JPS62123873A - Communication speed deciding system for facsimile equipment - Google Patents

Abstract

PURPOSE:To guarantee the picture quality of facsimile communication by deciding the communication speed depending on an error bit number in a training check (TCF) signals section so as to set the speed to a communication speed suitable for the line. CONSTITUTION:The transmission side sends a TCF signal from a modulator 1 to the reception side via a line 10. When the training of a MODEM or the like is not executed by the TCF signal due to the line condition, a training fault (FTT) signal is returned to the reception side and the retraining is requested and in this case, the information of error bit number at the reception side during the TCF signal section is added to the FTT signal by a signal adder 5 and the result is sent. A demodulator 2 at the transmission side demodulates the said returned signal and the error bit number information is stored in a memory 3. Then a controller 4 decides the communication speed in response to the error bit number to set the communication speed of the modulator 1.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for determining communication speed of a facsimile machine.
Especially for group 3 facsimile machines, training check (below) on the receiving side.

CF) relates to a communication speed determination method that determines the communication speed by returning the number of erroneous bi-sotos in a signal section to the transmitting side.

[Prior Art] Conventionally, in Group 3 facsimile machines, after sending TCP signals twice, training fails again (hereinafter referred to as FTT).
) When a signal was received, the communication speed was determined by lowering the communication speed by one step.

[Problem that the invention seeks to solve]

The conventional communication speed determination method described above lowers the communication speed by one step, but it has the disadvantage that facsimile communication may not be possible even if the communication speed is lowered by one step on a line with poor S,...'H. .

[Means for solving problems]

The communication speed determination method of the facsimile apparatus of the present invention provides a training check to the receiving side for detecting error signals in the signal section.
a signal adding means for adding soto number information and adding it to the 12-sig failure signal and returning it to the transmitting side; demodulating means for demodulating the training failure signal from the line on the transmitting side; and the number of demodulated error bits. The apparatus includes a memory means for storing information, and a control means for determining a communication speed according to the contents of the memory means, and the communication speed is determined based on the error bit number information in the training failure signal.

〔Example〕

Next, the present invention will be explained with reference to the drawings.

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

This embodiment has a modulator 1, a demodulator 2, a memory 3, and a controller 4 on the transmitting side, and a signal adder 5 on the receiving side.

In a group 3 facsimile machine, a TCP signal from the transmitting side is sent from the modulator 1 to the line 10 and sent to the receiving side according to a communication control procedure based on CCTTT Recommendation T.30. On the receiving side, if modem training cannot be performed using this TCP signal due to line conditions, etc., FT
The T signal is returned to the transmitting side to request retraining. At this time, in this embodiment, the signal adder 5 adds information on the number of error bits on the receiving side in the TCP signal section to the FTT signal and sends it to the transmitting side. Send it back. Regarding the addition of information signals other than control signals to this FTT signal,
It is an extension of CCIT'T Recommendation T.30 and is easy to implement.

On the transmitting side, the FTT signal returned via the line 10 is demodulated by the demodulator 2, and the error bi-soto number information in the demodulated FTT signal is stored in the memory 3. Controller 4
determines the communication speed according to the predetermined relationship between the number of error bits and the communication speed according to the contents of the memory 3, and modulator 1
Set the communication speed. The modulator 1 sends the TCP signal to the receiving side again at the set communication speed. In this way, preparations for reception on the receiving side are completed using the TCP signal at a communication speed that is suitable for the line condition and the condition of the receiving side. [Effects of the Invention] As explained above, the present invention determines the communication speed based on the number of error bits in the TCP signal section, thereby making it possible to determine the communication speed suitable for the line. This has the effect of guaranteeing the image quality of communications.

[Brief explanation of drawings]

FIG. 1 is a block diagram of one embodiment of the present invention. 1...Modulator, 2...Demodulator, 3...Memory, 4
...Controller, 5...Signal adder, 10...Line. M1 figure

Claims (1)

[Claims] The receiving side includes signal adding means for adding information on the number of error bits in the training check signal section to the training failure signal and returning it to the transmitting side; the transmitting side includes demodulating means for demodulating the training failure signal from the line; and a control means for determining a communication speed according to the contents of the memory means, the communication speed being determined based on the error bit number information in the training failure signal. A method for determining communication speed of a facsimile machine, which is characterized by: