JP2004112488A - Device, system and method for communication - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a communication device, a communication system, and a communication method with which transmission speed does not unnecessarily shift down even if a charge billing pulse is received while a recipient communication device receives information. <P>SOLUTION: When a request for retransmission is received from a destination communication device 1, the communication device for transmitting the information via a public network to the destination communication device 1 retransmits the information without change if a notification that an error occurs by the billing pulse is added to the request. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a communication device, a communication system, and a communication method for transmitting and receiving image information and the like via a public network, and unnecessarily shifts the communication speed even when a receiving communication device receives a charging pulse during information reception. The present invention relates to a communication device, a communication system, and a communication method that do not cause a down.
[0002]
[Prior art]
In a public line, a pulse signal of a certain frequency is put on a normal transmission / reception signal in order to count telephone charges. When performing communication on a public line, this often causes a communication error, and the line is often disconnected. Conventionally, in order to solve this kind of inconvenience, a technique has been proposed in a data communication terminal that requests retransmission without causing fallback even if a charging pulse is received during a training sequence (see Patent Document 1 and the like). .
[0003]
[Patent Document 1]
Japanese Patent Application Laid-Open No. 9-163023
[Problems to be solved by the invention]
However, the charging pulse may be generated during reception of the image information, but this cannot be dealt with by the conventional techniques described in the above-mentioned publications. In the receiving facsimile machine, if an error occurs due to the reception of the charging pulse, the line is disconnected.Therefore, a retransmission request must be sent to the sending facsimile device, and the transmitting facsimile device must retransmit the image information at a reduced communication speed. become. In this case, the transmission speed is reduced even when the error is not caused by the charging pulse.
[0005]
An object of the present invention is to provide a communication device, a communication system, and a communication method that do not unnecessarily cause a downshift in communication speed even when a receiving communication device receives a charging pulse during information reception.
[0006]
[Means for Solving the Problems]
The communication device according to the first aspect of the present invention is applied to a communication device that transmits information to a destination communication device via a public network. When a retransmission request is received from the destination communication device, When a notification that "an error has occurred due to a charging pulse" is added to the retransmission request, the information is retransmitted to the destination communication device without changing the transmission speed.
[0007]
The communication device according to the first aspect includes a counting unit that counts the notification that “an error has occurred due to the charging pulse”. When the count value of the counting unit reaches a certain value, the communication speed is reduced to reduce the information. Can be retransmitted to the destination communication device. Even if the transmitting side receives a notification from the receiving side that "an image information error has occurred due to the charging pulse", the receiving side may erroneously detect noise as the charging pulse. Since the number of times of the above notification from the side is counted by the counting means, it is possible to judge that the error is due to noise word detection when the number exceeds a certain number.
[0008]
In particular, the communication device of the first aspect is suitable when the information is image information and the information is transmitted to the destination communication device by facsimile transmission.
In recent years, a modem called a Si-DAA (Silicon Direct Access Arrangement) and a telephone line interface have appeared. The communication device according to the second aspect of the present invention uses the Si-DAA to detect the charging pulse. That is, the communication apparatus of the second embodiment is applied to a communication apparatus that receives information from a transmission source communication apparatus via a public network, and detects (accurately without cost) Si- When the apparatus has a DAA and can determine that the error is caused only by the billing pulse, it issues a retransmission request to the source communication apparatus with a notification that "an error has occurred due to the billing pulse".
[0009]
In particular, the communication device according to the second aspect is suitable when the information is image information and the reception of information from the transmission source communication device is performed by facsimile transmission. In the modem using the Si-DAA, the position of the charging pulse can be specified without increasing the cost, and it is easy to distinguish between the image information error due to noise and the image information error due to the charging pulse.
[0010]
In the communication system of the present invention, the communication device of the first aspect can be a destination communication device, and the communication device of the second aspect can be a source communication device.
[0011]
According to the communication method of the present invention, in a transmission destination communication apparatus, when a charging pulse is received during information reception and an error occurs at the time of receiving the pulse, a message that "an information error has occurred due to the charging pulse" is added to the retransmission request. When the source image information communication device receives the notification that "an information error has occurred due to the charging pulse", the source image information communication device transmits the image information without changing the transmission speed. It is characterized by resending.
[0012]
In the communication method of the present invention, the transmission source communication device counts a notification indicating that “an error has occurred due to a charging pulse”, and when the count value reaches a certain value, reduces the communication speed and updates the information. It can be retransmitted to the destination communication device.
[0013]
In the communication method according to the present invention, the information is image information, and the transmission of the information from the source communication device to the destination communication device can be performed by facsimile transmission.
[0014]
According to the present invention, a message that "an image information error has occurred due to a charging pulse" can be transmitted only when there is an image information error due to a charging pulse.
