JPH05122381A - Subscriber terminal equipment control system - Google Patents

Abstract

PURPOSE:To implement satellite line connection between two-wire analog subscriber terminal equipments arranged to other earth station and 2-wire analog subscriber terminal equipment arranged to one earth station in an excellent way. CONSTITUTION:A discrimination section 16 discriminates whether a response signal from a called party received by a control section 5 is a pseudo response signal sent from a 2/4-wire conversion section 12 or an incoming call signal to a substantial own station (earth station 1). Upon the receipt of the response signal, when a subscriber terminal equipment 1-1 is already hooked off, the signal is discriminated to be the pseudo response signal and when hooked on, it is discriminated to be a substantial incoming call signal. Upon the receipt of the pseudo response signal, the discrimination section 16 sets a ringer oscillation section 3. Thus, a dial number representing a dial pulse based on an open/close of a 2-wire loop by the subscriber terminal equipment 1-1 is accurately detected by an interface section 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a communication system between subscriber terminals, and more particularly, to a two-wire analog subscriber terminal by a dial pulse system arranged in a first earth station and a second earth station. The present invention relates to a subscriber terminal communication system for performing line connection between two-wire analog subscriber terminals by satellite communication.

[0002]

2. Description of the Related Art A subscriber terminal 1 in a first earth station 1 is shown in FIG.
-1 applies the conventional inter-subscriber terminal communication method for connecting the lines to the plurality of subscriber terminals 2-1 to 2-N gathered by the exchange 13 in the second earth station 2. 2 shows the configuration of the device.

As shown in FIG. 2, the earth station 1 comprises a subscriber terminal 1-1, a ringer oscillator 3, an interface 4, a controller 5, a modulator / demodulator 6 and a transceiver 7. In addition, the earth station 2 includes a transmitter / receiver 8, a modulator / demodulator 9, and a controller 1.
0, an interface unit 11, a two-line to four-line conversion unit 12, an exchange 13, and a plurality of subscriber terminals 2-1 to 2-N. Further, the subscriber terminal 1-1 and the subscriber terminal 2-
Among the 1 to 2-N, a satellite 14 has been launched for performing line connection with any subscriber terminal for communication.

Next, the operation when a line connection is made from the subscriber terminal 1-1 to the subscriber terminal 2-N will be described.

When the receiver of the subscriber terminal 1-1 of the earth station 1 is lifted (off-hook), the interface section 4 detects the loop current (IL) flowing through the subscriber terminal 1-1,
An off-hook signal is sent to the control unit 5. The control unit 5 sends an off-hook signal to the modulation / demodulation unit 6. The modulated wave of the off-hook signal from the modulation / demodulation unit 6 is transmitted via the transmission / reception unit 7 to the satellite 1
4 is transmitted.

Through the satellite 14, the modulated wave is transmitted to the earth station 2
The signal is received by the transmitter / receiver 8 and demodulated by the modulator / demodulator 9, and then sent to the controller 10. The control unit 10 causes the interface unit 11 to send the subscriber terminal 1-1 based on the demodulated signal.
The off-hook signal (incoming signal) of is transmitted. The interface unit 11 sends a ground signal to the 2-line-4 line (2W-4W) conversion unit 12 via the M line. The 2W-4W conversion unit 12 that has received the ground signal internally closes between the two lines connected to the exchange 13. Exchange 13
The subscriber terminal line is closed and the loop current (I
When L) flows, the call origination of the subscriber terminal 1-1 is detected, and the idle state is shifted to the standby state for dial number input.

Next, the subscriber terminal 1-1 selects an arbitrary subscriber terminal in the earth station 2 (subscriber terminal 2-N in this example) after the above-mentioned off-hook. In this case, a signal having a dial number according to the touch-tone (MF) method is sent from the subscriber terminal 1-1 to the modulation / demodulation unit 6 via the interface unit 4. The signal having this dial number is sent to the interface section 11 of the earth station 2 through the modulation / demodulation processing similar to the transmission of the off-hook signal, and is further input to the converter 13 via the signal line 15 dedicated to voice. Upon receiving the signal having this dial number, the exchange 13 selects the subscriber terminal 2-N from among the plurality of subscriber terminals 2-1 to 2-N.

As a result, the line between the subscriber terminal 1-1 and the subscriber terminal 2-N is connected through the satellite 14.

As described above, in the above-mentioned conventional subscriber control system, the subscriber terminal 1-1 to the subscriber terminal 2-2:
When the subscriber terminal 1-1 adopts the dial transmission method based on the MF method, the line connection is satisfactorily connected without any problem.

[0010]

However, in the above-mentioned conventional subscriber terminal control system, when the subscriber terminal 1-1 is set to the dial transmission system of the dial pulse system,
There was a problem that a good line connection could not be established.

The reason for this will be described in detail.

