JP2001057588A - In-band ringer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an in-band ringer by which a loopback test compensating a line loss from both the in-band ringer and an opposite in-band ringer can be executed and that can optically set the execution and the end of the loopback test. SOLUTION: The in-band ringer consists of a subscriber circuit 7 that has an interface for an opposite telephone set, a hybrid transformer 8, an echo canceller 9 that prevents a sneaked path of a received signal from a receiver side, a changeover circuit 10 that loops back a measurement signal at a loopback test, an in-band control signal generator 11, a measurement signal generator 12, a transmission amplifier 13, line transformers 14, 15, a reception amplifier 16, a filter 17 that eliminates the in-band control signal component from the received signal, a measurement terminal 18, a filter 19 that extracts in-band control signal component from the received signal, an in-band control signal detector 20 that reproduces the control signal, a control circuit 21 that controls the subscriber circuit 7, the changeover circuit 10, the measurement signal generator 12 and the in-band control signal generator 11, or the like, a test setting switch 22 that sets a loopback test at loopback test and a power supply circuit 23.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an in-band signal device (hereinafter referred to as an "in-band ringer"), and more particularly, to a remote-only device by transmitting a test start signal from one of the opposing devices to the other device. The present invention relates to an in-band ringer capable of performing a folding test of a device on both sides including a line.

[0002]

2. Description of the Related Art As a network connecting offices, a private branch exchange (hereinafter referred to as a PBX) of each office or a telephone terminal represented by a telephone is provided by a dedicated line or a private line provided by a telecommunications carrier. It is widely used because it is possible to realize a toll dial or extension of an extension line by connecting through such as an economical network. Further, a dedicated line provided by a communication carrier can be connected to a public line via a PBX or the like, and a more economical wide area network can be constructed. A dedicated line or a private line provided by a communication carrier used when constructing such a network often defines a frequency band that can be used by a user, and receives a dedicated line service for the above-described purpose. In this case, the frequency is generally limited to the voice band frequency of 0.3 kHz to 3.4 kHz. Therefore, when constructing a network using such a dedicated line, a low frequency or direct current signal such as a dial pulse signal, a 16 Hz calling signal, a direct current polarity signal, etc. required between the PBX and the PBX, between the PBX and the telephone set, etc. Since the signal cannot be transmitted, the signal is transmitted using an in-band ringer. The in-band ringer converts low-frequency or direct-current signals necessary for controlling the PBX and telephone into a voice band frequency that can be transmitted to a dedicated line, and transmits the converted signal. It also has a line loss compensation function.

FIG. 3 shows an example in which a conventional in-band ringer is applied to extension of an extension. An in-band ringer 2 connected to a PBX 1 and an in-band ringer 4 connected to a telephone 3 via a dedicated line. Constitute. In the network configured as described above, an operation when a call is received from another telephone to the telephone 3 via the PBX 1 will be described as an example. First, the PBX 1 selects a line in which the telephone 3 is accommodated, and then sets a 16 Hz for calling the telephone.
The signal is output with a predetermined repetition period. In the in-band ringer 2, the repetition cycle of 16 Hz
A signal is detected, and a specific in-band control signal composed of a voice band frequency output during standby is intermittently transmitted at a predetermined repetition cycle. The in-band ringer 4 detects the intermittent operation of a specific in-band control signal, thereby
Recognizing that the z signal has arrived, the 16 Hz oscillator built in the in-band ringer 4 outputs a 16 Hz signal having a predetermined cycle to the telephone 3 to ring the bell of the telephone. Next, when the telephone 3 is off-hook to make a call, the in-band ringer 4 detects the off-hook of the telephone 3 due to the current flowing through the loop on the telephone 3 side, and cuts off the in-band control signal output during standby. And
Therefore, the in-band ringers 2 and 4 both stop transmitting the in-band control signal, close the loop to the PBX 1 to which the in-band ringer 2 is connected, and shift to the call state.
Since the in-band ringer uses the in-band frequency as the control signal as described above, the in-band control signal is transmitted during no-call so as not to have an effect during a call.

