JP3280461B2 - Facsimile reception control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a facsimile reception control apparatus applied to a facsimile apparatus connected to an automobile telephone.

[0002]

2. Description of the Related Art Conventionally, it is difficult to accurately communicate image information in a mobile telephone radio line because noises such as fading and handoff characteristic of a radio line are mixed.
In particular, when the modem rate is set to a high speed (9600 bps, 7200 bps), the influence of the noise increases, and the communication error occurs.
(Image information error in facsimile communication) increases.

[0003] For this reason, in a mobile telephone radio line, communication is usually performed at a low modem rate (4800 bps, 2400 bps) or an error correction mode (ErrorColle) is used.
Section Mode (ECM). Especially in ECM,
Only the data that is erroneous due to noise is retransmitted, and retransmission is repeated while lowering the modem rate until communication can be performed correctly. Therefore, when the line quality is poor, the communication time is extended, but the effect of using the mobile telephone radio line is great.

[0004] Therefore, it is better that the modem rate in the non-ECM is low, but in the case of the ECM, communication can be performed at a high modem rate.

[0005]

However, some general facsimile machines currently on the market do not have the ECM function. Also, modem rate and ECM
It is the transmitting side that determines the setting of, and there is a problem that the receiving side cannot freely change the modem rate depending on the communication mode.

An object of the present invention is to provide a facsimile reception control device which can improve the quality of image information in a facsimile device connected to a car telephone.

[0007]

In order to achieve the above object, a facsimile reception control apparatus according to the present invention comprises means for selecting one of a telephone line and a car telephone radio line as a communication line, and a type of the communication line. Means for changing the threshold of the number of error bits for modem training, retransmission of only the data that caused an error due to noise, and connection in error correction mode where the retransmission is repeated while reducing the modem rate until communication can be performed properly,
Means for changing the threshold value of the number of error bits when connected in a mode other than the correction mode.

[0008] The present invention is characterized in that a means for changing a threshold value of the number of error bits according to a connected modem rate is provided.

Means for storing modem rate data, threshold data of the number of error bits when modem training is successful, error bit number and data detected in actual modem training, and communication result data;
Means for monitoring the number of error bits when a communication error occurs for each modem rate and changing a threshold value of the number of error bits.

Means for storing the number of error bits and data for each communication mode, and monitoring the number of error bits when a communication error occurs for each communication mode and for each modem rate to change the threshold value of the number of error bits. Means.

When the number of error bits is the same as the number of error bits at the time of a past communication failure, a means for generating a modem training error even within the threshold value of the number of error bits is provided.

[0012]

In the facsimile reception control device having the above-described configuration, the receiving side is connected to the telephone line or connected to the automobile telephone radio line and the ECM is set. By changing the threshold value of the number of error bits and responding to the modem training error, it is possible to perform communication in an appropriate state, and the image information quality is not reduced.

Also, when ECM is set, data is retransmitted, so that the modem rate may be higher. When non-ECM is set, there is no retransmission and no communication error occurs. Therefore, the modem rate needs to be set lower in advance. By appropriately setting the threshold value of the error bit, an appropriate threshold value can be set.

When a communication error occurs at the modem rate determined in the past communication, a plurality of data are stored as to how much the difference between the actually counted number of error bits and the threshold is. Review the settings as needed.

Further, by enabling the storage data to be stored separately in the ECM and the non-ECM, the threshold can be reviewed without being influenced by each other.

When the number of error bits is equal to the number of error bits in the past communication, even if the error bit number is equal to or less than the threshold value, a modem training error is caused to lower the modem rate and enable good communication.

[0017]

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

FIG. 2 is a block diagram of a system configuration according to a first embodiment of the present invention.
Reference numeral 2 denotes a plotter for printing image information, 3 an encoding / decoding unit for compressing and decompressing image information, 4 a communication control unit for checking modem training and controlling a predetermined protocol as described later, and 5 for communication. A modem that modulates and demodulates data, 6 is a network control unit that controls to meet the standards of each country for connection to the line, 7 is a switch that switches between the use of the mobile telephone radio line and the use of the general telephone line, etc. An operation display unit 8, which is equipped and communicates with an operator, is a system control unit that performs various controls as described below and performs a predetermined facsimile control.

FIG. 3 is a protocol flowchart in facsimile communication. FIG. 3 shows an example in which modem training has failed and the modem rate (modulation demodulation speed) has been shifted down to 4800 bps. FIG. 4 is a flowchart relating to modem training reception and success / failure determination.

