JPH0210713Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to a telephone system, and particularly to a telephone system for extending the accommodation line length of a high-performance telephone in which a private branch exchange or button telephone device is accommodated. .

[Prior art]

For example, as shown in FIG. 1A, a conventional button telephone device includes a plurality of button telephones 3, a main device 1 for controlling them, a wiring cable 5 for connecting a connector 2 to the main device 1, and each button telephone 3. and a cable 6 that connects the connector 2 to the connector 2.

The main device 1 includes a line for communicating with the central office line CO,
It consists of a circuit for communicating between the key telephones 3 and a common circuit for controlling the incoming calls to each telephone 3, indicating whether the telephone line is busy, on hold, etc. with lamps or sounds.

In addition, as shown in Fig. 1b, a conventional private branch exchange (PBX) includes a main distribution board 7 connected to the central office line,
It is composed of a central office trunk 8, a central office relay board 10, a private branch exchange 9, a terminal box 11, an extension telephone 12, and an extension line 13.

Since the private branch exchange 9 is installed in the subscriber's premises and the extension telephone 12 is usually installed in the same premises, the distance of the extension line 13 is short.

On average, the number of control signals that control the telephones housed in these pushbutton telephone devices and private branch exchanges is several dozen.
It is sufficient to have a transmission speed of ~100 b/s, and the range where the telephone is accommodated is several 100 b/s.
Since the distance is from several hundred meters to several hundred meters, a baseband transmission method is used in which digital signals are directly transmitted and received via control lines. Although this baseband transmission method has a simple and economical circuit configuration, it has the drawback that the possible transmission distance is limited to within several hundred meters.

As the scope of business of companies and organizations expands, there is an increasing desire to install high-performance telephones in remote locations with functions such as speed dialing, automatic forwarding, answering machines, display terminals, and data transmission.

[Purpose of invention]

The purpose of the present invention is to extend the line length that can be accommodated by high-performance telephones housed in private branch exchanges or pushbutton telephone equipment without degrading signal transmission performance, in order to solve the above-mentioned conventional problems. Our goal is to provide a telephone system that can.

[Summary of the idea]

In order to achieve the above object, the telephone system of the present invention includes a key telephone main device or a private branch exchange,
A telephone system in which a control line is provided between a telephone connected to the key telephone main unit or a private branch exchange, and control information for controlling the telephone is transmitted over the control line using baseband digital signals. When connecting an installed telephone and the key telephone main device or private branch exchange via a control line, the control signal is sent to each of the telephone and the key telephone main device or private branch exchange using a baseband digital signal. An adapter is provided that includes means for modulating the signal into a signal at a voice band frequency and means for demodulating the signal at the voice band frequency into a digital signal at the baseband, and control of the voice band frequency is performed on a control line between the adapters. It is characterized by transmission as a signal.

[Example of idea]

In button telephone equipment and private branch exchanges, signals sent and received between the high-performance telephone (hereinafter referred to simply as the telephone) and the key telephone main equipment or private branch exchange include voice signals for telephone calls, as well as telephone signals. Various control signals such as information for driving function display lamps, characters, symbol displays, etc., press information for telephone switch or function request button, etc. and, if necessary, electric power to be supplied to the telephone control circuit. be.

This invention enables remote installation of telephones by connecting an adapter to the telephone and exchange side, modulating control signals sent and received using baseband digital technology to a frequency within the audio band, and sending and receiving the control signals. .

Also, regarding audio signals and power supply,
There are various methods, but in this invention, if a distance outside the allowable limit is required for the audio signal,
As is conventional practice, remote installation is achieved by increasing the diameter of the transmission cable or inserting an amplifier for loss compensation. Furthermore, power is supplied to each telephone using a commercial power source, instead of being supplied to the telephone from an exchange or key telephone main unit as in the past.

FIG. 2 is a connection configuration diagram of a private branch exchange using an adapter showing an embodiment of the present invention.

