JPH0767151A - Speaking state monitor system for subscriber circuit - Google Patents

Abstract

PURPOSE:To switch a subscriber circuit in operation to a stand-by subscriber circuit by judging that there is no telephone call made when detecting the continuation of a voiceless state of a speech signal at the subscriber circuit in operation. CONSTITUTION:In a subscriber circuit 2, the speech signal from a subscriber terminal 1 is inputted to a speech detecting circuit 22 through a line switching circuit 21. When the speech signal exceeding a previously set voiceless state decision threshold value is imputted, the speech detecting circuit 22 outputs a reset signal to the reset terminal R of a counter circuit 23 which monitors a recovery time. The counter circuit 23 stops counting a voiceless state continuation time, so the output of the counter circuit 23 is fixed at a low level while the reset signal is inputted and then inputted to a peripheral control circuit 24. The peripheral control circuit 24 recognizes that the subscriber circuit 2 is in a speaking state from the low-level signal, and never perform line switching based upon the indication of a switching indication signal from the subscriber circuit 2 to the subscriber circuit 3 even if the indication signal arrives from a central control unit 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a call status monitoring system for subscriber circuits.

[0002]

2. Description of the Related Art A conventional call state monitoring system for a duplicated subscriber circuit is a direct current voltage between a tip line and a ring line in a subscriber circuit connected to a subscriber line during a call and a standby. Was deciding whether a call was in progress or a standby.

[0003]

In this conventional communication state monitoring system for a subscriber circuit, it is determined whether a call is in progress or in standby depending on a change in DC voltage between the tip line and the ring line during a call and during a standby. As the decision was made, for example, switching the line from the working side subscriber circuit of the duplexed subscriber line accommodating important subscribers to the standby side subscriber line, or a direct line at night on the private automatic telephone exchange (main telephone) When there is no change in the DC voltage between the tip wire and the ring wire, such as when switching to), the peripheral control circuit unconditionally waits for the standby side even if the working line is busy. There was a problem of switching to the line.

Therefore, an object of the present invention is to switch to the subscriber circuit on the standby side when it is judged that no call is being made when the silent circuit of the voice signal is detected by the subscriber circuit on the operating side. Another object of the present invention is to provide a call state monitoring method for the subscriber circuit.

[0005]

According to the present invention, in a subscriber circuit which is controlled by a central control unit and is connected to a subscriber terminal through a duplicated subscriber line, the first subscriber circuit of an operating system is provided. When the voiced state of the voice signal with the subscriber terminal is detected, this subscriber circuit switching is performed even if the instruction to switch to the second subscriber circuit of the standby system is received from the central control device. If the first subscriber circuit detects that the silent state of the voice signal has continued for a preset time without performing the second subscriber circuit, the second subscriber circuit is instructed by the switching instruction from the central control unit. It is possible to obtain a call state monitoring method for a subscriber circuit, which is characterized in that switching to the call is performed.

Further, the first and second subscriber circuits detect the presence / absence of a voice signal in the voice signal to / from the subscriber terminal on the basis of a predetermined silent state determination threshold value. The recovery monitor includes a detection unit, a recovery monitoring unit that is activated when the voice detection unit does not detect a voice signal and is reset when the voice signal is detected, and a peripheral control unit that controls call control. There is provided a call state monitoring method for a subscriber circuit, characterized in that the means notifies the peripheral control means of a call end signal when the means has not been reset within a predetermined recovery monitoring time after being activated.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of a call state monitoring system for a subscriber circuit according to the present invention.

Referring to FIG. 1, in this embodiment, first and second subscriber circuits 2 and 3 connected to a subscriber terminal 1 through a duplicated subscriber line and controlled by a central control unit 4.
It consists of

The first and second subscriber circuits 2 and 3 are voices for detecting the presence / absence of a voice signal in the voice signal to / from the subscriber terminal 1 on the basis of a predetermined silence determination threshold value. The voice detection circuits 22 and 32 of the detection means and the counter of the recovery monitoring means which is activated when the voice detection circuits 22 and 32 do not detect a voice signal and is reset when the voice signal is detected to count the silent time. Circuits 23, 33
And peripheral control circuits 24 and 3 of peripheral control means for controlling call control.
4 and the line switching circuit 21, which switches the connection with the subscriber terminal 1 by the switching signals from the peripheral control circuits 24 and 34,
31 and 31 are provided.

Next, the first subscriber circuit 2 is set to the working side,
The operation of this embodiment will be described with the second subscriber circuit 3 on the standby side.

