JPS59112751A - Call listening system - Google Patents

Abstract

PURPOSE:To listen to a call without giving any hindrance to the call by monitoring a dial signal from an extension terminal and performing listening connection processing only between the reception side of an extension terminal of a time- division call switch and the transmission side of a call trunk line. CONSTITUTION:When the trunk line 1 is engaged in a call with an extension telephone set EXT2 through a central office trunk COT4, an operator originates from a monitor board 3 in order to listen to a talk between two subscribers and then a central controller sets a channel CHC of the time-division channel switch 11, so the monitoring board 3 is connected to a dial monitoring circuit 8 through a line circuit 7. When the operator dials a special number for a request to listen, the circuit 8 outputs this number information to a control circuit 9. The circuit 9 reads a listening connection program out of a storage circuit 10 to set a CHD of the switch 11, and sends a dial tone from a tone generating circuit 9 to the operator. When the operator dials the number of the COT4 engaged in the call, the circuit 9 sets a CHE of the switch 11 while releasing the CHC and CHD, and the operator is allowed to listen to the talk.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a call listening system, and more particularly to a call listening system in a time-sharing private branch electronic exchange.

Conventionally, when attempting to listen to a call between two parties, a central office line and an extension line, from a supervisor's desk, for example, a so-called branch method has been used in which a handset on the supervisor's desk is connected to the line during the call.

However, this method has the disadvantage that the voice transmitted from the handset on the director's desk can be heard by the handsets of the two parties, thereby interfering with the communication between the two parties.

The purpose of the invention is to eliminate the above-mentioned drawbacks by preventing a listening request signal from a listener from sending a transmission signal from the listener to the communication path between the two parties, and to provide a wide range of applications. The purpose is to provide a call listening method.

In the call listening system μ1 time-sharing private electronic exchange@ according to the present invention, a dial monitoring circuit monitors a dial signal from an extension terminal, and the extension terminal of a time-sharing call path switch according to the output of the dial monitoring circuit. and a control circuit that performs listening connection processing only between the receiving post of the telephone line and the transmitting post of the telephone line.

The device is characterized in that it includes a storage circuit that stores a listening connection processing program for the control circuit.

Next, the present invention will be explained with reference to FIG.

FIG. 1 is a block diagram of a time-division type local electronic exchange (hereinafter simply referred to as "time-division exchange") showing a first embodiment of the call listening system of the present invention. In the same figure, the time division exchanges each have a central office line 11, a central office line trunk (hereinafter C0T) that interfaces with an extension telephone (hereinafter referred to as EXT) '2 and a supervisory board (hereinafter referred to as CBI) 3, a line circuit (hereinafter referred to as LC) 5 and LC7. , a tone generation circuit (hereinafter referred to as TNG) 6 that generates a second dial tone, and a dial monitoring circuit (hereinafter referred to as 5UP) 8 that monitors dial signals from an extension terminal such as the CBD 3.
, a time division channel switch (hereinafter referred to as TDSW) 11, a control circuit (hereinafter referred to as CNT) 9 that performs predetermined listening connection processing according to the 80P8 output, and a storage circuit that stores a listening connection processing program executed by the CNT 9. (hereinafter MEM
) 10. TDSWII (7) Sender Post VCIrl COT 4, T, C5, TNG
6 and LC7 are accommodated, and the receiving post has the corresponding C
0T4. LC5, LC7 and the above-mentioned S[JP8 are accommodated, and switching of desired time-division communication paths between these posts is performed under the control of a known central controller (not shown) and the above-mentioned CNT9. In addition.

Said C0T4. Both LC5 and LC7U include a coder/decoder C0DEC, and each of the above-mentioned central office line 1°E
Analog-to-digital conversion between the XT2 and CBD3 sides and the TDSWII side is also performed.

Next, the operation of this embodiment will be explained.
Assume that the telephone is connected to the central office line 1 via T4 and is in the middle of a call. Therefore, the transmission signal from the central office line 1 is transmitted to the C0T4. Channel ■, the call is received by the EXT2 via LC5, and the call is received by the E
The transmission signal from XT2 is from the corresponding LC5, channel ■, C0T.
4 and is transmitted to the central office line l. Here, the operator uses C to listen to the call between the two parties (office line
When calling from BD3.

A commonly known calling connection is made and the operator hears a dial tone. At this time, the central controller sets the channel ◎ of the TDSWII.
, connected to S[JP8 via channel ◎. Next, when the operator dials the special number for requesting a hearing, the 5U
P8rc counts the special number and outputs the number information to CNT9, and the CNT9 knows from the output that it is a listening request.
After reading the EMI Q listening connection processing program, the setting control of the channel [F] of the TDSW 11 is performed, so the second tone from the TNG 6 is transmitted to the channel @, L.
It is sent to the handler via C7. Thereafter, when the operator dials the number of the C0T4 during the call (for example, a number such as rOJ, r-IJ, etc. corresponding to each of a plurality of COTs), the CNT6 controls the setting of the channel (2) of the TD8W11 and Since the release control of channels ① and ② is performed, the transmission signal from the above-mentioned office line 1 is
It is received by the CBD3 via channel 0T4 and LC7, and the operator can listen to it. At this time, since the LC7 transmitting boss) U of the TD8W11 is not switched to any receiving post, the transmitting signal from the operator cannot be heard by the two parties in the conversation.

Next, FIG. 2 is a block diagram of a time division switch showing a second embodiment of the call listening system of the present invention. In the same figure, the same components as in the first embodiment are given the same reference numerals h as in FIG.
(shown in the figure) is replaced with an EXT 12, and if necessary, a recorder (hereinafter referred to as RCD) 13 is branch-connected to the EXT 12. Therefore, by the same operation as in the first embodiment, the subscriber can listen to the outgoing call signal from the central office line 1 using the EXT 12, and if the outgoing call is an important call such as a threatening call or an international call, It can be recorded on the RCD 13.

Note that the first thing. In the second embodiment, the transmission from the extension telephone during a call is not heard, but the listening and recording of important telephone calls is generally done in a nearby location in the same department, and the listener hears the transmission in real voice. be able to.

Furthermore, it is clear that the call listening method of the present invention can also be applied to the case where transmissions from a central office line during a call are listened to using multiple extension terminals.As explained above, according to the call listening method of the present invention, This has the effect of making it possible to listen to calls between the central office line and the extension line without interfering with it, and has a wide range of applications such as monitoring calls from a supervisor's desk and listening to and recording MW calls.

[Brief explanation of drawings]

FIGS. 1 and 2 are block diagrams of a time-sharing private branch electronic exchange illustrating first and second implementations of the call listening system of the present invention, respectively.

Claims (1)

[Claims] In a time-division private branch electronic exchange, there is a dial monitoring circuit that monitors dial signals from an extension terminal, and depending on the output direction of the dial monitoring circuit, the receiving post of the extension terminal of the time-division call path switch and the central office line during the call. 1. A call listening system comprising: a control circuit that performs listening connection processing only with a transmitting post; and a storage circuit that stores a listening connection processing program for the control circuit.