JP3914661B2 - Transmission level value control method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a transmission level value control method for changing a transmission level according to a reception level value of a receiver.
[0002]
[Prior art]
As a prior art regarding the transmission level value, there is one disclosed in JP-A-7-212563.
[0003]
This prior art can set an appropriate transmission level value corresponding to the half-duplex communication method and the full-duplex communication method. In addition, by registering information indicating whether the communication partner performs half-duplex communication or full-duplex communication, the occurrence of communication errors can be reduced and good communication can be performed. is there.
[0004]
[Problems to be solved by the invention]
However, in the prior art disclosed in the above-mentioned Japanese Patent Application Laid-Open No. 7-212563, the transmission level is only adjusted by an alternative process of the half-duplex communication method or the full-duplex communication method. However, there is a problem that it is premised that information on the communication partner is also registered in advance. In general, the transmission level value is set for each apparatus, but the reception level value on the receiver side varies depending on the attenuation by the line and the communication partner. Further, depending on the communication path (ISDN or the like), there is a case where the signal is hardly attenuated, and there is a problem that the signal may be distorted if the transmission level value on the transmitter side is high.
[0005]
The present invention has been made in view of the above problems, and an object thereof is to reduce as much as possible attenuation and distortion of a signal due to imbalance between a transmission level value and a reception level value.
[0006]
[Means for Solving the Problems]
In order to achieve this object, the present invention has the following features.
The transmission level value control method according to the present invention includes a first detection step in which a receiver that receives a CNG signal detects a reception level value of the CNG signal, and the reception level value detected by the receiver is transmitted through the NSF signal. A transmission step for transmitting to the transmitter; a second detection step for the transmitter to detect the reception level value of the receiver transmitted by the transmission step; and a target reception level value preset in the transmitter; A first comparison step for comparing the reception level value of the receiver with the result of comparison by the first comparison step , the reception level value of the receiver is equal to or less than a target reception level value when the reception level is low In this case, a first calculation step of obtaining a difference between the two reception level values, calculating a value obtained by adding the difference to the transmission level value of the transmitter, and a value calculated by the first calculation step Maximum transmission of the transmitter And a second comparison step for comparing the level value with the transmitter, wherein the transmitter changes the transmission level value of the transmitter as a result of the comparison in the second comparison step. is there.
[0007]
Further, in the transmission level value control method according to the present invention, the transmitter calculates that the value calculated in the first calculation step exceeds the maximum transmission level value of the transmitter as a result of the comparison in the second comparison step. The transmission level value of the transmitter is changed to the maximum transmission level value of the transmitter, and if the value calculated by the first calculation step is less than or equal to the maximum transmission level value of the transmitter, the transmission The transmission level value of the machine is changed to the value calculated by the first calculation step.
[0008]
The transmission level value control method according to the present invention includes a first detection step in which a receiver that has received a CNG signal detects a reception level value of the CNG signal, and the reception level value detected by the receiver is an NSF signal. A transmitting step for transmitting to the transmitter through a second detecting step in which the transmitter detects the reception level value of the receiver transmitted in the transmitting step, and a target reception level value preset in the transmitter And a reception level value of the receiver. As a result of the comparison by the first comparison step and the reception level value of the receiver, the reception level value of the receiver is a target reception level when the reception level is high. If the value is greater than or equal to the value, a difference between the two reception level values is obtained, and a first calculation step for calculating a value obtained by subtracting the difference from the transmission level value of the transmitter is calculated by the first calculation step. Value and the A second comparison step for comparing the transmission level value, and the transmitter changes the transmission level value of the transmitter as a result of the comparison in the second comparison step. It is.
[0009]
In the transmission level value control method according to the present invention, as a result of the comparison in the second comparison step, the transmitter has a value calculated in the first calculation step that is less than the minimum transmission level value of the transmitter. If the transmission level value of the transmitter is changed to the minimum transmission level value of the transmitter, and the value calculated by the first calculation step is equal to or greater than the minimum transmission level value of the transmitter, the transmission The transmission level value of the machine is changed to the value calculated by the first calculation step.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a facsimile apparatus according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.