[0015]
BEST MODE FOR CARRYING OUT THE INVENTION
FIG. 1 is a configuration block diagram showing an example of an embodiment of a facsimile apparatus according to the present invention. As shown in FIG. 1, the facsimile apparatus 1 includes a control unit 101, an operation display unit 102, a page memory (RAM) 103, a scanner 104, a DCR (image information compression and reproduction unit) 105, a plotter 106, , SAF (image information storage unit) 107, CCU (communication control unit) 108, modem DSP 109, and Si-DAA 110.
[0016]
The control unit 101 manages and controls the entire apparatus according to a built-in program. The operation display unit 102 includes a keyboard for the operator to give an instruction to the facsimile machine 1 and a display means for the facsimile machine to give a message or the like to the operator. The page memory 103 can temporarily store image information and the like in page units. The scanner 104 reads an image on a document. The DCR 105 can perform encoding (compression) and decoding (expansion). The plotter 106 can output the received image information decoded by the DCR 105 via the page memory 103, for example.
[0017]
The SAF 107 includes a nonvolatile memory, a large-capacity hard disk, or the like, and can store image information and the like. The CCU 108 can perform facsimile transmission and reception according to the G3 transmission control procedure. The modem DSP 109 includes a low-speed modem and a high-speed modem. The SiDAA 10 is an interface that connects a modem to a line.
[0018]
In the facsimile apparatus 1 having the above-described configuration, the document data (received document) received through the communication line is decoded by the modem DSP 109 through the Si-DAA 110, sent to the DCR 105 through the CCU 108, and reproduced in an image format. The image data is developed on the memory 103 as image data for one page.
[0019]
The image data developed on the page memory 103 is printed by a plotter 106 or transferred to a host device such as a computer via an interface (I / F) (not shown). On the other hand, the image data read by the scanner 104 is expanded on the page memory 103, image-compressed by the DCR 105, sent to the modem DSP 109 through the CCU 108, coded and transmitted to the communication line through the Si-DAA 110. Sent out.
[0020]
FIG. 2 shows a transmission control procedure performed between the facsimile machine 1 and the other party, that is, the reception-side facsimile machine at the time of facsimile transmission.
[0021]
First, the calling side (transmitting facsimile machine) transmits a calling signal (CNG signal). The called side (the receiving facsimile machine) receives the CNG signal, and returns a called terminal identification signal (CED signal) when the line is connected.
[0022]
Subsequently, the called side transmits a non-standard function identification signal (NSF signal), a called terminal identification signal (CSI signal), and a digital identification signal (DIS signal) to the calling side. At this time, the information of the functions of the receiving terminal such as the transmitting / receiving function, the terminal constant, the minimum transmission time of one line of the receiver, the data signal speed, the maximum paper width of the recording paper, and the like are transmitted by the NSF signal or the DIS signal. Are transmitted to the facsimile machine 1.
[0023]
Upon receiving the DIS signal, the calling side transmits a digital command signal (DCS signal), whereby transmission of the calling side and reception of the called side are determined, and subsequently, a transmitting terminal identification signal (TSI signal) is transmitted from the calling side. Signal) and a training signal (TCF signal). Upon receiving the TCF signal, the called side sends a reception preparation confirmation signal (CFR signal) to urge the calling side to transmit FAX data (PIX signal).
[0024]
Upon receiving the CFR signal, the calling side transmits a TCF signal, and then transmits a PIX signal to perform facsimile transmission. When the image information has been transmitted, the calling side transmits a partial page signal-procedure end (PPS-EOP signal). The called side that has received the PPS-EOP signal transmits an acknowledgment signal (MCF signal) to the calling side. Upon receiving the MCF signal, the calling side transmits a disconnection command (DNC signal), disconnects the line, and ends the facsimile transmission operation.
Note that the transmitting side can also transmit a non-standard function setting signal (NSS signal) instead of DCS / TSI.
[0025]
FIG. 3 shows a retransmission procedure for reducing the communication speed. The transmitting side transmits a PPS-EOP signal following the PIX signal (same as in FIG. 2 so far). On the other hand, if all image information has not been received on the receiving side, a partial page request signal (PPR signal) is transmitted. In response to this, the transmitting side transmits a continuation of correction (CTC signal). Upon receiving the CTC signal, the receiving side transmits a correction continuation response (CTR signal). When the transmitting side receives the CTR signal, it transmits a PIX with a reduced communication speed.
[0026]
FIG. 4 shows a retransmission procedure without reducing the communication speed. It is the same as FIG. 3 up to the point where the PPR signal is output from the receiving side. If the transmitting side determines that it is not necessary to reduce the communication speed, it receives the PPR signal and transmits the PIX signal at the same communication speed.
[0027]
FIG. 5 shows a flow on the receiving side during PIX reception. First, PIX reception (S101) is performed, and the frame number and PIX content notified from the PIX are stored (S102). Next, it is determined whether or not there is a charging pulse (S103). If there is, a charging pulse is stored and the frame number is also stored (S104). Then, it is determined whether the PIX is completed (S105). If it is determined in S103 that there is no operation, the process proceeds to S105. If “No” in S105, the process proceeds to S101. If "Yes", V21 reception is performed (S106). Then, it is determined whether all frames have been received (S107). If "Yes", the MCF is transmitted (S111). In the case of "No", it is determined whether or not there is an image error in a frame other than the frame where the charging pulse is present (S108). In the case of "No", the PPR in which "there is an image error due to the charging pulse" is transmitted. Then, it waits for both sides of the PIX and V21 signals (S112). If "Yes" in S108, normal PPR is transmitted (S110), and the process proceeds to S112.
