JPH04241562A - In-band signaling transmitter - Google Patents

Abstract

PURPOSE:To obtain the in-band signaling transmitter which can execute signaling even when any loss is generated on a line. CONSTITUTION:An instruction from a control part 19 is transmitted only in the case of no speaking while stopping the transmission of a detection signal during speaking according to the state of speaking or the state of an instruction from an in-band signal detector 18. A signal generator 15 at a transmission part receives a control signal according to information from the control part 19. When the control signal from a counter device (in-band signaling transmitter 3B) is detected by a detector 18 at the reception part of a transmitter 3A, the control signal is inputted from the detector 18 to the control part 19, and a logical output is transmitted so as to increase/decrease the gain of a variable gain controller 16. When starting speaking an SS signal from any one of the transmitters 3A and 3B is detected at an SS detector 17 and passed through the control part 19, and the transmission of an in-band signal is stopped. On the side of detecting the SS, the correction of the loss is stopped and on the side of the counter in-band signaling transmitter, the in-band signal is eliminated as well. Then, when an SR is detected, the correction of the loss is stopped.

Description

[Detailed description of the invention]

0001

[Field of Industrial Application] The present invention relates to a device capable of correcting line loss, and more particularly to a signaling transmission device built into an automatic gain control unit that uses an analog transmission line as a dedicated line and corrects line loss during no calls. .

0002

2. Description of the Related Art There are two possible methods for transmitting and receiving signals between telephones: one using a general telephone line and the other using a dedicated line. When using general telephone lines, telephone companies have exchange transmission equipment, and telephone dial signals and ringing signals are transmitted using dedicated transmission lines or signals outside the voice signal transmission band. A method is used in which the information is sent to the opponent. When transmitting and receiving telephone signals using an analog dedicated line, the frequency range is 0.3 [KHz] to 3.
A line that transmits and receives only voice signals in a band up to 4 KHz is used by borrowing it from a telephone company.

By the way, this is not a problem when performing one-to-one non-selection communication, but normally a communication network is constructed that requires selection of one-to-multiple lines via an exchange. In this case, a device (in-band signaling transmission device) is required to send and receive signaling and dial signals to and from the exchange of the other party. Using such an analog dedicated line to send and receive signals between telephones can be expected to significantly reduce the charge ratio for line usage compared to using a general telephone line, so it is useful for building a communication network within a company. It is commonly used in cases. When building an intra-company communication network using such in-band signaling transmission equipment, it is common to build a star-shaped communication network with the head office as the master station and the branch offices as slave stations. In-band signal transmission equipment corresponding to the number of lines is concentrated on the station side, and only the number of lines corresponding to the demand on the slave station side is required.

[0004] Furthermore, in the in-band signaling transmission device,
The hook status and dial signal are obtained from the exchange side using SS (Signal Send) signals. In the in-band signaling transmission device, the S
The S signal is converted into a change in one frequency or a plurality of frequencies within the transmission band (hereinafter referred to as an in-band signal) and then transmitted to the opposing station. On the other side, changes in the in-band signal are sent to the exchange as SR (Signal Receive) information, and the hook status and dial information are transmitted (signaling).

[0005]

[Problems to be Solved by the Invention] However, according to the conventional in-band signaling transmission device described above, if loss or gain occurs on the line and it becomes difficult to detect the presence or absence of an in-band signal, signaling cannot be performed. However, there were problems in that it was impossible to make a call, or that distortion occurred due to long-distance calls or excessive input.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems and provide an in-band signaling transmission device that can perform signaling even when loss occurs on a line.

[0007]

[Means for Solving the Problems] The in-band signaling transmission device of the present invention uses an in-band single frequency signal or multiple frequency signals in a transmission path for transmitting and receiving signals using a telephone line to transmit and receive signals from exchanges and telephones. A control signal generation circuit that can transmit a control signal to increase or decrease the gain of the opposite device, and a control signal generation circuit that can transmit a control signal to increase or decrease the gain of the opposite device, and the control signal generation circuit that generates a signal when a receiving side level differs from a reference level value. a receiving means for instructing the transmission of a control signal to a receiver; a gain adjusting means for varying the gain or loss to compensate for loss in the transmission path; and a gain adjusting means for detecting the control signal sent from the opposing device. The present invention is characterized by comprising a control signal detection circuit that adjusts the control signal.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be explained based on the illustrated embodiments.

FIG. 2 is a block diagram illustrating a system using an embodiment of the invention.

In FIG. 2, telephone 1A is connected to private branch exchange 2.
It is connected to the in-band signaling transmission device 3A via A. The in-band signaling transmission device 3A is connected to the in-band signaling transmission device 3B via a dedicated line 4. In-band signaling transmission device 3B is connected to telephone 1B via private branch exchange 2B.

FIG. 1 is a block diagram showing an embodiment of an in-band signaling transmission apparatus according to the present invention.

In FIG. 1, a transmit line 11, a receive line 12, an SS line 13, and an SR line 14 from a private branch exchange 2A are connected to the in-band signaling transmission device 3A. The in-band signaling transmission device 3B also has a sending line 11 and a receiving line 12 from the private branch exchange 2B.
, an SS line 13, and an SR line 14 are connected to each other. In-band signaling transmission devices 3A and 3B
have the same configuration, so the in-band signaling transmission device 3
The configuration of only A will be explained.

