JPH05207178A - Modem - Google Patents

Abstract

PURPOSE:To effectively use data compression by providing a data compression monitor part to monitor a data compression/extension part and automatically judging whether a data compression process can be used or not. CONSTITUTION:An NCU part 10 to control data transmission to a telephone line or data transmission to a telephone line network such as a call signal detection from the telephone line, MODEM part 11 and data compression/ extension part 12 are respectively controlled by a control part 101. This compression/extension part 12 is monitored by a data compression monitor part 100, data amounts before and after compression are compared, it is monitored whether the data compression is effectively functioned or not, and it is automatically judged whether the data compression process can be used or not. Thus, the data compression is effectively used without operating any selecting switch for the data compression process.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a modulator / demodulator having a data compression procedure for transmitting / receiving data using a telephone network.

[0002]

2. Description of the Related Art The operation of a modulator / demodulator having a conventional data compression procedure will be described below with reference to FIG. Figure 2
At the time of performing data communication etc. by telephone line,
A network control device (N which is a device for performing connection control such as call origination / reception processing, restoration / disconnection processing with the network)
network Control Unit: NC below
The U) unit 10 controls a series of processing operations for transmitting data to the telephone line network, such as data transmission to the telephone line or detection of a calling signal from the telephone line. The modulator / demodulator 11 modulates data from a terminal connected to the modulator / demodulator,
It demodulates the modulated signal received from the telephone line. The data compression / decompression unit 12 is a well-known Microcom's.
Network Protocol (hereinafter, MNP protocol) or CCITT Recommendation V.3. Data compression / decompression is performed by a procedure such as 42bis. The control unit 13 uses an NC for the modem to perform data transmission using the telephone line.
The U unit 10, the modulation / demodulation unit 11, and the data compression / decompression unit 12 are controlled.

[0003]

In the conventional modulation / demodulation device as described above, the operator is required to perform data transmission before data transmission.
The selection switch for using the data compression procedure is operated. When this data compression procedure is used, not all data can be compressed, and depending on the type of data, it is necessary to send a larger amount of data than what should have been sent. In some cases, it could not be used effectively. Conversely, if the operator decides not to use the data compression procedure, the data compression procedure may be used even if the data to be transmitted has the effect of reducing the amount of data by data compression. I could not do it.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to solve the above-mentioned problems, and the operator does not have to manually operate the selection switch of the data compression function prior to the data transmission, and the operator can adjust the contents according to the contents of the data to be transmitted. SUMMARY OF THE INVENTION It is an object of the present invention to provide a modulation / demodulation apparatus that can automatically use the data compression function to effectively use the data compression and further reduce the amount of data transmitted through the network.

[0005]

Means for Solving the Problems The solution means of the present invention for solving the above-mentioned problems is to transmit / receive data to / from the telephone line network such as data transmission to the telephone line network and detection of a calling signal from the telephone line. N for controlling a series of processing operations of
A CU unit, a modulator / demodulator that modulates data from a connected terminal and demodulates a modulated signal received from the telephone network, and data compression that compresses / decompresses the data to be transmitted / received based on a predetermined compression procedure. / Decompression unit and a control unit for controlling the NCU unit, the modulation / demodulation unit, and the data compression / decompression unit for performing data transmission / reception using the telephone line network, and transmitting / receiving data using the telephone line network. In the modulation / demodulation device for performing the above, the data length of the data compressed by the data compression / decompression unit is compared with the data length of the data before compression to monitor whether or not the data compression effectively works. A data compression monitoring unit is provided for controlling whether or not the data compression / decompression unit is used during data transmission / reception.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows a modulator / demodulator according to an embodiment of the present invention. The same reference numerals are omitted for the same functional units as in the conventional example. NCU unit 10, modem 10
1 and the data compression / decompression unit 12 perform the same operation as in the conventional example. The data compression monitoring unit 100 compares the data after the data compression with the data before the compression, and monitors whether the data compression effectively functions so that the data amount is reduced. The control unit 101 controls the NCU unit 10, the modulation / demodulation unit 11 and the data compression / decompression unit 12 so that the modulation / demodulation device of the present invention can perform data transmission using a telephone line, and also controls the data compression monitoring unit 100. To do. FIG. 3 is a network example in which a terminal A20 is connected to the modulation / demodulation apparatus A21 of the present invention, a terminal B23 is connected to the modulation / demodulation apparatus B22 of the present invention, and further, the modulation / demodulation apparatus A21 and the modulation / demodulation apparatus B22 are connected via a telephone network. Is shown.

In FIG. 2, it is assumed that the modulator / demodulator A21 and the modulator / demodulator B22 are performing data communication using a data compression procedure. Here, the case of transmitting the data C1 from the terminal A20 will be described. Modulator / demodulator A2
1 uses the data compression procedure, it compresses the data C1 from the terminal A20 and converts it into the data C2. The data compression monitoring unit 100 of the modulation / demodulation device A21 uses the data C1
When the data length of the data C2 is longer than that of the data C1, it is determined that the data compression procedure has not been effectively performed. On the contrary, when the data length of the data C2 is shorter than that of the data C1, it is determined that the data compression procedure is effectively performed. Then, the data compression monitoring unit 100 of the modulation / demodulation device A21, when it determines that the data compression is effectively performed, the modulation / demodulation device A21.
The control unit 101 is notified to also compress the next data. However, when the data compression monitoring unit 100 of the modulation / demodulation device A21 determines that the data compression has not been effectively performed, it notifies the control unit 101 of the modulation / demodulation device A21 not to compress the next data. Then, the modulation / demodulation equipment A21 sends this data C2 to the modulation / demodulation equipment B22 via the telephone network.

