JPH025652A - Communication control equipment and loop type network system - Google Patents

Abstract

PURPOSE:To cause plural terminal equipment to simultaneously make speaking through a common channel by connecting one master terminal equipment and plural slave terminal equipment through a two-channel digital line in a loop. CONSTITUTION:Master terminal equipment 11 and slave terminal equipment 121-12n are connected through a digital line 13 having two channels of (1) and (2) connected in a loop. The master terminal equipment 11 repeats signals which are superposed by digital addition by means of the slave terminal equipment 121-12n and circulated through the transmitting channel (1) of the line 13 to the receiving channel (2) of the digital line 13. When the signals on the channel (2) are received by means of the slave terminal equipment 121-12n, mutually transmitted voices can be heard.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a communication control device and network system for voice communication via a digital line.

BACKGROUND ART FIG. 4 shows a functional block configuration of a conventional communication control device and network system. In Figure 4,
The transmitted voice input to each terminal device 1 is converted into an analog voice signal in the transmitter/receiver section 2, further converted into a digital voice signal in the codec section 3, and then transmitted to each terminal device 1 by the line control section 4. The information is transmitted onto each transmission line 5 provided one by one.

The adder 6 superimposes the digital audio signals transmitted and inputted from each terminal device 1 via the transmitting line 5 by digital addition, and then sends the digital audio signals via the receiving line 7 provided for each terminal device #1. and output to each terminal device.

In each terminal device #1, the digital audio signal received from the reception line 7 by the line control unit 4 is converted into an analog audio signal by the codec unit 3, and then the signal can be received as audio via the transmitting/receiving unit 2.

In this way, even in the conventional communication control device and network system, simultaneous interaction between a plurality of terminal devices 1 can be realized by superimposing them in the adder 6.

Problems to be Solved by the Invention However, in the conventional communication control device and network system described above, in order to realize simultaneous calls between multiple terminal devices, each terminal device has one channel for sending and one channel for receiving calls. It was necessary to prepare a line, which caused the problem of poor equipment efficiency.

The present invention solves these conventional problems,
The object of the present invention is to provide an excellent communication control device and network system that allow a plurality of terminal devices to talk simultaneously on a common channel.

Means for Solving the Problems In order to achieve the above object, the present invention connects one mask terminal device and a plurality of slave terminal devices in a loop through a two-channel digital line.

Effects The present invention has the following effects due to the above configuration. That is, a plurality of slave terminal devices and one mask terminal device connected in a loop through a two-channel digital line use one channel as a sending line and the other channel as a receiving line.

When each slave terminal device transmits a call, the transmitting signal and the receiving signal of one channel are superimposed by an adding means, and then the signal is sent again onto the channel (transmitting line). At this time, when the transmitting signal from the terminal device reaches a predetermined level or higher, the signal switching means changes the receiving signal from the other channel (receiving line) of the slave terminal device to the transmitting signal of the slave terminal device. Switch to

In this way, the transmission signal from the slave terminal device is superimposed on one channel (transmission line) and after making one round, is transferred to the other channel (transmission line) by the mask device. Therefore, each slave terminal device can receive the transmit signals of all slave terminal devices by receiving the receive signal on its channel (receiving line).

Embodiment FIG. 1 shows the configuration of an embodiment of the present invention. In FIG. 1, 11 is a master terminal device, 121 to 12n
are slave terminal devices, and 13 is a digital line of two channels rlJ and r2J that connect one master terminal device 11 and a plurality of slave terminal devices #121 to #12n in a loop.

FIG. 2 shows the configuration of the mask terminal device 11. As shown in FIG. In FIG. 2, 14 is a line control unit that transmits and receives digital signals of channels ``1'' and ``2'' of the digital line 13, and 15 is a line control unit that converts analog audio signals into digital audio signals having the same bit rate as the digital line 13. , and a codec unit that performs mutual conversion, and vice versa, 16
is the input signal from channel "2" of the digital line 13 and the output from the codec section 15. A signal switching unit 17 for switching between the transmitting signal and the transmitting signal;
This is a transmitting/receiving section that converts the transmitted voice into an analog voice signal that can be input to the codec section 15, and also converts the received analog signal output from the codec section 15 into voice.

FIG. 3 shows the configuration of the slave terminal device 121 (-12n). In FIG. 3, 18 is a line control section, 19 is a codec section, 20 is a signal switching section, and 21 is a transmitter/receiver section, which are the same as those in FIG. 2 above.