[0028]
FIG. 6 shows a flow on the transmitting side during PIX transmission. First, PIX transmission is performed (S201). When the PIX transmission is completed, a PPS-EOP is transmitted (S202). Then, V21 reception is started (S203). If the MCF is received, the DCN is transmitted and the communication is terminated (S211). When the PPR is received in S203, the frame that could not be received is compared with the frame when the accounting pulse was present, and it is determined whether or not an image error is caused by the accounting pulse (S204). If “Yes”, the counter that counts “image error due to charging pulse” is set to +1 (S205). Then, the value is compared with a previously input N value (S206). When the counter becomes N or more, CTC is transmitted (S207). Then, after receiving the CTR (S208), the communication speed is reduced and PIX transmission is performed (S209). If the counter is less than N in S206, PIX transmission is performed while keeping the communication speed (S210). If “No” in S204, the process proceeds to S207.
[0029]
【The invention's effect】
According to the present invention, when the charging pulse is detected during the reception of the image information, the fact that "an image information error has occurred due to the charging pulse" is added to the retransmission request and notified to the transmitting side. When there is a retransmission request that "an image information error has occurred due to a pulse", retransmission is performed without lowering the communication speed. Therefore, even when an error due to noise is received, communication can be performed without lowering the communication speed.
[0030]
Further, since there is a counter for counting a retransmission request that "an image information error has occurred due to a charging pulse", even if noise is erroneously detected as a charging pulse, it is possible to retransmit at a reduced communication speed.
[0031]
Further, in the present invention, when the receiving communication device has the SiDAA, the retransmission request that "the image information error has occurred due to the charging pulse" can be made only when it can be specified that the image error has occurred only by the charging pulse. it can.
[Brief description of the drawings]
FIG. 1 is a configuration block diagram illustrating an example of an embodiment of a facsimile apparatus according to the present invention.
FIG. 2 is a diagram illustrating a transmission control procedure performed between a transmission-side facsimile apparatus and a reception-side facsimile apparatus.
FIG. 3 is a diagram illustrating a retransmission procedure when the transmission-side facsimile apparatus lowers the communication speed.
FIG. 4 is a diagram showing a retransmission procedure when the transmission-side facsimile apparatus does not lower the communication speed.
FIG. 5 is a diagram showing a flow on the receiving side during PIX reception.
FIG. 6 is a diagram showing a flow on the transmission side during PIX transmission.
[Explanation of symbols]
1 Facsimile machine 101 Control unit 102 Operation display unit 103 Page memory (RAM)
104 scanner 105 DCR (image information compression / reproduction unit)
106 plotter 107 SAF (image information storage unit)
108 CCU (communication control unit)
109 Modem DSP
110 Si-DAA

Claims (9)

In a communication device that transmits information to a destination communication device via a public network,
When a retransmission request is received from the transmission destination communication device and a notification that "an error has occurred due to a charging pulse" is added to the retransmission request, the information is transmitted without changing the transmission speed. A communication device for retransmitting to a destination communication device. Counting means for counting the notification that "an error has occurred due to the charging pulse", and when the count value of the counting means reaches a certain value, the communication speed is reduced and the information is retransmitted to the destination communication device. A communication device characterized in that: The communication device according to claim 1, wherein the information is image information, and the information is transmitted to the destination communication device by facsimile transmission. A communication device that receives information from a source communication device via a public network has a SiDAA that detects a charging pulse, and when it can be determined that the error is caused only by the charging pulse, the message “Error occurred due to the charging pulse. A communication device that issues a retransmission request to the source communication device with a notification to the effect. The communication device according to claim 4, wherein the information is image information, and the reception of the information from the transmission source communication device is performed by facsimile transmission. A communication system comprising: the communication device according to claim 1 as a destination communication device; and the communication device according to claim 4 or 5 as a source communication device. At the transmission destination communication device, when the charging pulse is received during the information reception, and an error occurs at the time of receiving the pulse, the fact that "an information error has occurred due to the charging pulse" is added to the retransmission request to the transmission source communication device. Notify,
The source image information communication device, when receiving a notification that the "information error has occurred due to the charging pulse", retransmit the image information to the destination communication device without changing the transmission speed,
A communication method, comprising: The transmission source communication device counts a notification that “an error has occurred due to a charging pulse”, and when the count value reaches a certain value, reduces the communication speed and retransmits the information to the transmission destination communication device. The communication method according to claim 7, wherein: 9. The communication method according to claim 7, wherein the information is image information, and the transmission of the information from the source communication device to the destination communication device is performed by facsimile transmission.

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