JPH07327100A - Master/slave facsimile equipment - Google Patents

Abstract

PURPOSE:To reduce line fault between an opposite equipment and a master set and between the master set and a slave set by allowing the master set to demodulate/ modulate data from the opposite equipment and sending the data to the slave set and demodulating/modulating the data from the slave set and sending the data to the opposite equipment. CONSTITUTION:The master set 5 is provided with a MODEM of TC9600bps of the V.29 comprising a modulation section and a demodulation section for facsimile communication with an opposite equipment 1, and with a MODEM of TC9600bps of the V.17 comprising a modulation section and a demodulation section for facsimile communication with the slave set 7. The slave set 7 is provided with a MODEM of TC9600bps of the V.17 comprising a modulation section and a demodulation section for radio communication with the master set 5. Furthermore, the opposite equipment 1 is provided with a MODEM of TC9600bps of the V.29 comprising a modulation section and a demodulation section. Through the constitution above, the master set 5 is not used merely as a radio repeater and the master set 5 demodulates/modulates data from the opposite equipment 1 and sends the resulting data to the slave set T and demodulates/modulates the data from the slave set 7 and sends the data to the opposite equipment 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a master-slave facsimile apparatus comprising a master unit connected to a communication partner via a communication line and a slave unit wirelessly connected to the master unit.

[0002]

2. Description of the Related Art A parent-child telephone is widely used which is composed of a handset which is wirelessly connected to a parent telephone and can communicate with a communication partner connected to a communication line via the parent telephone. Similar to this, a master-slave facsimile apparatus including a master connected to a communication line and a slave connected wirelessly has been published.

FIG. 11 is a block diagram showing the structure of such a parent-child facsimile apparatus. A master unit 5 is connected via a partner device 1 equipped with a facsimile device, an exchange 3, and a communication line 4, and a slave unit 7 is wirelessly connected to the master unit 5. The image data transmitted from the modem 2 of the partner facsimile machine 1 is transmitted via the exchange 3 and the communication line 4 to the wireless means 6 of the master unit 5.
Is transmitted to the modem 9 of the child device 7 via the wireless means 8 of the child device 7. The transmission from the child device 7 to the partner device 1 is the opposite. In this case, the master unit 5 relays wirelessly with the communication line 4 between the partner unit 1 and the slave unit 7.

[0004]

In the case of such communication, a line failure A which occurs in the wired line between the partner device 1 and the master device 5
Then, there is a line failure B caused by wireless communication between the master unit 5 and the slave unit 7. In general, the line failure B caused by wireless is larger than the wire failure A. In the case of a facsimile machine, it is not possible to listen again when it does not sound like a telephone, so the line faults A and B deteriorate the quality of the image data transmitted as it is.

The present invention has been made in view of the above-mentioned problems, and when demodulating modulated data, even if the data is distorted to some extent, it can be restored to the original data, and the parent device is simply Instead of wireless relay, the data demodulated and modulated in the master unit is sent to the slave unit, and the data from the slave unit is demodulated and modulated and transmitted to the partner unit, so that the master unit and the master unit and the master unit and the slave unit It is an object of the present invention to provide a parent-child facsimile machine with less line failure between machines.

[0006]

To achieve the above object, means for demodulating image data received from a communication partner via a communication circuit, means for modulating the demodulated image data, and wirelessly transmitting the modulated image data. It is composed of a master unit having a transmitting unit, a unit wirelessly receiving the image data transmitted from the parent unit, and a slave unit having a unit demodulating the received image data.

Further, a slave unit having means for modulating the image data to be transmitted and means for wirelessly transmitting the image data, means for wirelessly receiving the image data transmitted from the slave unit, and the received image The master unit is provided with means for demodulating data and means for modulating the demodulated image data.

Further, means for demodulating image data received from a communication partner via a communication line, means for modulating the demodulated image data using trellis coding, and means for wirelessly transmitting the modulated image data. And a slave unit having a unit for wirelessly receiving the image data transmitted from the master unit and a unit for Viterbi decoding the received image data.

