JP3622003B2 - Communication terminal device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a communication terminal device such as a facsimile device that transmits image data by facsimile to an opposite communication terminal device via a communication line using a modem in an error correction mode (ECM).
[0002]
[Prior art]
In a conventional facsimile apparatus, image data is transmitted to a destination facsimile apparatus via a communication line via a communication line using a modem, and before the facsimile transmission of the image data, The facsimile apparatus transmits a training signal to a destination facsimile apparatus, determines the transmission speed of the modem on the transmission side on the basis that the training signal can be received at a predetermined error rate or higher, and performs facsimile communication.
[0003]
Here, when the quality of the communication line is poor, the modem transmission speed is decreased by one step (this is called fallback), and fallback is performed until the receiving side can receive a training signal with a predetermined error rate or higher. It is configured to repeat. For example, the ITU-T recommendation specifies as follows. The so-called Super G3 V. In the 34 mode, the fallback is performed in the order of 33.6 kbps, 31.2 kbps, 28.8 kbps, 26.4 kbps, and 16.8 kbps. Then, for example, V.I. After fallback in the order of 14.4 kbps and 12 kbps in 17 mode, V. In 29 mode, it falls back in the order of 9600 bps and 7200 bps. Fallback is performed in the order of 4800 bps and 2400 bps in 27ter mode.
[0004]
[Problems to be solved by the invention]
In particular, when image data is transmitted by facsimile to an opposite communication terminal device via a communication line in an error correction mode (ECM), a fallback occurs when a partial page request signal (PPR signal) is received four times. In the facsimile communication, the fallback is reduced to the final transmission speed (2.4 kbps) of the modem, so that there is a problem that the communication time becomes long and the communication fee becomes expensive. In particular, in a high-speed modem having a maximum transmission rate of 33.6 kbps, the number of fallbacks is extremely large, and the communication time associated therewith becomes very long, resulting in an expensive communication fee. The communication line to be used changes every time the line connection is made, and in particular, the situation often changes greatly as the distance becomes longer.
[0005]
SUMMARY OF THE INVENTION An object of the present invention is to solve the above-described problems, and in a communication terminal apparatus such as a facsimile apparatus that transmits image data by facsimile to an opposite communication terminal apparatus via a communication line in an error correction mode (ECM) using a modem. An object of the present invention is to provide a communication terminal device that can reduce the number of times of fallback and keep the communication fee low.
[0006]
[Means for Solving the Problems]
A communication terminal apparatus according to the present invention uses a modem to transmit a partial page request signal a predetermined number of times in a facsimile terminal that transmits image data to a counterpart communication terminal apparatus via a communication line in an error correction mode (ECM). When receiving, when it has already fallen back to a predetermined transmission rate, it is characterized by comprising a communication control means for controlling to disconnect the communication line and set to wait for redialing.
[0007]
In the communication terminal apparatus, the communication control unit preferably waits for the redialing and then redials the transmission rate lower than the transmission rate before the fallback that is the starting transmission rate at the previous dialing. Control is performed so as to initiate a facsimile transmission by calling a communication terminal device of the other party at the transmission speed of the communication mode.
[0008]
Further, in the communication terminal apparatus, the communication control means preferably performs fallback to a re-slow transmission rate of the modem when performing facsimile transmission by a predetermined last redial.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments according to the present invention will be described below with reference to the drawings.
[0010]
<Embodiment>
FIG. 1 shows an embodiment according to the present invention, which has an ECM communication function for facsimile transmission of image data to a destination facsimile machine via a public telephone network using a fax modem 10 in an error correction mode (ECM). FIG. 2 is a block diagram showing a configuration of a facsimile machine 20 having a redial function during training.
[0011]
The main control unit 1 of the facsimile apparatus 20 according to this embodiment uses a fax modem 10 to transmit image data to the other party's facsimile apparatus via the public telephone network in error correction mode (ECM). When the page request signal (PPR signal) has been received a predetermined number of times (YES in step S27 in FIG. 3), if it has already fallen back to the predetermined transmission rate (YES in step S29), the communication line is disconnected (step S29). S31), and control is performed so that redial waiting is set (step S32).
