JPH10173784A - Call reception terminal selection system for agricultural community area information system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate the need for a muting circuit, required for a terminal equipment in the agricultural community area information system. SOLUTION: When a caller terminal hooks off, an exchange detects it and inverts the polarity of line and sends a dial tone 201 to a line. When a destination telephone number is entered from the caller terminal by a PB signal 202, the exchange restores the polarity of the line. The caller terminal detects it that the polarity change of the line is restored and sends an individual signal 203 specific to a terminal onto the line. The exchange discriminates the caller terminal, based on the individual signal 203 sent from the caller terminal and inverts the polarity of the line again and sends a ring back tone 205 after transmission of a called terminal selection signal 204. The called terminal discriminates it that the called terminal selection signal sent from the exchange is addressed to itself and transits to a call reception state.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a terminal control system for a cooperative rural area information system, and more particularly, to a method for selecting a terminating terminal during a call on the same line.

[0002]

2. Description of the Related Art In a conventional joint type rural area information system, in a method of selecting a receiving terminal during a call on the same line, a switching terminal transmits a receiving terminal selection signal on a line in order to place the receiving terminal in a receiving state. A signal of a frequency pattern corresponding to each terminal is used as the incoming terminal selection signal, and the incoming terminal selection signal uses a frequency component in a speech band.

[0003]

However, in the above-mentioned conventional cooperative rural area information system, the incoming terminal selection signal transmitted on the line during the same line communication has a frequency component within the communication band. In addition, a terminal muting function is required to prevent the selection signal from leaking to the receiver of the transmitting terminal, and there has been a problem that the circuit of the terminal is complicated.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned circumstances, and has been made to solve the above-mentioned problems inherent in the conventional technology. Therefore, an object of the present invention is to simplify the circuit configuration of a terminal. It is an object of the present invention to provide a new method of selecting a terminating terminal for a collaborative rural area information system.

[0005]

In order to achieve the above-mentioned object, according to the present invention, there is provided a terminating terminal selection method for a joint rural area information system, wherein a signal out of the communication band is used as a terminating terminal selection signal, and the terminating terminal is selected. In order to make a selection, control is performed not based on the frequency distribution pattern of the incoming terminal selection signal but on the transmission time.

That is, in the present invention, each terminal is provided with a unique selection signal transmission time, and the corresponding reception terminal shifts to the reception state depending on the difference in transmission time of the reception terminal selection signal, which is a signal outside the communication band. To control.

[0007]

Next, a preferred embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a block diagram showing a connection relationship between an exchange and terminals in a joint rural area information system according to the present invention, and shows a state in which five terminals are connected to one line.

Referring to FIG. 1, five terminals 103-1... Are connected to a pair of lines 102 connected to an exchange 101.
103-5 is connected. In the case of a call in which the calling terminal and the receiving terminal are on the same line, in order to hear a signal such as a dial tone and a ring back tone transmitted from the exchange 101 from the receiver of the calling terminal, a signal on the line is transmitted to the calling terminal. The receiver can be monitored.

Next, an example of the same line transmission sequence according to the present invention will be described with reference to FIG.

FIG. 2 is an identical line transmission sequence diagram showing one embodiment of the present invention.

Referring to FIGS. 1 and 2, when a calling terminal goes off-hook, exchange 101 detects this and inverts the line voltage, and sends dial tone 201 to line 102. The calling party's telephone number is the PB signal 202 from the calling terminal.
, The exchange 101 returns the line voltage to normal rotation. The transmitting terminal detects that the line voltage has been turned forward, and transmits a terminal-specific individual signal 203 on the line.

After discriminating the calling terminal from the individual signal 203 sent from the calling terminal, the exchange 101 inverts the line voltage again, sends a called terminal selection signal 204, and then sends a ring back tone 205. As the receiving terminal selection signal 204, a single tone of 20 Hz is transmitted for 2 × n wavelengths according to the ID number n (n = 1 to 5) of the receiving terminal. The receiving terminal determines that the receiving terminal selection signal transmitted from the exchange corresponds to its own terminal, and shifts to an incoming call state.

[0014]

As described above, according to the terminating terminal selection method for the joint type rural area information system according to the present invention,
By using a signal outside the communication band as the receiving terminal selection signal, the receiving terminal selection signal transmitted on the line does not leak to the receiver of the transmitting terminal, so that the conventionally required muting function becomes unnecessary. The advantage is that the circuit configuration of the terminal can be simplified.

[Brief description of the drawings]

FIG. 1 is a connection diagram of a joint-type terminal in a terminating-terminal selection method for a joint-type rural area information system according to the present invention.

FIG. 2 is an identical line transmission sequence diagram showing one embodiment of the present invention.

[Explanation of symbols]

 101 switchboard 102 shared line 103 terminal 201 dial tone 202 PB signal 203 individual signal 204 called terminal selection signal 205 ringback tone

Claims (3)

[Claims] 1. A wired broadcast exchange for a cooperative rural area information system, a plurality of wired broadcast telephone lines connected to the wired broadcast exchange, and a plurality of wired broadcast terminals connected to one wired broadcast telephone line In the joint rural area information system composed of the above, when the calling terminal and the receiving terminal are on the same line, a signal out of the communication band is used as the receiving terminal selection signal transmitted by the cable broadcast exchange on the line. A muting circuit in the terminal, which is necessary to prevent the receiving terminal selection signal from leaking from the receiver of the transmitting terminal, thereby eliminating the need for a muting circuit in the joint rural area information system. 2. A wired broadcast exchange for a cooperative rural area information system, a plurality of wired broadcast telephone lines connected to the wired broadcast exchange, and a plurality of wired broadcast terminals connected to one wired broadcast telephone line. In the collaborative rural area information system, the cable broadcast exchange inverts the line voltage and transmits a dial tone to the line when the off-hook of the calling terminal is detected, and the destination telephone number is transmitted from the calling terminal. When input as a PB signal, the line voltage is inverted, and the transmitting terminal transmits a terminal-specific individual signal on the line when detecting that the line voltage has been rotated,
Next, the exchange, after discriminating the transmission terminal by the individual signal transmitted from the transmission terminal, inverts the line voltage again, and transmits a ringback tone after transmitting a reception terminal selection signal, and the reception terminal transmits the ringback tone. A terminating terminal selection method for a collective rural area information system, characterized in that it determines that the terminating terminal selection signal transmitted from the exchange corresponds to the terminal itself, and shifts to an incoming call state. 3. The apparatus according to claim 2, further comprising transmitting a single tone of 20 Hz as the called terminal selection signal for 2 × n wavelengths according to the ID number n of the called terminal (n is a positive integer). The incoming terminal selection method for the joint rural area information system described.