JPH06178013A - Facsimile signal transmitter - Google Patents

Abstract

PURPOSE:To provide a facsimile signal transmitter which can perform the communication with no deterioration of the transmitting speed by supplying the facsimile signal and stopping the input of signal to an analyzed existing demodulation unit as long as the modem of an extended demodulation unit applies a modulation system based on an existing demodulation system. CONSTITUTION:A demodulation unit switch switches the facsimile signal switched by a transmission route switch 29 to a V.29 modulation unit 32 or a V.33 demodulation unit 33. Then the unit switch analyzes the modulation system of the facsimile signal by means of a modulation unit having a modem based on an existing modulation system and based on the control signal obtained by demodulating an input facsimile signal. When the facsimile signal to be transmitted is identical with a modulation system to which the modem of an extended demodulation unit is subject, the switching is carried out so that the facsimile signal is supplied to the extended demodulation unit. Then the input of signal is stopped to the analyzed existing demodulation unit, and a new facsimile signal is analyzed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a facsimile signal transmission device for multiplexing and transmitting facsimile signals.

[0002]

2. Description of the Related Art FIG. 7 is a block diagram showing an example of a conventional facsimile signal transmission apparatus. In the figure, reference numeral 1 is a facsimile modulator / demodulator (hereinafter referred to as a modem) which restores a facsimile signal modulated into an analog signal into a digital signal and modulates a digital facsimile signal into an analog signal, and 2 is demodulated by the modem 1. The received facsimile signal is multiplexed with other signals and sent to the bearer side,
This is a multiplexer that separates a facsimile signal from the multiplexed signal from the bearer side and distributes it to the modem 1.

Reference numeral 3 is an input terminal for inputting a facsimile signal modulated into an analog signal from the trunk side to the modem 1, and 4 is an output terminal for outputting a facsimile signal demodulated into an analog signal by the modem 1 to the trunk side. Is. Reference numeral 5 is an output terminal for outputting the facsimile signal multiplexed by the multiplexer 2 to the bearer side, and 6 is input to the multiplexer 2 the facsimile signal sent from the bearer side to be demultiplexed. It is an input terminal.

Here, there is an exchange that accommodates voice terminals, data terminals, facsimile terminals, etc. on the trunk side, and the bearer side is connected to a high-speed line. Further, FIG. 7 shows a case where N modems # 1 to #N and N input terminals 3 and output terminals 4 corresponding to each of them are provided.

Next, the operation will be described. Modem 1
International Telegraph and Telephone Advisory Committee (CCITT) Recommendation V. 21, V.I. 27 ter, V.I. It has a modulation / demodulation function conforming to 29. A facsimile signal based on an analog signal input to one of the input terminals 3 on the trunk side is 960 by the modem 1 corresponding to the input terminal 3.
It is restored to a digital signal such as 0 bps.

The digital signal restored by the modem 1 is sent to the multiplexer 2, and the multiplexer 2 multiplexes the digital signal with other signals and outputs it from the output terminal 5 on the bearer side to the high speed line. To do. In addition, the multiplexer 2
When receiving a signal from a high-speed line, takes out a digitized facsimile signal from the multiplexed signal input from the input terminal 6 on the bearer side and passes the digital signal to one of the modems 1. The modem 1 modulates the received digital signal, and outputs a facsimile signal by an analog signal which is a modulated wave to the corresponding output terminal 4
Output from. In this case, transmission / reception of the facsimile signal is performed in real time. Further, the N modems 1 can operate in parallel within the range of the multiplexing capability of the multiplexer 2.

In this system, the signal input to the input terminal 3 on the trunk side is limited to the facsimile signal. Therefore, in front of the input terminal 3 on the trunk side, the audio signal is controlled so as not to be supplied to the input terminal 3.

FIG. 8 is a functional block diagram showing an example of processing for a facsimile signal for multiplexing. In the figure, 1a is a demodulation unit of the modem 1, 1b is a modulation unit, and 7 is 30 in the digital signal output from the demodulation unit 1a.
An oversampling circuit that performs oversampling only on the control signal of 0 bps, and a stuffing control circuit 8 that performs stuffing control on the data output from the oversampling circuit 7.

