JPH10304011A - Communication control method and communication terminal equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To continue communication without interrupting a channel by requesting re-execution of a training of a primary channel for a transmitter side equipment prior to receiving data at a receiver side equipment. SOLUTION: In the embodiment where the communication terminal equipment is applied to a facsimile equipment, a CPU 1 acts like a control section of the facsimile equipment and connects to a ROM 2, a RAM 3, an NCU 4, and a MODEM 5 or the like. In the case that image data cannot normally be received at a receiver side equipment, the CPU 1 is in standby for a prescribed time till receiving valid image data. When the valid image data are received within the prescribed time, a prescribed processing step is advanced. In the case that the valid image data cannot be received within the prescribed time and no FCS error takes place, re-training processing of the primary channel is conducted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a communication control method and a communication terminal between communication terminals such as facsimile machines, and more particularly, to a full-duplex communication such as ITU-T (International Telecommunication Union). -When performing data communication such as facsimile communication in accordance with Recommendation V.34 of the Telecommunication Standardization Division, training of the primary channel (channel for data communication), which is the pre-procedure for full-duplex communication, has been completed. The present invention relates to a communication control method and a communication terminal device which facilitate recovery when data to be transmitted / received later cannot be normally received.

[0002]

2. Description of the Related Art Generally, a communication terminal device for performing data communication such as a facsimile device converts a digital signal into a voice signal at the time of transmission and transmits the signal to a general public telephone line, and receives a voice signal from a general public telephone line at the time of reception. A modem is provided for receiving signals and converting them to digital signals.

[0003] In the case of performing data communication with a conventional communication terminal device, a modulation / demodulation device based on a half-duplex system such as the ITU-T (International Telecommunication Union-Telecommunication Standardization Sector) recommendation V.17 communication procedure is used. It is used in accordance with the procedure specified in Recommendation T.30, which is also a currently common facsimile communication procedure of the G3 standard.

[0004]

When performing data communication such as the facsimile communication described above, transmission of data, which is the original communication content, is started from the transmitting device after a communication procedure is established between the transmitting and receiving devices. However, if the image data cannot be normally received by the receiving side device within a predetermined time, the line is disconnected as a communication error. In such a case, even if the line condition is temporarily poor, the user must dial again and perform the facsimile communication operation from the beginning, which is troublesome.

[0005] In recent years, an ultra-high-speed full-duplex communication procedure (hereinafter, referred to as a V.34 communication procedure) having a maximum transmission speed of 33.6 Kbps in accordance with the recommendation V.34 has been put to practical use. In such full-duplex communication, it is possible to transmit a signal from the other device and receive the signal while the signal is being transmitted from one device to the other device. Therefore, if the above communication procedure is already established,
By performing some kind of action from the receiving device to the transmitting device, it is possible to continue communication without disconnecting the line.

The present invention has been made in view of such circumstances. For example, when performing data communication such as facsimile communication between devices capable of full-duplex communication such as a V.34 communication procedure, the present invention is not limited thereto. If image data cannot be received normally at the receiving device after the training of the primary channel for heavy communication is completed, disconnect the line by requesting the receiving device to re-execute training of the primary channel from the receiving device. It is an object of the present invention to provide a communication control method and a communication terminal device capable of continuing communication without using a communication terminal.

[0007]

SUMMARY OF THE INVENTION A communication control method according to the present invention provides a full-duplex communication for transmitting and receiving data after training a primary channel for transmitting and receiving data that should be transmitted and received between the transmitting and receiving apparatuses. A communication control method to be performed, wherein a request is made to the transmitting device to re-execute training of the primary channel before receiving data at the receiving device.

According to the communication control method of the present invention, before the data to be transmitted and received is normally received by the receiving device, the receiving device re-executes the training of the primary channel from the receiving device to the transmitting device. Request if necessary.

Further, according to the communication control method of the present invention, the receiving side device transmits a signal requesting re-execution of training of the primary channel when the original data transmitted from the transmitting side cannot be detected within a predetermined time. It is characterized by doing.

In the communication control method according to the present invention, when data to be transmitted and received is not normally received by the receiving device within a predetermined time, the receiving device performs training of the primary channel with respect to the transmitting device. Can be requested again.

Further, the communication terminal device according to the present invention is a communication device for performing full-duplex communication in which data is received after training of a primary channel for transmitting and receiving data that should be transmitted and received between the transmitting and receiving sides.
Before receiving the data, it is possible to transmit a request signal for re-executing the training of the primary channel to the transmitting apparatus.

In such a communication terminal apparatus of the present invention, when data to be originally received is not normally received within a predetermined time when it becomes a receiving apparatus, a primary channel of the primary channel is transmitted to the transmitting apparatus. When a signal requesting re-execution of the training is transmitted and the transmitting apparatus re-executes the training of the primary channel accordingly, the original data can be re-received without disconnecting the line thereafter.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the drawings showing the embodiments. FIG. 1 is a block diagram showing a specific configuration example when a communication terminal device according to the present invention is applied to a facsimile device.