Further, there is provided a data buffer provided between the demodulating means and the trellis encoding means of the master unit for storing the TCF signal sent subsequently to the synchronizing signal from the communication partner, and modulating the master unit. Means for synchronizing the trellis-encoded data with the TCF from the data buffer.
Modulates the signal and outputs it.

Further, a slave unit having means for modulating the image data to be transmitted by using trellis coding and means for wirelessly transmitting the image data, and wirelessly receiving the image data transmitted from the slave unit. And a means for decoding the received image data by Viterbi decoding and a means for modulating the Viterbi decoded image data.

A data buffer is provided between the Viterbi decoding unit and the modulating unit of the base unit, and stores the image data transmitted following the synchronization signal from the modulating unit of the slave unit. The modulating means of the master unit modulates and outputs the image data from the data buffer following the synchronization signal.

[0012]

The function of modulation and demodulation used in facsimile communication will be explained.
-Y coordinates are expressed as coordinate points separated from each other (XY mapping), and the angle and distance of these coordinate points are phase- and amplitude-modulated. The demodulation is performed by reproducing the position of this coordinate point and obtaining the original bit combination corresponding to the position. FIG. 6 shows such an XY mapping, where each point corresponds to 16 coordinate points represented by 4 bits. FIG. 6A shows a state before data transmission, and FIG. 6B shows a state in which the position is distorted due to a line failure after data transmission. As long as each point can be discriminated even with such distortion, the original position shown in (a) can be discriminated, and the bit combination represented by the point can be reproduced. By demodulating in this way, the distortion due to the line interference can be considerably removed. The present invention uses such a distortion removal function by demodulation, in which data to be wirelessly transmitted is modulated, and wirelessly received data is demodulated so that distortion due to wireless transmission is removed to a large extent. Is.

By demodulating the image data from the communication partner device by the master device, the distortion of the data between the partner device and the master device is reduced, and the demodulated data is modulated and wirelessly transmitted to the slave device.
By demodulating this data on the slave unit side, the distortion due to the radio line failure between the master unit and the slave unit is reduced.

Further, the slave unit modulates image data, wirelessly transmits this to the master unit, and demodulates it in the master unit, whereby the data distorted due to the radio line failure can be restored to the original data, and this restoration is performed. By modulating the transmitted data and transmitting it to the partner device, the distortion of the data due to the transmission between the master device and the partner device is less than that when the master device simply relays the wireless data of the slave device.

Further, the master unit trellis-encodes and modulates the data to be transmitted to the slave unit, and the slave unit has the ability to correct data distortion caused by wireless transmission by demodulating and Viterbi decoding this data. It is possible to improve and reduce the transmission of erroneous data. This is because trellis coding and Viterbi decoding, which is this decoding method, are suitable for error correction.

In the facsimile communication with the communication partner, the master receives the synchronization signal and the subsequent TCF signal from the communication partner, demodulates it, trellis-encodes it, modulates it, and transmits it to the slave, but trellis-encoded it. The transmission time of the synchronization signal transmitted prior to the TCF signal is longer than the transmission time of the synchronization signal from the communication partner. As shown in the communication sequence diagram of FIG. 8, since the transmission time of the synchronization signal transmitted prior to the two TCF signals is different, the TCF signal from the communication partner is stored in the data buffer to absorb this difference, and the trellis code is used. After the transmission of the converted synchronizing signal, the trellis coded and modulated TCF signal is read out from the data buffer and transmitted.

The slave unit trellis-encodes the data to be transmitted to the master unit, and the master unit performs Viterbi decoding on this data, thereby improving the ability to correct the distortion of the data caused by the wireless transmission and transmitting the erroneous data. Can be reduced.

In the facsimile communication with the communication partner, the master unit transmits the synchronizing signal of the trellis coded image data received from the slave unit and modulates the image data transmitted subsequently. The image data is transmitted to the communication partner, but the synchronization signal of the image data is transmitted to the communication partner prior to the image data. In this case, since the synchronization signal sent to the communication partner takes longer than the synchronization signal sent from the slave unit prior to the trellis-encoded image data, the image data sent from the slave unit is stored in the data buffer. Then, after transmitting the synchronization signal to the communication partner, the image data read from the data buffer and modulated by the modulating unit of the master unit is transmitted to the communication partner. FIG. 9 shows the two synchronization signals transmitted prior to the image data in the communication sequence of FIG. 9 and the difference between the transmission times thereof.