Reference numeral 22 denotes an adder that superimposes the transmitted digital audio signal output from the codec section 19 and the input signal from channel "1" of the digital line 13 by digital addition.

Next, the operation of the above embodiment will be explained. In the embodiment described above, the transmitted voice input to the transmitter/receiver section 17 of the master terminal device 11 is converted into an analog voice signal, and further converted into a digital voice signal by the codec section 15. This digital audio signal is transmitted onto channel "1" (speech channel) of the digital line 13 by the line control unit #14.

Channel “2” of digital line 13 (receiving channel)
The received signal is input to the codec unit 15 via the signal switching unit 16 and converted into an analog audio signal, and then
The voice is converted into received voice by the voice transmitting/receiving unit 17.

Normally, the digital audio signal input to the codec section 15 is an input signal from channel "2" (receiving channel) of the digital line 13, but is transmitted from the codec section 15 to the transmitting channel "1" of the digital line 13. When the level of the signal transmitted exceeds a predetermined constant level (during voice transmission), the signal switching section 16 switches the input signal to the codec section 15 to the output signal from the codec section 15 (transmission audio signal). This achieves echo cancellation in the received voice during transmission.

Further, the signal received from the transmitting channel "1" of the digital line 13 is transmitted to the receiving channel 2 of the digital line 13 as it is in the line control unit 14.

On the other hand, in slave terminal devices #121 to #12, similarly to the case of the master terminal device 11, the transmitted voice is converted into a digital voice signal by the transmitting/receiving section 21 and the codec section 19, and then converted into a digital voice signal by the adding section 22. Line 13
It is superimposed by digital addition with the input signal from channel "1" (transmission channel) of , and is sent onto the transmission channel "1" of the digital line 13 via the line control section 18 .

Channel “2” of digital line 13 (receiving channel)
The signal received from the digital line 13 is sent back to the receiving channel "2" of the digital line 13 as it is at the line control unit 18, while being converted into audio by the codec unit 19 via the signal switching unit 20.

When transmitting a call, as in the case of the master terminal device 11, the signal switching unit 20 switches the received input signal to the codec unit 19 to the transmit signal from the codec unit 19 according to the level of the transmitted audio signal. , echo cancellation is realized when transmitting a voice.

The above-mentioned master terminal device 11 receives signals that are digitally added and superimposed by the plurality of slave terminal devices 121 to 12n and passed once on the transmitting channel "1" of the digital line 13 to the receiving channel "1" of the digital line 13. 2"
Relay on top. And a plurality of slave terminal devices 121
~12□ can listen to each other's transmitted voices by receiving the signal on the receiving channel "2".

Effects of the Invention As is clear from the embodiments described above, the present invention connects one mask terminal device and a plurality of slave terminal devices in a loop using a two-channel digital line so that they can transmit and receive calls on a common channel. It has the advantage that multiple terminal devices can make simultaneous calls using a small number of digital lines.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram showing the configuration of a communication control device and a loop type network system in an embodiment of the present invention, Fig. 2 is a functional block diagram of a mask terminal device of the communication control device, and Fig. 3 is a functional block diagram of a slave terminal device of the communication control device, and FIG. 4 is a connection configuration diagram of each terminal device in a conventional communication control device and network system. 11...Mask terminal device, 121-12n...Slave terminal device, 13...Digital line, 14.18.
・Line fee? Terube, 15. [:... codec section, 16.20...
・Signal switching unit, 17.21... Transceiver unit, 22...
- Addition section.

Claims (3)

[Claims] (1) A transmitting/receiving means for inputting and outputting audio signals, and a digital/analog converting means for converting analog audio signals input and output from the transmitting/receiving means into digital audio signals with the same bit rate as the digital line or vice versa. a switching means for switching the received signal according to the level of the transmitted audio signal from the own device; a line control means for transmitting and receiving the digital audio signal to and from the digital line;
A communication control device comprising signal switching means for switching input/output signals from the digital line between channels on the digital line. (2) A transmitting/receiving means for inputting and outputting audio signals, and a digital/analog conversion means for converting analog audio signals input and output from the transmitting/receiving means into digital audio signals with the same bit rate as the digital line, or vice versa. an adding means for adding, as a digital audio signal, the received signal from the digital line and the outgoing audio signal from the own device digitized by the digital/analog conversion means; A communication control device comprising a switching means for switching a received signal according to a level, and a line control means for transmitting and receiving the digital audio signal to and from a digital line. (3) A loop network system comprising a two-channel digital line that connects one communication control device according to claim (1) and a plurality of communication control devices according to claim (2) in a loop.