The in-band signaling transmission device 3A includes a control signal generating section 15, a variable gain amplifier 16, and an SS detector 17 in an internal transmitting section, and an in-band signal generating section for detecting the magnitude of a received in-band signal in a receiving section. It includes a signal detection section 18, a control section 19 that supplies a control signal to the control signal generation section 15, a control signal detection circuit 20, and an SR output device 21. Also,
22 is a gain increase control signal oscillator, and 23 is a gain decrease control signal oscillator. The receiving means includes an in-band signal detector 1
8. The control unit 19 is at least a component.

The operation of such an embodiment will be explained.

FIG. 3 is a timing chart for explaining the operation of the above embodiment.

First, the opposing in-band signaling transmission devices 3A and 3B transmit signaling from their own devices,
It is necessary to mutually transmit and receive in-band signals to compensate for line loss. In addition, the in-band signaling transmission device 3
A and 3B are in-band signals that transmit SS information (transmits hook status and dial pulse)
Corrects line loss during transmission. When the detecting circuit 18 of the receiving section of the own band signaling transmission device 3A side detects that the magnitude of the in-band signal on the receiving line 12 is out of the specified range (time t0), a long call or Since there is a risk of excessive input and affecting transmission and reception of in-band signals, the detection circuit 18 of the receiving section provides the detection result to the control section 19. When the loss is large (when the in-band signal is small (time t0)), the control unit 19 sends out the gain increase control signal from the gain increase control signal oscillator 11 to the dedicated line 4 to transmit the gain increase control signal to the opposing in-band signaling transmission device. 3B is instructed to increase the gain (time t11). The opposing in-band signaling transmission device 3B can detect this in its receiving section (time t12). As a result, the opposing in-band signaling transmission device 3B increases its gain (time t2), so that the in-band signal increases thereafter.

Note that when the line has a gain (when the in-band signal is large), the control unit 19 transmits the gain reduction control signal from the gain reduction control signal oscillator 12 to the dedicated line 4.
to instruct the game player to reduce the gain.

Depending on the state of the call and the state of the instruction from the in-band signal detector 18, the instruction from the control unit 19 stops transmitting the detection signal during the call and transmits it only when there is no call. The signal generator 15 of the transmitter transmits a control signal to the control signal generator 15 based on the information from the controller 19 . Further, when a control signal from the opposite device (in-band signaling transmission device 3B) is detected by the in-band signal detector 18 of the receiving section of the in-band signaling transmission device 3A, the control signal is output from the in-band signal detector 18. The signal is input to the control section 19, and from the control section 19, a logical output for increasing or decreasing the gain of the variable gain adjuster 16 of the transmitting section is sent.

When starting a call, the SS signal of either the local in-band signaling transmission device or the opposite in-band signaling transmission device is detected by the SS detector 17 (at time t31,
t4), the sending of the in-band signal through the control unit 19 is stopped (times t32, t4), the loss correction is stopped on the side that has detected SS, and the in-band signal is no longer on the opposite in-band signaling transmission device side, and the SR is stopped. When detected, loss correction is stopped (time t5).

As described above, in this embodiment, the in-house exchange 2
In-band signaling transmission devices 3A, 3B are connected between A, 2B and the dedicated line 4 to establish telephone calls and signaling. Further, when a normal telephone call is not made, if the magnitude of the inband signal detected by the inband signal detection circuit 18 deviates from the reference magnitude, the control unit 19 is instructed of the deviance. The control unit 19 transmits instructions from the in-band signal detection circuit 18 to the control signal transmission circuit 1 unless an SS signal or an SR signal is input.
Give instructions to 5. In addition, the control signal receiving circuit 2 of the receiving section
The gain adjustment instruction of 0 becomes valid under the condition that no SS signal or SR signal is input, and gain adjustment is performed.

[0021]

[Effects of the Invention] As explained above, according to the present invention, it can be used as a means for monitoring line loss and gain.
Distortion caused by long-distance communication due to line loss or insertion of gain can be detected without being pointed out by the user, and it is possible to provide a usage environment that does not cause any hindrance to the user's use.

[Brief explanation of the drawing]

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

FIG. 2 is a block diagram showing a system configuration to which an embodiment of the present invention is applied.

FIG. 3 is a diagram for explaining the operation of the embodiment of the present invention.

[Explanation of symbols]

3A, 3B In-band signaling transmission device 15 Control signal generator 16 Gain adjuster 17 SS detector 18 In-band signal detector 19 Control unit 20 Control signal detector 21 SR detector

Claims (1)

[Claims] Claim 1: In a device that transmits signaling for an exchange or a telephone using a single frequency signal or multiple frequency signals within a band within a transmission line that sends and receives signals using a telephone line, the gain of the opposing device is a control signal generating circuit capable of transmitting a control signal to raise or lower the level; a receiving means configured to instruct the control signal generating circuit to transmit a control signal when a receiving side level differs from a reference level value; and a transmission line. and a control signal detection circuit that detects a control signal sent from an opposing device and adjusts the gain adjustment means by detecting a control signal sent from an opposing device. In-band signaling transmission equipment.