Reference numeral 9 denotes a transmission gate whose stuff-controlled data passage is controlled, and reference numeral 10 denotes a transmission side multiplexing transmission line through which the data passed through the transmission gate 9 is transmitted.
Reference numeral 11 is a receiving side multiplexing transmission path through which the stuffed data is transmitted by the opposite device, and 12 is a receiving gate for controlling the passage thereof.

Reference numeral 13 is a destuffing control circuit for performing destuffing control on the data passing through the reception gate 12, and 14 is speed conversion of a control signal of 300 bps which is oversampled in the data subjected to destuffing control. And the data after speed conversion is processed by the modulator 1 of the modem 1.
It is a speed converter which outputs to b.

Next, the operation will be described. The analog facsimile signal input from the transmission line is converted into a digital facsimile signal by the demodulation unit 1 a of the modem 1 and input to the oversampling circuit 7.

When the facsimile signal, that is, the demodulation data output from the demodulation unit 1a is a control signal of 300 bps, the oversampling circuit 7 sets the demodulation data synchronized with the demodulation clock extracted by the demodulation unit 1a to 9600 bps. Convert to a corresponding signal. After that, the stuff control circuit 8 provides stuff data to absorb the difference from the transmission clock of the multiplex transmission line 10 on the transmitting side, and further adds stuff control information.

If the demodulated data output from the demodulator 1a is high-speed data such as 9600 bps, the oversampling process is not performed and only the stuff control is performed. The staff-controlled data is added with the staff-control information, for example, 1
One facsimile signal is a signal equivalent to 10 kbps.

The data placed on the multiplex transmission line 11 on the receiving side passes through the receiving gate 12 and is input to the destuffing control circuit 13. The destuffing control circuit 13 first determines whether the stuffing data is regular data or dummy data based on the stuffing control information included in the input data.

Here, when the data output from the destuffing control circuit 13 is a control signal of 300 bps, for example, the speed converter 14 speed-converts the received signal of 9600 bps into a signal of 300 bps. The data thus destuffed is input to the modulation unit 1b in synchronization with the modulation clock given from the modulation unit 1b of the modem 1, modulated and becomes an analog facsimile signal, and output to the output terminal 4.

FIG. 9 is a block diagram showing another conventional facsimile signal transmission apparatus for multiplexing and transmitting facsimile signals. In the figure, reference numeral 15 is a reception control unit that performs a reception operation facing a facsimile terminal existing on the trunk side (specifically, exists via an exchange or the like),
Reference numeral 16 is a transmission control unit that performs a transmission operation facing a facsimile terminal existing on the trunk side. Reference numeral 17 is a reception data storage device for storing the image data received by the reception control unit 15, and 18 is a transmission data storage device for storing the image data to be transmitted by the transmission control unit 16. In addition, in FIG.
The figure shows a case where N reception controllers 15 and transmission controllers 16 of #N are provided.

Next, the operation will be described. The arbitrary reception control unit 15 communicates with the facsimile terminal performing the transmission operation via the corresponding input terminal 3 and output terminal 4 on the trunk side. Then, the received image data is stored in the received data storage unit 17.

When there is an empty channel on the high-speed line side, the multiplexer 2 sends the image data in the received data storage 17 from the output terminal 5 on the bearer side as a part of the multiplexed signal. On the other hand, the multiplexed signal input from the high speed line side is input to the multiplexer 2 from the input terminal 6 on the bearer side. Then, the multiplexing device 2 extracts the image data from the multiplexed signal and stores the image data in the transmission data storage 18.

One of the transmission control units 16 calls a facsimile terminal which is a receiver and communicates with the facsimile terminal. That is, the transmission control unit 16 functions as a facsimile transmitter and transmits the image data in the transmission data storage 18 to the facsimile terminal. In addition,
When the transfer destination facsimile terminal is already in use, the transmission control unit 16 performs a retransmission operation after a predetermined time. Further, the transmission control unit 1 shown in N units in FIG.
One may be six. However, in that case, the average time that the image data stays in the transmission data storage 18 becomes long, and the immediacy of the facsimile communication is lost.