In FIG. 2, when the line connection processing from the subscriber terminal 1-1 to the subscriber terminal 2-N is performed,
When the geo signal is given from the interface unit 11 to the 2W-4W conversion unit 12, the 2W-4W conversion unit 12 closes the internal two-wire line and at the same time, the continuous geo signal to the interface unit 11 by the E line. To loop back. In this operation, the 2W-4W conversion unit 12 is connected to the two-line subscriber line of the exchange 13, and a response signal indicating that the subscriber terminal 2-N is off-hook is sent from the exchange 13 to the 2W-4W conversion unit 12. Since it cannot be received, it is performed for the purpose of artificially transmitting the response signal to the control unit 5 in the earth station 1 waiting for the off-hook signal response from the called side.

Here, referring to FIG. 3, superposition of the Ringer signal which is expected to occur when the subscriber terminal 1-1 sends out the signal having the dial number by the dial pulse method, that is, the cause of the above-mentioned problem. Will be described with reference to FIG.

As shown in FIG. 3, after the time TD elapses from the off-hook of the subscriber terminal 1-1 (FIG. 3 (a)), the ground signal is generated from the interface 11 (FIG. 3 (b)) and the time 2 ... After the elapse of TD, the control unit 5 receives the pseudo response signal (FIG. 3C) on the called side. At this time, the control unit 5
Activates the ringer oscillation operation of the ringer oscillator 3 (FIG. 3D). That is, the two-wire loop of the connected subscriber terminal 1-1 is opened and the loop current IL does not flow, so that the ringer oscillator 3 enters the standby state. Here, when the dial pulse of the first digit is sent from the subscriber terminal 1-1 and the two-wire loop is opened only for the time Top by the dial pulse of the first digit, the control unit 5 causes the ringer during this period. The oscillator 3 is turned on. Therefore, the interface unit 4
Cannot accurately detect the dial pulse sent from the subscriber terminal 1-1 by superimposing the ringer signal.

It is an object of the present invention to use a dial pulse system which is arranged in the first earth station by satellite communication.
It is an object of the present invention to provide a communication system between subscriber terminals that enables good line connection between the line analog subscriber terminal and the two-wire analog subscriber terminal arranged in the second earth station.

[0016]

DISCLOSURE OF THE INVENTION The present invention is directed to a dial pulse type two-wire analog subscriber terminal arranged in a first earth station and a two-wire analog subscriber terminal arranged in a second earth station. In the subscriber terminal communication system in which the line connection between the two is performed by satellite communication, the first earth station is connected to the interface unit and the Ringer oscillator unit connected to the two-wire analog subscriber terminal, and the interface unit. And a determination unit whose input side is connected to the interface unit and the control unit side and whose output side is connected to the Ringer oscillator unit. The determination unit is a two-wire line of the second earth station. When the calling signal sent from the -4 line conversion unit is detected by the control unit, the signal from the interface unit causes the 2-wire analog subscriber terminal of the first earth station to be off-hook. When it is determined that is obtained so as to stop the delivery of the ringer signal from the ringer oscillator part to 2-wire analogue subscriber terminals of said first earth station.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a subscriber terminal control system of the present invention will be described below with reference to the drawings.

FIG. 1 shows the configuration of an apparatus to which an embodiment of the subscriber terminal control system of the present invention is applied. Note that, in FIG. 1, those corresponding to those shown in FIG. 2 are designated by the same reference numerals.

As shown in FIG. 1, the earth station 1 includes a subscriber terminal 1-1, a ringer oscillator 3, an interface 4, a controller 5, a modulator / demodulator 6, a transmitter / receiver 7, and a determiner 16. ..

The subscriber terminal 1-1 is an analog two-wire type, and has a function of transmitting a voice band. The interface unit 4 monitors the off-hook state of the subscriber terminal 1-1 and supplies a loop current. The determination unit 16 determines the incoming call condition at the time of receiving the incoming call signal to the subscriber terminal 1-1. The control unit 5 controls the earth station 1. The ringer oscillation unit 3 sends a ringer signal to the subscriber terminal 1-1 under the control of the determination unit 16. The determination unit 16 may be incorporated in the control unit 5.

The earth station 2 includes a transmission / reception unit 8, a modulation / demodulation unit 9, a control unit 10, an interface unit 11, a two-wire-four-wire conversion unit (hereinafter referred to as a 2W-4W conversion unit) 12,
The exchange 13 and a plurality of subscriber terminals 2-1 to 2-N are provided. Further, the subscriber terminal 1-1 and the subscriber terminal 2
Among -1 to 2-N, a satellite 14 has been launched for performing line communication with any subscriber terminal for communication.

The subscriber terminals 2-1 to 2-N are also of analog two-wire type and have a function of transmitting voice bands.

Next, the subscriber terminal 1-1 to the subscriber terminal 2
The operation when the line is connected to -N will be described.

When the receiver of the subscriber terminal 1-1 of the earth station 1 is lifted (off-hook), the interface section 4 detects the loop current (IL) flowing through the subscriber terminal 1-1,
An off-hook signal is sent to the control unit 5. The control unit 5 sends an off-hook signal to the modulation / demodulation unit 6. The modulated wave of the off-hook signal from the modulation / demodulation unit 6 is transmitted via the transmission / reception unit 7 to the satellite 1
4 is transmitted.