In the first subscriber circuit 2, the voice signal from the subscriber terminal 1 is input to the voice detection circuit 22 through the break contact of the line switching circuit 21.

In the voice detection circuit 22, a silent state determination threshold value is set in advance in order to detect the presence or absence of a voice signal. Then, when a voice signal exceeding this silence determination threshold is input, the voice detection circuit 22 outputs a reset signal to the reset terminal R of the counter circuit 23 that monitors the recovery time.

Since the counter circuit 23 stops counting the silent duration when the reset signal is input, the output of the counter circuit 23 is fixed to the low level "L" while the reset signal is input and the peripheral control is performed. It is input to the circuit 24.

The peripheral control circuit 24 has the low level "L".
It is recognized that the subscriber circuit 2 is busy by the signal of.

In this state, even if the switching instruction signal from the first subscriber circuit 2 to the second subscriber circuit 3 arrives from the central control unit 4, the peripheral control circuit 24 switches the line according to this instruction. Do not execute. Therefore, a call in progress on the subscriber circuit 2 is protected.

Next, when the call in the subscriber circuit 2 ends, the voice detection circuit 22 does not detect a voice signal because the subscriber terminal 1 is on-hook and recognizes the silent state, and the counter circuit. An activation signal is output to the activation terminal S of 23.

With this start signal, the counter circuit 23 starts counting and monitors the silent state, and after a predetermined recovery monitoring time (for example, 20 seconds) elapses, the call is terminated by the subscriber circuit 2 and the peripheral control circuit is terminated. The high level “H” is output to 24.

In this state, the central control unit 4 operates the subscriber circuit 3
A switching instruction signal for switching to is output to the subscriber circuits 2 and 3.

When the switching instruction signal arrives at the subscriber circuit 2, the peripheral control circuit 24 sends a subscriber circuit switching signal to the line switching circuit 21, and the line switching circuit 21 opens the contact.

On the other hand, in the subscriber circuit 3, the peripheral control circuit 34
When a switching instruction signal from the central control unit 4 arrives, sends a subscriber circuit switching signal to the circuit switching circuit 31, and the line switching circuit 31 closes the contact.

Therefore, the subscriber circuit 3 becomes the working side subscriber circuit, the subscriber circuit 2 becomes the standby side subscriber circuit,
Switching of the subscriber circuit is completed.

As described above, in the present embodiment, even if there is no change in the DC voltage between the tip line and the ring line of the subscriber circuit during a call or during standby, the subscriber circuit is used by the subscriber circuit on the operating side. It is possible to monitor the voice signal from the terminal and switch to the subscriber circuit on the standby side when not in a call state.

[0024]

As described above, according to the present invention, by monitoring the voice signal from the subscriber terminal in the subscriber circuit on the operating side, the telephone line between the tip line and the ring line is monitored in the call state and the standby state. Even when a subscriber terminal with no change in DC voltage is connected, it is possible to reliably judge whether a call is in progress or not. Therefore, the operating side subscriber circuit of the duplexed subscriber line is switched to the standby side subscriber circuit. There is an effect that a call in progress can be protected at the time of switching the line to the line or switching to the direct line (main phone) at night in the private automatic telephone exchange.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a call state monitoring system of a subscriber circuit of the present invention.

[Explanation of symbols]

 1 subscriber terminal 2,3 subscriber circuit 4 central control device 21,31 line switching circuit 22,32 voice detection circuit 23,33 counter circuit 24,34 peripheral control circuit

Claims (2)

[Claims] 1. In a subscriber circuit which is controlled by a central control unit and is connected to a subscriber terminal through a duplicated subscriber line, a first subscriber circuit of an active system is a voice communication with the subscriber terminal. When the voiced state of the signal is detected, the subscriber circuit is not switched even if an instruction to switch to the second subscriber circuit of the standby system is received from the central controller, and the first subscriber circuit is not switched. Detects that the silent state of the voice signal has continued for a preset time or more, switching to the second subscriber circuit is performed by the switching instruction from the central control unit. Call state monitoring method for subscriber circuits. 2. A voice for detecting the presence or absence of a voice signal in a voice signal to and from the subscriber terminal based on a predetermined silence state determination threshold value. The recovery monitor includes a detection unit, a recovery monitoring unit that is activated when the voice detection unit does not detect a voice signal and is reset when the voice signal is detected, and a peripheral control unit that controls call control. 2. The call state monitoring system for a subscriber circuit according to claim 1, wherein the means notifies the peripheral control means of a call end signal when the means has not been reset within a predetermined recovery monitoring time after being activated.