JPH11177712A - Communication terminal equipment and communication system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a communication terminal equipment and a communication system which are capable of performing urgent communication at all timi. SOLUTION: Communication terminal equipment 102 connected to a digital line with plural data channel does not originate a call when there is only one dead channel. Then one data channel is secured as a result to enable execution of urgent communication any time. In addition, it is desirable to keep at least one data channel dead for telephone.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a communication terminal device connected to a digital line having a plurality of data channels and a communication system constituted by such a communication terminal device. The present invention relates to a communication terminal device and a communication system.

[0002]

2. Description of the Related Art In a digital line such as ISDN, one line has a plurality of data channels, and two communications can be performed simultaneously using the same telephone number. Further, in such a digital line, a plurality of communication terminal devices can be connected, and the communication terminal devices of the number of channels can simultaneously communicate. In the case of ISDN, there are two data channels called B channels, and up to eight communication terminal devices can be connected, of which two communication terminal devices can simultaneously communicate.

[0003] Communication terminal devices to be connected include a facsimile device, a digital telephone, a personal computer, and the like, and a communication system in which these various communication terminal devices are mixed can be constructed.

[0004]

When the plurality of communication terminals communicate with each other, all of the plurality of data channels may be in use. As described above, when urgent communication becomes necessary while all the data channels are in use, it is necessary to wait until one of the data channels becomes empty, which may be a problem.

Accordingly, an object of the present invention is to solve the above-mentioned problems and to provide a communication terminal device and a communication system capable of performing emergency communication at any time.

[0006]

According to one aspect of the present invention, there is provided a communication terminal device connected to a digital line having a plurality of data channels.
If there is only one free data channel, no transmission is made.

An interface for connecting to an analog line may be provided, and when there is only one free data channel, the signal may be transmitted through the analog line.

A communication system according to the present invention is a communication system in which a plurality of communication terminal devices are connected to a digital line having a plurality of data channels, and at least one data channel is reserved for telephone use.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a first embodiment of the present invention will be described in detail with reference to the accompanying drawings. Here, a facsimile apparatus having a G3, G4 facsimile communication function will be described as a communication terminal apparatus. FIG. 1 shows a flow of an operation in which the facsimile apparatus performs communication, and FIG. 2 shows a configuration of the communication system of the present invention. An internal circuit configuration of the facsimile apparatus is also shown.

First, as shown in FIG. 2, the communication system of the present invention comprises a digital service unit (DSU) 10 connected to an ISDN subscriber line switch (not shown).
1 is provided, and a plurality of communication terminal devices are connected to the inside wiring of the DSU 101. Here, at least the facsimile apparatus 102 and the digital telephone 103 are connected. It is also possible to connect a personal computer 104, and the personal computer 104 without an ISDN interface is connected via a terminal adapter (TA) 105.

The facsimile apparatus 102 includes a main control unit 1
ROM 2, RAM 3, reading unit (scanner) 4, recording unit (printer) 5, operation unit (operation panel) 6, display unit 7,
Image memory 8, Image codec 9, LAP-B10, S
It comprises an interface 11, a voice codec 12, and a G3 modem 13.

The main control section 1 is composed of an MPU and operates each section based on a program. The operation according to the present invention is also described in the program.

The ROM 2 stores a program to be executed by the main controller 1.

The RAM 3 is composed of an SRAM, a flash memory or the like, and stores temporary data generated when executing a program.

The reading section 4 includes an image pickup device such as a CCD.
The original can be read to generate binary image data.

The recording unit 5 includes a printer of an electrophotographic system or the like, and can record (print) image data received from another G3 or G4 facsimile machine.

The operation unit 6 includes numeric keys for inputting numbers, speed dial keys for speed dial operation, one touch keys for one touch operation, various function keys, start keys, and the like.

The display unit 7 is composed of an LCD display, and can display an operation state of the facsimile apparatus, a telephone number, an operation instruction, an error message, and the like.

The image memory 8 is composed of a DRAM and stores image data for facsimile transmission and reception.

The image codec 9 converts the binary image data read from the document into image data for facsimile transmission and reception, and converts the received image data into binary image data.

The LAP-B 10 performs data communication by controlling a protocol for the ISDN B channel. Two B channels are prepared, and B1c
h, B2ch.

The S interface 11 has a protocol processing function, a maintenance function, and an interface function, and further has a built-in LAP-D function for controlling a protocol for the ISDN D channel.

The voice codec 12 is for mutually converting digital data transmitted / received by ISDN and an analog voice signal used by the G3 modem 13.

The G3 modem 13 modulates and demodulates image data and analog audio signals in G3 communication.