[0020]

Since the conventional facsimile signal transmission apparatus is constructed as described above, the inputted facsimile signal is V.38. 29 or V. 27t
er could be demodulated if it was a standard facsimile signal using the existing modulation method, but according to CCITT's new recommendation, V. 33 and V.I. There are now facsimile signals of transmission rates of 14400 bps and 12000 bps using 17 modulation systems, and standard facsimile signals of 9600 bps and 7200 bps using trellis coding system, and these signals are input to the facsimile signal transmission device. In this case, it is necessary to return the signals to the voice route, and a multiplexer using adaptive quantized differential pulse code modulation of 32 kbps (hereinafter referred to as ADPCM) can transmit these signals without lowering the transmission rate. Since it is impossible, and since it adapts to these signals, the conventional facsimile signal transmission apparatus has a V. Three
3, V.I. If the number of demodulation units is increased by adding a demodulation unit equipped with a modem that supports 17 modulation systems,
There was a problem that the device became large.

The present invention has been made to solve the above-mentioned problems, and it is possible to reduce the number of demodulation units to be expanded by switching the demodulation units and increasing the usage efficiency of the modulator / demodulator. Also, 14400 bps
High-speed facsimile signals such as 32Kbps AD
Even with a multiplexer using PCM, the extended V. Three
3, V.I. By using the demodulation unit conforming to 17,
It is an object of the present invention to obtain a facsimile signal transmission device which can be multiplexed and communicated without lowering the transmission rate.

[0022]

According to a first aspect of the present invention, there is provided a facsimile signal transmission apparatus according to an existing modulation method of a facsimile signal from a control signal obtained by demodulating an inputted facsimile signal. Analyze using a demodulation unit that has a modem that conforms to the modulation method, and if the transmitted facsimile signal is a modulation method that the modem that the extended demodulation unit has complies with, send the facsimile signal to the extended demodulation unit. The input is switched to input, the signal input to the existing demodulation unit that has been analyzed is stopped, and a new facsimile signal is analyzed.

Further, in the facsimile signal transmitting apparatus according to the invention described in claim 2, the facsimile signal branched from the voice route is supplied to the extended demodulation unit together with the existing demodulation unit, and the modulation system is used for both of them. If the identified modulation method is a method that the modem of the existing demodulation unit complies with, the signal analysis in the extended demodulation unit is stopped and the signal is output only to the existing demodulation unit. Also, if it is a modulation method that the modem of the extended demodulation unit complies with, the analysis in the existing demodulation unit is stopped and the signal is input to the extended demodulation unit. is there.

In the facsimile signal transmitting apparatus according to the invention described in claim 3, the demodulation is performed by either the existing demodulation unit or the expanded demodulation unit.
If there is a shortage of modems to be analyzed, and a facsimile signal with a modulation method that the existing demodulation unit has is compliant with is detected, the demodulation unit that detects the signal should perform demodulation and multiplexing. , If the detected signal is a modulation method that the modem of the extended demodulation unit complies with, if the detected unit is an existing demodulation unit, the demodulation operation is stopped, and if it is an extended demodulation unit, it continues as it is. This is for demodulation and multiplexing.

[0025]

When the modulation system of the facsimile signal on the transmission line is identified, the demodulation unit switching device according to the first aspect of the invention selects the demodulation unit adapted to the modulation system.

The demodulation unit switcher according to the second aspect of the present invention transmits a facsimile signal to both demodulation units having modems having different modulation schemes, and a demodulation unit adapted according to the identified modulation scheme. Select and release demodulation units that are no longer needed.

According to the third aspect of the present invention, when the number of modems to be analyzed is insufficient, the demodulation unit performs analysis and demodulation with a demodulation unit that has a margin for analysis, and the demodulation unit is adapted to the modulation system. If it is determined that the demodulation unit is doing so, the demodulation unit performs demodulation and multiplexing.

[0028]

EXAMPLES Example 1. Embodiment 1 of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of the invention described in claim 1. In the figure, 21 is an input terminal on the trunk side for transmitting voice signals and facsimile signals, and 22 is an output terminal on the trunk side. The input terminal 21 and the output terminal 22 on the trunk side are, for example, voice terminals and facsimiles. It is connected to an exchange that accommodates terminals. Reference numeral 23 is a modem for modulating / demodulating the facsimile signal, and 24 is a multiplexing controller for controlling multiplexing of facsimile control signals and image data.

