JPS58105671A - Transmission controlling system of facsimile - Google Patents

Abstract

PURPOSE:To shorten the transmission controlling procedure of the transmission controlling system of fascimile, by using an automatic error resending requesting device which automatically shifts down the modem rate of picture information. CONSTITUTION:In the course of transmission of a digital facsimile, the function of a receiver 20 is transmitted first from the receiver 20 to a transmitter 10 by an HDLC frame (1). The transmitter 10 judges this and informs the receiver 20 of the communication mode, such as the width of the transmitting original, the auxiliary scan sending mode, the data compressing system, the modem mode, the modem rate, etc., by an HDLC frame (2). If an ARQ which can automatically shifts down the modem rate exists, a shortened protocol which does not make any modem training check is also informed at the time of the information. Then, a modem training signal (3) is sent under an indicated mode and a picture information signal (7) is also sent. When an error occurs, the modem rate is automatically shifted down by the ARQ function.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention (c. , which aims to shorten the facsimile transmission control procedure.

As a transmission control procedure for digital facsimile, CCI
It has been standardized by the TT T-30 recommendation as shown in Figure 1. That is, in FIG. 1, signal (1)
is the HDLC (high level procedure) that informs the receiver's functionality.
frame, signal 12) is an H signal indicating the transmission mode determined by signal (1) and the mode set on the transmitting side.
DLC frame, signal +31 is modem training at the modem rate specified by signal f2), signal (4) is a line status check based on a determined data pattern after modem training, signal (5) is OK due to line status check Or HDLC frame, signal notifying NG (
6) is a modem retrain signal sent when signal (5) is OK, and signal (7) is a transmission signal for image information. Image information transmission time is becoming shorter, and the ratio of transmission control procedure time to image information transmission time is increasing. For example, if you have an A4 size document at a modem rate of 960,
If you send it at 0bps, it can be sent in 15 to 20 seconds,
In the case of the control procedure shown in Figure 1, control procedure 1 before image information transmission
It takes 7 to 12 seconds to complete the process, which increases the functionality of the culm.

The time to check the line status (usually 1 to 2 seconds) is still too short compared to the time to transmit image information, so it is best to check the failure of image information transmission to avoid setting a modem rate that does not match the line status. Sometimes. On the other hand, ARQ (Automatic Error Repeat Request) is used to remove errors in image information data. In this case, ARQ detects the data error rate, and when the error rate exceeds a set value, the image information It has been considered to interrupt the transmission of the image information and shift down the modem rate to restart the transmission of the image information, but the present invention uses ARQ to automatically shift down the modem rate during image information transmission. This is an attempt to shorten the facsimile transmission control procedure.

FIG. 2 is a diagram showing an example of a facsimile to which the transmission control method according to the present invention is applied. Conversion unit 12, buffer] 3, data compression unit 14, A RQ
15, a modem 16, and a line network control section 17,
The receiver 20 includes a line network control unit 21, a modem 22, and an A RQ
23, data reproduction section 24, buffer 5, write conversion section 2
6, a plotter 29, etc., and as shown in the figure, in addition to a normal facsimile device, it is equipped with an ARQ that shifts down the modem rate during image information transmission,
Therefore, the transmission control procedure is shortened as shown in FIG. 3, that is, the signal (4) shown in FIG.
(5) and (6) are not transmitted. That is, the signals (4), +5), (
61 is for checking the line condition when transmitting image information data at the set modem rate.
In ARQ, where the modem rate is shifted down depending on the number of data retransmissions (when the set value is exceeded) during image information transmission, this step can be omitted and transmission of the image information signal can be started at the set modem rate. . In addition, if the other receiver cannot take such a shortening procedure (for example, if it has an ARQ that cannot automatically downshift the modem rate during image information transmission, or if it does not have an ARQ function), , the transmission control procedure can be performed in the manner shown in FIG. 1 by making a judgment based on the signal (1) in FIG. 1 or FIG. , by receiving and receiving signal (1), it determines the function of the receiver facsimile and sends signal (2), which informs the receiver of the communication mode, such as the width of the original to be sent, the sub-scanning feed mode, the data compression method, and the modem mode. , modem rate, etc. At that time, if there is an ARQ that can auto-shift down the transmitting/receiving mK modem rate, signal (2) notifies the user to perform a shortened protocol without performing a modem training check, and then modem mode, modem training signal at modem rate (
A signal (3)) is sent out, and image information is also sent out.

At this time, even if the modem rate set on the transmitting side does not match the characteristics of the transmission system and many errors occur, the modem rate is automatically downshifted by the ARQ function, so the modem rate matches the line condition of the transmission system. image information can be transmitted.

As is clear from the above description, the present invention (according to A
Since the modem rate is automatically downshifted during the transmission of image information using RQ, the facsimile transmission control procedure can be shortened.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an example of a conventional facsimile IJ transmission control procedure, FIG. 2 is a diagram showing an example of a facsimile IJ apparatus to which the transmission control procedure according to the present invention is applied, and FIG.
FIG. 3 is a diagram showing an example of a facsimile transmission control procedure according to the present invention. 10 Transmitter, 11 ・Document reading unit, 122 value conversion unit, 13 Buffer, 14...Data compression unit, +5
A.R.Q. ] +6 modem, 17 line network control unit, 20...receiver, 21 line network control unit, 22 modem, Otsu/ARQ, 2
4 data playback section, 25 buffer, ? 6...Writing converter, n plotter〇

Claims (1)

[Claims] means for encoding image information; means for transmitting the image information in blocks having a predetermined bit length; means for detecting transmission errors on a block-by-block basis; and retransmission requests on a block-by-block basis upon detection of transmission errors. A facsimile transmission control system (with a means to downshift the modem rate during the image information transmission depending on the number of retransmission requests) allows the facsimile transmission control system to perform image transmission without detecting the line status before transmitting the image information. A patented facsimile transmission control method that starts sending information.