KR100217740B1 - Method for automatically controlling data transmission velocity in facsimile - Google Patents

Abstract

1. TECHNICAL FIELD OF THE INVENTION

How to automatically adjust the data rate on the fax.

2. The technical problem to be solved by the invention

In the related art, since the transmission speed is determined using only zero data of the TCF signal, data can be transmitted at high speed even in a bad state of the line, and thus a reception error or data distortion occurs frequently.

3. Summary of the Solution of the Invention

A method for automatically adjusting data transmission speed by detecting a level of a training check signal received during protocol progress for document transmission and transmitting a line training failure signal until an appropriate data transmission speed is set for the detected level.

4. Important uses of the invention

Fax.

Description

How to adjust the automatic data rate on your fax

1 is a block diagram of a conventional facsimile.

2 shows the flow of the facsimile protocol proposed by the ITU Recommendation.

3 is a diagram illustrating a control flow for automatic data rate adjustment according to an embodiment of the present invention.

The present invention relates to a method for adjusting an automatic data transmission speed of a facsimile, and more particularly, to a method for automatically adjusting a transmission speed by checking a reception level of a training check signal received during a protocol progress before transmitting data.

In general, the facsimile machine must determine the other party's facsimile and transmission speed in order to transmit the original. For this purpose, the facsimile is determined by a predetermined protocol before the original is transmitted.

2 is a protocol progression performed on the facsimile proposed in the ITU Recommendation. Signals used when performing the protocol include a digital identification signal (DIS), a digital command signal (DCS), a training check signal (TCF) and a confirmation preparation signal (CFR). It consists of a line training failure signal (FTT).

(2a) of FIG. 2 is a protocol progression performed when a normal TCF signal is received, and (2b) of FIG. 2 is a protocol progression performed when an abnormal TCF signal is received.

Conventionally, this is done by checking the data of the received TCF signal to adjust the transmission speed. The TCF signal is a signal transmitted from a sending side facsimile to check the state of a line to which data is transmitted. On the other hand, the TCF signal has a form that transmits data of digitized format 0 for 1.5 seconds.

Therefore, the facsimile checks the zero data of the received TCF signal and counts the number of data in which an error has occurred to determine whether an error has occurred. When the error occurrence is detected, the receiving side fax sends an FTT signal corresponding to a line training failure signal. When the FTT is received, the transmitting side fax lowers the transmission rate and retransmits the TCF signal.

On the other hand, if the occurrence of the error is not detected, the receiving side fax sends a CFR signal corresponding to the reception ready signal. When the CFR signal is received, the transmitting side facsimile performs data transmission at a currently set transmission rate.

As described above, when the transmission rate is determined using only zero data of the TCF signal, there is a problem in that reception errors frequently occur because data can be transmitted at high speed even in a bad line state.

Accordingly, an object of the present invention is to provide a method for automatically adjusting to an appropriate transmission speed by checking a level of a received training check signal.

In order to achieve the above object of the present invention, it is characterized by detecting the level of the training check signal received during the protocol progress for document transmission and transmitting a line training failure signal until an appropriate data transmission rate is set for the detected level. .

Hereinafter, with reference to the drawings in accordance with an embodiment of the present invention.

First, the configuration of a conventional facsimile for implementing the automatic data transmission rate determination method to be implemented in the present invention will be described with reference to FIG.

The controller 110 generally controls the facsimile according to the program of the set mode. In particular, the control for determining the data transmission rate to be implemented in the present invention. A line interface unit (LIU) 112 forms a call path between a telephone line and a modem 114, an internal telephone 124, and an external telephone under the control of the controller 110. Under the control of the controller 110, the analog signal inputted through the LIU 112 is demodulated into a digital signal. Meanwhile, the digital signal provided from the controller 110 is modulated into an analog signal. The scanner 116 scans a document supplied under the control of the controller 110, converts the document into image data, and provides the scanned image to the controller 110. The printer 118 prints a document under the control of the control unit 110. OPE (Operating Panel) 120 is composed of a key matrix including a plurality of numeric keys and function keys for setting the function. In addition, the controller 110 provides key data generated according to a user's key manipulation. On the other hand, the OPE 120 is provided with a display unit for displaying the operation state of the facsimile under the control of the control unit 110. The memory 122 temporarily stores data generated when the mode is executed under the control of the controller 110.