[0019]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a diagram showing a connection between a parent-child facsimile machine of this embodiment and a partner machine. Reference numeral 1 is a partner machine for facsimile communication. 3 is an exchange, 4 is a communication line, 5 is a master, which is wirelessly connected to the slave 7.

FIG. 2 is a diagram showing the components related to the reception of the master unit 5 when the slave unit 7 receives the facsimile communication from the partner unit 1. The base unit 5 includes its own facsimile unit 10 and a receiving modem unit 11. The facsimile section 10 has a facsimile function excluding the modem function. The modem unit 11 at the time of reception has an analog filter 12 for passing data in a required band of analog data received from the exchange 3, and the analog filter 12
A demodulation unit 13 for demodulating the data from the device, a switching unit 14 for switching the demodulation unit 13 to the descrambler 15 or the modulation unit 16, a modulation unit 17 connected to the switching unit 14, and data input to the modulation unit 17. Data buffer 16
And a wireless transmission / reception unit 18 connected to the modulation unit 17.

The demodulation unit 13 is recommended by the ITN-T (International Telecommunication Union) V.5. It uses 29 9600 bps modems. The demodulation unit 13 includes an A / D converter 13a for converting analog data into digital data, an automatic equalizer 13b for flattening the amplitude characteristic and the delay characteristic in the carrier frequency transmission band according to the circuit condition, and the modulated signal. It is composed of a determiner 13c that restores the original data from the data. The modulation unit 17 is a V.I. 17 TC96
It uses a 00bps modem. TC9600bps
Indicates that trellis-coded data is transmitted at 9600 bps. This modem uses trellis coding, which is suitable for error correction and provides efficient coding gain, and Viterbi decoding, which is this decoding method. Modulator 17
Is a trellis encoder 17a for trellis-encoding the demodulated data, an XY mapper 17b for XY-mapping the encoded data, and a modulator 17c for modulating the XY-mapped data. D / A converter 17d for converting digital data into analog data
It is composed of

FIG. 3 is a diagram showing a portion related to this reception of the handset 7 when the handset 7 receives the facsimile communication from the partner side 1. The slave unit 7 includes a facsimile unit 20 and a receiving modem unit 21, and the facsimile unit 20 has a facsimile function excluding the modem function. When receiving, the modem unit 21 has a wireless transmission / reception unit 22 that wirelessly communicates with the base unit 5.
The analog filter 23, the demodulator 24, and the descrambler 25 that pass a predetermined band of the wirelessly received analog data. The demodulation unit 24 includes V. 17
TC9600 bps modem is adopted, and the Viterbi decoding system is used. The demodulation unit 24 includes an A / D converter 24a for converting analog data into digital data, an automatic equalizer 24b for flattening amplitude characteristics and delay characteristics in a transmission band of a carrier frequency according to a circuit condition,
A determiner 24c that determines the data on the XY mapping from the modulated data, and a Viterbi decoder 2 that decodes the trellis coding of the determined data to restore the original data.
It is composed of 4d.

FIG. 4 is a diagram showing components of the master unit 5 when the slave unit 7 sends a facsimile to the partner unit 1 in relation to this transmission. The base unit 5 includes a facsimile unit 10 excluding the modem function and a transmitting modem unit 30. The transmitting modem unit 30 includes the wireless transmission / reception unit 18 shown in FIG. 2, an analog filter 31 that passes a predetermined band of the output of the wireless transmission / reception unit 18, and a demodulation unit 32 that demodulates the output of the analog filter 31. , Demodulator 32
Switch 33 for switching the output of the demodulator to the descrambler 34 and the modulator 36, and the modulator 36 for modulating the output of the demodulator 32.
And a data buffer 35 for storing data input from the switch 33 to the modulator 36, and a scrambler 37 for scrambling the output of the facsimile unit 10 and outputting it to the modulator 36.