[0014]
FIG. 1 is a block diagram of a facsimile apparatus as an embodiment of the present invention. According to FIG. 1, a scanner 1 that reads a document image and retrieves image information, a plotter 2 that prints an image on recording paper, a compression of image information to be transmitted and a received image by a known encoding method such as the MH method. An encoding / decoding unit 3 that decodes information and reproduces the original image information; a modem 4 that modulates and demodulates the image information and transmits it, and transmits various procedure signals for transmission control; a telephone line and a telephone set 9 A network control device 5 that is connected and performs line control for making and receiving calls, an operation display unit 6 that displays the operation state of the device and allows the operator to perform various operations, and a system control unit that includes a microcomputer that controls the above-described units 7. Measure the reception level of the line from the reception level output from the system bus 8, telephone 9 and modem 4 which are the signal lines for the various parts to exchange various control signals and data with each other. And a reception level measuring unit 10 that.
[0015]
FIG. 2 is a flowchart showing an embodiment of the present invention. The facsimile apparatus (receiver) starts a receiving operation upon receiving a calling signal (ringing signal) from the line. After receiving the calling signal and closing the line, the CNG (Calling tone) signal sent from the transmitter is detected (step S101). The functions of the CNG signal are as follows: (1) the calling station is a non-voice terminal; (2) the device is in transmission mode and transmits if it receives a digital identification signal (DIS) indicating the standard capability of the called device. (3) If the device is capable of sending more than one document without the assistance of the operator, the transmitter waits for a digital identification signal (DIS) between the documents. There is a function to indicate that transmission is possible while the user is
[0016]
As a result of detecting the CNG signal for a certain period of time, if the CNG signal cannot be detected within this time (step S101 / NO), the ITU-T T.D. The receiving operation is performed according to the recommendation of 30 (step S105). When a CNG signal is detected (step S101 / YES), the reception level value when the CNG signal is received is read from the modem, and the reception level value is stored (step S102). Thereafter, the reception level value stored in the NSF (Non Standard Function) signal that identifies the request of a specific user outside the range of the ITU-T T series recommendation is transmitted to the transmitter side (step S103). Thereafter, a DIS signal is sent out (step S104). The receiving operation is performed according to the recommendation of 30 (step S105).
[0017]
FIG. 3 is a flowchart showing an embodiment of the present invention. The facsimile machine (transmitter) transmits a CNG signal when communicating with the partner machine (step S201). Thereafter, when an NSF signal is received from the partner machine (step S202 / YES), it is confirmed whether the NSF signal has reception level value information of the receiver (step S206). If there is reception level value information (step S206 / YES), the transmission level switching process shown in FIG. The transmission operation is performed according to the recommendation of 30 (step S208). When there is no reception level value information (step S206 / NO), the T.T. The transmission operation is performed according to the recommendation of 30 (step S208).
[0018]
If no NSF signal is received from the partner machine (step S202 / NO), a check is made to see if a DIS signal is received (step S203). If a DIS signal is received (step S203 / YES), ITU- T. T. The transmission operation is performed according to the recommendation of 30 (step S208). When the DIS signal is not received (step S203 / NO), the ITU-T T.D. The CNG signal is transmitted until a predetermined time (T1 = 35 ± 5 seconds) elapses (step S204) in accordance with the recommendation of 30. When the time is over (step S204 / YES), the line is released (step S205).
[0019]
FIG. 4 is a flowchart of transmission level value switching processing according to the embodiment of the present invention. When the reception level value transmitted by the NSF signal is equal to or lower than the target reception level value when the preset reception level value is low (step S301 / YES), the difference from the target level value is calculated. Calculate and add the difference to the current transmission level value. If the value calculated in this way is less than or equal to the maximum transmission level value of the transmitter (NO in step S302), the current transmission level value is changed to the calculated value and a signal is transmitted (step S304). If the calculated value exceeds the maximum transmission level value of the transmitter (step S302 / YES), the current transmission level value is changed to the maximum transmission level value of the transmitter and a signal is transmitted (step S303).
