JPH06177986A - External line incoming call interrupt method for conference trunk of automatic exchange and its interruption device - Google Patents

Abstract

PURPOSE:To stop a busy tone of an extension terminal side caused when an external line incoming call is finished early by interrupting a communication path from the external line incoming call with an operation signal from the extension terminal equipment in response to listening to the busy tone. CONSTITUTION:When a terminal equipment C terminates its call during the conference speech state, a busy tone is heard during the talking state between terminal equipments A and B. In this case, when a control signal is generated from the terminal equipment A or B, a speech path (d) of a trunk line from the terminal equipment C hearing the busy tone is interrupted and a speech path only between the terminal equipments A and B is set by speech paths a and b via a mixing circuit MIX in a conference trunk CNF or a usual extension speech path (c) not via the MIX in the CNF. Thus, the terminal equipments A and B making extension talking execute clear conference talking without hearing the busy tone. Furthermore, it is preferred to generate the control signal by depressing a specific function key K1 or a specific number of the extension terminal equipment.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to telephone exchanges, and more particularly to conference trunks in automatic exchanges.

[0002]

2. Description of the Related Art Generally, in a switchboard, a speech path portion forming a speech path between a calling party and a called party is provided with a switch circuit network for connecting a large number of incoming lines and outgoing lines and a connecting line. It is composed of a call monitoring circuit for monitoring the state of. This call monitoring circuit is installed for each incoming / outgoing line and controls transmission / reception of signals to each line and monitoring of the call status,
It is a part that controls input / output of control information to / from the exchange control device. The subscriber line monitoring circuit is called a subscriber circuit, and the relay line monitoring circuit is called a trunk circuit.

Also, a conference call is known in which a call is made between a plurality of terminals for one incoming call to the outside line. It is a conference trunk that makes this conference call in the trunk circuit provided in the automatic exchange. A conference call when an external line is received by the conference trunk in the conventional automatic exchange will be described below with reference to the block diagram of the conventional conference call shown in FIG.

In FIG. 4, A to C are terminals, and C.I. C is a speech path, EX is an automatic exchange, COT is an outside trunk, SL
C is an extension circuit, CNF is a conference trunk, MIX is a mixing circuit, BT is a busy tone, and BTD is a busy tone detecting means. In FIG. 4, the terminal C is a communication channel C. C
Automatic exchange E via (Comm Carrier)
It is connected to X and further to terminals A and C.

In the automatic exchange EX, the communication path C.
The outside line from C is an outside line trunk COT (Central
The line is input through the Office Trunk, and the extension circuits SLC (Subscribe) are connected to the terminals A and B.
er Line Circuit). Then, the terminal A, the terminal B, and the terminal C enable mutual calls by passing through the mixing circuit MIX of the conference trunk CNF (Conference), and the conference call is performed.

The procedure of the conference call by the conventional conference trunk will be described below with reference to the signal flow charts of the conference call by the conventional conference trunks of FIGS. 4 and 5. (1) First, the terminal A sends an incoming call to the terminal C. (2) The automatic exchange EX transfers this incoming call to the outside trunk CO
It receives at T and sends an incoming call signal to the terminal C. Also,
At the same time, the automatic exchange EX sends to the terminal A an incoming call ringing sound notifying that the terminal C is being called. (3) Terminal A receives the incoming call from terminal C and responds. (4) A call is made between the terminals A and C according to the response from the terminal A. The state of this call is indicated by the broken line indicated by in FIG. (5) During the call between the terminal A and the terminal C, the terminal A
Puts the call on hold. In this hold,
The hold sound is sent to the terminal C. (6) The terminal A makes an incoming call to the terminal B through the extension circuit SLC. (7) When the terminal A makes a call, an incoming call ringing signal is sent to the terminal B, and at the same time, an incoming call ringing tone is sent to the terminal C indicating that the terminal B is being called. (8) Terminal B receives the incoming call from terminal A and responds. (9) An extension call between the terminal A and the terminal B is made according to the response from the terminal B. The state of this extension call is indicated by the broken line shown by in FIG. 4, and the call is made through each extension circuit SLC. During this time, the hold tone is being sent to the terminal C. (10) In the extension call state, a conference call is performed between the terminals A, B, and C by operating the terminals. (11) In this conference call, the audio signal of each terminal is the mixing circuit MIX in the conference trunk CNF.
Done by The call path for this conference call is
This is indicated by the solid line indicated by in FIG.