The demodulation section 32 has the same structure as the demodulation section 24 shown in FIG. Seventeen TC9600 bps modems are adopted and the Viterbi decoding system is used. The demodulation unit 32 is paired with the modulation unit 17 of FIG. 1
7 TC9600bps modem. The modulator 36 includes an XY mapper 36a for XY mapping bit data, a modulator 36b for modulating the mapped data, and a D / A converter 36c for converting the modulated data into analog data. It Modulator 3
6 is paired with the demodulation unit 13 of FIG. 29 of 9600
You are configuring a bps modem.

FIG. 5 is a diagram showing the components related to this transmission of the child device 7 when the child device 7 sends a facsimile to the partner device 1. The handset 7 is composed of a facsimile section 20 excluding the modem mechanism and a transmitting modem section 40.
The transmitting modem unit 40 includes a scrambler 41 that scrambles the output of the facsimile unit 20, a modulating unit 42 that performs trellis coding and modulation, and the wireless transmitting and receiving unit 2 illustrated in FIG.
It consists of 2. The modulator 42 is the modulator 1 shown in FIG.
7 has the same configuration as that of V.7. Seventeen TC9600 bps modems have been adopted and trellis coding schemes have been used. The modulator 42 is paired with the demodulator 24 of FIG.
V. Configures 17 TC9600 bps modems.

As described above, the master unit 5 is provided with the V.V.I. composed of the modulation unit 36 and the demodulation unit 13 for performing facsimile communication with the partner device 1. 29, a 9600 bps modem, and a V.V. comprising a modulator 17 and a demodulator 32 for wireless communication with the child device 7. 1
7 is provided with a TC9600 bps modem, and the slave unit 7 includes a V.2 including a modulation unit 42 and a demodulation unit 24 when performing wireless communication with the master unit 5. There are 17 TC9600 bps modems. In addition, V. 29 of 9600b
It is assumed that the modulator and demodulator of the ps modem are provided.

The reason why the line interference due to transmission can be reduced by such modulation and demodulation will be described.

FIG. Of 29 9600 bps modems
It is a figure explaining XY mapping. (A) is XY
16 that represent mapping and are represented by 4-bit combinations
(2 ^Four= 16). Data to send is 4
It is divided into bits and expressed as one of 16 points.
(X-Y mapping), modulated and transmitted.
(B) shows that the coordinate points can be restored due to the line failure during transmission.
Shows a state that is distorted every time. Even if distorted like this, each point is separated
If so, the original coordinate point can be determined and the data can be restored.
In (c), the coordinate points cannot be restored due to the line failure during transmission.
The following shows cases in which distortion and error always occur. Adjacent seats
In the state where the control points overlap and it cannot be determined which coordinate point
Communication error. Therefore, wireless communication between the master unit 5 and the slave unit 7
By modulating and demodulating
It can be significantly reduced.

FIG. 7 shows XY of trellis-encoded data.
It is a figure which shows a part of mapping. (A) is X before transmission
-Y mapping is shown, and (b) shows coordinate points distorted by transmission. The trellis-encoded data has few line failures, and even if the trellis-encoded data is in the state shown in FIG. 7B, it can be restored by Viterbi decoding. The S / N resistance is usually 4 dB stronger than that of 29,9600 bps. In the present embodiment, by utilizing this characteristic, in wireless communication between the master unit 5 and the slave unit 7, V.V. using trellis coded Viterbi decoding is used. I have 17 modems.

Next, the operation of the slave unit 7 for receiving image data from the partner unit 1 will be described. FIG. 8 shows a communication sequence when the slave unit 7 receives image data from the partner unit 1 via the master unit 5. First, V.S. Two
The line is established by the 9600 bps modem. When a CNG (calling tone) signal is transmitted from the partner device 1, the master device 5 receives a CED (callee terminal identification signal) and a DIS.
(Digital identification signal, which indicates that the called terminal has the receiving function of the ITN-T standard) is transmitted. On the other hand, the partner machine 1 outputs a DCS (digital command signal), and subsequently transmits a synchronization signal and a TCF (training check) signal. The synchronization signal transmits data such as the coefficient of the automatic equalizer in order to initialize each part of the modem before the TCF, and is also called a modem training signal. V. For 29, 9600 bps, this time is 25
3 ms. Following the signal, the TCF is transmitted.
The TCF is a signal that confirms the training of the modem receiving the facsimile message and checks if the channel is available at this transmission rate.