In FIG. 1, reference numeral 1 denotes a CPU (central processing unit) which functions as a control unit of the facsimile apparatus, and a ROM (Read) in which a program for controlling the operation of the entire facsimile apparatus is stored in advance. Only Memor
y) 2 and a RAM (Random Access Memory) 3 functioning as a storage unit for storing data necessary for control by the CPU 1 or data that needs to be temporarily stored during operation.

The CPU 1 has an NCU (Network Control Unit).
nit) 4 and modem 5 are connected. NCU 4 is CPU 1
, And controls the connection between the line L and the facsimile machine, and has a function of transmitting a dial pulse corresponding to the telephone number of the communication partner and a function of detecting an incoming call. The line L is connected to a general public telephone line (not shown).

The modem 5 modulates and demodulates the transmission / reception data, specifically, modulates the transmission data into a voice signal and sends it to the line L via the NCU 4, and conversely, the voice received from the line L via the NCU 4 Demodulate the signal into a digital signal. Although there are products with various capabilities as the modem 5, in this example, it is assumed that the modem 5 is capable of a V.34 communication procedure compatible with full-duplex communication.

The CPU 1 is further connected to a reading unit 6, an image memory 7, a codec 8, a recording unit 9, an operation unit 10, a display unit 11, and the like. The reading unit 6 reads a document image using, for example, a CCD image sensor. The image memory 7 stores image data read by the reading unit 6 and image data received from outside via the line L and the modem 5. The codec 8 encodes the image data to be transmitted and decodes the received image data. Recorder 9
Records the received image data or the image data read by the reading unit 6 on recording paper (paper). The operation unit 10 includes ten keys for inputting numbers such as telephone numbers, one-touch keys, abbreviated keys, operation keys for instructing various operations, and the like. The display unit 11 includes a CRT display or an LCD (Liquid Crystal Display) that displays various information such as a telephone number input by operating the operation unit 10.

Next, the operation of the facsimile apparatus which is the communication terminal apparatus of the present invention having the above-described configuration, that is, the procedure of the method of the present invention, the control procedure by the CPU 1 in the receiving side (called side) apparatus will be described. This will be described below with reference to the flowcharts of FIGS. In the following description, it is assumed that the transmitting side (calling side) device also has the same function.

First, when communication starts after receiving a call,
A pre-procedure based on the V.8 communication procedure is performed to determine an actual communication speed (step S11).

Next, probing and equalizer training are performed according to the V.34 communication procedure (step S1).
2). This is the primary channel which is the channel for data communication by exchanging information such as modem capability, line probing result, data mode modulation parameters, etc. between both the transmitting and receiving devices. Is performed to determine the communication speed.

Thereafter, facsimile communication (T.30 communication procedure in the present embodiment) based on ITU-T recommendation T30 is started (step S13). When a signal of the T.30 communication procedure is normally received from the transmitting device within a predetermined time (step S14)
"YES" in step S20, "NO" in step S20),
Transmission is performed according to 30 communication procedures (step S15). As described above, the pre-procedure of the T.30 communication procedure, which is facsimile communication, is completed and the original image data can be transmitted / received.Since the transmitting apparatus starts transmitting image data, the receiving apparatus transmits the image data. Receive (Step S16).

After receiving the image data of the facsimile communication, the receiving apparatus receives a signal of the T.30 communication procedure ("YES" in step S17), and correspondingly receives the signal of the T.30.
The communication procedure is transmitted (step S18), and
If reception is performed again in the T.30 communication procedure (Step S1
9) Assuming that the facsimile communication has ended, the entire process ends.

It should be noted that the CPU 1 of the receiving side apparatus executes step S1.
If the reception by the T.30 communication procedure is not performed within the predetermined time in step 7 (“NO” in step S20), the processing is interrupted as a communication error.

By the way, in the case where the receiving side apparatus cannot normally receive the image data in step S16,
This will be described with reference to the flowchart of FIG. 3 showing the details of the processing in step S16.

First, the CPU 1 waits for a predetermined time until valid image data is received (steps S31 and S4).
1). If valid image data is received within the predetermined time (“YES” in step S31, “NO” in step S41), then the CP
U1 determines whether or not it is a high-speed signal (G3 or more) (step S32). If it is not a high-speed signal (step S32)
NO ") A predetermined process (FSK reception) is performed (step S33).
In the case of high-speed communication (“YES” in step S32),
CPU 1 then performs an FCS error check (step S3
4) If no FCS error has occurred (step S3
4 "YES"), Check if RTC signal received
(Step S35), and check whether an RCP frame has been received (Step S36). If an RTC signal has been received ("YES" in step S35), or
If a frame has been received (step S36), the process proceeds to step S17 described above.

