JPS6378652A - Analog subscriber circuit of four-wire system - Google Patents

Abstract

PURPOSE:To eliminate the need of a provision for a power supplying line other than a call line, by using the transmission line of a fourwire system analog subscriber circuit requiring no call current at time of a call, as the power supplying line for the operating power source of a subscriber terminal equipment. CONSTITUTION:The subscriber terminal equipment(TEL) always receives the supplying of the operating power source of the subscriber terminal equipment(TEL)13 itself from the transmission lines(line A and B) of the four-wire system analog subscriber circuit(SUBT)1 being connected by a subscriber line(SUBL)17. When an outgoing operation is performed at the subscriber terminal equipment(TEL)13, a DC loop is formed in a transmission circuit(TRS)14 in the subscriber terminal equipment(TEL)13, and an outgoing is detected at a subscriber interface circuit(SLIC)9 in the four-wire system analog subscriber(SUBT)1. As a result, outgoing sound is sent to the reception circuit(RCV)15 of the N subscriber terminal equipment(TEL) 13 passing through the subscriber line(SUBL)17.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a four-wire analog subscriber circuit in a commonly controlled telephone switching system.

[Conventional technology]

In a subscriber terminal device that is connected to a two-wire analog subscriber circuit and is supplied with operating power from the subscriber circuit, if the subscriber terminal device is provided with a calling function, During a call, a direct current supply (talking current supply) is required to the telephone line, and power for operation of the subscriber terminal cannot be sent from the telephone line to the subscriber terminal.
A power supply line separate from the communication line must be provided.

However, if the subscriber terminal device is only provided with the function of receiving calls, it is possible to supply power for operating the subscriber terminal device using the telephone line. This is Tokukai Showa 5
This technology is applicable to No. 5-124354 "Terminal connection method".

[Problem that the invention seeks to solve]

The above-mentioned conventional technology does not take into consideration the problem that a power supply line to the subscriber terminal device is required in addition to the telephone line, and that the various equipment and facility man-hours associated with this power supply line are large. When the above-mentioned prior art is applied to a 4Ns type analog subscriber circuit, similar problems remain.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems caused by the provision of a power supply line in a four-wire analog subscriber circuit.

[Means for solving problems]

The above purpose is to use the transmission line of a 4-wire analog subscriber circuit, which does not require communication current during a call, as a power supply line for the operating power supply of the subscriber terminal equipment, thereby supplying power to lines other than the communication line. There is no need to provide a line, and the above objective is achieved.

[Effect]

The transmission line of a 4-wire analog subscriber circuit can be used as a power supply line to the subscriber terminal device if an AC signal in the audio band can be transmitted from the transmission line to the subscriber terminal device without any hindrance. can also be used.

This makes the power supply circuit of the operating power supply of the subscriber terminal device connected to the transmission line of the 4-wire analog subscriber circuit high impedance with respect to the AC signal passing through the transmission line. This can be realized by sufficiently reducing the loss of the AC signal caused by the power supply circuit in the transmission line.

〔Example〕

Hereinafter, one embodiment of the present invention will be explained based on the first factor.
The 4-wire analog subscriber circuit (SUBT) 1 in the figure is a subscriber circuit accommodated in a time division exchange.
) 2 receives control information for the subscriber circuit (SUBT) 10 from a trunk interface circuit (TIC, ) not shown, and controls the subscriber circuit (SUBT) 1. The subscriber line M (SUBT) 1 also receives and passes information to the trunk interface circuit (TIC). The codec (CODEC) 3 converts the AC signal within the audio band from analog to digital and from digital to analog under the control of the control circuit (CTL) 2. A level adjustment circuit (LVC) 4 adjusts the level of the analog occupancy signal of the codec (CODEC) s. Transformer (LO, Ll) 5.6 is a balanced/unbalanced conversion circuit, capacitor (Co, CI
) 7.8 is a DC blocking capacitor, subscriber interface circuit (SLIC) 9 is a subscriber terminal equipment (
Detection of call origination (response) or disconnection (end of call) from 13 to 13;
TRY) 14 is supplied with a transmitting current. The terminal power supply circuit (PWS) 15 is connected to the subscriber terminal device (place) 13.
The operating power is supplied to the power supply circuit (POW) 16 of the subscriber terminal gj: 13. Subscriber terminal equipment ft
(Position) 13 F) Earpiece u (RCV) 15 C.
It receives transmission signals from a 4-wire analog subscriber circuit (SUBT) 1. Blockage line (RPOlRPl) 1
1.12 Subscriber Interface Circuit (SLIC)
9 and the terminal power supply circuit (PWS) 10 have a high impedance to AC signals in the voice band passing through the D%E line and the A and B lines of the 4@ type analog subscriber circuit (SUBT) 1. ing.

Below, an explanation will be given of an example K of the calling operation from the subscriber terminal #(device) 1s.

The subscriber terminal equipment @ (T, WL, ) is the subscriber line (8
The subscriber terminal equipment (TEi,) 15 receives power supply for its own operation at all times from the transmission lines (A, B) of the 4-wire analog subscriber circuit (SUBT) 1 connected to the UBL line 171C. ing.

When a call operation is performed on the subscriber terminal (TEh) 13, the mouthpiece (T) of the subscriber terminal (TEh) 13 is activated.
A DC loop is formed in R8) 14, and the subscriber interface 7 of the 4-wire analog subscriber circuit (SUBT) 1 is formed.
Transmission is detected in the nice circuit (SLIC) 9. The outgoing call information is sent to the trunk interface circuit (TIC) via the control circuit (CTL) 2 and processed at the time of outgoing call.
) 2 HWRI 7- code, code 7” y
9 (C0DEC) 3, Rehe #i Sei Oo Road (LVC)
4), and is sent to the receiving circuit (Cv) 15 of the subscriber terminal device t (location) 13 through the subscriber 11j route C3UBL) 17. The transmission level of the tone is 12
4-wire analog subscriber circuit (80BT) 1
It is hardly attenuated by the influence of the terminal power supply circuit (PWS) 1o.

As described above, according to the embodiment, power is supplied simultaneously to the subscriber terminal device connected to the 4-wire analog subscriber circuit and supplied with operating power from the 41M analog subscriber circuit. This has the advantage that it can be carried out using the transmission line of a four-wire analog subscriber circuit.

〔Effect of the invention〕

According to the present invention, power supply to subscriber terminal devices connected to a 4-wire analog subscriber circuit and supplied with operating power from the 4-wire analog subscriber circuit is controlled by communication between the devices. This can be done using a power line, which has the effect of eliminating the need to provide a dedicated line for power supply.

[Brief explanation of the drawing]

Part 1 (2) is a configuration diagram showing an embodiment of a four-wire analog subscriber circuit according to the present invention, and a configuration diagram of a subscriber terminal device connected to the four-wire analog subscriber circuit. 2... Control circuit, 6... Codec, 4... Level adjustment circuit, 7.8... DC blocking capacitor, 10...
... Terminal power supply circuit, 11.12 ... Blockage line, 1
3...M input terminal device, 14...Talking circuit, 15.
... Receiving circuit, 16... Power supply circuit, 17... Subscriber line.

Claims (1)

[Claims] 1. In an analog subscriber circuit with a 4-wire telephone line and a subscriber terminal device that operates by receiving power from the subscriber circuit, the transmission line of the subscriber circuit that does not require telephone current is used. A power supply for operating the subscriber terminal device connected to the subscriber circuit can be supplied to the subscriber terminal device without providing a dedicated line for power supply other than a telephone line. 4-wire analog subscriber circuit.