[0012]
In addition, when the main control unit 1 waits for the above redial and redials, the main control unit 1 uses the transmission speed of the communication mode having a transmission speed lower than the transmission speed before the fallback that is the starting transmission speed at the previous dialing. The communication terminal device is called to start facsimile transmission (steps S41-43 in FIG. 4). Further, the main control unit 1 is characterized in that when performing facsimile transmission by a predetermined last redial, the main control unit 1 falls back to the low-speed transmission speed possessed by the modem (steps S81 to S90 in FIG. 5).
[0013]
In FIG. 1, a facsimile machine 20 has a conventional facsimile communication function such as a G3 system, and also uses a fax modem 10 to send image data to a destination facsimile machine via a public telephone network in an error correction mode (ECM). It has an ECM communication function for facsimile transmission, and a redial function during training. The main control unit 1 is specifically composed of a CPU, and is connected to the following hardware units via the bus 13 to control them, and executes various software functions to be described later. The image reading unit 2 reads a document with a scanner using a CCD or the like, and outputs dot image data converted into black and white binary. The image recording unit 3 is an electrophotographic printer or the like, and prints out image data received from another facsimile apparatus by facsimile communication as a hard copy and records it. The display unit 4 is a display device such as a liquid crystal display device (LCD) or a CRT display, and displays the operation state of the facsimile device 20 and displays image data of a document to be transmitted and received image data. .
[0014]
The operation unit 5 includes character keys necessary for operating the facsimile apparatus 20, a dial keypad, a speed dial key, a one-touch dial key, various function keys, and the like. In addition, you may comprise so that a part or all of the various keys of this operation part 5 may be substituted by making the above-mentioned display part 4 into a touch panel system.
[0015]
The ROM 6 stores in advance various software programs that are necessary for the operation of the facsimile apparatus 20 and executed by the main control unit 1. Here, the programs are at least used for the facsimile transmission processing of FIGS. 2 to 5. Includes programs. The RAM 7 is configured by SRAM, flash memory, or the like, and is used as a working area for the main control unit 1 to store temporary data generated when the program is executed. When a flash memory is used as the RAM 7, the contents of the data are not lost even when the power is cut off due to a power failure, movement of the device, or the like. The image memory 8 is composed of a DRAM or the like, and stores image data to be transmitted or received image data. Note that the RAM 7 and the image memory 8 may be constituted by a hard disk memory.
[0016]
The fax modem 10 is a modem connected to the public telephone line L and having a function of a fax modem for normal facsimile communication. The fax modem 10 demodulates data of outgoing telephone number information received as an FSK signal and sends it to the main control unit 1. Output. An NCU (Network Control Unit) 11 is a hardware circuit that performs an operation of closing and opening a DC loop of an analog public telephone line L and having an automatic dial function. Is connected to the public telephone line L. Here, the NCU 11 detects the ID receiving terminal activation signal and the normal telephone call signal in the outgoing telephone number notification service, and transmits the primary response signal and the secondary response signal in the outgoing telephone number notification service as necessary. can do. The NCU 11 may be connected to a baseband transmission type digital line (for example, an ISDN line) via a predetermined terminal adapter and a DSU (Subscriber Line Terminating Unit: Digital Service Unit).
[0017]
The facsimile apparatus 20 of the present embodiment configured as described above uses the fax modem 10 to send image data in error correction mode (ECM) via the public telephone network in addition to the normal G3 type facsimile communication function. And an ECM communication function for facsimile transmission to a destination facsimile machine, and a redial function during training. In the facsimile communication function, the dot image data read by the image reading unit 2 is encoded by software in accordance with an encoding method such as MH, MR, or MMR defined in the facsimile communication standard, and then the counterpart facsimile machine On the other hand, the encoded data received from the facsimile machine of the other party is also decoded into image data by software and output from the image recording unit 3 as a hard copy. The image memory 8 stores the image data as necessary, and conversely outputs the stored image data as necessary.
