JPH06303276A - Communication system - Google Patents

Abstract

PURPOSE:To execute facsimile communication, etc., while effectively utilizing a digital communication network with sufficiently large transmission capacitance in comparison with a facsimile signal. CONSTITUTION:The both output signals of a facsimile equipment and a voice transmitting/receiving device 21 are received so that the transmission/reception is executed with the digital communication network 29. The signal of the facsimile equipment 20 is modulated/demodulated by a picture signal modulating/ demodulating part 42. The signal of the voice transmitting/receiving device 21 is band compression-encoded or decoded by an analog signal converting part 41. Either of the signals are made into a packet by a packet generating/ resolving part 45 and multiplexed in a packet multiplexing part 46. That is, a transmission line is effectively used by the multiplexing of a packet signal.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a communication system for efficiently transmitting a signal output from a facsimile machine via a digital communication network.

[0002]

2. Description of the Related Art A facsimile machine sends and receives image signals using a telephone line. FIG. 2 shows a block diagram of a general facsimile apparatus. This apparatus includes a reading section 2 for reading an original image 1, a facsimile signal processing section 3, a device control section 4, an image modulation / demodulation section 5, a control signal modulation / demodulation section 6, a connection signal transmission / reception section 7, a telephone line corresponding section 8 and the like. Is equipped with. The reading unit 2 is a unit that optically reads the image information described in the original image 1 and converts it into an electric signal. The facsimile signal processing unit 3 is a unit that performs such a signal compression process and the like, as well as a received signal decompression process and printing. The image modulation / demodulation unit 5 is a unit that performs modulation / demodulation for adapting the image signal converted into an electric signal and a general analog transmission telephone line 10.

The device control unit 4 includes various parts of the device and a telephone line 10.
This is a part for exchanging control signals with other facsimile machines connected to the device and controlling communication. The control signal modulation / demodulation unit 6 is a unit for converting a digital control signal, which is exchanged with a communication partner, into an analog signal, and sending the analog signal to the telephone line 10 or receiving the analog signal. The connection signal transmission / reception unit 7 is a unit that performs necessary call control and the like for performing line connection before performing communication. The telephone line corresponding part 8 is an interface part with the telephone line 10.
The signal from the facsimile device is connected to the telephone line 10 as an analog signal via the telephone line corresponding unit 8.

As described above, the facsimile apparatus connected to the general telephone line 10 operates so as to send the image signal as an analog signal to the telephone line 10 and receive the analog signal to restore the image. On the other hand, in recent years, digital communication using a band compression coding method has been performed on a dedicated line or the like that connects business establishments. The above facsimile device cannot be directly connected to such a digital communication network.

Therefore, conventionally, the following communication system has been put into practical use. FIG. 3 shows a block diagram of a conventional communication system. In this system, output signals of the facsimile device 20, the voice transmitting / receiving device 21 and the like are transferred to the digital communication network 29.
It is configured to transmit via. Here, an A / D converter 22, a D / A converter 24, and a D / A converter 24 are provided between the facsimile device 20, the voice transceiver 21, and the digital communication network 29.
A demodulator 23, a modulator 25, an identification unit 26, etc. are arranged. In addition to this, changeover switches 27 and 28 are provided.

In this system, the facsimile machine 20
The analog image signal output from the digital communication network 2 is demodulated by the demodulator 23 and converted into a digital signal.
It is sent to 9. The analog voice signal output from the voice transmitting / receiving device 21 is band-compressed and encoded by the A / D converter 22 and output to the digital communication network 29. In the case of a facsimile signal, the signal received from the digital communication network 29 is converted into an analog signal by the modulator 25 and sent to the facsimile device 20. Further, in the case of a voice signal, it is decoded by the D / A converter 24 and sent to the voice transmitting / receiving device 21. In the communication system as described above, the identifying unit 26 identifies whether the signal to be transmitted / received is a voice signal or a facsimile signal, and the changeover switch 2 is accordingly identified.
7 and 28 are operated to set the mode to perform band compression encoding / decoding or demodulation modulation.

FIG. 4 is a diagram for explaining the facsimile mode setting operation. When transmitting and receiving the above-mentioned facsimile signals, it is necessary to have a conversation for mode setting between the facsimile apparatuses which mutually transmit and receive signals. For this purpose, as shown in FIG. 4, the procedures of phase A, phase B, phase C, phase D, and phase E are provided. Phase A is a call setup procedure for connecting a transmission path, Phase B is a pre-message procedure, Phase C is a message procedure, Phase D is a post-message procedure, and Phase E is a call release procedure.