In FIG. 2, 100 is an exchange, 400 is a telephone, 200 and 300 are remote installation adapters for control side C and telephone side T, 101 is a control circuit, 110 is a subscriber circuit, 500, 501, and 502 are control lines, and 600 , 601, 602 are voice lines.

In addition, in FIG. 2, the control lines 500 to 5
02 and voice lines 600 to 602 are half-duplex lines that can be used both for up and down lines.
602 is an independent uplink and downlink line, only control lines 500 to 502 are independent uplink and downlink lines, power feeding lines can be independent, and these are combined and superimposed, or multiplex lines are used. There are various methods that can be used, but these differ only in the method of inserting and extracting the control signal, and the present invention can be applied to all of them.

In FIG. 2, a control circuit 10 of an exchange 100
A control signal for controlling the telephone 400 sent from the control circuit 11 in the subscriber circuit 110 is sent from the control circuit 11 in the subscriber circuit 110.
4, is converted into a baseband digital signal by the driver/receiver 115, and is transmitted to the control line (C) 50 via the pulse transformer 118.
Sent to 0. In the high-performance telephone remote installation adapter (C) 200 of the present invention, the control signal sent from the subscriber circuit 110 via the line 500 is received by the driver/receiver 202 via the pulse transformer 209. The signal is transmitted to the transmission/reception control circuit 203. Control circuits 203 and 304 of adapter 200 are control circuits that temporarily store control information transmitted from both sides of telephone 400 or exchange 100 in internal memory, and transmit respective control signals in opposite directions at predetermined time intervals. It is. For example, when transmitting according to the time relationship shown in Figure 3, the control signal sent from the telephone side is sent to the exchange side immediately after the control signal sent from the exchange side is sent to the telephone side. Control. Therefore, the control circuit 203 has already activated the telephone 40.
The switch information and function button information of the telephone 400 received from the 0 side are sent to the exchange 100 side via the driver/receiver 202 and the pulse transformer 209 in the opposite direction to the above. On the other hand, the control signal received from the exchange 100 side is modulated into a voice band frequency signal by the modem 204, level-adjusted by the equivalent amplifier 205, and then passed through the voice transformer 210 and the control line (L) 501.
is sent to the telephone 400 side via. Line (L) 501 is a local leased line or a long-distance leased line (carrier line), and is a line for connecting to telephone 400 installed in a remote location away from exchange 100. The high-performance telephone remote installation adapter (T) 300 on the telephone side receives the voice band control signal transmitted via the line 501 via the audio transformer 309, and performs frequency correction and level correction using the equivalent amplifier 302. After that, the modem 303 converts the signal back into a digital signal, and the signal transmission/reception control circuit 3
04. The control circuit 304 sends the switch information and function button information of the telephone 400, which have already been received from the telephone 400 side, to the exchange 100 side via the modem 303, equivalent amplifier 302, and audio transformer 309 in the opposite direction to the above. Send. On the other hand, the control signal received from the exchange 100 is converted into a baseband digital signal by the driver/receiver 305 and sent to the telephone 400 via the pulse transformer 310 and the control line (T) 502. In telephone 400,
A control signal sent from the exchange side via a control line (T) 502 is received by a driver/receiver 401 via a pulse transformer 407 and transmitted to a signal transmission/reception control circuit 402. Control circuit 40
2 controls the function button/lamp/display 403 according to the received control signal, and conversely sends function button information etc. to the driver/receiver 401,
Pulse transformer 407, control line (T) 502
It is sent to the exchange side via.

Next, the voice signal is transmitted from the communication path switch 102 of the exchange 100 to the PCM code decoder of the subscriber circuit 110, to the filter 112, and to the 4-wire 2-wire switching circuit 113.
Audio line (C) from audio transformer 117 through
600, and the adapters 200 and 300 respectively pass the audio transformer to the equivalent amplifier 20.
1,301, the audio is amplified and sent to the audio circuit 404 of the telephone 400 and the handset 406. The voice signal from telephone 400 to exchange 100 is also sent in the opposite direction to the above path.

