KR20080070198A - Data transmitting method of facsimile - Google Patents

Abstract

A data transmission method of a facsimile is provided to increase a success rate by complementing communication errors by changing communication modes based on an ECM(Error Correction Mode) to thus prevent charging of an additional fee. When a transmission facsimile is in a phase C(300), it receives a PPR(Partial Page Request) signal requesting re-transmission of transmitted facsimile data from a reception facsimile(310). The transmission facsimile checks whether a NON-ECM change bits have been set in a DCS(Digital Identification Signal)(320). If the NON-ECM change bits have been set, the transmission facsimile checks whether the number of reception times of PPR signals received from the reception facsimile is larger than a pre-set N number of times(340). If the number of reception times of PPR signals is larger than the pre-set N number of times, the transmission facsimile transmits a PPS(Partial Page Signal)-COM(Change Of Mode) signal for instructing changing from an ECM to a NON-ECM to the reception facsimile(350). The reception facsimile transmits a DIS for changing the ECM to the NON-ECM to the transmission facsimile, and the transmission facsimile checks whether it has received the DIS(370). When the transmission facsimile has received the DIS, it performs a phase V to proceed with the NON-ECM(380) and executes a Phase B based on the NON-ECM(390).

Description

Data transmitting method of facsimile

FIG. 1 is a reference diagram illustrating a process of correcting an error according to a conventional error correction mode (ECM) when an error occurs in a frame transmitted from a sending fax.

2 is a block diagram illustrating a configuration according to an embodiment of the multifunction apparatus 200 having a fax function to which the present invention is applied.

3 is a flowchart illustrating a method of transmitting data of a fax according to an embodiment of the present invention.

The present invention relates to a method for transmitting data in a facsimile (hereinafter referred to as a 'fax'), and more particularly, to a data transmission method for improving communication efficiency by reducing communication errors.

In general, a fax or multifunction device transmits data on a public switched telephone network (PSTN). However, the success rate of the communication is affected by the complex communication line environment. Each communication line continues to evolve, and most of them use UTP (Unshielded Twisted Pair) cable network or Voice over Internet Protocol (VoIP) in most corporate and user environments. In particular, communication conditions such as overseas communication Increasingly, e-mail success rates are falling, which is a problem.

FIG. 1 is a reference diagram illustrating a process of correcting an error according to a conventional error correction mode (ECM) when an error occurs in a frame transmitted from a sending fax.

As shown in Fig. 1, when a calling tone (CNG) signal is sent from a sending fax to a receiving fax, the receiving fax sends a call to tone (CED) in response to the call. .

When the call is connected, the receiving side fax transmits a digital identification signal (DIS) signal to the transmitting side fax. In this case, when the DIS signal is sent, various information about the receiving side path such as the speed, capacity, resolution, paper size, and paper type of the receiving side fax is informed. The sending side fax transmits a digital command signal (DCS; Digital Command Signal), which is a digital setup command corresponding to the standard capacity confirmed by the DIS, to the receiving side fax, and subsequently, the training sequence to the receiving side fax. Send it.

Receiving fax receiving the training sequence, if there is no transmission error in the training sequence, the CFR (ConFirmation to Receive) signal to confirm that the entire procedure (procedure) for the message transmission is completed and the message transmission starts Is sent to the sender's fax machine. If the process is successful, the actual data is transmitted. If an error occurs in the data during the transmission, the receiving side fax transmits a Partial Page Request (PPR) signal requesting retransmission to the sending side fax. The sending fax machine retransmits the fax data in response to the request for retransmission of the receiving fax machine, and the receiving fax machine sends an MCF (Message ConFirmation) signal to the sending fax machine to confirm receipt of the data. If a PPS-EOP (Partial Page Signal-End Of Page) signal is sent to the receiving fax machine indicating that the data transmitted from the sending fax machine is the last data, the receiving fax sends the MCF signal. When the transmission of the message is completed in this way, the sender data transmits a DCN (DisCoNect) signal for removing the call to the receiving fax machine, performs a post message procedure, and releases the call.

In order to correct an error of the fax data by the above procedure, the sending fax machine has a storage device such as a memory for retransmitting the error frame, and the receiving fax machine receives the received frame before the error occurs. It is provided with a storage device for storing and additionally storing a frame re-transmitted later.