Since such a signal is generally a narrow band signal, in the communication system shown in FIG.
Communication is performed via the D converter 22 and the D / A converter 24. Then, in the phase B, the conversation between the facsimiles is confirmed by the identification unit 26, and then the transmission using the demodulator 23 and the modulator 25 is performed. Phase B as described above is a part where the facsimile devices perform a conversation necessary for matching the image conversion methods and for transmitting and receiving images. When such a conversation is performed, it is necessary to notify the other party of the start. is there.

FIG. 5 is an explanatory diagram of signals in phase B.
A preamble signal 31 as shown in the figure is used as a signal for such notification to the other party. As a result, the start time of the phase B can be known, and the binary code information 32 and the like are subsequently transmitted. FIG. 6 shows an operation procedure explanatory diagram of phase B. As shown in this figure, in phase B, the digital identification signal of (1) is transmitted, the confirmation signal of (14) is transmitted, and the process proceeds to phase D. According to the communication procedure as described above, the facsimile signal is transmitted / received in such a manner as to bypass the band compression type encoder. The technology as described above is described in Akazawa et al., "Facsimile / Voice Converter for Digital Private Line (MUXIA.VX)", International Communication Research, Sept. 19
90 No 144.

[0010]

By the way, the facsimile signal is usually a very low speed signal of about 9600 BPS. On the other hand, the digital communication network transmits audio signals of 16 KB.
It is encoded into PS (bits / second) and transmitted. Therefore, if the above digital communication network is occupied by a facsimile machine, 16 KBPS-9600 BPS, i.e. 6.4
There is a problem that the transmission capacity of KBPS is wasted.

The present invention has been made in view of the above points, and is a communication system capable of performing facsimile communication and the like while effectively utilizing a digital communication network having a transmission capacity sufficiently larger than that of a facsimile signal. It is intended to provide.

[0012]

A communication system of the present invention receives output signals of a plurality of terminal devices including a facsimile device, transmits the output signals to a digital communication network, and receives the digital signals from the digital communication network. It has a transmission / reception interface, and this transmission / reception interface
An image signal modulation / demodulation unit that modulates an image signal output from the facsimile device to generate a digital signal and supplies the digital signal to a packet generation / decomposition unit, and demodulates a digital signal received through the packet generation / decomposition unit and transfers the digital signal to the facsimile device. And the analog signal output from the other terminal device is band-compressed and supplied to the packet generation / decomposition unit, while the signal received via the packet generation / decomposition unit is decoded and converted into an analog signal. To the analog signal converter, and the signals input from the analog signal converter and the image signal converter are added with source information and destination information for identifying the source terminal device and the destination terminal device, respectively. While generating a packet signal, a packet generation / decomposition unit that decomposes the signal input from the packet multiplexing unit and a plurality of packets A packet multiplexing unit that multiplexes the packet signal input from the packet generation / decomposition unit and transmits the packet signal to the digital communication network, and receives the packet signal from the digital communication network and distributes the packet signal to the corresponding packet generation / decomposition unit. It is characterized by having.

[0013]

This communication system receives both output signals of the facsimile device and the voice transmitting / receiving device and transmits / receives them through the digital communication network. The signal of the facsimile machine is modulated or demodulated by the image signal modulator / demodulator. Further, the signal of the voice transmitting / receiving device is band-compression coded or decoded by the analog signal converter. Also,
Both signals are packetized by the packet generation / decomposition unit and multiplexed by the packet multiplexing unit. That is, the transmission path is efficiently used by multiplexing the packet signals.

[0014]

The present invention will be described in detail below with reference to the embodiments shown in the drawings. FIG. 1 is a block diagram showing a communication system embodiment of the present invention. In this system, signals of terminal devices such as the facsimile device 20 and the voice transmitting / receiving device 21 are transmitted / received via the digital communication network 29.
In the illustrated embodiment, the facsimile device 20 and the voice transmitting / receiving device 21 are connected to the digital communication network 29 via a transmitting / receiving interface 40.

The transmission / reception interface 40 includes an analog signal converter 41, an image signal modulator / demodulator 42, a control signal modulator / demodulator 43, a monitor controller 44, and a packet generator / disassembler 45.
And a packet multiplexing unit 46. When the input signal is an analog signal output from the voice transmitting / receiving device 21 or the like, the analog signal conversion unit 41 band-compresses and converts the analog signal into a digital signal, and the packet generation / decomposition unit 4
5 and the function of inversely converting the signal received from the packet generation / decomposition unit 45. The image signal modulation / demodulation unit 42 has a function of demodulating an analog facsimile image signal output from the facsimile device 20 into an original facsimile image signal and converting the original facsimile image signal into a digital signal or vice versa. Is. In this system as well, as in the case of the prior art, the signal of the facsimile apparatus is directly demodulated into the original digital signal and sent to the digital communication network without band compression coding.

The control signal modulator / demodulator 43 is a part for modulating / demodulating a control signal exchanged between facsimiles.
The monitoring control unit 44 is a unit that monitors the exchange of control signals between the facsimile devices and controls the generation and separation of packets. The packet generation / decomposition unit 45 includes an analog signal conversion unit 41, an image signal modulation / demodulation unit 42 or a control signal modulation / demodulation unit 43.
Is a part having a function of packetizing the output signal of 1) under the control of the monitor control part 44 and outputting it to the packet multiplexing part 46. The packet generation / decomposition unit 45 also has a function of decomposing the packet signal received from the packet multiplexing unit 46 and sending it to the analog signal conversion unit 41, the image signal modulation / demodulation unit 42 or the control signal modulation / demodulation unit 43. .

FIG. 7 is a diagram for explaining the contents of packets handled by the packet generation / decomposition unit 45. (A) is an explanatory diagram of image packet contents, and (b) is an explanatory diagram of voice packet contents. First, in (a), the image packet includes destination information 56, source information 57, a packet control signal 58, a facsimile image signal 52, a facsimile control signal 53 and C.
It consists of RC59. The destination information 56 is information for identifying the other party of communication, and the source information 57 is information for identifying the device that transmitted this packet. The packet control signal 58 is a signal including information for identifying whether it is an image packet signal or a voice packet signal, or indicating whether or not the facsimile control signal 53 is included in the image packet. The facsimile image signal 52 is a signal that should be actually transmitted and received by the facsimile device. The facsimile control signal 53 is a control signal for the above-described facsimile communication for performing mode setting and the like between the facsimile devices. CRC5
Reference numeral 9 is a signal for detecting a packet error.

On the other hand, the voice packet is composed of destination information 56, source information 57, a packet control signal 58, a voice signal 51 and a CRC 59. Each signal except the audio signal 51 is exactly the same as the image packet. The packet configuration itself as described above is the same as that used for normal packet communication. Such packet signals are exchanged between the packet multiplexing unit 46 and the packet generation / decomposition unit 45. The packet multiplexing unit 46 is a unit having a function of multiplexing the above-mentioned packets and outputting them to the digital communication network 29, or vice versa. Here, in addition to the packet generation / decomposition unit 45 shown in this figure, some packet generation / decomposition units (not shown) connected to other facsimile devices or other terminal devices are connected, and the digital communication network 29 can be efficiently used by multiplexing. I am aiming for various uses.

FIG. 8 shows an explanatory diagram of the operation of the communication system of the present invention. The communication system as described above operates as follows. First, the audio signal 5 output from the audio transceiver 21 or the like
1 is band-compressed and encoded by the analog signal conversion unit 41, and converted into a voice packet 54 as shown in FIG. 7B by the packet generation / decomposition unit 45.

On the other hand, as shown in FIG. 8, the facsimile image signal 52 and the facsimile control signal 53 are demodulated by the image signal modulator / demodulator 42 and converted into digital signals.
The packet generation / decomposition unit 45 forms an image packet 55. The content of this signal is as shown in FIG. At this time, the monitoring control unit 44 shown in FIG. 1 constantly monitors the digital side of the control signal modulation / demodulation unit 43, that is, the packet generation / decomposition unit 45 side. Control signal modulator / demodulator 4
3 is provided with the same modulator / demodulator as the control signal modulator / demodulator provided inside the facsimile machine 20 as shown in FIG. 2, and only signals passing through the control signal modulator / demodulator in the facsimile machine are significant. It is output as a signal.
Therefore, the signals of phase B and phase D can be recognized as digital information. This is monitored to recognize the facsimile transmission control procedure.

When the input signal is a facsimile signal and is in the states of phase B and phase D, the preamble signal described above is detected. When this signal is detected, the monitoring control unit 44 commands the packet generation / decomposition unit 45 to generate an image packet. As a result, it is determined whether the input signal of the transmission / reception interface 40 is voice packetized or image packetized. The packet multiplexing unit 46 in FIG. 8 receives the voice packet 54 and the image packet 55 as described above, or receives the same signal from the other packet generation / decomposition unit and outputs it to the digital communication network 29. Therefore, as shown in the figure, various packet signals 61, 62, 63 can efficiently use the digital communication network 29 and perform multiplex communication.

