JPS59152770A - Conference communication system - Google Patents

Abstract

PURPOSE:To realize the conference communication for a few participants and lots of participants by changing over the system into an optimum adding system automatically in response to the number of participants of conference and connecting route. CONSTITUTION:In starting the conference communication, the information of the like of conference participants transmitted to a time division exchange from a subscriber is transmitted to a conference communication control circuit 5 via a control information line 7 and a control information receiving circuit 8. The conference communication control circuit calculates the number of conference participants by this information and sets the selected speakers according to the specified algorithm. A sound volume detecting circuit 4 detects the communication sound volume according to the subscriber by an input highway 1 and informs it to a conference communication control circuit 5. The control circuit 5 selects the number of subscribers set by a prescribed algorithm by the larger sound volume, transmits its information to a sound synthesis control circuit 6, the sound for an optimum number of participants is mixed by a sound synthesis circuit 3 and the result is shared to each participant from the output highway 2.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a conference call system in which six or more subscribers simultaneously make calls via an exchange.

Conventional methods for implementing conference calls include simply adding the signals of the subscribers participating in the conference, and subtracting the signal component of the subscriber's own signal when receiving the call.

However, in this method, a large number of loops are formed by participants, so it is necessary to attenuate calls in order to satisfy the quasi-ringing and ringing conditions. Therefore, there is no problem in conference calls involving a relatively small number of people, but there is a drawback in that it is not possible to obtain satisfactory call quality in conference calls involving a large number of people.

In addition, as a means of realizing a multi-person conference call, there is a speaker selection method using an audio switch. This method constantly monitors the volume of conference participants, selects the speaker with the highest volume, and allows other participants to hear this audio.Since loops are restricted, conference calls with multiple participants are possible. Become. however,
This method had the drawback that noise was generated when the topic was cut off using the voice switch, and when switches were turned on and off, resulting in lower call quality than the above-mentioned method in conference calls with a small number of people.

The present invention automatically switches to the optimal addition method according to the number of conference participants and the connection route, in order to realize conference calls from small to large numbers of people with good call quality. Explain.

FIG. 1 is a block diagram of the present invention, and FIG. 2 is a circuit diagram of a speech synthesis image. In FIG. 1, reference numeral 1 denotes an input way for transmitting time-division multiplexed voice samples via a time-division switch or the like (not shown), and a conference call is performed in the voice sample voice synthesis circuit 3 corresponding to each subscriber. In order to do this, speaker selection and voice addition are performed, and the results are output to the output device 2. 4 is a volume detection circuit that detects the call volume at fixed time intervals for each subscriber using the input voice sample 1 as input, 5 is a conference call control circuit, 6 is a voice synthesis control circuit, and 7 is a The control information line 8 is a control information receiving circuit.

Before starting a conference call, when a certain subscriber sends information on conference participants to the time division exchange, the control information receiving circuit 8 connects the control information line 7 connected to the control device of the exchange to 3113, Participate in

The conference call control circuit 5 receives the time slot information of the subscriber who is currently in attendance and informs it to the conference call control circuit 5. The conference call circuit 5 calculates the number of conference participants based on this information! The number of speakers selected is set according to the participants according to a certain algorithm. Sound (D) The detection circuit 4 detects the call volume corresponding to the input highway 1 and the 17 subscribers,
The conference call control circuit 5 is notified. Based on the result from the volume detection circuit 4, the conference call control circuit 5 selects the number of subscribers with the highest call volume based on the number of speakers selected according to the number of participants in the conference. Thereafter, the voice synthesis control circuit 6 issues an ACT signal to the time slots corresponding to those selected subscribers. The voice synthesis circuit 3 adds only the voice signals of the subscriber with the ACT signal of the voice synthesis control circuit 6, outputs it to the output highway 2, and distributes it to each participant via the exchange. In this way, a conference call can be realized in which the number of participants is changed depending on the number of participants.

FIG. 2 shows a specific circuit of the speech synthesis circuit 3 shown in FIG.
In the figure, 9 is an adder, 10.11 is a memory that holds the addition result, 12.13 is a selector that selects one of the memories 10.11, 14 is a selector that selects whether or not to add, and 15 is a memory that holds the addition result. This circuit subtracts the audio of , and controls the level of the addition result.

The time division multiplexed signal from input highway 1 circulates through a loop of adder 9 and memory 10.11. At this time, the selector 14 selects A from the information from the speech synthesis control circuit 6.
Time slot with CT signal ← L1 Memo IJ 10
．． 11, and 0" is selected for other time slots. As a result, the output from LC of the speech synthesis circuit 6 is selected.
It is possible to select and add as many speakers as there are time slots with T signals.

The reason there are two sides of memory 10.11 is to prevent the timing of reading and writing from colliding.Selector 12
Execute the switch with . The selector 13 reads out the result when all audio additions are completed at the end of one frame.

The subtractor 15 subtracts the voice signal of the subscriber selected as a speaker from the time slot coming to him to eliminate his own voice in order to prevent his own voice from returning to him. . Also, depending on the number of people added, the necessary attenuation amount is given to satisfy the ringing and quasi-ringing conditions. Similar effects can be obtained by controlling external readout of the memories 1o and 11 instead of the selector 140 in FIG.

Further, in FIG. 1, connection route information of subscribers participating in the conference is received through the control information line 7 and the control information receiving circuit 8, and the conference call control circuit 5 selects the number of speakers according to this information. You can also set The following operations are similar to those described above.

As described above, according to the present invention, the number of people whose voices are added can be varied depending on the situation of the conference call, so conference calls from a small number of people to a large number of people can be realized with good call quality.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of a conference call system according to the present invention, and FIG. 2 is a diagram showing an example of the speech synthesis circuit shown in FIG. 1. 1... Input highway 2... Output highway 3... Speech synthesis circuit 4... Volume detection circuit 5
...Conference call control circuit 6..Speech synthesis control circuit 7..Control information line 8..Control information receiving circuit 9..Adder 10.11..Memory 12
．． 15.14...Selector 15...Subtractor agent block ``Akio Takahashi + 1 Figure

Claims (2)

[Claims] (1) In a conference call in which two or more subscribers are talking at the same time, a means is provided to constantly monitor the conference call status and detect the call volume in response to the subscribers at regular intervals, and the subscriber participating in the conference The number of subscribers to be added is determined using a certain algorithm based on the information on the number of participants, and the determined number of subscribers is selected in order from the subscriber with the highest volume at a certain time interval, and their voices are added up and the conference is started. A conference call method characterized by making calls. (2) In the conference call method described in (1) above, information on the connection route types of subscribers participating in the conference is received as control information from the exchange, and the number of people to be added is determined based on that information. A conference call system according to item (1) of the scope of the patent application, characterized in that: