JPS6340067B2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a multi-service telephone device that simultaneously handles voice information, non-voice data, and information at a lower speed than voice such as facsimile information, making it possible to provide advanced communication services. .

Conventionally, the following methods have been proposed as this type of composite service.

(1) Two subscriber lines are used, one for calls between telephones, and the other for communication between low-speed information terminals that are slower than voice other than voice, such as data terminals or facsimile terminals. Make use of it.

(2) There is only one subscriber line, but the telephone and low-speed information terminals such as data terminals or facsimile terminals are connected at the same time, and each terminal is switched manually or automatically depending on the time of day.

(3) Although there is only one subscriber line, telephones and low-speed information terminals such as data terminals or facsimile terminals are connected at the same time, and each communication is frequency-divided.

However, in each of these methods, (1) requires two subscriber lines, (2) does not allow simultaneous communication of voice and low-speed information, and (3) requires frequency band division. Each had drawbacks, such as the high cost of the transmitting and receiving circuits and the significant deterioration of voice quality.

The purpose of this invention is to utilize a digital telephone,
A composite system that allows voice information and low-speed information such as data and facsimile information to be transmitted simultaneously over a single subscriber line, without significantly degrading voice quality, and that can be constructed at a very low cost. The purpose is to provide service telephone equipment. According to the present invention, an audio signal is sampled at a constant period, each sample value is digitally encoded, and the audio digital code, data, and a low-speed digital code such as a facsimile are assembled and transmitted as one frame. Each frame of the transmitted signal is separated into a voice digital code and a low-speed digital code.

FIG. 1 shows the configuration of a digital telephone. The voice input from the transmitter 11 is supplied to the analog-to-digital converter 13 through the transmitter amplifier 12.
It is sampled at a constant period, and each sample value is, for example, 8
It is converted into a bit digital signal. This digital signal is combined with the control signal from the control circuit 15 in the transmission shift register 14 and input to the speed conversion circuit 16. The speed conversion circuit 16 performs conversion between the transmission speed on the subscriber line 17 and the clock speed inside the telephone. The voice signal combined with the control signal is transmitted to the subscriber line 17 via the speed conversion circuit 16 and the transmitting/receiving circuit 18.

On the other hand, the received signal from the subscriber line 17 is separated from the transmitted signal in the transmitting/receiving circuit 18, passes through the speed converting circuit 16, and enters the receiving shift register 19. The reception shift register 19 separates the audio signal and the control signal, the control signal goes to the control circuit 15, and the audio signal is converted into an analog signal by the digital-to-analog converter 21. This analog signal passes through a receiver amplifier 22 and a receiver 23 and is output as audio.

For transmission control, the dial key 24 is controlled, and a control signal is sent to the transmission shift register 1 through the control circuit 15.
4. The received control signal drives the tone circuit 25 through the control circuit 15, and the output tone is emitted from the speaker 26.

FIG. 2 shows an example of a frame structure as a transmission format of the digitized subscriber line 17.
Bit F for frame synchronization and bit S for control signals between the telephone and the exchange to which the telephone is connected.
are placed at both ends of a word, and these bits F and S
In between, 8 bits or less of audio code 27 representing one digitized sample value is placed. The synchronization bit F and the control signal bit S may not be added every frame, but may be added once every several frames.

FIG. 3 and the following are embodiments of the present invention, in which one frame is constructed by combining a digitized voice code and a low-speed digital code such as data or facsimile. For example, as shown in FIG. 3, the audio digital code 27 is made up of 7 bits, and 1 bit of the low-speed code D is inserted between the audio code 27 and the control bit S. Alternatively, as shown in FIG. 4, the voice code 27 is 6 bits, and the data code 1 bit D
and 1 bit
and the control bit S.

When one bit in one frame is allocated for data terminal communication or facsimile terminal communication as shown in FIG. and the facsimile terminal 32 are switched and connected.

As shown in Figure 4, if one bit is allocated in one frame for data terminal communication and the other bit is allocated for facsimile terminal communication, the sixth
As shown in the figure, the switch 29 in FIG. 5 is omitted and a data terminal 31 and a facsimile terminal 32 are always connected to the digital telephone 28. In this way, three types of services, voice, data, and facsimile, can be provided simultaneously. Since 1 or 2 bits are allocated to low-speed codes for data terminals, facsimile terminals, etc., and the number of bits of the voice code is correspondingly reduced, the quality of the voice deteriorates somewhat.

However, it does not interfere with calls.

FIG. 7 shows a control circuit portion of a telephone device in which the present invention is implemented. The audio code from the input terminal 33 is temporarily stored in a temporary storage register 34. When transmitting voice codes and low-speed codes at the same time by the second transmission means, a switch 3 is used as a switching means.
5 to the data input line 36 side, and register 34
The lowest digit 30 bits of the audio code in the voice code are replaced by a low speed signal inputted from the data input line 36 by the replacement means and inputted to the transmission register 37. The remaining 7 bits of the voice code in register 34 are input to transmission register 37 through voice code transfer bus 38.

When the low-speed code is not transmitted by the first transmission means, the switch 35 is connected to the register 34 side, and the 8-bit voice code in the register 34 is input to the transmission register 37 through the switch 35 and the transfer bus 38. One bit of synchronization signal is added from the synchronization signal generator 41 to the first stage 39 of the transmission register 37, and one control bit from the control circuit 15 is added to the first stage 39 of the transmission register 37, and one control bit from the control circuit 15 is added to the next stage 42 of the final stage 42, that is, the next stage 43 to which the switch 35 is connected. The contents of the transmission register 37 are sent to the transmission signal line 44.

The received code from the received signal line 45 is input to the receiving register 46, and the voice code 7 of the received code is input to the receiving register 46.
The bits are input through an audio code transfer bus 47 to a temporary storage register 48, which sends them through an audio code output terminal 49 to a digital-to-analog converter.

Further, the low speed code in the second stage 51 of the receiving register 46 is outputted by the switch 52 via the data output line 53 to the low speed information terminal. If no composite service is to be performed, switch 52 is toggled to supply the contents of second stage 51 of register 46 to least significant digit 54 of temporary storage register 48, and all eight bits are used for transmitting voice codes. Receive register 4
The synchronization signal obtained at the final stage 55 in 6 is input to the synchronization detection circuit 56, and the synchronization detection circuit 56 synchronizes and controls the receiving digital-to-analog converter, as well as the synchronization signal generation circuit 41 and other parts of this telephone. The entire device is synchronously controlled. The synchronizing signal generating circuit 41 is configured to alternately generate codes "1" and "0" for each frame, for example. At the time of making a call, when the telephone switch is controlled, a signal from the transmission control line 57 is sent as a DC control signal to the subscriber's line through the control circuit 15, and a frame-structured signal is sent from the exchange in which the subscriber is accommodated to the telephone equipment. and detects the synchronization signal F,
The telephone equipment operates in synchronization with a synchronization signal from the exchange. When the subscriber performs a dial operation from this, the code is sent out as a control bit S through the control circuit 15.

The control bit S is extracted from the first stage 58 in the reception register 46 and inputted to the control circuit 15, and the control signal is sent to the tone circuit through the control line 59.
A ring tone is generated. After the call state is established, the switches 35 and 52 of each telephone device can be controlled by the call as necessary to simultaneously send and receive low-speed information and voice. It is also possible to send a signal to the exchange in which the subscriber is accommodated, so that the exchange controls the switches 35 and 52 of both subscribers simultaneously.

For low-speed information such as 200 bits/second or 1200 bits/second, such as in so-called asynchronous terminals, one bit is sent in multiple consecutive words (frames), and the other side Information can be recovered by detecting the state of the low rate code bit. When the low speed information is relatively high speed, the operation of the low speed information terminal may be synchronously controlled by the output of the synchronization detection circuit 56.

As explained above, by assembling the voice code of one sample value and the low-speed code as one frame, and configuring them to be separated from each frame, composite services can be easily provided, and a simple changeover switch 35 can be used. , 52 can control composite services.

As for low-speed information, in addition to data terminals and facsimile terminals, any terminal capable of transmitting digital codes can be connected to a telephone set for simultaneous transmission. When low-speed information is not transmitted, the number of bits in the voice code does not need to be increased. In other words, the switches 35 and 52 may be on or off switches.

[Brief explanation of the drawing]

Figure 1 is a block diagram showing the configuration of a digital telephone, Figure 2 is a diagram showing a frame configuration that transmits only voice codes, and Figure 3 is a diagram showing a frame configuration that simultaneously transmits voice codes and data or facsimile terminal communication codes. Figure 4 is a diagram showing a frame structure for simultaneously transmitting voice codes, data terminal communication codes, and facsimile terminal communication codes, and Figures 5 and 6 are diagrams showing connections between a telephone, a data terminal, and a facsimile terminal, respectively. Block diagram showing 7th
The figure is a block diagram showing the configuration of the control circuit portion of the multi-service telephone device according to the present invention. 15: Control circuit, 27: Voice code, 28: Digital telephone, 31: Data terminal, 32: Facsimile terminal, 37: Transmission register, 41: Synchronization signal generation circuit, 48: Reception register, 56: Synchronization signal detection circuit, F : Synchronization code, S: Control code, D:
Data code, X: facsimile code.

Claims (1)

[Claims] 1. Audio encoding means for sampling an audio signal at a fixed period and encoding each sample value into a digital code of a fixed number of bits; and a first transmission means for transmitting the digital coded audio signal as one frame; replacing means for replacing some bits of the digital code with a low-speed digital code other than an audio signal; a second transmission means for transmitting the data as a signal, a switching means for switching between the first transmission means and the second transmission means, and a voice encoding means for each frame of the transmitted digital code signal. a multi-service telephone device comprising: means for distributing the digital code of voice encoded by the voice code and the low-speed digital code other than voice substituted by the replacing means;