Since the in-band ringer is installed opposite to both ends of the dedicated line, it is necessary to dispatch a coordinator to both sides to check the line state or check the reception level when operating the apparatus. For the purpose of reducing the number of adjustment steps, it is common to provide a remote test function for remotely investigating the state of the user from the station side where the apparatus is centrally installed. The remote test of the in-band ringer is performed remotely by setting the switch from the in-band ringer at the office, and the measurement signal is output from the measurement signal generator provided in the in-band ringer at the office. This is performed by measuring the level of the signal received by the in-band ringer on the user side.
The inband ringer on the user side is forcibly kept in the test state for 5 minutes when set to the test state by remote control of the inband ringer on the office side.

[0005]

However, in the conventional in-band ringer, the remote loopback test can be performed only from the station side and cannot be performed when a test from the user is required. 5 after the start
After the minutes, even if the test is in progress, the user automatically returns to the standby state. Conversely, when the remote return test is started, the user must wait 5 minutes for the automatic return even if the test ends. When the measurement signal is looped back by the in-band ringer on the user side during the loop-back test, the loop is returned without compensating for the loss of the dedicated line, so the level received at the office is affected by the loss of the dedicated line, and the measurement becomes complicated. And other problems. The present invention has been made in order to solve the problem of the conventional in-band ringer as described above, and can perform a loop-back test that compensates for line loss from both opposing in-band ringers. It is an object of the present invention to provide an in-band ringer whose termination can be arbitrarily set.

[0006]

In order to achieve the above object, an invention of an in-band ringer according to the present invention comprises a private branch exchange or a telephone terminal installed at both ends of a band-limited communication line. In the in-band signal device connected via the communication line, an in-band control signal generator for outputting a plurality of in-band control signal combination signals serving as a test start signal during a loopback test to a dedicated line; A switching circuit for returning the in-band control signal received during the detection of the start signal to a dedicated line via an amplifier for compensating for the loss of the communication line. The invention according to claim 2 of the in-band ringer according to the present invention is the in-band ringer according to claim 1, wherein the in-band ringer is installed at both ends of a band-limited communication line, and a private branch exchange and a private branch exchange are connected. It is configured to be connectable via the communication line. The invention according to claim 3 of the in-band ringer according to the present invention is directed to claim 1 or 2.
In the in-band ringer described above, the band-limited communication line is configured to be a 4-wire line or a 2-wire line.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail based on illustrated embodiments. FIG. 1 is a view showing an embodiment in which the function of installing the in-band ringer according to the present invention on the telephone side is provided. As shown in FIG.
And an in-band ringer 6. The in-band ringer 6 includes a subscriber circuit 7 having an interface for a telephone, a hybrid transformer 8 for performing 2-wire / 4-wire conversion, and a signal wraparound from the receiving side. An echo canceller 9 for preventing, a switching circuit 10 for returning the measurement signal at the time of the return test, an in-band control signal generator 11 for converting a control signal between the telephone and the PBX into an in-band frequency and outputting the same, and outputting the measurement signal at the time of the return test Measurement signal generator 12
A transmission amplifier 13 for adjusting an output level, line transformers 14 and 15 for connecting to a dedicated line, a reception amplifier 16 for amplifying a reception level to a predetermined value, and removing an in-band control signal component from a reception signal. A filter 17 for performing level measurement during a loopback test, a filter 19 for extracting an in-band control signal component from a received signal,
An in-band control signal detector 20 for reproducing a control signal from an in-band control signal component extracted by the filter 19, a subscriber circuit 7, a switching circuit 10, an in-band control signal generator 11, a measurement signal generator 12, and the like. A control circuit 21 for controlling the test, and a test setting switch 22 for setting a test during the loopback test
And a power supply circuit 23 for supplying power to the device. In the in-band ringer provided with the PBX interface installed on the PBX side, the subscriber circuit 7 and the control circuit 21 provided in the in-band ringer 6 are composed of a PBX.
All other functions are the same as those of the in-band ringer 6.