However, according to the related art, when the sender transmits the compressed data for a fax transmission in units of 64 bytes or 2568 bytes, the receiving fax machine checks whether an error occurs in the corresponding frame. If an error occurs in a frame, the receiving fax sends a Partial Page Request (PPR) signal to the sending fax that requests retransmission of the failed frame. Here, the PPR includes information on an error frame. The receiving fax machine analyzes the PPR signal and retransmits the frame requested by the receiving party.

However, due to the nature of the error correction mode, if an error occurs in any one of the received frames, the receiving fax machine sends a PPR signal to the sending fax machine if an error occurs in the frame even if the erroring bit is one bit. Sends a request for retransmission of the frame. Therefore, there is a case in which communication errors occur while continuously transmitting and receiving PPR and PPS (Partial Page Siganl) signals. In fact, due to this field problem, many facsimile machines or multifunction manufacturers are providing a troubleshooting shooting guide to change the transmission mode set to ECM mode to NON-ECM mode and retransmit when a communication error occurs. It is enough.

In practice, however, when the communication is attempted by switching to the NON-ECM mode, the communication is generally successful. Therefore, in recent years, the ECM mode does not function properly.

The present invention relates to a method for transmitting data in a facsimile, and in particular, to effectively reduce communication errors caused by various causes in various communication environments and improve data communication efficiency based on ECM mode, but by communicating through communication mode switching. The present invention relates to a data transmission method that can improve communication rate by preventing an additional charge caused by reconnecting to a communication network by improving success rate by improving error rate and reducing communication time.

In order to solve the above technical problem, a fax data transmission method according to the present invention includes (a) a request for retransmission of a receiving side fax (PPR; Partial Page Request) while transmitting data in an error correction mode (ECM). Switching the transmission mode of the data from the error correction mode (ECM) to a non-error transmission mode (NON-ECM) when the number of times is equal to or greater than a preset number of times; And (b) transmitting the data in the switched non-error transmission mode (NON-ECM).

In addition, in step (a), if the number of retransmission requests (PPRs) is greater than or equal to the predetermined number of times, a mode change signal (PPS_COM; Change OF Mode) is instructed to instruct the receiving side to change the transmission mode of the data. Receiving a digital identification signal (DIS) from the received fax in response to the transmitted mode switching signal; And (a2) switching the error correction mode to the non-error correction mode when the digital identification signal DIS is transmitted.

In addition, in step (a1), the mode change signal may be transmitted according to a high-level data link control (HDLC) protocol.

In addition, in step (a1), the mode switching signal is repeated until the number of times that the digital identification signal DIS has not been received after the mode switching signal PPS_COM (Change OF Mode) is transmitted is a preset number. Can transmit

In addition, the data transmission method of the facsimile comprises the steps of receiving a digital identification signal (DIS) including information on whether the receiving side fax supports the switching of the transmission mode; And a digital command signal (DCS; Digital Command Signal) including information on whether to apply the switching of the switching mode with reference to the information on whether to support the switching of the transmission mode. The method may further include transmitting the data, and the steps (a) to (c) may be performed when the digital command signal DCS includes information indicating that the switching mode is switched.

Hereinafter, a method of transmitting data of a facsimile according to a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

In general, Group 3 (G3) fax protocols process a single call in five steps (Phase A, B, C, D, E). Phase A is a call setup step, and Phase B is a step of performing a pre-message procedure, which determines which side to transmit, how much to speed, and how much to size a page. Phase C is a step of transmitting a message such as an image or data, Phase D is a step of performing a post message procedure, and Phase E is a step of releasing a call. In the present invention, when a PPR (retransmission request) signal is received from a receiving fax machine during the data transmission in the phase C phase of transmitting fax data in ECM mode, the present invention switches the communication mode from ECM mode to NON-ECM mode according to a predetermined condition. The present invention relates to a data transmission method of a facsimile for transmitting data.

2 is a block diagram illustrating a configuration according to an embodiment of the multifunction apparatus 200 having a fax function to which the present invention is applied. The central processing unit 210 controls the multifunction device as a whole according to the set program. The system memory 220 stores an operation program and a general control program of the central processing unit 210 and stores data according to program execution of the central processing unit 210. The ROM memory 230 is a nonvolatile memory in which a control program is stored, and the RAM memory 240 is a volatile memory that temporarily stores data and image data according to program execution.

The print engine 250 prints data in the system memory 220 or prints data transmitted to the printer driver 250 of the host computer. The computer interface unit 290 can print data by transferring print data from the host to the print engine unit 250. The media card 110 allows the host computer to manage the folder of the card and read / write card and image files from the host computer through the media card interface 100 of the multifunction apparatus.