3 is a diagram illustrating a control flow for adjusting a transmission speed according to the level of a training check signal.

3 is a process of checking a level of a TCF signal corresponding to a received training check signal, comparing a transmission rate set to a level of the detected TCF signal with an appropriate level, and setting the transmission rate to be inappropriate. In this case, a process of transmitting a line training failure signal is performed, and when a predetermined training check signal is received in response to the set transmission rate or the transmission rate change request, a reception preparation signal is transmitted.

Hereinafter, an operation according to an exemplary embodiment of the present invention will be described in detail with reference to the above configuration.

If the control unit 110 detects the reception of the TCF signal transmitted from the counterpart facsimile in step 310 through the modem 114, the controller 110 checks the level of the received TCF signal. Step 312 is a step of checking the Receive Line Signal Detector (RLSD) level of the TCF signal using the level detection circuit provided in the modem 114.

Meanwhile, in step 314 and 316, the controller 110 compares the detected level with a predetermined level. For example, the predetermined level is divided into -39 dBm, -45 dBm and -45 dBm or less. In addition, the appropriate transmission rate corresponding to the predetermined level is 9600bps when the signal is within -39dBm, 7200bps when the signal is within -45dBm, and 4800bps when the channel is below -45dBm.

If this is shown as a table it can be represented as shown in Table 1 below.

Therefore, the controller 110 compares the RLSD (Receive Line Signal Detector) level checked by the TCF signal with the set level disclosed in Table 1.

That is, in step 314, it is compared whether the RLSD level is within -39 dBm. In step 316, the RLSD level is compared with -45dBm or less. If the RLSD level does not fall within -45dBm, it is determined to be -48dBm or less.

If the RLSD level is -45 dBm or less, the controller 110 determines whether the transmission rate is set to 4800bps in step 324. On the other hand, if it is determined in step 316 to be within -48dBm, the controller 110 proceeds to step 318 to determine whether the transmission rate is set to 7200bps. However, if it is determined that the control unit 110 is within -39dBm in step 314 or is set to an appropriate transmission rate in steps 318 and 324, the controller 110 proceeds to step 330. In step 330, a CFR signal that is ready to receive data is transmitted. The setting of the transmission rate generally means a transmission rate determined by negotiation with the other party's facsimile by protocol progression.

However, if it is determined in step 318 and step 324 that the proper transmission speed is not the control unit 110 proceeds to step 320 and step 326. In step 320 and step 326, the control unit 110 transmits an FTT signal which is a line training failure signal requesting to reset the transmission speed.

On the other hand, the other side facsimile sets the transmission rate lower than the currently set transmission rate when the TCF signal is received. For example, if the TCF signal is received while the current transmission rate is set to 9600bps, the transmission rate is set to 7200bps and then the TCF signal is transmitted.

The controller 110 detects whether the TCF signal is re-received in step 322 and 328 in response to the FTT signal after transmitting the FTT signal in steps 320 and 326. When the TCF signal is re-received, the controller 110 returns to step 318 and step 324 to determine whether it is reset at an appropriate transmission rate.

As described above, the present invention has an effect of preventing errors and distortion of a received document by automatically setting an appropriate transmission speed in response to a line attenuation factor when transmitting a document using a facsimile.

Claims (1)

A method for determining a transmission speed of a facsimile, the method comprising: determining a transmission speed by a protocol for receiving an original, detecting a reception of a training check signal after the transmission speed is determined, and receiving the training check signal. Sequentially comparing a level with preset levels, determining a level range to which the level of the training check signal belongs, determining whether the determined transmission rate is appropriate in correspondence with the determined level range, and determining the determined transmission rate. Transmitting a reception ready signal when the transmission rate is appropriate; transmitting a line training failure signal when the determined transmission rate is not appropriate; and receiving the adjusted transmission rate in response to the line training failure signal. It is determined whether the speed is appropriate in correspondence with the determined level range. And a process of transmitting the line training failure signal when the adjusted transmission rate is not appropriate and transmitting the reception ready signal when the adjusted transmission rate is appropriate. How to adjust the data rate.