The receiving side monitors the control signal in the packet as described above, that is, the packet control signal 58 of the image packet and the voice packet shown in FIG. 7, and when it recognizes that the signal is a facsimile signal, the conversion or conversion is performed. Modulation / demodulation operation is switched. The end of communication is confirmed by the monitoring control unit 44 detecting a communication end code such as EOM in the packet control signal 58. When the communication of the facsimile device 20 is completed, the transmission / reception interface 40 thereafter generates a voice packet.

With the above-described structure, in the digital communication network 29, when transmitting a facsimile signal, the transmission path is occupied only when the image packet is generated, and in the case of a facsimile signal having a small amount of information, the speed of the facsimile signal. The transmission line is occupied only for the time period commensurate with, and the remaining time period can be effectively used for other signal transmission. Therefore, there is no problem of occupying a voice signal transmission line for a certain period of time for transmitting and receiving a facsimile signal as in the conventional case, and an economical transmission system is provided.

The present invention is not limited to the above embodiments. In the above embodiments, the analog signal converter 41, the image signal modulator / demodulator 42, and the control signal modulator / demodulator 43 are all described as circuits that perform conversion, inverse conversion, or modulation and demodulation.
Any of these may be decomposed into a circuit having a different structure in which modulation and demodulation are performed separately. Packet generation / decomposition unit 4
The packet generator 5 and the packet disassembling unit may be configured separately for 5, too. Further, the block configuration of the transmission / reception interface 40 may be changed to various configurations having the above functions.

[0025]

The communication system of the present invention described above is
When a digital communication network is shared by a voice transmitter / receiver, a facsimile machine, etc., these signals are packetized, multiplexed by a packet multiplexer and sent to the digital communication network, so that the communication path is occupied by a relatively low speed facsimile signal. And the economical communication system can be established. That is, since the facsimile signal having a small amount of information is configured to occupy the transmission path only for the time zone commensurate with the speed of the facsimile signal, there is an effect that the other remaining time zones can be effectively used for another signal transmission. .

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a communication system of the present invention.

FIG. 2 is a block diagram of a general facsimile apparatus.

FIG. 3 is a block diagram of a conventional communication system.

FIG. 4 is an explanatory diagram of a mode setting operation of a facsimile.

FIG. 5 is an explanatory diagram of signals in phase B.

FIG. 6 is a diagram illustrating an operation procedure of phase B.

7A and 7B are explanatory diagrams of packet contents; FIG. 7A is an explanatory diagram of image packet contents, and FIG. 7B is an explanatory diagram of voice packet contents.

FIG. 8 is an explanatory diagram of a communication system operation of the present invention.

[Explanation of symbols]

 20 Facsimile device 21 Voice transmitting / receiving device 29 Digital communication network 40 Transmission / reception interface 41 Analog signal conversion unit 42 Image signal modulation / demodulation unit 43 Control signal modulation / demodulation unit 45 Packet generation / decomposition unit 46 Packet multiplexing unit

Claims (1)

[Claims] 1. A transmission / reception interface for receiving output signals of a plurality of terminal devices including a facsimile device, transmitting the output signals to a digital communication network, and receiving the digital signal from the digital communication network, the transmission / reception interface comprising: An image signal modulation / demodulation unit that modulates an image signal output from a facsimile device to generate a digital signal and supplies the digital signal to a packet generation / decomposition unit, and demodulates a digital signal received through the packet generation / decomposition unit and transfers the demodulated signal to the facsimile device. , The analog signal output from the other terminal device is band-compressed and supplied to the packet generation / decomposition unit, while the signal received via the packet generation / decomposition unit is decoded and converted into an analog signal to the corresponding terminal device. An analog signal conversion unit for transferring, and the analog signal conversion unit and the image signal conversion unit. Generate a packet signal in which source information and destination information for identifying the source terminal device and the destination terminal device are added to the signal input from the unit, and the signal input from the packet multiplexing unit is decomposed. A packet generation / decomposition unit and a packet signal input from a plurality of packet generation / decomposition units are multiplexed and transmitted to the digital communication network.
A packet multiplexing unit that receives a packet signal from the digital communication network and distributes the packet signal to a corresponding packet generation / decomposition unit.