JPS5925505B2 - Conference call method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a conference call system, and more particularly to a conference call system for conducting a call between three or more parties, for example, in a telephone switching network.

Figure 1 shows an exchange capable of conference calls, which is the background of this invention.
It is a block diagram showing an example.

FIG. 2 is a block diagram of an audio mixing device 5 used for a conventional conference call system. The configuration will be explained with reference to FIGS. 1 and 2. 1 is an exchange; 2 is a switch circuit network for connecting telephones, trunk lines, and various devices housed in the exchange 1 in any combination; 3; 4 is a trunk for accommodating a trunk line, 4 is a telephone set, 5 is an audio mixing device for mixing and distributing audio signals, 6 is an audio mixing circuit that constitutes the audio mixing device 5, and T is a switch circuit for the audio mixing device. A two-wire line terminal connected via the network 2, 8 a 2-wire/4-wire conversion circuit for performing 2-wire to 4-wire conversion, and 9 connected to the audio mixing device 5 via the switch circuit network 2. 10 is a 4-wire input terminal of a 4-wire line, and 10 is a 4-wire output terminal of an S-wire line. FIG. 3 is an illustrative diagram of an exchange network constituted by a plurality of exchanges, and particularly shows the case of four exchanges. As an example of an exchange network, if four exchanges 1, A, B, C, and D (hereinafter each exchange is referred to as IA, IB, IC, and ID) are installed, the
A trunk line 11 is installed between C and IB and ID. Fourth
This figure is a connection diagram for making a conference call in the exchange network shown in FIG. 3.

In the illustration, a-i is added after 4 to identify the telephone 4 accommodated in each exchange 4A-ID.
Next, the operation of a conventional conference call will be described with reference to FIGS. 1 to 4. For example, if telephone 4a requests telephone exchange IA to make a conference call using telephones 4a, 4b34c, 4d, 4e, 4f, 4g, 4i, and 4i, exchange IA will call the telephones participating in the conference housed within its own office. 4a, 4b, and conference participating telephones 4c, 4d34e, 4f, accommodated in other exchanges.
4g, 4re, 4i selection request to exchange IB, IC, ID
give to Accordingly, after each exchange selects conference participating telephones within its own office, the conference participating telephones 4a and 4b housed in exchange IA are connected to the audio mixer 5 of exchange IA.
conference participating telephones 4c, 4d, 4e, 4f, 4g, 4re 34, which are directly connected to the
i is individually connected to the audio mixing device 5 of the exchange IA via trunk lines 11. The voice mixing device 5 of the exchange IA is connected to conference participating telephones 4a, 4b, 4c, 4d, 4e, 4f, 4.
Mix the audio signals from g, 4re, and 4i and send this to each telephone conversation. Through such operations, a conference call is performed. However, since the conventional conference call system is configured to mix the audio signals of all the conference participating telephones 4a to 41 by the audio mixing device 5 belonging to one exchange 1A, exchanges other than this exchange The conference participating telephones 4c to 41 accommodated in 1B to 1D must be individually connected to the audio mixing device 5 of the exchange 1A using trunk lines, and a large number of trunk lines are required for one conference call. The drawback was that the trunk line was occupied and the trunk line could not be used efficiently.

SUMMARY OF THE INVENTION An object of the present invention is to provide a conference call system that can reduce the number of trunk lines required for a conference call, and is intended to eliminate the drawbacks of the conventional conference call system described above. .

The above objects and other objects and features of the invention will become more apparent from the following detailed description with reference to the drawings.

To summarize this invention, in a conference call using telephones housed in multiple exchanges, each exchange receives voice signals that come in from the previous exchange via a trunk line and are directly accommodated in the exchange. This is a conference call system in which audio signals from telephones are mixed by an audio mixer and the mixed signals are sent to the next exchange to make a conference call.

FIG. 5 is a block diagram showing an example of the audio mixing device 5 included in each exchange for achieving the conference call system of the present invention. The audio mixing device 5, which is a feature of this embodiment, has a mixing output terminal 12 that outputs the audio signal mixed by the audio mixing circuit 6, and a mixed output terminal 12 that outputs the audio signal mixed by the audio mixing circuit 6, and the mixed output terminal 12 that outputs the audio signal mixed by the audio mixing circuit 6. The mixing input terminal 13 into which the audio signal is input, and the signals sent to the 2-wire line terminal 7 and the 4-wire output terminal 10 are output from the audio mixing circuit 6. is provided with a changeover switch 14 for selecting whether to use the mixed voice signal returned from the next exchange. Since the other configurations are the same as those in FIG. 2, the same parts are designated by the same reference numerals and the explanation thereof will be omitted. FIG. 6 is a connection diagram for making a conference call according to the present invention in the exchange network shown in FIG. 3 described above.

Next, referring to FIGS. 1, 5} and 6, the connection state between each exchange in this embodiment will be explained. The two-wire line terminal 7 or the four-wire input terminal 9 and the four-wire output terminal 10 of the audio mixer 5 of the exchange 1 (for example 1A) are connected via the switch network 2. The mixed audio signal sent from the previous exchange (for example, 1A) via the trunk line 11 is sent to the 4-wire input terminal 9 and the 4-wire output terminal via the switch circuit 2 of the next exchange (for example, 1B). Connect to 10. For example, the signal output from the mixing output terminal 12 of the audio mixing device 5 of the exchange 1B is transmitted to all telephones participating in the conference (
4a to 41), the changeover switch 14 is switched to the mixed output terminal 12 side and this signal is sent to the preceding exchange (for example, 1A) and the telephone participating in the conference in the local office. If not, it is necessary to continue mixing, so switch to the mixing input terminal 13 side and connect it to the next exchange (for example, 1C) via the switch network 2.
, 1D). Next, referring to FIG. 6, the operation along the flow of a specific audio signal will be described.