Reference numeral 25 is a voice output terminal on the bearer side for transferring a voice signal, 26 is a voice input terminal on the bearer side, 27 is a facsimile output terminal on the bearer side for transferring a facsimile signal, and 28 is the same. This is a facsimile input terminal on the bearer side. The route connected to the voice output terminal 25 and the voice input terminal 26 on the bearer side constitutes a voice signal route (hereinafter referred to as a voice route), and the bearer side facsimile output terminal 27 and the facsimile input terminal 28 are connected to each other. The route connected to (1) constitutes a facsimile signal route (hereinafter referred to as a facsimile route).

29 is in accordance with the command from the multiplexing controller 24,
It is a transmission route switching device that switches whether the signal input from the input terminal 21 on the trunk side is output to the output terminal 25 of the voice route, the modem 23 side, or both. . Reference numeral 30 is a reception route switching device that switches between transmitting the output of the modem 23 from the trunk side output terminal 22 and transmitting the signal input to the voice route input terminal 26 from the trunk side output terminal 22.

32 is the existing CCITT Recommendation V.34. Demodulation unit (V.29
33 is an expanded recommendation V. 33. A demodulation unit (V.3
3 demodulation units). In addition, this V. 29 demodulation unit 32 is a control signal D demodulated from a facsimile signal
Modem 2 that analyzes the OS signal to identify the modulation method of the input facsimile signal and is adapted to the identified modulation method
The demodulation unit 32 or 33 having 3 has a function of generating a switching instruction for connecting the inputted facsimile signal.

A facsimile signal 34, which has been switched by the transmission route switch 29, is sent to the V. 29 demodulation unit 32 and V.29. 33 is a demodulation unit switch for switching to any of the 33 demodulation units 33. 35 is V. 29 is a transmission processor having a function of controlling switching of the demodulation unit switch 34 in accordance with a unit switching instruction output from the 29 demodulation unit 32, and 36 is a reception processor having a similar control function of the demodulation unit switch 34.

Further, FIG. 2 is a system configuration diagram of a system in which the facsimile signal transmitting apparatus thus configured is connected by a high-speed digital line through a multiplexer having a voice inserting function (hereinafter referred to as DSI function). is there. In the figure, 37 and 38 are facsimile signal transmission devices each having the configuration shown in FIG. 1, and 39 and 40 are D connected to each facsimile signal transmission device 37 or 38.
Digital multiplexer having SI function (hereinafter referred to as DCM
E device). Reference numerals 41 and 42 are high-speed digital lines connecting the DCME devices 39 and 40 to each other.

Reference numeral 43 is a voice route formed by a route connected to voice routes of the voice output terminal 25 and the voice input terminal 26 on the bearer side of the facsimile signal transmission device 37, and 44 is the facsimile output terminal 27 on the bearer side. And a facsimile route formed by a route connected to the facsimile input terminal 28. 45
Is an output terminal on the trunk side of the facsimile signal transmission device 38, and 46 is an input terminal on the trunk side.

The functions of the DCME devices 39 and 40 will be described. CCITT for DCME equipment
Recommendation Q. 50 of these DCME devices 19, 20
Recommendation Q. Complies with 50. FIG. 3 shows a system in which only the DCME device is provided, in which the DCME
The trunk input 47 or 51 is input to the devices 39 and 40, and the trunk output 48 is input from the DCME devices 39 and 40.
Or 50 is outputting. In addition, trunk input 47
The trunk output 48, the trunk input 51, and the trunk output 50 are connected to an exchange or the like.

FIG. 4 is an explanatory diagram showing the format of input / output signals of the DCME device. DCME device 39
Receives a signal from the trunk side in a signal format 53 as shown in the lower part of FIG. Then, it is detected whether or not the voice channel is voiced, and if voiced, a free channel on the bearer side is searched. If there is an empty channel, an audio signal is set to that channel and the signal format 52 as shown in the upper part of FIG.
Sends the signal to the bearer side. When the voice channel on the trunk side becomes unvoiced, the signal on the corresponding channel on the bearer side is stopped. Then, the connection state of each channel is set to the assignment channel (AC).

When the signal in the signal format 52 is input from the bearer side, the partner DCME device 40 reconfigures the signal and outputs it to the trunk output 50. In this way, the sound signal input to the DCME device 39 is D
It is output from the CME device 40 to the corresponding voice channel on the trunk side.

