JPH01198858A - Conference telephone system - Google Patents

Abstract

PURPOSE:To attain a conference telephone service without being limited by the number of the terminals of a conference trunk by allocating one terminal of the conference trunks to a channel for the multidrop of a ring type transmission path. CONSTITUTION:When a conference participation request signal is sent out in order that a terminal TEL 2 may participate in a conference with a bidirectional call, a connection device 3 for a conference audience and speaker detects it and disconnects a connection indicated by a dotted line which is a multidrop connection with the terminal TEL 2. The terminal TEL 2 and the terminal T3 of the conference trunk 2 are bidirectionally connected as shown by a dotted line B through the ring type transmission path, a connection between a calling terminal TEL 1 and the terminal T1 of a trunk 2 for a conference is also made into the bidirectional connection and the bidirectional call between the calling terminal TEL 1 and the TEL 2 can be attained. Conference telephone listening and speaking participants from the terminal TEL 3 to the TEL n remain in the condition of conference listening and speaking. Thus, when there are five terminals of a trunk for a conference, a four persons conference and the conference telephone service by (n-4) persons conference listening and speaking can be realized.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a conference telephone system, and more particularly to a conference telephone system that uses a ring-type LAN and provides a dedicated listening line and allows a large number of participants.

[Conventional technology]

Regarding the operating procedure of the conventional conference telephone system, the terminal of the conference trunk in the block diagram of the conventional conference telephone system shown in Figure 4 is 5.
This will be explained with reference to the case of a terminal.

The calling end device L connects the terminal T4 of the conference trunk T by making a call.
, and then sequentially connect up to five conference call participants to the conference trunk T.

With the completion of this connection, the total number of callers and conference call participants is 2. Place 3. Place 4. Simultaneous calls from 5 stations were possible.

[Problem that the invention seeks to solve]

In the conventional conference phone system described above, one terminal of the conference trunk is required for each conference call participant, so the number of conference call participants is limited to the number of terminals provided on the conference trunk. In other words, if the number of conference call participants increases, the number of terminals provided on the conference trunk must correspond to the number of conference call participants, and in that case, the technical problem of simultaneous calls for a large number of people must also be dealt with separately. There are drawbacks that require consideration.

SUMMARY OF THE INVENTION An object of the present invention is to provide a conference telephone system that allows a larger number of participants to participate while keeping the number of simultaneous call terminals on the conference telephone trunk within the range possible using conventional technology.

[Means for solving problems]

The conference telephone system of the present invention is a conference telephone system using a ring type LAN in which a plurality of conference participants talk at the same time. A conference trunk having a terminal and N terminals connected to N channels (N is a natural number of 2 or more) used as a two-way communication line, and connected to the channel used as the listening line and connected to the same channel. The conference phone detects a conference entry request signal issued by a participant listening to the conference call and issues the conference entry request signal to one of the vacant channels among the N channels used as the two-way communication line. It is configured to include a connection device for conference listening sound that has a function of switching the connection of listening participants.

〔Example〕

Next, the present invention will be described with reference to the drawings, taking as an example a case where the conference trunk circuit has five lines.

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

The transmission line 1 has terminals Tl, T2°T3 . of the conference trunk 2.
T4. The five terminals of T5, the connection device 3 for conference listening sound, the calling terminal which is the host of the conference, and the plurality of end devices which are conference participants are connected at 2 degrees and 3. -=-, position n-1, and position n are connected. The broken line in Figure 1 indicates the calling terminal 'FEL1
calls a conference, and all other terminals in the conference group have multi-drop connections to terminal T2 of the same conference trunk 2. 0 Calling end device L uses a ring-type transmission line. It is connected to the terminal T1 of the conference trunk 2 via the dashed line 5. From end device 2 to n,
The voice of the calling end device L, which is under the control of the conference listening audio connection device 3 and is connected to one direction of the same channel of the ring type transmission line as shown by the broken line 6, and is transmitted from the terminal T2 of the conference trunk 2. can listen and speak.

Next, the case where the end device 2 participates in the conference through two-way communication is explained in the second example.
This will be explained with reference to the figures. From the listening state in Figure 1, the end device 2
In order to participate in a conference through two-way communication, a conference entry request signal such as hooking is sent out. Then, the conference entry request signal is detected from the conference listening audio connection device 3, and the multi-drop connection with the end device 2, as shown by the broken line 7, is disconnected, as shown by the broken line 7 in FIG. 2, and the terminal TE-L 2 and the terminal T3 of the conference trunk 2 are bidirectionally connected as shown by the broken line 8 via a ring type transmission line, and the calling end device I and the terminal T1 of the conference trunk 2 are also bidirectionally connected. Then, two-way communication between the calling end device L and the end device 2 becomes possible. The conference call listening participants from end device 3 to end device n remain in the conference listening state. This conference entry request will be accepted as long as the terminals of the conference trunk 2 are free. In this embodiment, the conference trunk has 5 terminals, so
A conference telephone service can be realized using a 4-party conference and a conference listening session for n-4 parties. When the end device 2 makes a connection change request again such as hooking, the conference listening party connecting device 3 detects the connection again and switches the conference trunk 2. A multi-drop connection is made to the channel exiting from terminal T2, and terminal T3 of conference trunk 2 becomes empty. As described above, by assigning one terminal of the conference trunk 2 to the multi-drop channel of the ring-type transmission line, a conference call can be held without being limited by the number of terminals of the conference trunk 2, and the conference can be held in both directions. Only when it is necessary to participate, two-way communication becomes possible by connecting to the empty terminal of the conference trunk 2 via the ring type 4 transmission line.

〔Effect of the invention〕

As explained above, one terminal of a conference trunk is connected to a multidrop channel of a ring transmission line, and multiple terminals called for a conference call are connected to that multidrop channel to participate in a two-way call. By connecting to empty terminals of the conference trunk only in the case of a conference call, there is an effect that a conference telephone service can be realized without being limited by the number of terminals of the conference trunk.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an embodiment of the present invention, FIG. 2 is an explanatory diagram when a terminal participates in a two-way call, and FIG. 3 is a block diagram of a conventional conference telephone system. 1... Transmission line, 2... Trunk for conference, 3... Connection device for conference listeners, 5, 6.7.
8...Dashed lines indicating connections, Tl, T2. T3. T
4. T5...Conference trunk terminal, position I...
...Calling terminal, position 2. Place 3. Place n-1, Place n.-...Terminal. Agent Patent Attorney Uchi Hara Oki n Oki n-+ Oki 3 Oki 2 1st picture n Oki 7L-I Oki 3 Oki 2 Fig. 2

Claims (1)

[Claims] In a conference telephone system using a ring-type LAN where multiple conference participants talk simultaneously, one terminal connects to one channel in the transmission line used as a dedicated listening line and is used as a two-way communication line. a conference trunk having N terminals connected to N channels (N is a natural number of 2 or more), and a conference telephone listening participant connected to the channel used as the listening dedicated line and connected to the same channel. A function of detecting a conference entry request signal issued by a conference call and switching the connection of the conference call listening participant who issued the conference entry request signal to one of the vacant channels among the N channels used as the two-way communication line. and a connection device for conference listeners having a conference call system.