The OPE (Operating Panel) 30 has a plurality of keys and applies key data according to pressing a predetermined key to the central processing unit 10 and displays the operating state of the system by the display data of the central processing unit 10. Displayed by the LCD / LED display 40. It is a part that inputs voice data through C-mic, and the input voice data is converted into digital data in MODEM / DSP and stored in memory.

The scanner 60 converts the analog image data obtained from the image reading sensor into an appropriate digital image format through an image processor 120 and stores it in a memory.

The media card interface unit 100 is a central processing unit for a circuit interface to a media card such as smart media, a memory stick, a compact flash, and a file structure within the card. The control of (10) is performed, and when the image is read from the card, the image processing unit 120 converts the image into an appropriate image manipulation and format, if necessary, and transmits the image to the host computer, the print engine unit, or the system memory.

The modem 70 transmits various tones and provides a demodulation function related to communication.

The network control unit (NCU) unit 80 is operated under the control of the central processing unit 10 to form a call loop of the telephone line and interface the telephone line with the modem 70.

Based on the configuration of the present invention described above with reference to Figure 3 will be described a method of data transmission of the facsimile according to an embodiment of the present invention.

In FIG. 3, when the sending side fax is in the phase C step (step 300) of transmitting data in the ECM mode, the transmitting side fax receives a PPR signal requesting retransmission of the fax data transmitted from the receiving side fax (step 310). When the sending fax receives a retransmission request (PPR) from the receiving fax, it determines whether the DCS signal has the NON-ECM Mode change bit set on the DCS signal as to whether to switch the transmission mode from ECM mode to NON-ECM mode. Inspect (step 320). According to an embodiment of the present invention, the receiving side fax converts the transmission mode to the NON-ECM mode when the receiving side fax is able to support the transmission mode switching function on the DIS signal, that is, when it reaches the predetermined condition while transmitting in the ECM mode. Includes information on whether fax data can be sent and received and sends it to the sending fax. For example, assign a bit to the DIS signal as to whether the receiving fax can or cannot support the transfer mode switching function. If the receiving fax can support the transfer mode switching function, the bit value is set to 1. If it cannot support this, it can be set to 0 and sent to the sending fax. According to another embodiment, the corresponding bit may be allocated to the DIS signal only when the receiving side fax can support the transmission mode switching function, and the corresponding bit may not be allocated if the receiving side fax cannot support the transmission mode switching function.

If the NON-ECM Mode change bit is not set in the DCS signal of the sender's fax in step 320, the process proceeds to a normal mode for correcting an error of the fax data using the PPR signal (step 330). If the NON-ECM Mode change bit is set, the process proceeds to switching the transmission mode from the ECM mode to the NON-ECM mode (steps 340 to 390).

First, it is checked whether the number of PPR signals received from the receiving side FAX on the current page is greater than a predetermined number of times N (an integer of 1 or more) (step 340). In step 340, if the number of PPR signals received on the current page is greater than N, the PPS-COM signal for commanding the transition from the ECM mode to the NON-ECM mode is transmitted to the receiving side fax. Step 350). However, if the number of PPR signals received on the current page is less than or equal to N, the process proceeds to the normal mode without switching the mode.

After receiving the PPS-COM signal from the receiving fax machine, if the DIS signal is sent back to the sending fax machine to switch from the ECM mode to the NON-ECM mode, the sending fax machine checks whether the DIS signal has been received. Step 370). For example, if the communication environment is poor or there is a problem with other sending / receiving faxes, the receiving or sending fax may not receive the PPS-COM signal or the DIS signal, respectively.

In step 370, when the sending side fax does not receive the DIS signal, the sending side fax checks whether the number of times the DIS signal has not been received after transmitting the PPS-COM signal reaches a preset M number (step 360). ). In this example, it is assumed that after the sending fax machine transmits the PPS-COM signal, the number of times that the DIS signal has not been received is three times. That is, the sender FAX attempts to transmit the PPS-COM signal three times in succession, and if it succeeds before the three attempts, it proceeds to the procedure for switching to the transmission mode. If the signal is not received, the transfer mode switching process is stopped and the process proceeds to the normal mode. In this case, after proceeding to the normal mode, it may be arranged to stop the entire transmission process of the fax data according to the fax transmission protocol of the normal mode. If the sender's fax attempts to communicate with the receiver's fax three times and fails, the current network status may be inadequate for sending fax data.