The operation of FIG. 1 will be described. In the subscriber circuit 7, a control signal processed between the PBX and the telephone is exchanged. From the PBX side, the telephone is transmitted via the subscriber circuit 7 of the in-band ringer 6. 5, 16Hz
From the telephone side to the PBX side via the subscriber circuit 7 of the in-band ringer 6 to transmit the call signal, the transmission of the other party response signal by reversing the polarity of the DC voltage, and the supply of the communication current.
Transmission of a dial pulse, transmission of a response signal by a DC loop current, transmission of a disconnection signal, and the like are performed. Next, the communication signal output from the telephone 5 is
After performing the wire / four-wire conversion, the echo canceller 9 removes the echo component wrapping around from the two-wire receiving side via the hybrid transformer 8 and inputs it to the switching circuit 10. In the switching circuit 10, as an input to the transmission amplifier 13, a call signal output from the telephone 5 during normal operation is normally input.
At the time of the loopback test on the side under test, each of the received measurement signals is output. The control signal detected by the subscriber circuit 7 is
Under the control of the control circuit 21, the signal is converted into an in-band control signal obtained by combining a plurality of in-band frequencies output by the in-band control signal generator 11, and is output to the transmission amplifier 13. On the other hand, when performing the loopback test on the test side, the measurement signal is output from the measurement signal generator 12 to the transmission amplifier 13.
After adjusting the transmission level to the dedicated line, the transmission amplifier 13 outputs the signal to the dedicated line via the line transformer 14.

A reception signal received from the opposing in-band ringer is transmitted to a reception amplifier 1 via a line transformer 15.
6 and amplify to a desired level. After removing the in-band control signal component by the filter 17, the amplified received signal is output to the telephone 5 via the hybrid transformer 8 as a call signal. The output of the filter 17 is connected to the switching circuit 10 so as to output the measurement signal received when it becomes the test side during the loopback test to the transmission amplifier 13. The output of the filter 17 is provided with a measuring terminal 18 for measuring a folding level during a test. next,
The filter 19 extracts the in-band control signal component from the received signal, and the in-band control signal detector 20 reproduces the control signal. The control circuit 21 is operated by the reproduced control signal to control the subscriber circuit 7 and the like as described above. A test setting switch 22 is connected to the control circuit 21 to start or stop the loopback test and to set the output of the measurement signal generator 12. In the power supply circuit 23, a stable DC voltage is generated and supplied to the inside of the device.

FIG. 2 is a configuration diagram showing one embodiment when the in-band ringer according to the present invention is performing a folding test. This figure comprises a PBX-side in-band ringer 24 and a telephone-side in-band ringer 25, and describes only the functions necessary for the loopback test. Since the components of both in-band ringers are the same as the components described in FIG. 1, the operation when the loopback test is performed from the PBX-side in-band ringer 24 to the telephone-side in-band ringer 25 will be described. I do. First, at the start of the folding test, after confirming that the in-band ringer is in the standby state, the PBX
When the test start key of the test setting switch 22 of the side in-band ringer 24 is turned on, a combination signal of a plurality of in-band control signals serving as a test start signal from the in-band control signal generator 11a is controlled by the control circuit 21a. It is sent to the in-band ringer 25. The combination signal of the plurality of in-band control signals must be a combination that does not match the combination signal of the plurality of in-band control signals related to the control signal transmitted and received between the telephone and the PBX. A method of alternately intermittently interposing each other is also an example.