The TCF is generated by the demodulation unit 13 shown in FIG.
It is demodulated and restored to the original data before modulation, and the switch 1
4 to be stored in the data buffer 16. Base unit 5
The V. When receiving the synchronization signal C1 based on the V.29 modem, the modulator 17 outputs the V.29 signal. A synchronization signal C2 based on the 17 modem is wirelessly transmitted to the handset 6. In this case, V. 17
The transmission time of the sync signal C2 based on this modem is 1393m
s, and V. The transmission time of the synchronization signal C1 by the 29-modem is specified to be 253 ms. 17 is 1140 ms longer. Therefore, V. 29 sync signals C
When the TCF is transmitted subsequent to 1, the TCF is temporarily stored in the data buffer 16, and VCF. When the transmission of the synchronization signal C2 of 17 is completed, the TCF is read from the data buffer 16, modulated by the modulator 17, and wirelessly transmitted to the slave 7. Thus, V. 29 and V.I. A data buffer 16 is provided to absorb the difference in the transmission lengths of the 17 synchronization signals C1 and C2.

When the slave unit 7 receives the TCF, it returns a CFR (reception preparation confirmation signal). In this case, the master unit 5 only relays this and transmits it to the partner unit 1. The partner machine 1 is CF
When R is received, the image data is transmitted. Prior to this, the V. 29 synchronization signals C1 are transmitted. Image data is transmitted following this synchronization signal C1. Upon receiving this synchronization signal C1, the modulator 17 receives the V.V. The synchronizing signal C17 is transmitted, which is a synchronizing signal C2 'whose transmission time is significantly shorter than that of the preceding synchronizing signal C2. The transmission time of the sync signal C2 'is defined as 142 ms, which is shorter than the sync signal C1. Therefore, in the case of image data, it is not necessary to store the image data in the data buffer 14, and when the image data input subsequent to the synchronization signal C1 is demodulated by the demodulation unit 13, the switching unit 14 causes the modulation unit 1 to perform the demodulation.
7, sent to V.7. It is modulated by the 17 modem and wirelessly transmitted to the child device 7. When the transmission of the image data is completed, the other device sends an EOM (message end signal) to the child device 7, and when the child device 7 sends an MCF (message confirmation signal) to the other device 1, the other device 1 sends the parent device 5 DCN (disconnection command signal) is transmitted to and transmission ends.

As described above, the V.S. Two
Transmission is performed by the modem of No. 9 and the base unit 5 transmits V.9. 29 modem to demodulate the data, It is modulated by the modem of No. 17 and wirelessly transmitted to the slave unit 7. 1
The received data is obtained by demodulating with the 7 modem. As a result, radio line failures are greatly reduced. In addition, conventional partner machine 1
The data modulated by the modulation unit was transmitted to the slave unit 7 only by relaying the master unit 5. However, since the data is demodulated by the master unit 5 once to reduce the line faults, the data is wirelessly transmitted to the slave unit 7. Also, the line fault caused by the transmission between the partner device 1 and the master unit 5 is eliminated and is transmitted to the slave unit 7, and the line fault is greatly reduced as compared with the conventional method.

