetermined inquiry request signal from the remote station via the terrestrial communication network. When transmitted to the center station, the center station receives the interrogation request signal, selects any one of the remote stations that have received the interrogation request signal,
A predetermined inquiry permission signal is transmitted to the selected remote station via the terrestrial communication network, and the center station information is transmitted via the terrestrial communication network to the remote station which transmitted the inquiry permission signal. The remote station receiving the inquiry permission signal switches the common information received via the communication satellite to the center station information transmitted via the terrestrial communication network, and receives the common information. Transmitting the specific information consisting of video and audio about the question from the remote station to the center station via a network, the center station receiving the specific information transmitted from the remote station, The information is synthesized with the center station information and transmitted as common information to the remote station via the communication satellite. The center station transmits a query end signal to the center station via the terrestrial communication network, ends transmission of the specific information, ends output from the center station via the terrestrial communication network, and ends the question. The remote station receives and displays common information sent via the communication satellite instead of the center station information sent via the terrestrial communication network, and displays the satellite communication and the terrestrial communication. A video / audio delay compensation method for a multipoint video / audio communication system used. 2. A communication satellite for relaying communication, multipoint video / audio communication using terrestrial communication and satellite communication for communicating between a center station and one or more remote stations using the communication satellite. In the video / audio delay compensating device for the system, the center station includes a camera that generates a video in the local station, a microphone that generates a voice in the local station, and the video and the voice generated in the local station. video and for outputting the center station information composed and the specific information as synthesized common information
A voice synthesizing device, a satellite communication device that converts the common information into a radio signal and sends it to the communication satellite, and generates and outputs a predetermined question reception signal when receiving a predetermined question reception instruction, and outputs a predetermined question request signal. Upon receiving the signal, a predetermined reception display indicating that this signal has been received is displayed, and upon receiving a predetermined selection designation in the own station, a predetermined question permission signal is generated and output to the remote station which transmitted the received question request signal. controller and the question reception signal the inquiry permission signal output to the answer control unit and received through the terrestrial network and sent over the terrestrial network the query request signal received from the reply controller the received from the reply control unit and transmitting the inquiry permission signal and the center station information to the remote station that sent the query request signal through the ground communication network The specific information via the terrestrial network
And a wired communication device for outputting the center station information to the terrestrial communication network when receiving a predetermined query completion signal when receiving the information, and for receiving the predetermined inquiry end signal, A satellite receiving device that receives the wireless signal via a satellite, converts the received signal into the common information, and outputs the received signal; and receives the inquiry reception signal, the inquiry permission signal, the video signal, and the audio signal via the terrestrial communication network. When receiving the interrogation request signal in the station and receiving the interrogation request signal in the own station, the interrogation permission signal is output when the interrogation request signal is output through the terrestrial communication network and the video signal and the audio signal generated in the own station are received.
Of the question completion signal sent to the terrestrial communications network as the specific information when it is received into said terrestrial communications network of the specific information that has been transmitted to it and sent via the terrestrial network to receive from the local station A transmission / reception device that terminates transmission, displays a questionable display when the question reception signal is received from the transmission / reception device, and generates a question request signal when a predetermined question request designation is received, and outputs the generated question request signal to the transmission / reception device to output the question permission signal. A question control device that outputs a switching control signal when receiving from the transmission / reception device and shuts off the output of the switching control signal when a predetermined end signal is input, while the switching control signal is being input, wherein the video signal and audio signal generated by the local station which is output from the transceiver received via the terrestrial network to together and outputs to the terrestrial communications network A video / audio switching device that outputs an image signal and an audio signal to its own station and outputs the common information output by the satellite receiving device as a video signal and an audio signal when there is no switching control signal; a camera for outputting signals to the generated the transceiver device, microphone and it multipoint video and using satellite communications and ground communications, characterized in comprising a which generates audio signals of the local station and outputs to the transceiver Video / audio delay compensation device for audio communication system.