The modulator / demodulator B22 is the modulator / demodulator A2.
When the data C2 is received from 1, the data compression / decompression unit 12 decompresses the data C2 to restore the original data C1. The data compression monitoring unit 100 of the modulation / demodulation device B22 compares the restored data C1 with the received data C2, and when the data length of the data C2 is longer than the data C1, the data compression procedure is effectively performed. Judge that there is no. Conversely, data C
If the data length of the data C2 is shorter than 1, the data compression monitoring unit 100 of the modulation / demodulation device B22 determines that the data compression procedure is effectively performed, and that the data compression is effectively performed. If so, the modulation / demodulation device B2
The second control unit 101 is notified that the next data is also compressed and transmitted. Conversely, when it is determined that the data compression is not effectively performed, the data compression monitoring unit 100 notifies the control unit 101 of the modulation / demodulation device B22 that the next data has not been compressed. Therefore, if the data compression monitoring units 100 of both the modulation / demodulation device A21 and the modulation / demodulation device B22 are set to have the same determination criteria, if the data compression is not effectively performed, the data compression procedure is stopped. , Data transmission can be performed.

On the other hand, the modulator / demodulator A21 and the modulator / demodulator B22
Suppose that they are communicating data without using the data compression procedure. Here, it is assumed that the data C3 is transmitted from the terminal A20. Since the modem device A21 does not use the data compression procedure, it does not compress and transmit the data C3. However, in order to know what the data length will be if it is compressed, the data compression / decompression unit 12 compresses the data C3 and converts it into the data C4. And
The data compression monitoring unit 100 of the modulation / demodulation device A21 uses the data C
3 is compared with the data length of the data C4, and if the data length of the data C4 is longer than that of the data C3, it is determined that the data compression procedure cannot be effectively performed. On the contrary, when the data length of the data C4 is shorter than that of the data C3, it is determined that the data compression procedure can be effectively performed. When the data compression monitoring unit 100 of the modulation / demodulation device A21 determines that the data compression can be effectively performed, it notifies the control unit 101 of the modulation / demodulation device A21 to compress the next data. Therefore,
Unlike the data C1, the data to be transmitted next to the data C1 is compressed and transmitted from the modulator / demodulator A21. On the contrary, when it is judged that the data compression cannot be performed effectively,
The data compression monitoring unit 100 notifies the control unit 101 of the modulation / demodulation device A21 not to compress the next data. Therefore, the data following the data C1 is transmitted without being compressed.

Thus, the modulation / demodulation device B22 is the modulation / demodulation device A.
When the data C3 is received from 21, the data C3 is compressed to create the data C4 in order to determine how long the received data C3 will be if it is compressed.
The data compression monitoring unit 100 of the modulation / demodulation device B22 compares the data C3 and the data C4, and if the data length of the data C4 is longer than the data C3, determines that the data compression procedure cannot be effectively performed, and reverses the procedure. From data C3 to data C4
If is short, it is judged that the data compression procedure can be effectively performed. When the data compression monitoring unit 100 of the modulation / demodulation device B22 determines that the data compression can be effectively performed, it notifies the control unit 101 of the modulation / demodulation device B22 that the next data will be compressed and transmitted. On the contrary, when it is determined that the data compression cannot be effectively performed, the modem B
It notifies the control unit 102 of No. 22 that the next data is not compressed. Therefore, if the data compression monitoring unit 100 on the transmitting side determines that data compression can be effectively performed by making the judgment criteria of the data compression monitoring units 100 of both the modulation / demodulation device A21 and the modulation / demodulation device B22 equal, It can be modified in the middle of the transmission so that the data transmission is performed using the data compression procedure.

[0011]

As described above, according to the present invention,
It is not necessary for the operator to operate the data compression procedure selection switch based on the data to be transmitted, and the modulator / demodulator on the receiving side automatically determines whether to use the data compression procedure according to the data to be transmitted. Since data is restored by doing so, correct data reception can always be performed. As a result, the data compression procedure can be effectively used, and the telephone line network with less transmission amount can be efficiently used.

[Brief description of drawings]

FIG. 1 is a block diagram of an embodiment of the present invention.

FIG. 2 is a block diagram of a conventional example.

FIG. 3 is a network configuration diagram using a modulation / demodulation device of the present invention.

[Explanation of Codes] 10 NCU section 11 Modulation / demodulation section 12 Data compression / decompression section 13,101 Control section 100 Data compression monitoring section 21,22 Modulation / demodulation device 20,23 Terminal

Claims (1)

[Claims] 1. An NCU unit for controlling a series of processing operations for transmitting and receiving data to and from the telephone line network such as data transmission to the telephone line network and detection of a calling signal from the telephone line.
A modulation / demodulation unit that modulates data from a connected terminal and demodulates a modulated signal received from the telephone line network; and a data compression / decompression unit that compresses / decompresses the data to be transmitted / received based on a predetermined compression procedure. A modulation / demodulation device for transmitting / receiving data using the telephone line network, the control unit controlling the NCU unit, the modulation / demodulation unit and the data compression / decompression unit, and transmitting / receiving data using the telephone line network. In, the data length of the data compressed by the data compression / decompression unit is compared with the data length of the data before compression to monitor whether or not the data compression effectively works, and The modulation / demodulation device further comprises a data compression monitoring unit for controlling whether or not to use the data compression / decompression unit.