As described above, since only the voice signal is transmitted on the bearer side, the number of channels can be reduced. The number of channels is reduced to 1/4 to 1/5 by the ADPCM function that reduces the number of transmission bits together with the DSI function.

By the way, the recommendation Q. 64 kbp for 50
s Clear channel and voice band data transmission path setting request signal are defined. Since the signal on the voice channel on the bearer side has a low transmission rate by adopting ADPCM, terminal data of 64 kbps cannot be transmitted on that channel. However, when the 64 kbps channel prepared on the bearer side is used, such data can be transmitted. That is, when such data is generated, the DCME device 19 receives 64 kbps.
On-demand request, and a 64 kbps clear channel may be set.

The 64 kbps clear channel on-demand request is output from the exchange or the like in the configuration shown in FIG. That is, the exchange or the like sends out the 64 kbps on-demand request signal (SIG) using the time slot (TS) # 16 in the signal format 53 on the trunk side shown in the lower part of FIG. Then, an empty channel is searched for, and a 64 kbps clear channel such as CH # 1 and CH # 2 in the signal format 53 shown in FIG. 4 is set as an empty channel.

As described above, the 64 kbps clear channel is allocated when an on-demand request is generated, and is allocated at a random position in the signal format 53. The facsimile signal transmission devices 37 and 38 shown in FIG. 2 issue an on-demand request to the DCME devices 39 and 40, that is,
Recommendation Q. It is intended to transmit a facsimile signal by using 50 64 kbps clear channel setting function.

Next, the operation of the first embodiment shown in FIG. 1 will be described. Here, FIG. 5 is an explanatory diagram showing the input / output format of the DCME device of this facsimile signal transmission device. The signal input to the input terminal 21 on the trunk side is first supplied to the output terminal 25 of the voice route and the modem 23 by the transmission route switch 29. Until the modem 23 detects a facsimile signal, the signal on the trunk side is output through the output terminal 25 of the voice route to the DCME.
Provided to device 39. As described above, the DCME device 39 transfers the sound signal using the idle channel.

If the signal on the trunk side is composed of the signal format 55 shown in the lower part of FIG. 5 and the facsimile signal is set in TS # 1, the modem 23 can demodulate the facsimile control signal from the facsimile signal. become. The demodulation result is notified to the multiplexing controller 24.

When the multiplexing controller 24 recognizes that the modem 23 demodulates and outputs the control signal, the multiplexing controller 24 gives a switching instruction to the transmission route switcher 29. In response to the switching instruction, the transmission route switch 29 prevents the trunk side signal from being output to the output terminal 25 of the voice route.
As a result, the output of the output terminal 25 of the voice route becomes silent.

Further, the multiplexing controller 24 uses the TS in the signal format 54 of the facsimile route shown in the middle part of FIG.
# 16 is used to request the DCME device 39 to set the 64 kbps clear channel. Furthermore, the multiplexing controller 2
4 outputs the output of the modem 23 to C, as shown in the middle part of FIG.
It is set to H # 1 and transferred to the DCME device 39. Here, CH # 1 in the signal format 54 is 64 kb.
ps, facsimile image data is 9.6k
For bps, it may be divided into 6 sub-channels, as shown at 56 in FIG. That is, it is possible to set the outputs of the plurality of modems 23 to CH # 1.
If the transmission route is lower than 9.6 kbps, more subchannels can be set.

Upon receiving the on-demand request for the 64 kbps clear channel, the DCME device 39 searches for an empty channel on the bearer side and sets CH # 1 which is an empty channel 64 kbps clear channel as shown in the upper part of FIG. Facsimile control signals and image data are C
It is transmitted to the partner DCME device 40 using H # 1. The DCME device 40 which received it transfers the content of CH # 1 to the facsimile signal transmission device 38.

Further, the multiplexing controller 24 exchanges information with the multiplexing controller of the facsimile signal transmitting device 38 on the other side so that the signal format 5 of the facsimile route can be exchanged.
4 sets a FAX assignment channel (hereinafter referred to as ACF). In this ACF, a transmission rate of image data, an array of multiplexed data, a supplemental status of 64 kbps clear channel, a usage status, etc. are set.