In FIG. 3 and FIG. 4, upon receiving the call, the receiving side sends a CED signal indicating that the connection has been established (S4).
-1) Then, attributes such as resolution or paper size are set to DI
The transmission side is notified by the S signal (S4-2). The transmitting side is the D
The DCS signal is sent to the receiving side with reference to the IS signal (S4-
3). The DCS signal includes information such as a modem rate for modem training, an error bit threshold, and whether or not ECM is set. Therefore, after receiving the DCS signal, the receiving side sets a threshold value for modem training success / failure (S4-4).

That is, upon receiving the modem training signal and the TCF signal for checking it (S4-5),
If there is a bit in which all of the actually received data should be "0" and become "1", it is determined as an error bit (YES in S4-6), and the error bit counter is incremented (S4). −7).

When the modem training signal ends (S4
-8), comparing the count value of the error bit with the threshold value of the number of error bits, and if the count value is greater than the threshold value (S4-9
NO), the receiving side determines that the modem training failed
The signal is sent to the transmission side (S4-10), and the modem training is performed at the modem rate (9600 bp) as shown in FIG.
s, 7200bps, 4800bps) and repeat (S
4-3 to S4-10).

However, if count value ≦ threshold,
(YES in S4-9), the receiving side responds to the transmitting side with a CFR signal as the modem training success (S4-11). Then, the transmitting side starts transmitting the PIX signal (image information signal).
(S4-12), the end of transmission is notified by the EOP signal (S4-1).
3).

The modem rate is determined as described above.

On the receiving side, when the image information is normally received,
(YES in S4-14), responds with an MCF signal (S4-15), and if there is an error in the image information (NO in S4-14), sends an RTN signal (retransmission signal) (S4-16) and a DCN signal Then, the operation shifts to the call disconnection (S4-17).

Table 1 shows a memory map for comparing the error bit of the modem training with the communication result. If the modem training is successful with a value close to the threshold, there is a high possibility that a communication error (NG) will occur.

[0027]

[Table 1]

Further, a comparison between the error bit of the modem training and the communication result is made for each communication mode (ECM or EC).
(Table 2) shows a memory map when the operation is performed in a normal mode other than M. Even if the modem training is successful with a value close to the threshold, the communication result is likely to be OK in the case of ECM.

[0029]

[Table 2]

FIG. 1 is a flow chart of the main part of the control processing of the first embodiment. When the line type is selected at the time of modem training (S1-1), and the connection line is a general line (telephone line). If the threshold of the number of error bits is "5"
(S1-2), and the mobile phone radio line and E
If CM is set, set threshold value of error bit number to “10”
(S1-3).

As described above, the threshold value can be changed for each communication mode on the receiving side of the mobile telephone radio line, and the quality of image information can be improved because the modem training NG is responded.

FIG. 5 is a flowchart of the main part of the control processing of the second embodiment. The line type selected at the time of modem training is (S5-1), and if it is a general line, the threshold is set to "5" ( S5-2), and with a car phone wireless line,
If the ECM has been set, the threshold is set in accordance with the modem rate (S5-3).

In the second embodiment, the modem rate is 9600 bp
The thresholds are set to 10, 10, 20, and 40 corresponding to s, 7200 bps, 4800 bps, and 2400 bps, respectively. The reason why the threshold value of the mobile telephone radio line is set lower than the threshold value of the general line is that the modem rate is set once in the non-ECM unlike the ECM, so that no error occurs. It is necessary. Meanwhile, ECM
Since there is retransmission, the modem rate may be increased.

FIG. 6 is a flowchart of the main part of the control processing of the third embodiment, in which the line type is selected (S6-
1) If the mobile phone radio line is used and ECM is set, thresholds (TH96, TH72, TH72,
TH48, TH24) are set (S6-2). If it is a general line, the threshold is set to "5" (S6-3).

FIG. 7 is a flowchart of the threshold updating process according to the third embodiment. The modem rate data (rat (x)) and the error bit number threshold data (thr (x)) when the modem training is successful. , The number of error bits and data (err (x)) detected in the actual modem training, and the communication result and data (res (x)) are stored in the system control unit 8 (S
7-1), when a communication error occurs for each modem rate (rat (x)) (YES in S7-2), the number of error bits (err (x)) is monitored and the threshold value is TH (rat (x)). ) Is changed (S7-3). More specifically, the difference between the actually counted number of error bits and the threshold is stored in plural numbers, and the setting of the threshold is reviewed as needed.