The modulated wave is transmitted to the earth station 2 through the satellite 14.
The signal is received by the transmitter / receiver 8 and demodulated by the modulator / demodulator 9, and then sent to the controller 10. The control unit 10 causes the interface unit 11 to send the subscriber terminal 1-1 based on the demodulated signal.
The off-hook signal (incoming signal) of is transmitted. The interface unit 11 sends a ground signal to the 2W-4W conversion unit 12 via the M line. 2W-4W which received the ground signal
The conversion unit 12 internally closes a space between two lines connected to the exchange 13. When the subscriber terminal line is closed and the loop current (IL) flows, the exchange 13 detects the call from the subscriber terminal 1-1 and shifts from the idle state to the waiting state for dial number input.

At this time, that is, the 2W-4W converter 1
When 2 loops back the ground signal to the interface unit 11, the earth station 2 returns a response signal to the control unit 5.

When the response signal is returned, the off-hook signal of the subscriber terminal 1-1 is already input from the interface unit 4 to the determination unit 16. Therefore,
Even if the determination unit 16 receives the response signal from the control unit 5, the determination unit 16 does not turn on the ringer oscillation unit 3. Therefore, when a dial pulse (a signal having a dial number) for opening and closing the 2-wire loop is transmitted from the subscriber terminal 1-1, the interface unit 4 can accurately detect the dial number. become.

The signal having this dial number is sent to the control unit 5, coded here, subjected to modulation / demodulation processing in the modulation / demodulation unit 6, and decoded in the control unit 10 in the receiving side earth station 2. The decoded signal is sent to the 2W-4W conversion unit 12 through the M line of the interface unit 11.

The 2W-4W converter 12 sends the signal having the received dial number to the exchange 13 by the open / close of the two-line loop. Subsequently, when the exchange 13 receives the dial number, it connects the line to the called subscriber terminal 2-N.

As a result, the line between the subscriber terminal 1-1 and the subscriber terminal 2-N is connected through the satellite 14.

As described above, according to the above-described embodiment, whether the response signal from the called side received by the control unit 5 by the determination unit 16 is the pseudo response signal sent from the 2W-4W conversion unit 12 or not. , Or the original incoming signal to its own station (earth station 1) is determined. When the response signal is received, when the subscriber terminal 1-1 is already in the off-hook state, it is determined that it is a pseudo response signal, and conversely, when it is in the on-hook state, it is determined that it is the original incoming signal. It

Therefore, when the pseudo response signal is received, the ringer oscillator 3 is controlled so as not to be turned on so that the dial number represented by the dial pulse by the open / close of the two-wire loop by the subscriber terminal 1-1. Can be accurately detected by the interface unit 4. Therefore, the line can be satisfactorily connected to the subscriber terminal 2-N.

As is apparent from the above description, in the subscriber terminal control system of the present invention, the determination unit causes the response signal from the called side received by the control unit to be 2W-4.
Whether it is a pseudo response signal sent from the W conversion unit,
Alternatively, it is possible to determine whether it is the original incoming signal to the own station. For this reason, the line connection between the two-wire analog subscriber terminal by the dial pulse method arranged in the first earth station and the two-wire analog subscriber terminal arranged in the second earth station is performed by satellite communication. It has an effect that it can be satisfactorily performed.

According to the present invention, it is possible to obtain a derivative effect that it is possible to realize a subscriber terminal control system that can support both the MF system and the dial pulse system.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of an apparatus to which an embodiment of a subscriber terminal control system of the present invention is applied.

FIG. 2 is a block diagram showing a configuration of an apparatus to which a subscriber terminal control system according to a conventional technique is applied.

FIG. 3 is a diagram used for explaining the operation of the apparatus shown in FIG.

[Explanation of symbols]

 1, 2 Earth station 1-1 Subscriber terminal 2-1 to 2-N Subscriber terminal 16 Judgment unit

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location H04M 3/02 Z 8843-5K

Claims (1)

[Claims] 1. A line connection between a two-wire type analog subscriber terminal arranged in a first earth station by a dial pulse system and a two-wire type analog subscriber terminal arranged in a second earth station is established by satellite communication. In the subscriber terminal communication system to be performed, the first earth station includes an interface unit and a Ringer oscillator unit connected to the two-wire analog subscriber terminal, a control unit connected to the interface unit, and an input side as described above. An interface unit and a determination unit connected to the control unit side and having an output side connected to the Ringer oscillator unit are provided, and the determination unit is transmitted from the 2-wire to 4-wire conversion unit of the second earth station. When a calling signal is detected from the control unit,
When it is determined by the signal from the interface section that the two-wire analog subscriber terminal of the first earth station is in the off-hook state, the ringer oscillator section outputs the two-wire analog terminal of the first earth station. A subscriber terminal control system characterized in that transmission of a ringer signal to the subscriber terminal is stopped.