JPS61173578A - Facsimile communication system - Google Patents

Abstract

PURPOSE:To eliminate the waste of circuit holding time by allowing a called station to stop sending out a CED (Called station identification) signal when detecting a CNG (Calling tone) signal from an originating station and sends a specific initial identification signal at a specific time later. CONSTITUTION:When the called station detects the CNG signal from the originating station, the CED signal for displaying a called no-tone terminal is not sent out before being sent out or stopped while sent. Then, a DIS (digital identification) signal, a CSI (called subscriber identification) signal, and an NSF (nonstandard facility) signal are sent out as initial identification signals to the originating station with a delay of 70+ or -20ms after the detection, thereby transmitting the ability of the called station to the originating station while indicting the called station is facsimile equipment. The originating station sends out a DCS (digital instruction) signal, a TSI (transmitting subscriber identification) signal, and an NSS (nonstandard facility setting) signal as initial instructions to the called station according to the initial identification signals and then starts the procedure of phase C. When the CNG signal is not detected, the called station follows the same procedure as usual.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a facsimile communication system, and in particular,
Recommendation T3 Recommendation Concerns the facsimile communication system in Ic when a facsimile call is made (7A).

[Conventional technology]

In the conventional facsimile communication system based on CCITT Recommendation T3 Recommendation A30, when a 7A facsimile call occurs, communication between the calling station and the called party is performed based on the control sequence shown in Figure 2. .

However, FIG. 2 shows a case where the calling station is the transmitting side and the receiving side of the called side is in the 03 type automatic reception format.

In Figure 2, when a call is placed to the called party by dialing on the calling party, the called party's NCU (line control unit) disconnects the telephone line by detecting a ringtone signal from the calling station. Switch to the facsimile IJ device side. If the automatic reception function is set, the communication switch is turned on and the machine enters facsimile reception mode.

Then, after 1.8 to 2.5 seconds, VC2, and for 6 to 4.0 seconds, CBD (C
alled 5tation 1dentificat
ion ) signal is sent to the calling station.

On the other hand, after the line is closed, a CNG (Calling tone) signal is sent from the calling station to the called side, which is displayed on a non-voice terminal, and the called side detects the CNG signal and confirms that the communication partner station is a facsimile machine. Recognize that.

After the calling station sends the CNG signal, the CE sent from the called side
By detecting the D signal, it is confirmed that the called party is a facsimile terminal, and the phase A communication ends.

After a delay of 75±20 m5 after the end of the transmission of the CED signal, the called party enters the phase B Brimessage procedure and sends a DIS (Digital Identification) signal featuring standard CCITT capability as an initial identification signal to the calling station. A C3l (called subscriber identification) signal for identifying the called subscriber and an N8F (non-standard equipment) signal for identifying a non-standard mode are transmitted.

When the calling station detects the initial identification signal, it sends D as an incoming call command.
DC of response to standard capability identified by I8 signal
8 (digital command) signal, the indicated TRI (transmitting subscriber identification) signal, which is the identification of the transmitting station, and the N5S (non-standard equipment setting) signal in response to the NSF signal, are sent to the called party. Let's move on to the steps.

[Problem that the invention seeks to solve]

Such a control sequence requires 4.4 to 6.5 seconds for the called party to send the CED signal.

The calling terminal can confirm that it is a facsimile machine by detecting the initial identification signal without detecting the CED signal. Moreover, the length of time required to transmit the above CHD signal is
As the speed of facsimile communication increases, this value has become a value that cannot be ignored.

That is, in the conventional facsimile communication system, since confirmation of the called terminal device is performed repeatedly, the time required for one communication unit becomes long, and there is a drawback that the line holding time is wasted.

[Means for solving problems]

The facsimile communication system of the present invention is a facsimile communication system in which the called side sends a CED signal to the calling station when the line is closed, and when the called side detects a CNG signal from the calling station ( 5, the transmission of the ED double signal is stopped, and after a predetermined time elapses, a predetermined initial identification signal is sent to the calling station.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a control sequence diagram showing one embodiment of the present invention.

In FIG. 1, a calling party makes a call to a called party, and when the called party detects a ring tone signal from the calling station, the called party's NCU switches the telephone line to a facsimile machine. When the called party is in reception mode and the automatic reception function is not set, the communication switch is turned on and the facsimile reception state is entered.

When the called side detects a CNG signal from the calling station, it will not send the CED signal if it is not yet started sending out the CED signal that indicates the called non-voice terminal at the time of detection, and it will not send the CED signal even if it is being sent. If so, stop sending.

Subsequently, with a delay of 70±20m5 after the detection of the CNG signal, the DIS signal and CHI signal are transmitted as the above-mentioned initial identification signals.
A signal, NSF signal, is sent to the calling station to indicate that the called party is a facsimile machine, and at the same time to convey its capabilities to the calling station.

In response to the initial identification signal, the calling station sends the DO8 signal, T'SI signal, and NSS signal as the above-mentioned incoming call command to the called party, and then the procedure of phase C is settled.

If a CNG signal cannot be detected, the called party performs the same procedure as before.

The addition of the CED signal transmission stop operation described above can be easily realized by changing the communication control microprocessor program in the facsimile machine.
ITT Recommendation T3 Recommendation A30 can be implemented in a conventional 037 axis device.

〔Effect of the invention〕

As described above, the facsimile communication system of the present invention reduces the time required to send the CED signal by stopping the sending of the CED signal when the called party detects the CNG signal. This has five benefits: it reduces the time required, prevents wasted line holding, and improves line usage efficiency.

[Brief explanation of the drawing]

Fig. 1 is a control sequence diagram showing one embodiment of the present invention, and Fig. 2 is a control sequence diagram showing an example of the conventional technology.

Claims (1)

[Claims] When the line is closed, the called side sends a CED (Ca) to the calling station.
lled station identity
On) In the facsimile communication system that sends out signals,
The called party receives CNG (Calling) from the calling station.
1. A facsimile communication system characterized in that when a CED signal is detected, transmission of the CED signal is stopped, and after a predetermined period of time, a predetermined initial identification signal is sent to the calling station.