[0018]
Furthermore, V.C. is capable of high-speed data communication such as facsimile communication. 34 mode and V. An 8-mode communication procedure will be described. When data communication is performed with a communication terminal device such as a facsimile device, the recommendation V. of ITU-T, for example, of the half duplex method. The modem uses a modem that conforms to the 17-mode communication procedure, etc., and is a G3 standard facsimile communication procedure. Follow the procedure specified in 30. Also, the recommendation V.I. An ultra-high speed communication procedure (hereinafter referred to as a V.34 mode communication procedure) with a maximum transmission rate of 33.6 kbps conforming to the standard No. 34 has been put into practical use. In the 34-mode communication procedure, at the start of communication and during execution of communication, the receiving side designates the transmission rate according to the line status at that time, specifically S / N (signal to noise power ratio) and bandwidth. Thus, the transmission side changes the transmission rate so that transmission is performed at the transmission rate specified on the reception side. V. In the case of performing data communication in the 34-mode communication procedure, the same recommendation V. The actual transmission rate is determined by performing the pre-procedure in 8 communication procedures.
[0019]
The fax modem 10 used in the present embodiment is a V.16. 34 mode, This is a high-speed modem capable of 17-mode communication procedures, the transmission speed can be changed during communication execution, and the status of the communication line at that time, specifically S / N, from the signal received from the communication partner Bandwidth data can be monitored from the outside as a status. That is, line probing processing is performed with the transmission side device. As a result of this processing, the S / N and bandwidth of the line at that time are output as status from the fax modem 10, and the main control unit 1 Is read and processing based on it is performed.
[0020]
2 to 5 are flowcharts showing facsimile transmission processing executed by the main control unit 1 of the facsimile apparatus 20 of FIG.
[0021]
In step S1 of FIG. 2, a call is made to the destination, and in step S2, a T0 timer is started. Next, after sending a CNG signal in step S3, it is determined in step S4 whether or not an ANSam signal or DIS signal has been detected. If not detected, the process returns to step S3. If an ANSam signal is detected, step S11 is performed. On the other hand, when the DIS signal is detected, the process returns to step S5. In step S5, the V.V. It is determined whether the 8th ability is valid. If YES, the process proceeds to step S8. If NO, the process proceeds to step S6. In step S6, ITU-T recommendation T.I. After executing the G3 mode normal facsimile transmission processing based on 30, the line is opened in step S7 and the facsimile transmission processing is terminated. On the other hand, in step S8, a CI signal is transmitted, and it is determined whether or not an ANSam signal or DIS signal is detected in step S9. If not detected, the process returns to step S8, but if an ANSam signal is detected, step S11 is performed. On the other hand, when the DIS signal is detected, the process returns to step S5.
[0022]
In step S11, a CM signal is transmitted. In step S12, it is determined whether a JM signal is detected. If YES, the process proceeds to step S13. If NO, the process returns to step S11. Next, the CJ signal is transmitted in step S13, the communication mode is determined based on the CM signal FIF in step S14, and the communication mode determined in step S15 is V.30. It is determined whether or not the mode is 34 mode. If NO, the process proceeds to step S6. If YES, the process proceeds to step S16. In step S16, the transmission rate is determined based on the determined communication mode and set to the INFOoc signal, a predetermined line probing process is executed in step S17, and a predetermined equalizer training process is executed in step S18. The process proceeds to step S19 in FIG.
[0023]
In step S19 in FIG. In the 34 mode, the transmission speed is set to 33.6 kbps, and the parameter Nppr for counting the number of times of receiving the PPR signal is reset to 0 in step S20, and then one block of image data is transmitted in step S21. Next, in step S22, it is determined whether or not a PPR signal is received. If YES, the process proceeds to step S26, and if NO, the process proceeds to step S23. In step S23, it is determined whether transmission of image data for one page has been completed. If NO, the process returns to step S21. If YES, the process proceeds to step S24. Next, in step S24, it is determined whether or not the transmission of the image data of all the pages has been completed. If NO, the process returns to step S21. If YES, the process proceeds to step S25 to open the line and perform the facsimile transmission process. finish.
[0024]
In step S26 of FIG. 3, the PPR signal reception count Nppr is incremented by 1. In step S27, it is determined whether Nppr ≧ 4. If NO, the image of the previous transmission block is determined in step S28. The process returns to step S21 with data as a transmission target. On the other hand, when YES is determined in the step S27, it is determined whether or not the transmission rate is 16.8 kbps in the step S29. When NO is determined, the fallback is performed in the step S30, that is, the fax modem 10 is only one stage. After the transmission speed is reduced, the process returns to step S21. On the other hand, if “YES” in the step S29, a DCN signal is transmitted in a step S31, the line is opened and the line is disconnected, and a redial waiting for 3 minutes is performed in a step S32, and then the process proceeds to a step S41 in FIG. move on.