Therefore, non-E in a mobile telephone radio line
If there is no noise even in the CM, connection can be made at a high modem rate, and an optimum value of the threshold value of the number of error bits can be obtained for each line.

FIG. 8 is a flowchart of the main part of the control processing of the fourth embodiment, and FIG. 9 is a flowchart of the threshold updating processing of the fourth embodiment. The difference between the fourth embodiment and the third embodiment is as follows. By monitoring the number of error bits (err (x)) when a communication error occurs for each communication mode (mod (x)) and for each modem rate (rat (x)), the threshold value is TH (rat (x), mod (x))
And the number of error bits for each communication mode.
The point is that data is stored.

Therefore, since the data storage areas of the ECM and the non-ECM are different, the threshold value can be reviewed for each mode without being influenced by each other.

Further, using the memory maps of Tables 1 and 2 as an empirical value, if the result of previous communication is NG even if the error bit is smaller than the threshold value, the modem training is failed and the modem rate is reduced. If the communication error is expected by starting the communication after shifting down, the image information quality can be improved by shifting down even below the threshold value.

[0040]

As described above, in the facsimile reception control apparatus according to the first aspect of the present invention, the training NG is performed by changing the threshold value for each communication mode on the receiving side of the mobile telephone radio line. Since a response can be made, the quality of image information can be improved.

According to the configuration of the second aspect, the threshold value of the error bit can be set for each modem rate on the receiving side, so that the image information quality can be improved.

According to the third aspect of the present invention, when a communication error occurs at the modem rate determined in the past communication,
A plurality of the difference between the actually counted error bit number and the threshold are stored, and the setting of the threshold can be reviewed at any time, so that the modem rate can be set according to the line condition, Image information quality can be improved.

In the configuration according to the fourth aspect, the storage area in the configuration according to the third aspect is provided for each communication mode such as the ECM and the non-ECM, so that the threshold value is reviewed for each mode.
Since (optimization) is performed, the modem rate can be set according to the line condition, and the image information quality can be improved.

According to the fifth aspect of the present invention, if the number of error bits equal to the number of error bits in the past communication is equal to or less than the threshold value, a modem training error is determined.
The modem rate can be set according to the line status, and the image information quality can be improved.

[Brief description of the drawings]

FIG. 1 is a flowchart of a main part in control processing of a first embodiment of a facsimile reception control device of the present invention.

FIG. 2 is a block diagram of a system configuration according to the first embodiment.

FIG. 3 is a protocol flowchart in facsimile communication.

FIG. 4 is a flowchart related to modem training reception and success / failure determination.

FIG. 5 is a flowchart of a main part in control processing according to a second embodiment of the present invention.

FIG. 6 is a flowchart of a main part in control processing according to a third embodiment of the present invention.

FIG. 7 is a flowchart of a threshold update process according to the third embodiment.

FIG. 8 is a flowchart of a main part in a control process according to a fourth embodiment of the present invention.

FIG. 9 is a flowchart of a threshold update process according to the fourth embodiment.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... scanner, 2 ... plotter, 3 ... encoding / decoding part, 4 ... communication control part, 5 ... modem, 6 ... network control part,
7: operation display unit, 8: system control unit

Claims (5)

(57) [Claims] 1. A means for selecting one of a telephone line and a car telephone radio line as a communication line, a means for changing a threshold value of the number of error bits for modem training according to the type of communication line, Means for changing the threshold value of the number of error bits depending on whether the connection is made in the error correction mode, in which retransmission is repeated while lowering the modem rate until communication can be performed properly, and when the connection is made in a mode other than the error correction mode. A facsimile reception control device comprising: 2. The facsimile reception control device according to claim 1, further comprising means for changing a threshold value of the number of error bits according to a connected modem rate. 3. Modem rate data when the modem training is successful, threshold value data of the number of error bits, data,
A means capable of storing the number of error bits, data, communication results, and data detected in actual modem training, and monitoring the number of error bits when a communication error occurs for each modem rate and changing the threshold of the number of error bits The facsimile reception control device according to claim 1 or 2, further comprising: 4. A means for storing the number of error bits and data for each communication mode, and monitoring the number of error bits when a communication error occurs for each communication mode and for each modem rate to set a threshold value for the number of error bits. 4. The facsimile reception control device according to claim 3, further comprising means for changing. 5. The method according to claim 3, further comprising means for setting a modem training error even when the number of error bits is equal to the number of error bits in the past communication failure even within the threshold value of the number of error bits. Facsimile reception control device.