[0007]

The above-mentioned conventional conference trunk of the automatic exchange has the following problems. (A) When an incoming call to the outside line ends during a conference call, a busy tone BT is heard on the extension side, which is inconvenient. (B) The busy tone detecting means BTD for monitoring disconnection of an external line incoming call needs to be installed for each external line, which is uneconomical in terms of installation cost and the like.

Regarding the above problems, the above (1) to
Subsequent to the description of (11), a serial number will be described. First, the above (a) will be described. (12) In FIGS. 4 and 5, during the conference call in (11), the terminal C goes on-hook and ends the call. Since the automatic exchange EX cannot detect the disconnection of the terminal C, which is an incoming call, even when the call between the terminals A and B is continued, the setting of the call path is still the solid line in FIG.

In other words, the external line from the terminal C is the mixing circuit MI of the external line trunk COT and the conference trunk CNF.
The terminals A and B are still connected through X. (13) Due to the continuation of the connection state of the outside line from the terminal C, the busy tone BT is sent to the terminal A as shown in FIG. 4 and the busy tone BT is sent to the terminal B as shown in FIG. It

Therefore, when the outside line incoming call from the terminal C is terminated during the conference call, the busy tone BT is heard during the call between the terminal A and the terminal B. In addition, busy tone B is used to monitor the disconnection of this outside line incoming call.
Although it is necessary to detect T, in order to detect this busy tone BT, it is necessary to install the busy tone detecting means BTD shown by the alternate long and short dash line in FIG.

Next, the above (b) will be described. (14) The busy tone BT from the outside line of the terminal C is detected by the busy tone detecting means BTD. This busy tone BT disconnects the connection with the terminal C making the incoming call and stops the busy tone BT. This busy tone detecting means BTD needs to be installed for each outside line connected to the automatic exchange EX, and the number of busy tone detecting means BTD increases according to the number of outside lines, resulting in an increase in cost.

The present invention solves the above-mentioned problem of the conference trunk in the conventional automatic exchange, and disconnects the outside line connection while maintaining the call between the extension lines without adding the busy tone detecting means BTD. The purpose is to stop the busy tone BT on the extension terminal side, which occurs when an outside call is terminated first, and to make a good call.

[0013]

In order to achieve the above-mentioned object, the present invention provides a method for disconnecting an external line incoming call of a conference trunk of an automatic exchange, by using the extension of an external line incoming call terminated during a conference call. This is detected by listening to the busy tone on the terminal side, and the call path from the external line incoming call is cut off by an operation signal from the extension terminal side.

Further, in the method of disconnecting an outside line incoming call of the conference trunk of the automatic exchange, the operation signal can be generated by operating a specific key or a specific number on the extension terminal side. Further, in the method of disconnecting an outside line incoming call of the conference trunk of the automatic exchange, the operation signal is composed of a signal for instructing disconnection of the outside line incoming call and a signal for specifying the office line of the outside line incoming call.

Further, the device for disconnecting an external line incoming call of the conference trunk of the automatic exchange has an internal line circuit to which an external line trunk for inputting an external line incoming call and a terminal are connected, and the terminal has a communication path from the external line incoming call. It has an operation means for generating an operation signal for disconnecting. Further, the operating means may be a specific key on the extension terminal side, or setting of a specific number and determining the specific number.

Further, the operation means can be composed of means for generating an operation signal for disconnecting an outside line incoming call and means for specifying a station line of the outside line incoming call.

[0017]

The present invention is a method for disconnecting an external line incoming call of a conference trunk of an automatic exchange, after receiving an external line incoming call,
When a conference call is being made on the extension terminal side of the automatic exchange, the external call is terminated first and the extension terminal side of the automatic exchange responds to the busy tone heard from the outside line, and then the specific key on the extension terminal side Alternatively, by operating a specific number or the like, the call path from the external incoming call is cut off so that the busy tone on the extension terminal side cannot be heard.

Further, in a device for disconnecting an outside line incoming call of a conference trunk of an automatic exchange, a call path from an outside line incoming call is set by a specific key of an extension terminal or a setting of a specific number and a means for judging the specific number. By generating an operation signal for disconnecting and a signal for specifying the office line of the external incoming call, the call path from the external incoming call is disconnected so that the busy tone on the extension terminal side cannot be heard.

[0019]

Embodiments of the present invention will now be described in detail with reference to the drawings. A conference call when an outside line is received by the conference trunk in the automatic exchange of the present invention will be described below with reference to the block diagram of the conference call of the present invention shown in FIG. 1, A to C are terminals, and C.I. C is the communication path, E
X is an automatic exchange, COT is an external trunk, SLC is an internal circuit, CNF is a conference trunk, MIX is a mixing circuit, BT is a busy tone, K1 is a function key, and K2 is an office line key.