[0020]
If the reception level value transmitted by the NSF signal is not less than the target reception level value when the preset reception level value is low (step S301 / NO), the target when the reception level value is high The received level value is compared (step S305). If the reception level value on the receiver side is equal to or higher than the target reception level value when the reception level value is high (step S305 / YES), the difference from the target level value is calculated, and the difference is calculated from the current transmission level value. Reduce. When the value calculated in this way is equal to or higher than the minimum transmission level value of the transmitter (NO in step S306), the current transmission level value is changed to the calculated value and a signal is transmitted (step S308). If the calculated value is less than the minimum transmission level value of the transmitter (step S306 / YES), the current transmission level value is changed to the minimum transmission level value of the transmitter and a signal is transmitted (step S307).
[0021]
When the reception level value transmitted by the NSF signal is within the range of the target reception level value when the preset reception level value is high or low (step S305 / NO), the transmission level Since the imbalance between the value and the reception level value is small, the signal is transmitted without changing the transmission level value (step S309).
[0022]
The signals transmitted by changing the transmission level value are all signals after the NSS signal, which is a digital command response to information included in the DCS signal, NSF signal, etc., which is identified by the DIS signal and responds to the standard function. Switches the transmission level value.
[0023]
To summarize the switching process in FIG. 4, when the reception level value of the receiver deviates from the target reception level value range (steps S301 and S305), how far the target reception level value range deviates is calculated. In principle, the value is adjusted by adjusting the value (steps S304 and S309). However, there is a limit to the range of transmission level adjustment, and when the range is exceeded, transmission at the highest or lowest transmission level value of the transmitter can be used to imbalance the transmission level value and the reception level value as much as possible. (Steps S303 and 307).
[0024]
A specific example of the switching process of FIG.
When the reception level value is low, the target reception level value is -38 dBm
Receiver level value of receiver is -40dBm
The current transmission level value of the transmitter is -11 dBm
If the maximum transmission level value of the transmitter is -8 dBm,
The transmission level value is increased by −38 − (− 40) = 2 dBm and is transmitted as −11 + 2 = −9 dBm.
[0025]
Further, when the reception level value is low, the target reception level value is −39 dBm.
The reception level value of the receiver is -43 dBm
The current transmission level value of the transmitter is -11 dBm
If the maximum transmission level value of the transmitter is -8 dBm,
The transmission level value is transmitted as -8 dBm which is the maximum transmission level value.
[0026]
When the reception level value is high, the target reception level value is -16 dBm
Receiver level value of receiver is -13dBm
The current transmission level value of the transmitter is -11 dBm
If the minimum transmission level value of the transmitter is -15 dBm,
The transmission level value is reduced by −16 − (− 13) = − 3 dBm, and transmission is performed as −11−3 = −14 dBm.
[0027]
Further, when the reception level value is high, the target reception level value is −16 dBm.
The reception level value of the receiver is -11 dBm.
The current transmission level value of the transmitter is -11 dBm
If the minimum transmission level value of the transmitter is -15 dBm,
The transmission level value is transmitted as -15 dBm, which is the lowest transmission level value.
[0028]
【The invention's effect】
As is apparent from the above description, according to the present invention , it is possible to perform good communication by changing the transmission level value based on the reception level value transmitted from the receiver.
[0029]
Further , according to the present invention , by setting two target reception level values, the transmission level value is changed when the reception level value is unacceptably high or low with respect to the transmission level value. For this reason, it is possible to distribute the appropriate processing.
[0030]
Further , according to the present invention, when the reception level value of the receiver is equal to or lower than the target reception level value when the reception level value is low, the degree of deviation is calculated and the amount is added to the current transmission level value. Thus, it is possible to change to an appropriate transmission level value. Further, since the transmission level value has a limit due to the change width, it is possible to select an appropriate change value by determining whether the limit is exceeded.
