JPS6278970A - Transmission control system - Google Patents

Abstract

PURPOSE:To reduce a communication trouble due to an echo and to improve a reliability and a serviceability by disposing a silence interval of a required time after a digital identification DIS signal outputted sequentially to a Callee station identification CED signal and performing a facsimile communication under a condition in which an echo suppressor functions. CONSTITUTION:When a receiver of a Callee station transmits an ED signal after a line is connected, an echo suppressor of a relay exchange stops a function by, for instance, 2,100Hz component of a CED signal. The Callee station transmits subsequently a DIS signal, and a transmitter receives it by a signal receiver 4 and at the same time counts the DIS signal by a counter. A transmission control means receives the second DIS signal transmitted three seconds after the first DIS signal, thereafter, transmits a DCS signal from a signal transmitter 2 and continues an ordinary facsimile signal procedure thereafter. The function of the echo suppressor stopped once by, for instance, 2,100Hz component of the CED signal is recovered in a silence interval between the two DIS signals.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention J The present invention relates to a transmission control method for a facsimile machine, and particularly to a transmission control method suitable for facsimile communication using an international telephone line.

[Background of the Invention] Conventional facsimile transmission control devices comply with CCITT Recommendation T.
, 30, the called station and the called station identification signal (C
ED) followed by a digital identification signal (I) IS), the calling station immediately sends a digital command signal (DO8).
was responding. Therefore, this conventional transmission control method is
This has the disadvantage that the echo suppressor of the relay exchange becomes inoperable, resulting in communication failure due to echoes.

[Objective of the Invention] An object of the present invention is to provide a transmission control method that completely prevents facsimile transmission from being disturbed by echoes that sometimes occur in long-distance communications such as international telephone lines, and allows communication to continue normally. It is in.

[Summary of the invention] If the echo suppressor of the relay exchange is disabled by the CED signal of the called station, the 400
If there is a no-signal period of m sec or more, the echo sublet T- recovers within this no-signal period. Therefore, in the transmission control system of the present invention, a no-signal period is provided for a required time after the DIS signal is sent out following the CED signal.

[Embodiment J of the invention Hereinafter, one embodiment of the present invention will be described with reference to side A.

1 and 2 are GIs explaining the first embodiment of the present invention.
FIG. 2 is a diagram showing the transmission procedure and main part configuration of I-facsimile. When the receiver of the called station sends a CED signal after connecting the line, the echo suppressor of the relay exchange sends the CED signal 21oo.
Hz&: Stops the accuracy by minutes. The called station continues with D.
IS signal is sent, but transmission 8! receives this signal at the signal receiver 4, and at the same time counts the DIS signal at the received signal counter. The transmission control means 1 receives the second DIS signal, which is sent out three seconds after the first DIS signal.
The C3C12 signal transmitter 2 sends the signal, and thereafter the normal facsimile signal procedure continues. Once 2100 of CHD signal
The function of the echo suppressor stopped by the H2 component returns to the no-signal area (j41) between the two DIS signals.

This embodiment can be easily implemented by simply providing a received signal counter in the transmission control means.

FIG. 3 (This is a diagram showing 11 km of the transmitter according to the second embodiment of the present invention. After receiving the DIS signal, the transmitter measures a certain period of time TD using the reception timer 5, and then calculates the time T.

After the elapsed time, all DC8 signals are responded. Apart from this, on the receiving side, a training check signal (TCF'
) After a certain period of time T has elapsed after reception, it responds with a received $ confirmation signal (CFR).

As described above, as in the first embodiment and Ii'f1, the function of the echo suppressor can be simultaneously produced by the no-signal period TD (400 m5ec or more).

This embodiment can be easily implemented by simply receiving a received signal timer in the transmission 1tiIII1# means.

[Effect of the Invention J] According to the present invention, facsimile aId'ic can be performed with the echo suppressor functioning, thereby reducing communication failures due to echoes and improving reliability and serviceability for users.

[Brief explanation of drawings]

FIG. 1 shows an fN transmitter 11m according to the first embodiment of the present invention.
Explanatory diagram, Figure 2 is a configuration diagram of the main parts of the transmission control device,
FIG. 3 is an explanatory diagram of the key signal transmission procedure according to the second embodiment of the present invention. DESCRIPTION OF SYMBOLS 1...Transmission control means, 2...Signal sender, 5...Reception signal counter, 4...Signal receiver, 5...Reception signal timer

Claims (1)

[Claims] 1. In a transmission control system for a facsimile device, CED
A transmission control method characterized by providing a required no-signal period after a DIS signal is sent out following a DIS signal. 2. The transmission control system according to claim 1, wherein the DIS signal is sent out again after the required no-signal period, and normal facsimile procedures are performed thereafter. 3. The transmission control system according to claim 1, wherein a response signal is sent after measuring the required no-signal period.