JPH1175225A - Subscriber circuit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a subscriber circuit where power consumption is reduced while keeping the same speech quality as that of a conventional circuit. SOLUTION: A coder 6 converts an analog signal received from a terminal 1 and converted into a 4-wire signal at a 2/4-wire conversion circuit 4 into a PCM signal. A decoder 7 converts the PCM signal from a host device of an exchange into an analog signal. When a terminal detection circuit 8 detects that a transmission exclusive terminal 1 is connected to a subscriber line 2, a control circuit 9 sets the coder 6 to be an ON state and the decoder 7 to be an OFF state. When a detection circuit 8 detects that a reception exclusive terminal 1 connects to the subscriber line 2, the control circuit 9 sets the coder 6 to be an OFF state and the decoder 7 to be an ON state. When the terminal 1 is other than the transmission exclusive terminal and the reception exclusive terminal, the control circuit 9 sets the coder 6 to be an ON state and the decoder 7 to be an ON state.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a subscriber circuit accommodating a subscriber line, and more particularly to a subscriber circuit having an encoder and a decoder.

[0002]

2. Description of the Related Art Conventionally, a subscriber circuit for accommodating a subscriber line is known (for example, Japanese Patent Application Laid-Open No. 60-186164).
No.). In this subscriber circuit, power consumption is reduced by supplying power to a terminal (telephone) from a power supply circuit in the subscriber circuit only when data is transmitted and received.

[0003]

However, in such a subscriber circuit, an encoder for encoding an analog signal into a PCM signal and a decoder for decoding a PCM signal into an analog signal are always in an active state. Therefore, there is a problem that power consumption is large, and it is difficult to reduce the size of the device and achieve high-density mounting. The present invention has been made in order to solve the above-described problems, and while ensuring the same call quality as that of the related art,
It is an object of the present invention to provide a subscriber circuit capable of reducing power consumption.

[0004]

The subscriber circuit of the present invention comprises:
A power supply circuit for supplying a call current to a subscriber terminal via a subscriber line, a two-wire / four-wire conversion circuit for mutually converting a two-wire signal and a four-wire signal, An encoder for converting an analog signal on the 4-wire side of the 4-wire conversion circuit into a PCM signal and having an on / off switching function;
A decoder for converting a signal into an analog signal and outputting the signal to a two-wire / four-wire conversion circuit and having an on / off switching function, a terminal detection circuit for detecting a terminal connected to a subscriber line, and the terminal detection circuit And a control circuit for controlling the switching of the encoder and the decoder in accordance with the detection result of. In this way, the terminal connected to the subscriber line is detected by the terminal detection circuit, and the control circuit controls the switching of the encoder and the decoder according to the terminal. The terminal detection circuit detects whether a terminal connected to the subscriber line is a transmission-only terminal or a reception-only terminal, and the control circuit includes: When the terminal detection circuit detects that a transmission-only terminal is connected to the line, it turns the encoder on and the decoder off, and the terminal detection circuit detects that the reception-only terminal is connected to the subscriber line Then, the encoder is turned off and the decoder is turned on.

[0005]

Next, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a block diagram of a subscriber circuit according to an embodiment of the present invention. The subscriber circuit of the present embodiment installed for each subscriber line 2 includes a power supply circuit 3 for supplying a call current to the subscriber terminal 1 via the subscriber line 2, a two-line signal from the terminal 1, and a switch side. 2-wire 4-wire conversion circuit 4 for mutually converting 4-wire signals of the communication path of the communication line, and a balancing network circuit 5 for suppressing the 4-wire input signal from appearing at the 4-wire output terminal via the 2-wire subscriber line. 2 line 4
On / off switching built-in encoder 6 for converting a 4-wire output analog signal of line conversion circuit 4 into a PCM signal in a telephone voice signal band, and on / off switching built-in decoding for converting a PCM signal into a telephone voice signal band analog signal A terminal detecting circuit 8 for detecting the terminal 1 connected to the subscriber line 2, and a control circuit 9 for controlling the switching of the encoder 6 and the decoder 7 according to the detection result of the terminal detecting circuit 8. I have.

Next, the operation of such a subscriber circuit will be described. The power supply circuit 3 supplies power to the terminal 1 via the subscriber line 2. The two-wire / four-wire conversion circuit 4 mutually converts a two-wire signal from the terminal 1 and a four-wire signal on a communication path on the exchange side.

