JPH02271770A - Three party talking system - Google Patents

Abstract

PURPOSE:To relieve the economical load by providing a switch changing over either of two voice channels or the both uniformly to an ISDN terminal equip ment. CONSTITUTION:Voice signals A,C inputted from a transmitter 9 of subscribers A,C reach an ISDN terminal equipment 2. The signals A,c are separated by an SEP 7, the signal A is outputted to a PADa and the signal C is outputted to a PADb. when the subscriber B does not operate an SW 8, since the signals A,C reaches a receiver 10 via the PADa, PADb, the attenuated signals A,C are heard with equal sound volume, when the subscriber B throws the SW 8 to the position (a), since the signal A is inputted directly to the receiver 10 while not being attenuated by the PADa, the signal A is heard clearly. Thus, it is possible to receive the voice signal level without attenuating it and the economical load on the side of the ISDN terminal equipment is relieved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a three-way call system, and particularly relates to a three-way call system between ISDN terminals.

[Conventional technology]

Conventional three-way communication systems use analog transmission paths to connect subscriber terminals and exchanges, so the level of input signals is controlled to be within a certain range due to constraints on signal transmission. For this reason, when audio signals from three sources are sent to the same transmission path, the level of the composite signal obtained by combining these audio signals is also controlled to fall within the above-mentioned certain range.

[Problem to be solved by the invention]

In the conventional three-party communication system described above, the level of the composite signal that synthesizes the audio signals output from the three parties is controlled to stay within a certain range, so when simply combining two signals, it is necessary to The problem is that the level of the signals must be lower than usual, and the volume of each signal is lowered to reach the receiver. In addition, some devices use an audio switch, etc. to control the transmission of the audio signal of only the speaker at the maximum audio level, but in this case, an audio switch and control device must be installed for each subscriber terminal. However, there is a problem in that the economic burden increases.

The purpose of the present invention is to use two voice channels, which are the basic functions of an ISDN terminal, and to connect the ISDN terminal primarily to one of the two voice channels operated by the subscriber or to connect equally to both. By providing a selector switch that has the function of selecting and connecting ISD, it is possible to receive the audio signal at a high level, and
The purpose of the present invention is to provide a three-way communication system that reduces the economic burden on the N terminal side.

[Means to solve the problem]

The three-way call system of the present invention is a basic access ISD consisting of two voice channels and one data channel.
I SDN that connects based on the N user interface
In the three-way communication system of the terminal, the ISDN terminal is provided with a changeover switch that has the function of selecting whether to connect primarily to one of the two voice channels operated by the subscriber or to connect equally to both. This is the configuration in which it is provided.

〔Example〕

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

FIG. 1 is a block diagram of one embodiment of the present invention.

Three ISDN terminals 1, 2.3 are connected to subscriber A, respectively.
, B, and C are used.

The I SDN terminals 1, 2.3 are connected to the network of the I SDN exchange 4 (hereinafter N
(denoted as W) 5. A three-way telephone trunk (hereinafter referred to as TWT) 6 is accommodated in the NW5. IS
Each of the DN terminals 1 and 2.3 includes a signal separator (hereinafter referred to as SPE) 7 that separates the two received voice channels.
and subscriber A.

A changeover switch (hereinafter referred to as SW) 8 for selectively connecting the output of 5PE7, and attenuators (hereinafter referred to as PAD) a and b for attenuating the audio signal when SW8 is not operated; A transmitter 9 and a receiver 10 are provided.

Next, the operation will be explained.

Assume that subscriber A desires to make a three-way call and calls the ISDN exchange 4, and dials the three-way call service request special number and the subscriber numbers of subscribers B and C.

I SDN exchange 4 receives the call from subscriber A, and
TWT between SDN terminals 1, 2.3 via NW5
Connect with 6. At this time, the I SDN exchange 4
The two audio signals arriving at the SDN terminal are controlled to use different audio channels.

The operation when performing a three-way call in this state will be described.

Since the three ISDN terminals 1, 2, and 3 have equal functions, only the ISDN terminal 2 will be described.

Audio signals A and C input from the transmitters 9 of subscribers A and C arrive at the 15DN terminal 2 . Audio signals A and C are
5EP7, audio signal A is output to the PADa side, and audio signal C is output to the PADb side. If subscriber B does not operate SW8, the voice signals A and C reach the handset 10 via PADa and PADb, respectively, so that the subscriber B hears the attenuated voice signals A and C at the same volume. Here, subscriber B sends SW8 to a
When tilted to the side, the audio signal A is directly input to the handset 10 without being attenuated by PADa, so the audio signal A can be heard clearly.

Furthermore, with this circuit configuration, even when subscribers A and B are talking to each other and subscriber C is listening, the audio signal C is not cut off, and some audio is transmitted to subscriber A and subscriber C.
Since subscriber C has already reached subscriber B, if subscriber C expresses some kind of intention, it is easy to convey it to subscribers A and B.

〔Effect of the invention〕

As explained above, the present invention uses two voice channels, which are the basic functions of an rSDN terminal, and connects an ISDN terminal to either one of the two voice channels operated by the subscriber or both. By providing a changeover switch that has the function of selecting whether to connect the ISDN terminals equally and connecting them, it is possible to receive the audio signal at a high level, and there is an effect that the economic burden on the ISDN terminal side can be reduced.

[Brief explanation of drawings]

FIG. 1 is a block diagram of one embodiment of the present invention. 1.2.3...I SDN terminal, 4...
-I SDN exchange, 5...-...Network (N
W), 6...Three-way call trunk (TWT)
, 7... Signal separator (SPE), 8...
・Selector switch (SW), 9...Transmitter, 10
...Handset, A, B, C...Subscriber,
a, b...Attenuator (PAD). Agent Patent Attorney Oto Uchihara

Claims (1)

[Claims] In a three-way call system for ISDN terminals that connect based on a basic access ISDN user interface consisting of two voice channels and one data channel,
A three-way call characterized in that the ISDN terminal is provided with a changeover switch that has a function of selecting whether to connect primarily to one of the two voice channels operated by the subscriber or to connect equally to both. method.