[0025]
In step S41 of FIG. 4, a call is made to the destination, and in step S42, facsimile pre-processing such as CNG signal transmission, NSF, CSI and DIS signal detection, DCS, TSI and NSS signal transmission is executed. In S43 After the transmission speed of 14.4 kbps is set in the 17 mode, the PPR signal reception count Nppr is reset to 0 in step S44. Next, in step S51, one block of image data is transmitted. In step S52, it is determined whether or not a PPR signal is received. If YES, the process proceeds to step S56. If NO, the process proceeds to step S53. In step S53, it is determined whether transmission of image data for one page has been completed. If NO, the process returns to step S51. If YES, the process proceeds to step S54. Next, in step S54, it is determined whether or not the transmission of the image data of all the pages has been completed. If NO, the process returns to step S51. If YES, the process proceeds to step S55 to open the line and perform the facsimile transmission process. finish.
[0026]
In step S56 in FIG. 4, the PPR signal reception count Nppr is incremented by 1. In step S57, it is determined whether Nppr ≧ 4. If NO, the image of the previous transmission block is determined in step S58. The process returns to step S51 with the data as a transmission target. On the other hand, when YES is determined in the step S57, it is determined whether or not the transmission speed is 12.0 kbps in a step S59. When NO is determined, the fallback is performed in the step S60, that is, the fax modem 10 is only one stage. After the transmission speed is reduced, the process returns to step S51. On the other hand, if “YES” in the step S59, a DCN signal is transmitted in a step S61, the line is opened and the line is disconnected, and a redial waiting for 3 minutes is performed in a step S62, and then the process proceeds to a step S71 in FIG. move on.
[0027]
In step S71 in FIG. 5, a call is made to the destination, and in step S72, facsimile pre-processing such as CNG signal transmission, NSF, CSI and DIS signal detection, DCS, TSI and NSS signal transmission is executed. In S73 After the transmission speed of 9600 bps is set in the 29 mode, the PPR signal reception count Nppr is reset to 0 in step S74. Next, in step S81, one block of image data is transmitted. In step S82, it is determined whether a PPR signal has been received. If YES, the process proceeds to step S86. If NO, the process proceeds to step S83. In step S83, it is determined whether transmission of image data for one page has been completed. If NO, the process returns to step S81. If YES, the process proceeds to step S84. Next, in step S84, it is determined whether or not the transmission of the image data of all pages has been completed. If NO, the process returns to step S81. If YES, the process proceeds to step S85, the line is opened, and the facsimile transmission process is performed. finish.
[0028]
In step S86 of FIG. 5, the PPR signal reception count Nppr is incremented by 1. In step S87, it is determined whether Nppr ≧ 4. If NO, the image of the previous transmission block is determined in step S88. The process returns to step S81 with the data as a transmission target. On the other hand, when YES is determined in the step S87, the transmission rate is V.S in the step S89. It is determined whether or not 2400 bps is obtained in the 27 mode. If NO, the system falls back in step S90, that is, the transmission speed of the fax modem 10 is reduced by one step, and then the process returns to step S81. On the other hand, if YES in step S89, a DCN signal is sent in step S91, the line is opened and the line is disconnected in step S85, and the facsimile transmission process is terminated.
[0029]
In the facsimile transmission process shown in FIGS. 2 to 5, an example pattern of fallback and redial call is shown, and the process is performed as follows. That is, V.I. Facsimile transmission is started at the start transmission speed of 33.6 kbps in 34 mode, and when it falls back in the order of 31.2 kbps, 28.8 kbps, 26.4 kbps, and 16.8 kbps, the line is disconnected and redial waiting is performed. Then V. Facsimile transmission is started at the start transmission speed of 14.4 kbps in 17 mode, and when it falls back to 12 kbps, the line is disconnected and redial waiting is performed. Furthermore, V. Facsimile transmission starts at 9600 bps starting transmission speed in 29 mode, falls back to 7200 bps. When it falls back in the order of 4800 bps and 2400 bps in 27ter mode, it is processed as a communication error.