The on / off switching built-in encoder 6 converts a 4-wire analog signal sent from the terminal 1 and converted into a 4-wire system by the 2-wire / 4-wire conversion circuit 4 into a PCM signal in a telephone voice signal band. The PCM signal is output to a host device (not shown) of the exchange. Further, the encoder 6 includes a two-wire / four-wire conversion circuit 4 and a connection (ON) with a higher-level device / 2-wire / four-wire conversion circuit
And an on / off switching means (not shown) such as disconnection (off) from a higher-level device or on / off of power supply to an internal circuit of the encoder 6.

The on / off switching built-in decoder 7 converts the PCM signal output from the host device of the exchange into an analog signal in the telephone voice signal band, and
Output to the line conversion circuit 4. This 4-wire analog signal is converted into a 2-wire signal by a 2-wire / 4-wire conversion circuit 4 and transmitted to the terminal 1. Then, the decoder 7 has a two-wire / four-wire conversion circuit 4
And connection with a higher-level device (ON) / 2-wire 4-wire conversion circuit 4 and disconnection from a higher-level device (OFF), or decoder 7
And an on / off switching means (not shown) for turning on / off the power supply to the internal circuit.

Here, when the terminal detection circuit 8 detects that the transmission-only terminal 1 is connected to the subscriber line 2, the control circuit 9 controls the on / off switching means of the encoder 6 and the decoder 7 respectively. A signal is output to switch the encoder 6 on and the decoder 7 off. When the terminal detection circuit 8 detects that the reception-only terminal 1 is connected to the subscriber line 2, the control circuit 9 outputs a control signal to the on / off switching means of the encoder 6 and the decoder 7, respectively. Then, the encoder 6 is turned off and the decoder 7 is turned on.

When the terminal 1 connected to the subscriber line 2 is a terminal other than the transmission-only terminal and the reception-only terminal, the control circuit 9 turns on both the encoder 6 and the decoder 7. As described above, when the transmission-only terminal is connected to the subscriber line 2, the encoder 6 is turned on, the decoder 7 is turned off, and when the reception-only terminal is connected, the encoder 6 is turned off, By turning on the decoder 7, power consumption can be reduced.

When a transmission-only terminal is connected to the subscriber line 2, an encoder 6 necessary for transmitting a signal from the transmission-only terminal is turned on, and a reception-only terminal is connected to the subscriber line 2. When the terminal 1 connected to the subscriber line 2 is a terminal other than the transmission-only terminal and the reception-only terminal, the decoder 7 is turned on. 6. By performing appropriate switching control for turning on both the decoders 7, it is possible to ensure the same communication quality as in the related art.

[0012]

According to the present invention, a terminal connected to a subscriber line is detected by a terminal detection circuit, and a control circuit controls switching of an encoder and a decoder according to the terminal connected to the subscriber line. By doing so, power consumption can be reduced. In addition, since the encoder and the decoder are appropriately switched according to the use of the terminal connected to the subscriber line, it is possible to ensure the same communication quality as in the related art.

[Brief description of the drawings]

FIG. 1 is a block diagram of a subscriber circuit according to an embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Terminal, 2 ... Subscriber line, 3 ... Power supply circuit, 4 ... 2-wire 4-wire conversion circuit, 5 ... Balancing network circuit, 6 ... On / off switching built-in encoder, 7 ... On / off switching built-in decoder, 8: terminal detection circuit, 9: control circuit.

Claims (2)

[Claims] 1. A power supply circuit for supplying a call current to a subscriber terminal via a subscriber line, a two-wire / four-wire conversion circuit for mutually converting a two-wire signal and a four-wire signal, PC output analog signal on 4-wire side of circuit
An encoder for converting to an M signal and having an on / off switching function, a decoder for converting a PCM signal to an analog signal and outputting the analog signal to a two-wire / four-wire conversion circuit, and having an on / off switching function; A terminal detection circuit for detecting a terminal connected to a subscriber line, and a control circuit for performing switching control of the encoder and the decoder in accordance with a detection result of the terminal detection circuit. . 2. The subscriber circuit according to claim 1, wherein the terminal detection circuit detects whether a terminal connected to the subscriber line is a transmission-only terminal or a reception-only terminal. When the terminal detection circuit detects that the transmission-only terminal is connected to the subscriber line, the control circuit turns the encoder on and the decoder off, and the reception-only terminal is connected to the subscriber line. A subscriber circuit, which turns off the encoder and turns on the decoder when the terminal detection circuit detects the above.