Next, the operation of the handset 7 transmitting the image data to the partner machine 1 will be described. FIG. 9 shows a communication sequence in which image data is transmitted from the slave unit 7 to the partner unit 1 via the master unit 5. CNG is transmitted from the remote unit 7 to the partner unit 1, CED and DIS are transmitted from the partner unit 1, and the DSP is transmitted from the remote unit 7.
After sending the V. The synchronization signal C2 by the 17 modem and the subsequent TCF are transmitted to the master unit 5. The master unit 5 transmits the synchronization signal C1 to the partner unit 1. The TCF is transmitted to the V.T. It is demodulated by the modem of No. 17 and the V.V. Two
The data is modulated by the modem 9 and transmitted to the partner device 1. In this case, however, since the synchronization signal C1 has a shorter transmission time than the synchronization signal C2, it is not necessary to store the TCF in the data buffer 35 and adjust the time. When the CFR is transmitted from the partner device 1, the slave device 7 transmits the synchronization signal C2 ′ and subsequently the image data. When the synchronization signal C2 'is transmitted from the slave unit 7, the modulation unit 36 shown in FIG. The synchronization signal C1 based on the 29 modem is transmitted to the partner device 1. Since the synchronization signal C1 has a longer transmission time than the synchronization signal C2 ', the image data is demodulated by the demodulation unit 32 and stored in the data buffer 35. The synchronization signal C1 is read from the transmission end data buffer 35 and modulated by the modulation unit 36. The transmitted image data is transmitted to the partner device 1. When the transmission of image data is completed, E
OM is transmitted, and the slave unit 7 is sent to the MCF from the partner unit 1.
Sends DCN and ends the transmission.

In this way, V.S. 17
Wireless transmission is performed by the modem of V. 17
Data is demodulated by the V. The data is modulated by the 29 modem and transmitted to the partner device 1. As a result, radio line failures are greatly reduced. Conventionally, the data modulated by the slave unit 7 was transmitted to the partner unit 1 only by relaying the master unit 5, but it is transmitted to the partner unit 1 after being demodulated by the master unit 5 to reduce the line fault. As a result, the influence of the line failure is greatly reduced as compared with the conventional method, and the facsimile communication with a low probability of data error becomes possible.

In the above description, the modems used for the partner device 1 and the master device 5 are V.V. I used 29 9600bps modem,
V. Other transfer speeds such as 29 7200 bps may be used. Also, as a modem that uses trellis coding / Viterbi decoding, V. Although it is assumed that 17 is used, another modem may be used. Further, the master unit 5 does not necessarily need a facsimile function capable of transmitting and receiving image data by the master unit itself.

Next, the experimental results of this embodiment will be described. In the experiment, the relationship between the error rate and the electric field strength was obtained for this example and the conventional example shown in FIG. In the conventional example, the partner device 1 and the slave device 7 are V. I have 29 modems. Figure 10
Is the electric field strength (dBμV) on the horizontal axis, and the probability that a 1-bit error will occur when 10 ^X bits are transmitted on the vertical axis is ^-X of 10 ^-X .
Indicates. The electric field strength indicates the electric field strength at the position B of the antenna shown in FIG. 5, and the output level of the modulation section 42 in the input section A of the wireless reception section 22 is set to −11 dBm. The polygonal line 1 indicates the present embodiment, and the polygonal line 2 indicates V.I. 29 at 9600b
ps, broken line 3 is V.p. When the transmission speed is 7200 bps in No. 29, the broken line 4 is V. Transmission speed of 4800 bps at 29
Is the case. Comparing the polygonal line 1 and the polygonal line 2 having the same transmission rate, when the error rate is 10 ⁻⁶ , the polygonal line 1 of the present embodiment has an electric field strength 5 dB μV less than that of the polygonal line 2. If the electric field strength is the same, it means that the error rate of the present embodiment is greatly reduced as compared with the conventional example of broken line 2. If the transmission speed is lowered, the error rate becomes lower than that of this embodiment as shown by broken lines 3 and 4.

[0039]

As is apparent from the above description, according to the present invention, when the slave unit receives from the communication partner, the master unit demodulates the data from the communication partner and then modulates and wirelessly transmits the data. By receiving the demodulated data and demodulating it, the line interference can be reduced. In addition, when transmitting from the slave unit to the communication partner, the data modulated by the slave unit is wirelessly transmitted,
The master unit can reduce the line failure by demodulating the received data, modulating it, and transmitting it to the communication partner. In addition, the master unit modulates the trellis-encoded data and wirelessly transmits the data, and the slave unit receives the data, demodulates it, and then performs Viterbi decoding, so that the line failure due to the radio can be significantly reduced. In addition, the slave unit modulates the trellis-encoded data and wirelessly transmits it, and the master unit receives and demodulates it.
By viterbi decoding, it is possible to significantly reduce radio line failures. Further, the master unit is provided with a modulator and a demodulator having different modem standards in series, and when transmitting the sync signal and the TCF signal or the sync signal and the image data from one to the other, the communication time of the sync signal is used by the modulator and the demodulator. Even if they are different, a data buffer is provided between the modulation unit and the demodulation unit to absorb the time difference, so that it is possible to connect modems of different standards.