[0031]
Further , according to the present invention, when the reception level value of the receiver is equal to or higher than the target reception level value when the reception level value is high, the degree of deviation is calculated and the amount is subtracted from the current transmission level value. Thus, it is possible to change to an appropriate transmission level value. Further, since the transmission level value has a limit due to the change width, it is possible to select an appropriate change value by determining whether the limit is exceeded.
[0032]
Further , according to the present invention, when the reception level value of the receiver is within the two target reception level values, the transmission level value that does not need to be changed is transmitted as it is without changing the transmission level value. It becomes possible.
[0033]
Further, according to the present invention, it is possible to change to the optimum transmission level value within the range of the change range of the transmission level value by determining whether or not the upper limit of the transmission level value range is exceeded.
[0034]
Further, according to the present invention, it is possible to change the transmission level value to the optimum transmission level value within the range of the change range of the transmission level value by determining whether or not the lower limit of the transmission level value range is exceeded.
[Brief description of the drawings]
FIG. 1 is a block diagram of a facsimile machine (transceiver) according to an embodiment of the present invention.
FIG. 2 is a flowchart showing an operation on the receiver side in the embodiment of the present invention.
FIG. 3 is a flowchart showing an operation on the transmitter side in the embodiment of the present invention.
FIG. 4 is a flowchart showing an operation related to a transmission level value switching process in the embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Scanner 2 Plotter 3 Encoding / decoding part 4 Modem 5 Network control device 6 Operation display part 7 System control part 8 System bus 9 Telephone 10 Reception level measurement part

Claims (4)

A first detection step in which a receiver that receives the CNG signal detects a reception level value of the CNG signal;
A transmission step of transmitting a reception level value detected by the receiver to the transmitter through an NSF signal;
A second detection step in which the transmitter detects a reception level value of the receiver transmitted in the transmission step;
A preset target receiving level value to the transmitter, a first comparison step of comparing the a reception level value of the receiver,
If the reception level value of the receiver is equal to or lower than a target reception level value when the reception level is low as a result of the comparison in the first comparison step, a difference between the two reception level values is obtained, and the transmitter A first calculation step of calculating a value obtained by adding the difference to the transmission level value of
A second comparison step of comparing the value calculated by the first calculation step with the maximum transmission level value of the transmitter;
The transmitter changes the transmission level value of the transmitter as a result of the comparison in the second comparison step. The transmitter is a result of the comparison in the second comparison step,
If the value calculated by the first calculation step exceeds the maximum transmission level value of the transmitter, the transmission level value of the transmitter is changed to the maximum transmission level value of the transmitter,
When the value calculated by the first calculation step is equal to or less than the maximum transmission level value of the transmitter, the transmission level value of the transmitter is changed to the value calculated by the first calculation step. The transmission level value control method according to claim 1, wherein: A first detection step in which a receiver that receives the CNG signal detects a reception level value of the CNG signal;
A transmission step of transmitting a reception level value detected by the receiver to the transmitter through an NSF signal;
A second detection step in which the transmitter detects a reception level value of the receiver transmitted in the transmission step;
A preset target receiving level value to the transmitter, a first comparison step of comparing the a reception level value of the receiver,
If the reception level value of the receiver is equal to or higher than a target reception level value when the reception level is high as a result of the comparison in the first comparison step, a difference between the two reception level values is obtained, and the transmitter A first calculation step of calculating a value obtained by subtracting the difference from the transmission level value of
A second comparison step of comparing the value calculated by the first calculation step with the lowest transmission level value of the transmitter;
The transmitter changes the transmission level value of the transmitter as a result of the comparison in the second comparison step. The transmitter is a result of the comparison in the second comparison step,
If the value calculated by the first calculation step is less than the minimum transmission level value of the transmitter, change the transmission level value of the transmitter to the minimum transmission level value of the transmitter,
When the value calculated by the first calculation step is equal to or higher than the minimum transmission level value of the transmitter, the transmission level value of the transmitter is changed to the value calculated by the first calculation step. 4. The transmission level value control method according to claim 3, wherein:

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