Note that, in addition to the above configuration, the G3 modem 1
4 and the NCU 15 may be provided so as to be connectable to the PSTN.

In the first embodiment, when the facsimile apparatus attempts communication, if there is only one free data channel, no transmission is made. As shown in FIG. 1, when the operator presses the start key of the operation unit 6 for the purpose of starting transmission by G3 or G4 via ISDN, the S interface 11 of the facsimile apparatus is pressed.
Transmits the setup of both B1ch and B2ch. The purpose of transmitting the setup of both data channels here is to confirm whether both are free.

If there is no rejection from the ISDN for both setups, start communication using one data channel.

ISDN for any setup
If the data channel is rejected, 0 or 1
It turns out that there is only one. Therefore, the facsimile apparatus suspends the transmission and displays the fact on the display unit 7. For example, this transmission is treated as a reservation, and "reserving" is displayed.
Thereby, transmission after a predetermined time (for example, three minutes) has elapsed is reserved. However, if the number of reservations exceeds the predetermined number, the reservation of further transmission is rejected and the process is terminated. If the number of reservations does not exceed the predetermined number, the setup of both data channels is transmitted again after the predetermined time has elapsed. If there are still 0 or 1 free data channels, the transmission is reserved again and the number of reservations is counted. As a result, transmission is not performed unless both data channels are free during the predetermined time × the predetermined number of times.

As described above, the facsimile apparatus 102
When there is only one available data channel, no transmission is made, so that one available data channel is continuously available. Therefore, when another communication terminal device performs emergency communication, the available data channel can be used. In addition, if other communication terminal devices are similarly prevented from transmitting when there is only one available data channel,
This communication system always has one free data channel. Furthermore, if the digital telephone 103 is set to make a call even if there is only one free data channel, virtually one data channel is reserved for the digital telephone 103, and any emergency Communication becomes possible. In addition, one data channel may be opened for a specific communication terminal device, not limited to the digital telephone 103. Further, even in the case of a communication terminal device that does not make a call when there is only one available data channel, a call may be made by a predetermined operation in an emergency.

Next, a second embodiment will be described.

FIG. 3 shows a flow of an operation in which the facsimile apparatus performs communication. This facsimile apparatus is provided with a G3 modem 14 and an NCU 15 in FIG. 2 so that it can be connected to the PSTN.

When the start key of the operation unit 6 is pressed, the S interface 11 of the facsimile apparatus causes the B1ch,
Transmit both setups for B2ch. ISD if no rejection from ISDN for both setups
Initiate communication using one of the N data channels.

ISDN for any setup
If the data channel is rejected, 0 or 1
It turns out that there is only one. In this case, the facsimile machine uses PSTN instead of ISDN,
It checks whether the PSTN line is free.

If the PSTN line is free, the PSTN
G3 communication is started.

If the PSTN line is not free, this transmission is treated as a reservation and "reserving" is displayed. If both data channels are free for a predetermined time × a predetermined number of times, or if the PSTN line does not become free,
Reject the transmission and end.

As described above, the facsimile apparatus 102
When there is only one free data channel, the call is transmitted via the PSTN, so that communication can be performed while securing one free data channel.

[0037]

The present invention exhibits the following excellent effects.

(1) When there is only one available data channel, no transmission is made, so one data channel is secured and emergency communication can be performed at any time.

(2) When there is only one free data channel, the signal is transmitted through the analog line. Therefore, one data channel is secured and emergency communication can be performed at any time.

(3) Since at least one data channel is reserved for telephone calls, telephone calls can be made at any time.

[Brief description of the drawings]

FIG. 1 is a flowchart of a communication operation of a facsimile apparatus according to a first embodiment of the present invention.

FIG. 2 is a configuration diagram illustrating an embodiment of a communication system according to the present invention.

FIG. 3 is a flowchart of a communication operation of the facsimile apparatus according to the second embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Main control part 2 ROM 3 RAM 4 Reading part 5 Recording part 6 Operation part 7 Display part 8 Image memory 9 Image codec 10 LAP-B 11 S interface 12 Audio codec 13 G3 modem

Claims (3)

[Claims] 1. A communication terminal device connected to a digital line having a plurality of data channels, wherein when there is only one available data channel, no communication is made. 2. An apparatus according to claim 1, further comprising an interface for connecting to an analog line, wherein when there is only one vacancy in said data channel, the signal is transmitted through the analog line.
The communication terminal device according to claim 1. 3. A communication system in which a plurality of communication terminals are connected to a digital line having a plurality of data channels, wherein at least one data channel is reserved for telephone use.