[0030]
As described above, according to the present embodiment, the main control unit 1 of the facsimile machine 20 uses the fax modem 10 to transmit image data in the error correction mode (ECM) via the public telephone network. When a partial page request signal (PPR signal) has been received a predetermined number of times (YES in step S27 in FIG. 3), and when it has already fallen back to a predetermined transmission speed (YES in step S29). Then, control is performed so that the communication line is disconnected (step S31) and waiting for redialing is set (step S32). Therefore, by trying to improve the line status by redialing without falling back to darkness, the number of times of fallback can be reduced, the communication time can be shortened, and the communication fee can be kept low.
[0031]
In addition, when the main control unit 1 waits for the above redial and redials, the main control unit 1 uses the transmission speed of the communication mode having a transmission speed lower than the transmission speed before the fallback that is the starting transmission speed at the previous dialing. The communication terminal device is called to start facsimile transmission (steps S41-43 in FIG. 4). Accordingly, reliable facsimile communication can be expected without trying to transmit from the same speed unnecessarily, and the number of times of fallback can be reduced, the communication time can be shortened, and the communication fee can be kept low.
[0032]
Further, when performing facsimile transmission by a predetermined last redial, the main control unit 1 falls back to the low-speed transmission speed possessed by the modem (steps S81 to S90 in FIG. 5). Therefore, facsimile transmission can be performed more reliably by attempting communication at the transmission speed of the fax modem 10 as much as possible.
[0033]
Further, examples other than the fallback and redial call patterns shown in FIGS. 2 to 5 will be described below. Here, only the last redial transmission allows fallback to a minimum speed of 2400 bps, and the first start mode is an example in which the super G3 mode is used and the number of redials is two.
[0034]
<Pattern 1>
At the time of the first facsimile transmission, V. The 34 mode transmission speed starts at 33.6 kbps, falls back with a CTC signal (correction continuation signal) and a CTR signal (correction continuation response signal), and waits for redialing when a PPR signal is received four times at a transmission speed of 14400 bps. When making a second facsimile transmission by redialing, Communication is performed at a transmission speed of 14400 bps in 17 mode, fallback is performed using a CTC signal and a CTR signal, and when a PPR signal is received four times even at a transmission speed of 7200 bps, redialing is awaited. When making a third facsimile transmission by redialing, V. 29 mode transmission speed of 9600 bps, fallback with CTC signal and CTR signal, If a PPR signal is received four times even at a transmission speed of 2400 bps in 27ter mode, a communication error is assumed.
[0035]
<Pattern 2>
At the time of the first facsimile transmission, V. The 34 mode transmission speed starts at 33.6 kbps, falls back with a CTC signal (correction continuation signal) and a CTR signal (correction continuation response signal), and waits for redialing when a PPR signal is received four times at a transmission speed of 14400 bps. When making a second facsimile transmission by redialing, It communicates at a transmission rate of 33.6 kbps in 34 mode, falls back with a CTC signal and a CTR signal, and waits for redial when receiving a PPR signal four times even at a transmission rate of 7200 bps. When making a third facsimile transmission by redialing, V. 34 mode transmission speed of 33.6 kbps, fallback with CTC and CTR signals, If a PPR signal is received four times even at a transmission speed of 2400 bps in 27ter mode, a communication error is assumed. In this pattern 2, the transmission speed starting with each facsimile transmission is set to be the same.
[0036]
<Pattern 3>
At the time of the first facsimile transmission, V. The 34 mode transmission speed starts at 33.6 kbps, falls back with a CTC signal (correction continuation signal) and a CTR signal (correction continuation response signal), and waits for redialing when a PPR signal is received four times at a transmission speed of 14400 bps. When making a second facsimile transmission by redialing, Communication is performed at a transmission rate of 28.8 kbps in 34 mode, fallback is performed with a CTC signal and a CTR signal, and when a PPR signal is received four times even at a transmission rate of 7200 bps, a redial is waited. When making a third facsimile transmission by redialing, V. 34 mode transmission speed of 16.8 kbps, fallback with CTC and CTR signals, If a PPR signal is received four times even at a transmission speed of 2400 bps in 27ter mode, a communication error is assumed. In this pattern 3, the transmission rate starting with each facsimile transmission is set to V.P. It is lowered sequentially within the 34 mode.