[Brief description of drawings]

FIG. 1 is a diagram showing a connection between a parent-child facsimile apparatus of this embodiment and a partner apparatus.

FIG. 2 is a diagram showing components related to the reception of a master unit when the slave unit receives a facsimile communication from a partner unit.

FIG. 3 is a diagram showing a portion related to this reception of a slave unit when the slave unit receives a facsimile from a partner device.

FIG. 4 is a diagram showing components related to this transmission of the master unit when the slave unit performs facsimile transmission to the partner unit.

[Fig. 5] When a slave unit sends a facsimile to a partner unit,
Diagram showing components related to this transmission of the child machine

FIG. Explanatory drawing of XY mapping of 29 9600 bps modem

FIG. 7 is a diagram showing a part of XY mapping of trellis-encoded data.

FIG. 8 is a communication sequence diagram when the child device receives image data from the other device through the parent device.

FIG. 9 is a communication sequence diagram in which the child device transmits image data to the other device.

FIG. 10 is a diagram showing experimental results of this example.

FIG. 11 is a diagram showing a communication configuration of a conventional parent-child facsimile machine.

[Explanation of symbols]

 1 Remote Unit 3 Switch 4 Communication Line 5 Base Unit 7 Slave Unit 10 Master Unit Facsimile Unit 13 Base Unit Reception Demodulation Unit 17 Base Unit Reception Modulation Unit 18 Base Unit Wireless Transceiver Unit 20 Handset Facsimile Unit 22 Wireless transmitter / receiver unit of slave unit 24 Demodulator unit at reception of slave unit 32 Demodulator unit at transmission of master unit 36 Transmit time modulation unit of master unit 42 Transmit time modulator unit of slave unit

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display area // H04L 1/00 B

Claims (6)

[Claims] 1. A master unit comprising means for demodulating image data received from a communication partner via a communication circuit, means for modulating the demodulated image data, and means for wirelessly transmitting the modulated image data, A parent-child facsimile apparatus comprising: a slave unit including a unit that wirelessly receives the image data transmitted from the master unit and a unit that demodulates the received image data. 2. A means for modulating image data to be transmitted,
A slave unit including a unit for wirelessly transmitting the image data, a unit for wirelessly receiving the image data transmitted from the slave unit, a unit for demodulating the received image data, and a unit for modulating the demodulated image data. A parent-child facsimile machine comprising a parent machine having a means for performing. 3. A means for demodulating image data received from a communication partner via a communication line, a means for modulating the demodulated image data using trellis coding, and a means for wirelessly transmitting the modulated image data. A base unit equipped with
A parent-child facsimile machine including a unit for wirelessly receiving the image data transmitted from the master unit, a unit for demodulating the received image data, and a slave unit including a unit for decoding the demodulated image data in Viterbi. . 4. The base unit is provided with a data buffer provided between the demodulating unit and the trellis encoding unit of the base unit for storing a TCF signal sent subsequently to a synchronization signal from a communication partner. 4. The parent-child facsimile machine according to claim 3, wherein said means modulates and outputs the TCF signal from the data buffer following the sync signal of the trellis-encoded data. 5. A slave unit comprising means for modulating the image data to be transmitted using trellis coding, means for wirelessly transmitting this image data, and wirelessly receiving the image data transmitted from this slave unit. A parent-child facsimile apparatus comprising: a means, a means for decoding the received image data by Viterbi decoding, and a master unit having means for modulating the Viterbi decoded image data. 6. A data buffer is provided between the Viterbi decoding unit and the modulating unit of the master unit, and stores a data buffer for storing image data transmitted subsequently to the synchronization signal from the modulating unit of the slave unit. 6. The master-slave facsimile apparatus according to claim 5, wherein the modulating unit of the master unit modulates and outputs the image data from the data buffer following the synchronization signal.