For example, telephone 4a is telephone 4b, 4c, 4d, 4e,
When a conference call using 4f, 4g, 4h, and 41 is requested to the exchange 1A, the exchange 1A selects the conference participating telephone 4b housed within its own station, and also selects the conference participating telephone 4c housed in another exchange. ,4d,4e,4
f, 4g, 4h, 41 selection requests to exchanges 1B, 1C,
Submit to 1D. Accordingly, in exchange 1C, telephones 4f and 4g
- Mix the future voice signals and send to switch 1B-1.
It is sent to the exchange 1B via one trunk line 11 between C and C. Further, the exchange 1D selects the telephones 4h and 41, mixes the voice signals from these, and sends the mixed voice signals to the exchange 1B through the single trunk line 11 between the exchanges 1B and 1D. Said exchange 1B
Select telephones 4c, 4d, and 4e to receive future voice signals and telephones 4f and 4 sent from exchange 1C.
The mixed voice signal of telephones 4c, 4d, 4e, 4f, 4g, 4h, 41 is obtained by mixing the mixed voice signal of telephones 4c, 4d, 4e, 4f, 4g, 4h, 41 sent from exchange 1D with the mixed voice signal of telephones 4h, 41 sent from exchange 1D. .

This is sent to exchange 1A via one trunk line 11 between exchanges 1A and 1B. In the exchange 1A, telephones 4a,
The voice signal from 4b and the mixed voice signals from telephones 4c, 4d, 4e, 4f, 4g, 4h, and 41 sent from exchange 1B are mixed to form a total mixed voice signal from telephones 4a to 41. This total mixed audio signal is 1A-1B above.
The signal is supplied to all telephones participating in the conference by tracing the trunk lines between 1B and 1C, and between 1B and 1D in reverse, and a conference call is thereby performed. In addition, in the above-mentioned embodiment, the exchange 1A
Although the case has been described in which the audio signals of all participants in the conference are finally mixed by the audio mixing device 5, any other exchange may be used. Also, in the above explanation, the case where the trunk line is a 4-wire type and the extension telephone is a 2-wire type or a 4-wire type is explained, but if the trunk line is a 2-wire type, the following can be done. .

Figure 7 shows the audio mixing device 5 when the relay line is a two-wire system.
FIG. In the figure, if the relay line is a two-wire type, the mixed output terminal 12 and terminal 13 shown in FIG.
The audio signal inputted to the line/four-line conversion circuit 8 and input from the mixed input/output terminal 15 is configured to be converted from two lines to four lines by the two-line/four-line conversion circuit 8 . Also, when a mixed audio signal is output, it is converted from 4-wire to 2-wire by the 2-wire/4-wire conversion circuit 8 and output from the mixed input/output terminal 15. Note that the same applies even if a relay-only exchange is provided in the exchange.

As described above, according to the present invention, the audio mixing device of each exchange mixes the mixed audio signal coming from the previous exchange via the trunk line and the audio signal from the telephone participating in the conference within the local exchange. Mixing: The output is sent to the next exchange via a single trunk line.The final exchange mixes the audio signals from all telephones participating in the conference and then sends them back, so the audio signals are monopolized by conference calls. This has the effect of reducing the number of trunk lines.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an exchange capable of making conference calls, which is the background of the present invention. FIG. 2 is a block diagram of an audio mixing device used in a conventional conference call system. FIG. 3 is an illustrative diagram of a switching network constituted by a plurality of switching equipment. FIG. 4 is a connection diagram for making a conference call in the exchange network shown in FIG. 3. FIG. 5 is a block diagram of an audio mixing device included in each exchange in an embodiment for achieving the conference call system of the present invention. FIG. 6 is a connection diagram for making a conference call according to the present invention in the exchange network shown in FIG. 3. FIG. 7 is a block diagram of another embodiment of the audio mixing device. In the figure, 1, 1A to 1D are exchanges, 2 is a switch circuit network, 3 is a trunk line track, 4, 4a to 41 are telephones, 5 is a tone mixing device, 6 is an audio mixing circuit, and 7 is a two-wire circuit. Terminal, 8 is 2-wire 4-wire conversion circuit, 9 is 4-wire input terminal, 10 is 4
line output terminal, 11 is a relay line, 12 is a mixed output terminal, 13
14 shows a mixing input terminal, 14 shows a changeover switch, and 15 shows a mixing input/output terminal.

Claims (1)

[Claims] 1. A conference call system in which a conference call is made between telephones housed in different exchanges, each of which includes an audio addition circuit for mixing audio, and mixes audio with the mixed audio from the previous exchange. The audio signals from the telephones of the own station are mixed by the audio adding circuit, the output is sent to the next exchange, and by repeating this, the audio signals from the telephones of all the conference participants can be mixed. conference call method.