Next, when the in-band control signal detector 20b detects the test start signal in the telephone-side in-band ringer 25, the switching circuit 10 is operated under the control of the control circuit 21b, and a filter 17b for extracting a call signal is provided.
Is returned to the transmission side, and the in-band control signal generator 11b is operated under the control of the control circuit 21b.
The same combination signal as the test start signal is sent to the PBX-side in-band ringer 24. The PBX-side in-band ringer 24 receives the test start signal, recognizes the completion of the folding operation of the telephone-side in-band ringer 25, turns on the measurement signal transmission switch of the test setting switch, and outputs the measurement signal. . The output measurement signal is transmitted to the transmission amplifier 1 of the PBX side in-band ringer 24.
3a, transmitted to the telephone-side in-band ringer 25 via the line transformer 14a, and received by the reception amplifier 16 via the line transformer 15b of the telephone-side in-band ringer 25.
b, and compensates for the line loss of the dedicated line, then removes the in-band control signal component by the filter 17b and switches the switching circuit 1
0, and returns to the PBX side in-band ringer 24 via the transmission amplifier 13b and the line transformer 14b.
To send to. In the PBX-side in-band ringer 24, the signal is input to the filter 17a via the line transformer 15a and the receiving amplifier 16a, and after removing the in-band control signal component, the signal is output to the level measurement terminal 18. On the other hand, when the loopback test is ended, when the test start key of the test setting switch 22 is turned off, the control circuit 21a is operated to stop the test start signal output from the in-band control signal generator 11a, and the PBX side All the test functions of the in-band ringer 24 and the telephone-side in-band ringer 25 are restored.
In addition, 1 kHz is often used as the measurement signal frequency, and 2.6 kHz, 3.0 kHz or the like is often used as the in-band control signal frequency. For level measurement, more detailed measurement can be performed by connecting an external measuring device to the in-band ringer and using it as a signal generator. In the above, the case of performing the loopback test operation from the PBX side in-band ringer has been described. However, the telephone side inband ringer has the same function, and the loopback test can be performed from the telephone side inband ringer. It is.

[0012]

According to the present invention, as described above, claims 1 and 2
(3) Remote return test can be performed from both the office and user side, and the test can be started or restored immediately by operating the test setting switch. Dedicated for remote return test Since the loss of the line can be compensated, it is very effective in maintaining the in-band ringer.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing an embodiment in a case where a function of installing an in-band ringer according to the present invention on a telephone side is provided.

FIG. 2 is a configuration diagram showing one embodiment when an in-band ringer according to the present invention is performing a folding test.

FIG. 3 shows an example in which a conventional in-band ringer is used when extending an extension.

[Explanation of symbols]

1, PBX, 2, 4, Inbandlinger,
3, 5, telephone, 6. in-band ringer,
7 ··· Subscriber circuit, 8 ·· Hybrid transformer,
9. Echo canceller, 10. Switching circuit,
11, 11a, 11b ··· in-band control signal generator
12 ·· Measurement signal generator, 13, 13a, 13b
..Transmission amplifiers, 14, 14a, 14b, 15, 1
5a, 15b line transformer, 16, 16a,
16b ··· Reception amplifier, 17, 17a, 17b ··· Filter, 18 ··· Level measurement terminal, 19, 19a, 1
9b filter, 20, 20a, 20b in-band control signal detector, 21, 21a, 21b control circuit, 22 test setting switch, 23 power supply circuit

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Atsushi Fujisawa 2-1-1 Kotani, Samukawa-cho, Koza-gun, Kanagawa F-term in Toyo Tsushinki Co., Ltd. 5K027 CC06 LL05 LL08

Claims (3)

[Claims] An in-band signal device installed at both ends of a band-limited communication line and connecting a private branch exchange or a telephone terminal via the communication line, wherein a plurality of bands serving as a test start signal at a loopback test are provided. An in-band control signal generator that outputs a control signal combination signal to a dedicated line, and an in-band control signal received during detection of the test start signal from the dedicated line via an amplifier that compensates for loss in the communication line. A signal device in a voice band, comprising: a switching circuit for returning the signal to a dedicated line. 2. The system according to claim 1, wherein said in-band signal device is installed at both ends of a band-limited communication line so that a private branch exchange and a private branch exchange can be connected via said communication line. In-band signal device. 3. The in-band signal apparatus according to claim 1, wherein the communication line whose band is limited is a four-wire system or a two-wire system.