[0037]
In the above pattern example, V.V. Facsimile transmission is started in 34 mode. 17 mode or V. The facsimile transmission may be started in the 29 mode or the like.
[0038]
<Modification>
In the above embodiment, the example of the facsimile apparatus 20 has been described. However, the present invention is not limited to this, and for example, a telephone, a data communication apparatus, etc. connected to a public network such as a public telephone network or a public digital circuit network. It can apply to the communication terminal device containing.
[0039]
In the above embodiment, the threshold value of the number of PPR signal receptions is set to 4 in step S27 of FIG. 3, step S57 of FIG. 4, and step S87 of FIG. It is good also as a predetermined number.
[0040]
In the above embodiment, the fax modem 10 is a high-speed modem, but the present invention is not limited to this, and may be a modem having a transmission speed of 14.4 kbps or 9.6 kbps.
[0041]
【The invention's effect】
As described above in detail, according to the communication terminal apparatus according to the present invention, in the communication terminal apparatus that transmits the image data by facsimile to the communication terminal apparatus of the other party through the communication line in the error correction mode (ECM) using the modem. When a partial page request signal is received a predetermined number of times, and when it has already fallen back to a predetermined transmission rate, a communication control means is provided for controlling the communication line to be disconnected and set to wait for redialing. Therefore, by trying to improve the line status by redialing without falling back to darkness, the number of times of fallback can be reduced, the communication time can be shortened, and the communication fee can be kept low.
[0042]
In the communication terminal apparatus, the communication control unit preferably waits for the redialing and then redials the transmission rate lower than the transmission rate before the fallback that is the starting transmission rate at the previous dialing. Control is performed so as to initiate a facsimile transmission by calling the communication terminal device of the other party at the transmission speed of the communication mode. Accordingly, reliable facsimile communication can be expected without trying to transmit from the same speed unnecessarily, and the number of times of fallback can be reduced, the communication time can be shortened, and the communication fee can be kept low.
[0043]
Further, in the communication terminal device, the communication control means preferably falls back to a re-slow transmission rate of the modem when performing facsimile transmission by a predetermined last redial. Therefore, facsimile transmission can be performed more reliably by attempting communication at the possible transmission speed of the modem.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a configuration of a facsimile machine 20 having a redial function during training according to an embodiment of the present invention.
FIG. 2 is a flowchart showing a first part of a facsimile transmission process executed by the main control unit 1 of the facsimile machine 20 of FIG.
FIG. 3 is a flowchart showing a second part of a facsimile transmission process executed by the main control unit 1 of the facsimile apparatus 20 of FIG. 1;
4 is a flowchart showing a third part of facsimile transmission processing executed by the main control unit 1 of the facsimile apparatus 20 of FIG. 1; FIG.
FIG. 5 is a flowchart showing a fourth part of facsimile transmission processing executed by the main control unit 1 of the facsimile apparatus 20 of FIG. 1;
[Explanation of symbols]
1 ... main control part,
2. Image reading unit,
3 ... image recording unit,
4 ... display part,
5 ... operation part,
6 ... ROM,
7 ... RAM,
8 ... Image memory,
10. Fax modem,
11 ... NCU,
13 ... Bus
20 ... facsimile machine,
L: Public telephone line.

Claims (2)

In a communication terminal device for facsimile transmission of image data to a counterpart communication terminal device via a communication line in an error correction mode (ECM) using a modem,
When a partial page request signal has been received a predetermined number of times, and if it has already fallen back to a predetermined transmission rate, control is performed to disconnect the communication line and set it to wait for redialing. When starting the facsimile transmission by calling the communication terminal device of the other party at the transmission rate of the communication mode having the same transmission rate as the transmission rate before the fallback that is the starting transmission rate at the time of the previous dial, A communication terminal apparatus comprising: a communication control means for controlling so that a facsimile transmission is performed by decreasing a transmission rate at the time of fallback at each redial as the redialing proceeds . The communication control means, when performing facsimile transmission by the predetermined last redial, communication terminal apparatus according to claim 1, wherein the to fall back to a transmission rate of re low speed the modem has.

Images