This ACF is sent from the multiplexing controller 24 to the DCM.
The data is transferred to the E device 39, and the DCME device 39 transmits it to the bearer side signal format 52 as shown in the upper part of FIG.
And send it to the DCME device 40. This ACF is further provided by the multiplexing controller 24 of the facsimile signal transmission device 38.
Transferred to. The other side multiplexing controller 24
Based on the content of F, a switching instruction is issued to the reception route switching unit 30 and the received content of CH # 1 is passed to the modem 23. The modem 23 modulates the signal given from the multiplexing controller 24 and modulates the modulated wave into the facsimile channel F1 of TS # 1 in the signal format 55.
And outputs to the reception route switcher 30. The reception route switcher 30 outputs the output of the modem to the trunk side according to the instruction from the multiplexing controller 24, so that the output of the modem 23 is output from the trunk side output terminal 45.

When the multiplexing controller 24 recognizes the end of the facsimile communication based on the content of the control signal demodulated and output by the modem 23, the ACF notifies the multiplexing controller 24 on the other side of the fact. Also, the transmission route switch 2
A switching instruction is given to 9 so that the trunk side output is output to the output terminal 25 of the voice route. Further, the multiplexing controller 24 on the partner side gives a switching instruction to the reception route switcher 30 so that the input signal of the input terminal 26 of the voice route is output to the trunk side.

After that, the DCME device 39 detects the C on the bearer side.
Release H # 1. As a result, the channel that was CH # 1 becomes an empty channel. A new 64 kbps clear channel is set when another facsimile communication is started while the facsimile signal is being transmitted by CH # 1. The channel not used as the 64 kbps clear channel is used for voice transmission using the DSI function. Therefore, each channel on the bearer side is efficiently used for the voice signal and the facsimile signal, and the transmission efficiency of the system shown in FIG. 2 is higher than that of the system using only the DCME devices 39 and 40 shown in FIG.

Such a facsimile signal transmission device 3
7 and 38, the input facsimile signal has a transmission rate of 300, 2400, 4800, 7200, 9
It is 600, 12000, 14400 bps. Therefore, the facsimile transmission devices 37 and 38 need to demodulate all of these transmission rates.

Therefore, the facsimile signal transmission device 3
The demodulation units 32 and 33 of the V. 33, V.I. It is necessary to include a modem 23 capable of demodulating signals up to 14400 bps conforming to 17 standard. Therefore, CCITT Recommendation V. V.29 with a modem 23 compliant with V.29. 29, which modulation method is used to communicate the image data of the facsimile signal input to the demodulation unit 32, that is, V. 1 of CCITT recommendation. 33, V.I.
17, V.I. 29, V.I. It is necessary to identify the 27ter.

Here, which modulation method is used to communicate image data depends on the CCITT in the facsimile signal.
Recommendation V. It can be identified by analyzing the DCS signal of the facsimile control signal using the modulation method of No. 21.

V. If the facsimile signal input to the demodulation unit 32 is recognized by the analysis of the DCS signal as trying to communicate the image data in a modulation method that cannot be demodulated, V.29. The 29 demodulation unit 32 outputs a unit switching instruction to the transmission processor 35 and the reception processor 36.

V. 29: Transmitting processor 35 and receiving processor 3 notified of the switching instruction from the demodulation unit 32
6 controls the demodulation unit switch 34 so that the V.6. Two
9 The signal output to the demodulation unit 32 is stopped, and the modem 23
Also stop the connection signal to V. The facsimile signal of the channel is prevented from being input to the demodulation unit 32 of the V.29 demodulation unit 32, and the facsimile signal is transmitted to the V.29. 33 Input to the demodulation unit 33. Further, at that time, the transmission processor 35 and the reception processor 36 are 33 demodulation unit 3
3 is notified of information on the modulation method and the transmission rate.

Information on the modulation method and transmission rate is notified, and V.V. The 33 demodulation unit 33 starts demodulation of the inputted facsimile signal in accordance with the instructed modulation method and transmission rate.

On the other hand, V. From the DCS signal analyzed by the demodulation unit 32, the facsimile signal communicated on the channel is V.29. 29, V.I. When it is identified that the data is transmitted using the modulation method of 27 ter, V.27 29 demodulation unit 32 does not issue a demodulation unit switching request instruction,
The facsimile signal of that channel is continuously demodulated.