In FIG. 1, the terminal C is a communication path C. It is connected to the automatic exchange EX via C and is further connected to the terminals A and C. In the automatic exchange EX, the communication path C. The external line from C is input through the external line trunk COT, and is output to the terminals A and B through the internal line circuit SLC. The terminals A, B and C are respectively connected to the mixing circuit MI of the conference trunk CNF.
Mutual calls are made possible by passing X, and a conference call is performed.

Further, the terminals A and B have functional means for disconnecting the communication path and station line designating means for designating an external line. The functional means is the terminal A,
It can be configured by the function key K1 provided in the terminal B or means for determining setting of a specific number and pressing of the specific number. Further, the station line designating means is also the terminal A,
The station line key K2 provided in the terminal B or means for determining setting of a specific number and pressing of the specific number can be used.

The function key of the terminal on the extension terminal side, the means for determining the setting of the specific number and the pressing of the specific number can disconnect the busy tone BT from the outside line. It is possible to disconnect an outside line incoming call of the conference trunk of the exchange. The procedure of the conference call by the conference trunk of the present invention will be described below with reference to the signal flow charts of the conference call by the conference trunk of the present invention of FIGS. 1 and 2 and the external line of the conference call by the conference trunk of the present invention of FIG. This will be described with reference to the flowchart for disconnecting an incoming call. In the following, step S indicates step S shown in FIG. 3, and number indicates the number shown in FIG. Step S1: (1) First, the terminal A sends an incoming call to the terminal C. (2) The automatic exchange EX transfers this incoming call to the outside trunk CO
When it is received at T and an incoming call is detected in the external trunk COT, the extension circuit SLC sends a ringer which is an incoming call signal to the terminal C. At the same time, the automatic exchange EX sends to the terminal A an incoming call ringing sound notifying that the terminal C is being called. (3) Terminal A receives the incoming call from terminal C and responds. Step S2: (4) A call is made between the terminals A and C according to the response from the terminal A. The state of this call is indicated by the broken line indicated by in FIG. Step S3: (5) During the call between the terminal A and the terminal C, the terminal A
Puts the call on hold. In this hold,
The automatic exchange EX sends a hold tone to the terminal C. Step S4: (6) The terminal A makes an incoming call to the terminal B through the extension circuit SLC. (7) When the terminal A makes a call, an incoming call ringing signal is sent to the terminal B, and at the same time, an incoming call ringing tone is sent to the terminal C indicating that the terminal B is being called. (8) Terminal B receives the incoming call from terminal A and responds. Step S5: (9) An extension call between the terminal A and the terminal B is made according to the response from the terminal B. The state of this extension call is shown by the solid line in FIG. 1, and the call is made through each extension circuit SLC. During this time, the hold tone is being sent to the terminal C. Step S6: (10) In the state of the extension call, a conference call is made between the terminal A, the terminal B, and the terminal C by operating the key of the terminal A or operating the terminal with a specific number or the like. Step S7: (11) In this conference call, each terminal A to
The C audio signal is mixed between the three parties by the mixing circuit MIX in the conference trunk CNF. As a result, the conference call state is established among the three parties of the terminals A, B, and C. By this conference call state, the extension call path shown in FIG. 1 is canceled. Therefore, the call path in the conference call state is shown by the solid line and the broken line indicated by a, b, and d in FIG. Step S8: (12) In the conference call state, the terminal C goes on hook to end the call. At this time, the automatic exchange EX cannot detect the disconnection of the terminal C, which is an incoming call. Therefore, even when the call between the terminals A and B is continued, the call path is set by a, b, and d in FIG. It remains as indicated by the solid and dashed lines shown.

That is, the outside line from the terminal C passes through the mixing circuit MIX in the outside line trunk COT and the conference trunk CNF shown by the broken line of d in FIG.
And is still connected to the terminal B. Step S9: (13) Due to the continuation of the connection state of the outside line from the terminal C, the busy tone BT is sent to the terminal A as shown by in FIG. 1, and the busy tone BT is sent to the terminal B as shown in in FIG. Is sent.

Therefore, when the outside call is terminated during the conference call, the busy tone BT is heard during the call between the terminals A and B. Step S10: (14) When a busy tone BT from the outside line is heard on the terminal side during the conference call, the specific function key K1 or the specific number is pressed on the terminal A or the terminal B. Step S11: (15) Furthermore, the station line key K2 defining the station line where the busy tone BT is heard is pressed or a specific number corresponding to the station line is operated.