When neither the RTC signal nor the RCP frame is received (both "NO" in steps S35 and S36)
CPU 1 is a unit sent from the transmitting device
A process of receiving and taking in (normally one page) image data is performed (step S37), and the process returns to step S31 to receive the next one unit of image data.

On the other hand, if valid image data cannot be received within the predetermined time in step S31 ("N" in step S41)
O "," YES "in step S32), and if an FCS error has occurred (" NO "in step S34), a primary channel retrain process characterizing the method of the present invention is performed (step S42).

FIG. 4 is a time chart showing the procedure of the primary channel retraining process in step S42.

If the receiving device cannot normally receive image data within a predetermined time, it transmits tone B,
It waits for tone A to be transmitted from the transmitting device. Upon receiving the tone A, the tone B is transmitted for at least 50 milliseconds, then the inverted signal of the tone B is transmitted for 10 milliseconds, and the transmission side apparatus waits for the transmission of the inverted signal of the tone A. On the other hand, the transmitting device transmits the probing signal L1 for 10 milliseconds and transmits the same L2 for 160 milliseconds after transmitting the inverted signal of tone A, and then transmits tone A.

Upon receiving the inverted signal of tone A, the receiving device enters a state of waiting for reception of probing signals L1 and L2, and upon receiving both signals, transmits tone B and then transmits INFOh for notifying communication parameters for 25 milliseconds. I do.

Upon receiving this INFOh, the transmitting apparatus starts equalizing training for the primary channel. The transmitting device first transmits the signal S for 128T, then transmits the inverted signal of the signal T for 16T, and then transmits the signal PP for 288T.
During the transmission, and further transmits the signal TRN. Note that the time from the start of transmission of the signal PP to the end of transmission of the signal TRN needs to be within 2000 ms.

As described above, when the transmitting apparatus sequentially transmits the signal S, its inverted signal, PP, and TRN, the receiving apparatus detects the signal S and its inverted signal to detect the next signal PP. And train the primary channel using TRN. After transmitting the signal TRN for the period specified by INFOh, the receiving device transmits the control channel and the image data. The image data is received again by the receiving device in accordance with the flowchart of FIG. By the primary channel retraining process of step S42 of the method of the present invention, the T.30 communication procedure, which is facsimile communication, can be restarted without disconnecting the line even if the line has been disconnected once. Becomes possible.

In the above embodiment, the case where the V.34 communication procedure is applied to facsimile communication has been described, but it goes without saying that the present invention is applicable to general full-duplex communication. The case where the data transmitted by the V.34 communication procedure is image data of facsimile communication has been described, but it goes without saying that other digital data may be used.

[0034]

As described above in detail, according to the communication control method of the present invention, the data transmission / reception is performed after training the primary channel for transmitting / receiving data that should be transmitted / received between the transmission / reception devices. When performing duplex communication, a request is made from the receiving device to the transmitting device when it is necessary to re-execute training of the primary channel before data to be transmitted / received is normally received by the receiving device. It becomes possible.

According to the communication control method of the present invention,
If data that should be transmitted / received at the receiving device is not normally received at the receiving device within a predetermined time, the receiving device can request the transmitting device to re-execute the primary channel training. Become.

Further, according to the communication terminal device of the present invention,
In a communication device that performs full-duplex communication that receives data after training a primary channel for transmitting and receiving data that should be originally transmitted and received between the transmitting and receiving sides, before transmitting data, Since it is possible to transmit a request signal for re-executing the training of the primary channel, communication is continued as it is when the line state is only temporarily poor, and data reception is executed again.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration example of an embodiment when a communication terminal device of the present invention is embodied as a facsimile device.

FIG. 2 is a flowchart illustrating a procedure of a communication control method of the present invention executed by the communication terminal device of the present invention.

FIG. 3 is a flowchart illustrating a procedure of a communication control method of the present invention executed by the communication terminal device of the present invention.

FIG. 4 is a time chart showing a procedure of a primary channel retrain process of the communication control method of the present invention.

[Explanation of symbols]

 1 CPU, 5 modem, L communication line.

Claims (3)

[Claims] 1. A communication control method for performing full-duplex communication for transmitting and receiving data after performing training of a primary channel for transmitting and receiving data that should be transmitted and received between the transmitting and receiving devices. Before receiving the data, the communication control method may request the transmitting device to re-execute the training of the primary channel. 2. The reception-side apparatus transmits a signal requesting re-execution of training of a primary channel when original data transmitted from the transmission side cannot be detected within a predetermined time. Claim 1
3. The communication control method according to 1. 3. A communication apparatus for performing full-duplex communication for receiving data after performing training of a primary channel for transmitting and receiving data that should be transmitted and received between the transmitting and receiving sides, before receiving the data. A communication terminal device capable of transmitting a request signal for re-executing the training of the primary channel to a transmitting device.