As described above, by classifying the demodulation units to be used according to the modulation system of the transmitted facsimile signal, the V.V. 33,
V. It is possible to demodulate and multiplex facsimile signals having a high transmission rate such as 17, and it is possible to improve transmission efficiency by multiplexing these facsimile signals that could not be demodulated.

Example 2. In the first embodiment, V. Two
The case where the modulation method of the facsimile signal is identified only by the demodulation unit 32 has been described. 29 demodulation unit 32 and V.29. Both of the 33 demodulation units 33 may identify the modulation method. FIG. 6 is a flow chart showing the operation of each demodulation unit 32, 33 in one embodiment of such an invention as defined in claim 2.

First, in step ST1, an answer tone of 2100 Hz for facsimile identification is detected. Then, in step ST2, the signal of the channel in which the answer tone is detected is V.50. 29 demodulation unit 32 and V.29. 33 is input to both of the demodulation units 33. These V. 29 demodulation unit 32 and V.29. Each of the 33 demodulation units 33 monitors the DCS signal of the facsimile signal input in step ST3.

When the DCS signal is detected by the monitoring in step ST3, the original transmission line is disconnected in step ST4 and switched to the transmission line dedicated to facsimile.
The modulation method of the facsimile signal transmitted at T5 is analyzed from the detected DCS signal. V. 29 demodulation unit 32 and V.29. The 33 demodulation unit is this step ST
The modulation method analyzed in 5 is notified to the transmission processor 35 and the reception processor 36.

Here, the identified modulation method is V. 33,
V. If it is 17, the process proceeds to step ST6, and V. Two
After the 9 demodulation unit 32 notifies the transmission processor 35 and the reception processor 36 of the modulation scheme and the transmission rate,
It waits for a disconnection request from the reception processor 36. on the other hand,
If the transmitted facsimile signal is V. 29, V.I. 27te
In the case of transmission by the r modulation method, the processing is step ST7.
Go to V. The 33 demodulation unit 33 notifies the transmission processor 35 and the reception processor 36 of the modulation method and the transmission rate, and then waits for a disconnection request from the reception processor 36. At this time, V. The 29 demodulation unit 32 continues demodulation.

In the above embodiment, the facsimile signal is branched from the voice route and supplied to the two demodulation units 32 and 33. The demodulation data is output from the two demodulation units 32 and 33 to the transmission processor 35 and is transmitted to the reception processor 36 on the partner station side through the facsimile route. One of the data may be selected and transmitted to the partner station.

Thus, the V. 29 demodulation unit 32 and V.29. By discriminating one facsimile signal and analyzing the modulation method in both of the 33 demodulation units 33, the discrimination ability is improved and the time difference between switching of the demodulation units 32, 33 can be reduced.

Example 3. In the first embodiment, the facsimile signal modulation method is V.V. The case where the demodulation unit 32 analyzes the data has been described. The V.29 demodulation unit 32 is not the only option. The 33 demodulation unit 33 may also be analyzed.

That is, V. 29 if all of the demodulation units 32 are in use, or if there are no channels to demodulate for analysis, the analyzed signal from the voice route will be V.29. 33 is supplied to the demodulation unit 33, and the V. 33 demodulation unit 3
At 3, the facsimile signal is detected and the modulation method is analyzed.

On the contrary, V. In case the channel of the demodulation unit 33 is unavailable, the analyzed modulation scheme is V.33. 33, V.I. If it is 17, the transmission processor 35 and the reception processor 36 that have received the modulation scheme notified from the demodulation unit give an instruction to analyze the connected modem 32, demodulate this channel, and transmit the signal from the voice route. Stop the branch. Therefore, the facsimile signal of this channel should pass through the voice route.

In this case, after identifying the modulation method,
Although the demodulation operation is stopped, the signal is continuously branched from the voice route, the monitoring is continued until the transmission route of the transmitted facsimile signal is lowered, and the transmission is performed when the transmission rate reaches the demodulation rate. It is also possible to switch the route to a facsimile route and demodulate and multiplex.