By this operation, the office line to be cut can be specified. Step S12, Step S13: (16) When the pressing of the specific function key K1 is detected or when the pressing of the specific number is determined, the call path is set only between the terminals A and B. To set.

This call path is set by setting the call path via the mixing circuit MIX circuit in the conference trunk CNF as shown in FIGS. 1A and 1B and in the conference trunk CNF as shown in FIG. 1C. It is possible to set either of the two extension communication paths that are normal extension communication paths that do not pass through the mixing circuit MIX circuit. Step S14: (17) Next, the call path of the office line identified in step S11 is disconnected. This surely disconnects the communication path of the office line from the terminal C where the busy tone BT indicated by the broken line of FIG. 1 is heard. In the case of FIG.
The call paths to be disconnected are the call path from the terminal C to the terminal A and the call path from the terminal C to the terminal B.

Therefore, by this operation, the call path between the terminal A and the terminal B is set, the busy tone BT from the outside line is disconnected, and the incoming call during the call can be set as it is. As described above, according to the method and the apparatus for disconnecting the outside line incoming call of the conference trunk of the automatic exchange of the present invention, when the outside line incoming call is terminated and the busy tone BT is heard on the extension side in the conference call of the automatic exchange. By operating the key assigned to the extension terminal or a specific number or the like, the call path of the busy tone BT station line can be disconnected and a good call can be made between the extension terminals.

The present invention is not limited to the above embodiments, but various modifications can be made based on the spirit of the present invention, and these are not excluded from the scope of the present invention.

[0029]

As described above in detail, according to the present invention, when an external incoming call is terminated and a busy tone is heard on the extension terminal side during a conference call in an automatic exchange, the extension terminal side can appropriately operate. This has the effect of disconnecting the busy tone and making a clear conference call without listening to the busy tone to the terminal during the extension call.

[Brief description of drawings]

FIG. 1 is a block diagram of a conference call of the present invention.

FIG. 2 is a signal flow diagram of a conference call through the conference trunk of the present invention.

FIG. 3 is a flowchart of disconnecting an outside line incoming call of a conference call by the conference trunk of the present invention.

FIG. 4 is a block diagram of a conventional conference call.

FIG. 5 is a signal flow diagram of a conference call using a conventional conference trunk.

[Explanation of symbols]

 A to C terminal C.I. C Call Path EX Automatic Switch COT Outer Trunk SLC Extension Circuit CNF Conference Trunk MIX Mixing Circuit BT Busy Tone K1 Function Key K2 Station Line Key

Claims (8)

[Claims] 1. In a conference trunk of an automatic exchange, (a) the termination of an incoming call to an outside line during a conference call is detected by listening to a busy tone on the extension terminal side, and (b) an operation signal from the extension terminal side. A method for disconnecting an external line incoming call from a conference trunk of an automatic exchange, characterized in that the call path from the external line incoming call is disconnected by the above. 2. The method for disconnecting an outside line incoming call from a conference trunk of an automatic exchange according to claim 1, wherein the operation signal is generated by pressing a specific key on the extension terminal side. 3. The method for disconnecting an outside line incoming call of a conference trunk of an automatic exchange according to claim 1, wherein the operation signal is generated by pressing a specific number on the extension terminal side. 4. The external line incoming call of the conference trunk of the automatic exchange according to claim 1, wherein the operation signal comprises a signal for instructing disconnection of the external line incoming call and a signal specifying a central line of the external line incoming call. Call disconnection method. 5. A conference trunk of an automatic exchange, wherein: (a) the automatic exchange has an outside line trunk for inputting an outside line incoming call and an extension line circuit to which a terminal is connected; and (b) the terminal receives an outside line incoming call. An outside line incoming call disconnecting device for a conference trunk of an automatic exchange, characterized in that it has an operating means for generating an operation signal for disconnecting the call path. 6. The apparatus for disconnecting an outside line incoming call of a conference trunk of an automatic exchange according to claim 5, wherein the operation means is a specific key on the extension terminal side. 7. The apparatus for disconnecting an outside line incoming call of a conference trunk of an automatic exchange according to claim 5, wherein the operation means is for setting a specific number on the extension terminal side and determining the specific number. 8. The conference of the automatic exchange according to claim 5, 6 or 7, wherein said operation means comprises means for generating an operation signal for disconnecting said outside line incoming call and means for specifying a station line of said outside line incoming call. External line incoming call disconnecting device for trunk.