FIG. 3 shows the time relationship between transmission and reception of the aforementioned control signals, focusing on the waveforms on the control line (C) 500, control line (L) 501, and control line (T) 502. In the figure, ','' indicate the signals sent from the exchange 100 to the telephone 400.
'' respectively indicate signals sent from the telephone 400 to the exchange 100.

In the embodiment shown in FIGS. 2 and 3,
A control signal sent from the exchange 100 side or the telephone 400 side is transmitted as it is to the telephone 400 or exchange 100 through the adapter 200 or 300, but depending on the number of bits of the control signal and the transfer cycle, the control signal may be sent to the modulator/demodulator 204. Alternatively, it may become impossible to transmit the modulated signal by H.303 within the voice band, or the modulator/demodulator may become expensive. Therefore, in particular, in a system that employs a method in which control signals are transmitted periodically and a signal of "no information" is transmitted when there is no information to be sent or received, the control circuit 203 or 304 may If it is determined that there is no information, the transmission and reception of the signal is omitted, or if the information cannot be transmitted in time, it is temporarily stored and transmitted sequentially using the period of no information. By doing so, it is possible to configure an inexpensive modulator/demodulator within the voice band.

Furthermore, in the examples shown in FIGS. 2 and 3, the adapters 200 and 300 are provided as a pair in one-to-one correspondence between the subscriber circuit 110 on the exchange 100 side and the telephone 400, but the transmission speed of the control signal is In cases where the speed is relatively slow and the amount of information is not large, economy can be achieved by accommodating the control lines of multiple subscriber circuits 110 and telephones 400 at the same time and operating the control circuits 203 or 304 in a time-sharing manner. Is possible.

〔Effect of the invention〕

As explained above, according to the present invention, since the control signal is transmitted and received as a frequency signal in the voice band, an amplifier can be inserted and a long-distance carrier line can be used. , smart telephones housed in private branch exchanges or key telephone equipment can be installed in remote locations.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of a conventional key telephone device and private branch exchange, Fig. 2 is a block diagram of a private branch exchange using an adapter showing an embodiment of the present invention, and Fig. 3 is a block diagram of a private branch exchange using an adapter according to an embodiment of the present invention.
3 is a time chart showing the waveform of a control signal in the figure. 100: Private branch exchange (time division exchange), 10
1: Control circuit, 102: Communication path switch, 11
0: Subscriber circuit, 111: PCM code decoder, 1
12: Filter, 113: 4-wire 2-wire exchange circuit, 1
14, 203, 304, 402: Signal transmission and reception control circuit, 115, 202, 305, 401: Driver receiver, 116, 206, 306, 40
5: Power receiving circuit, 117, 207, 208, 21
0,307,308,309,408: Audio transformer, 118,209,310,407: Pulse transformer, 200,300: Telephone remote installation adapter, 201,205,301,302: Equivalent amplifier, 204,303: Modulation/demodulation Vessel, 400:
High-performance telephone, 403: Function button/lamp/display, 404: Audio circuit, 406: Handset, 500, 501, 502: Control line, 6
00,601,602: Voice line.

Claims (1)

[Scope of utility model registration request] A control line is provided between a key telephone main device or private branch exchange and a telephone connected to the key telephone main device or private branch exchange, and control information for controlling the telephone is transmitted via baseband digital signals on the control line. In the telephone system that transmits,
When connecting a telephone installed in a remote location and the key telephone main device or private branch exchange via a control line, the above control signal is transmitted to each of the telephone and the key telephone main device or private branch exchange based on the above control signal. An adapter is provided with means for modulating a digital signal in the voice band frequency into a signal in the voice band frequency, and a means for demodulating the signal in the voice band frequency into a digital signal in the baseband. A telephone system characterized by transmission using frequency control signals.