[0069]

As described above, according to the first aspect of the present invention, the demodulation unit using the modem conforming to the extended modulation system is introduced, and the existing demodulation unit is used for the modulation system of the facsimile signal. Analyze, if it is a modulation method that the modem of the expanded demodulation unit complies with, input the facsimile signal to the expanded demodulation unit and stop the signal input to the existing demodulation unit that has been analyzed. Since it has been configured, by expanding the existing system or replacing the demodulation unit, ADPCM of 32 kbps
14400bp that could not be communicated on the transmission line using
The data of s can be communicated without reducing the transmission speed, and the unit to be demodulated is switched according to the modulation method, so that there is an effect that the change of the existing system can be reduced.

According to the second aspect of the present invention, the signal branched from the voice route is input to both the existing demodulation unit and the expanded demodulation unit to identify the modulation method, and the modulation method is applied after the identification. Since the demodulation unit is configured to be selected, there is an effect that the discrimination ability is improved and the time difference generated at the time of switching can be reduced.

According to the third aspect of the present invention, the unit for analyzing the modulation method of the facsimile is not limited to the existing demodulation unit, and the extended demodulation unit is also analyzed. Transmission is possible without being affected by the number of modems, and there is an effect that a system in which the demodulation unit can be effectively used can be obtained.

[Brief description of drawings]

FIG. 1 is a block diagram showing a first embodiment of the present invention.

FIG. 2 is a block diagram showing a system composed of a facsimile signal transmission apparatus and a DCME apparatus according to the above embodiment.

FIG. 3 is a block diagram showing a transmission system using a DCME device.

FIG. 4 is an explanatory diagram showing a format of an input / output signal of the DCME device.

FIG. 5 is an explanatory diagram showing an input / output format of the facsimile signal transmission device and the DCME device in the above embodiment.

FIG. 6 is a flowchart showing the operation of the facsimile signal transmission apparatus according to the second embodiment of the present invention.

FIG. 7 is a block diagram showing an example of a conventional facsimile signal transmission device.

FIG. 8 is a functional configuration diagram for explaining processing of a conventional facsimile signal transmission device.

FIG. 9 is a block diagram showing another example of a conventional facsimile signal transmission device.

[Explanation of symbols]

 23 modem 32 demodulation unit (V.29 demodulation unit) 33 demodulation unit (V.33 demodulation unit) 34 demodulation unit switch 37, 38 facsimile signal transmission device 39, 40 DCME device

Claims (3)

[Claims] 1. A multiplexing device having a voice insertion function and a transmission line in which a facsimile signal and various data signals coexist, are arranged to transfer a signal on the transmission line to the multiplexing device, and In a facsimile signal transmission device for transferring a signal supplied from a multiplexer to the transmission line, a facsimile modulator / demodulator conforming to a different modulation method is provided, and the facsimile signal input from the transmission line is demodulated and controlled. A plurality of demodulation units for outputting signals and image data, wherein one of the demodulation units discriminates a modulation system of the inputted facsimile signal from the demodulated control signal, and a facsimile adapted to the identified modulation system. Switching instruction for connecting the input facsimile signal to the demodulation unit having a modulator / demodulator And a demodulation unit switching device for connecting the input facsimile signal to the designated demodulation unit based on the switching instruction. 2. A multiplexing device having a voice insertion function and a transmission line in which a facsimile signal and various data signals coexist, are arranged to transfer the signal on the transmission line to the multiplexing device, and In a facsimile signal transmission device for transferring a signal supplied from a multiplexer to the transmission line, a facsimile modulator / demodulator conforming to a different modulation method is provided, and the facsimile signal input from the transmission line is demodulated and controlled. A plurality of demodulation units that output signals and image data and that identify from the control signal that demodulates the modulation system of the input facsimile signal, and connect to each of the demodulation units based on the identification result of the modulation system. The facsimile signal that had been received by the facsimile modulator / demodulator adapted to the identified modulation method. A facsimile signal transmission device, comprising: a demodulation unit switcher connected only to a tone control unit. 3. When the facsimile modulator / demodulator analyzes and demodulates the facsimile signal with a demodulation unit having a margin, and the demodulation unit that has analyzed does not have a facsimile modulator / demodulator adapted to the analyzed modulation method. Is
When each of the demodulation units has a function of stopping the demodulation operation in the demodulation unit and continuously performing demodulation and multiplexing in the demodulation unit when the adapted facsimile modulator / demodulator is present. The facsimile signal transmission device according to claim 1 or 2.