When the sender FAX receives the DIS signal in step 370, the process proceeds to a phase V process to proceed to the NON-ECM mode (step 380), and executes a phase B step based on the NON-ECM mode (step Step 390).

According to another embodiment of the present invention, ITU-T Rec. In the case of the V.34 mode, if the number of PPR signals received in step 340 is greater than the N number, the transmitting side fax transmits a Return to Control for Partial page (RCP) sequence signal and controls the control channel resynchronization procedure (control). channel resynchromization procedure, and after resetting the control channel, transmit the PPS-COM signal, and the receiving side fax sends the DIS signal to transmit the fax data by switching the transmission mode to the NON-ECM mode. Upon receiving the DIS signal from the sending fax machine, it proceeds to Phase B phase and resumes from V.17 mode from Phase B phase. At this time, the transmission and reception of the fax data has a pause of a predetermined time to initialize the existing channel, and to proceed from the phase B phase.

As described above, when the transmission error occurs for various reasons during the transmission of the fax data in the ECM mode, the present invention enables the transmission mode to be switched from the ECM mode to the NON-ECM mode according to the user's setting. Reduce transmission errors caused by communication. When fax data is communicated in an environment with poor communication rate through a UTP cable network or a VoIP network, fax data is communicated in the ECM mode, thereby reducing the number of communication errors that occur and improving the communication rate. As such, communication reliability is reduced by reducing the communication error occurrence rate, thereby reducing communication time and preventing additional charges incurred by reconnecting to a communication network.

The present invention can be embodied as code that can be read by a computer (including all devices having an information processing function) in a computer-readable recording medium. The computer-readable recording medium includes all kinds of recording devices in which data that can be read by a computer system is stored. Examples of computer-readable recording devices include ROM, RAM, CD-ROM, magnetic tape, floppy disks, optical data storage devices, and the like.

Although described with reference to the embodiments shown in the drawings to aid in understanding of the present invention, this is merely exemplary, those skilled in the art that various modifications and equivalent other embodiments are possible from this. Will understand. Therefore, the true technical protection scope of the present invention will be defined by the appended claims.

As described above, in the facsimile transmission method according to the present invention, if an error occurs during transmission in the ECM mode, the fax data is transmitted by switching the transmission mode to the NON-ECM mode according to a predetermined condition, and thus, in various communication environments, Effectively reduce the communication error caused by the cause. In addition, the data communication efficiency can be improved, and the ECM mode is the basic, but communication error can be compensated by switching the communication mode to increase the success rate, thereby preventing additional charges caused by reconnecting to the communication network, and reducing the communication time to increase the communication rate. have.

Claims (5)

(a) If the number of Partial Page Requests (PPRs) of a receiving fax machine is greater than a preset number during transmission of data in Error Correction Mode (ECM), the transmission mode of the data may be changed to the error correction mode. Switching to a non-error transmission mode (NON-ECM) at (ECM); And (b) transmitting the data in the switched non-error transmission mode (NON-ECM). The method of claim 1, wherein step (a) (a1) When the number of retransmission requests (PPR) is greater than or equal to the predetermined number of times, a mode change signal (PPS_COM; Change OF Mode) indicating the change of the transmission mode of the data is transmitted to the reception fax, and the received mode change signal is transmitted to the received mode change signal. In response to receiving a digital identification signal (DIS) from the received fax; And and (a2) converting the error correction mode to the non-error correction mode when the digital identification signal DIS is transmitted. The method of claim 2, wherein step (a1) A method of data transmission of a facsimile, characterized in that for transmitting the mode switch signal in accordance with High-Level Data Link Control (HDLC) protocol. The method of claim 2, wherein step (a1) After the mode switching signal (PPS_COM; Change OF Mode) of the facsimile characterized in that the repeated transmission of the mode switching signal until the number of times that the digital identification signal (DIS) has not been transmitted to a predetermined number Data transmission method. The method of claim 1, wherein the facsimile data transmission method is Receiving a digital identification signal (DIS) including information on whether the receiving side fax supports switching of the transmission mode; And Transmitting a digital command signal (DCS; Digital Command Signal) including information on whether to switch the switching mode by referring to the information on whether to support the switching of the transmission mode. More steps, The steps (a) to (c) are performed when the digital command signal DCS includes information indicating that the switchover mode is applied.

Images