JPH0226170A - Control system for call mode switching - Google Patents

Abstract

PURPOSE:To automatically set a call mode by providing a mode register and a call mode control part in each terminal equipment and switching the call mode in correspondence to opponent call mode information, which are sent from an opponent terminal equipment, and self-call mode information in the case of calling. CONSTITUTION:In the case of the calling, both transmitting and receiving terminal equipments sends the self-call mode information to the opponent terminal equipment. The mode information are registered to a mode register 8 and a call information control part 10 sets the call mode to correspond to the opponent call mode information and self-terminal call mode information. Then, a system 2 for sound mode or a system 4 for TV telephone mode is connected to a communication line control part 6 and communication can be executed through a communication line 12 with the mode. Thus, the call mode in an ISDN channel is automatically set.

Description

[Detailed Description of the Invention] (Summary) This invention relates to a call mode switching control method that allows a desired call mode to be set on a calling/receiving terminal by sending and receiving call mode information during communication. System and/or TV for voice call mode
A communication line control unit for connecting one of the systems for telephone mode to tSDN is used to talk to the other party's terminal device [In the SDN terminal device, a mode register for registering call mode information and a call mode control unit and transmits self-terminal call mode information to the other party's terminal device when making a call, and connects the system to the communication line control unit with call mode information determined according to the received other party's terminal call mode information and the own terminal's call mode. , the telephone call in the telephone call mode is carried out via a telephone channel established between the two terminal devices.

[Industrial application field]

The present invention relates to a call mode switching control method that allows setting a desired call mode to a calling/receiving terminal by sending and receiving call mode information during communication.

Conventionally, in communications that add moving images to audio, for example, as shown in TV conference systems, both the audio signal and the moving image signal are sent using a dedicated line, or the moving image signal is sent over a dedicated line, and the audio signal is sent over a public line. The method used was to send it using . In addition, the system used dedicated terminals for both parties, and was limited to a specific user.

With the development of communication technology, traditional communication networks are being replaced by ISDN. Since ISDN handles various media in an integrated manner, integrated services between terminals handling different media are required. In particular, voice calls using one B channel similar to voice calls in conventional analog networks,
Video telephony, which uses one B channel effectively to transmit both audio and video on one B channel, is a discreet type of communication service, and compatibility between the two services is strongly required. Ru. In addition, the user is not limited to a specific person, and it is required that the device can be used widely by the general public.

[Conventional technology]

In that case, the configuration of the TV telephone terminal device is as shown in FIG.
OM24, RAM26, display interface 2
8. The image/audio cODEc 30, the communication line ink face 32 and the audio C0DEC 34 are connected, the display device 36 is connected to the display interface 28, the TV camera 38 is connected to the image/audio C0DEC 30, and the handset 40 is connected to the audio C0DEC 34. is connected, and its communication line ink face 32 is connected to IS.
ISDN via DN standard interface points S, T
connected to. The audio signal from the own terminal handset 40 and the image signal from the TV camera 38 are processed by the program stored in the ROM 24 using the RAM 26.
By executing PO22, image/audio C0D for video phone
When a call is made via the EC 30 and the communication line interface 32, it is transmitted on the B channel allocated in advance.

In addition, the audio data and image data sent from the other party's terminal via the above-mentioned B channel in accordance with the transmission control procedure are taken in and decoded in accordance with the reception control procedure in the corresponding component for both data in transmission, and the audio data is The analog audio signal is supplied to the handset 40, and the TV image signal for the image is supplied to the display device 36 via the display interface 28, and the other party's image is displayed on the display screen.

When using this videophone terminal device to communicate only by voice, a voice C0DEC 34 is provided for voice calls in which the signal formation on the B channel is different from that of a videophone, and is used when making a videophone call and a voice call. It is necessary to switch C0DEC.

Conventional communications that include moving images in addition to audio, such as a TV conference system, are based on the premise that terminals dedicated to both parties are used, so such switching is not necessary.

[Problem to be solved by the invention]

As mentioned above, the TV phone terminal device shown in FIG.
If you connect to , and manually select the call mode,
Not only is an operation required to make a call in the desired call mode, but if a mistake is made in the call mode selection operation, the TV phone mode signal transmitted via the B channel described above may be changed to the normal one shown in Figure 6. Audio C0DEC3 is sent via switch SW4, which is turned on by mistake, instead of switch SW5.
Due to the above-mentioned mistake such as inputting to 4, a deadlock condition occurs in the terminal, making it impossible to make a call.

The present invention was created in view of such problems, and an object of the present invention is to provide a call mode switching control system that can automatically set the call mode.

[Means for Solving the Problems] FIG. 1 shows a block diagram of the principle of the present invention. The present invention is based on I
The feature lies in the fact that a mode register 8 and a call mode control section 10 are newly provided for each terminal device in order to automatically set a desired call mode in the originating and receiving TV telephone terminal device connected to the SDN. The mode register 8 is for registering call mode information, and the call mode control unit 1
0 is system 2 for voice call mode or system 4 for video phone mode, depending on the call mode information determined according to the call mode information of the other party and the call mode information of the own terminal sent from the other party's terminal device when making a call. is connected to the communication line control unit 6, and calls are made in that mode.

[For production]

When making a call, both the calling and receiving terminal devices send their own terminal call mode information to the other party's terminal device via a B channel established according to a known connection control procedure.

The system 2 or system 4 is connected to the communication line control section 6 using the communication mode information determined according to the transmitted communication mode information of the other party's terminal and the communication mode information of the own terminal. System 2 processes audio signals in the set call mode, and system 4 processes audio signals and image signals in the set call mode. Do the following.

〔Example〕

An embodiment of the present invention will be described with reference to FIGS. 2 to 6.

FIG. 2 shows a hardware configuration diagram of each TV telephone terminal device, and FIG. 3 shows a processing flow performed within the hardware when the TV telephone terminal device becomes a calling terminal. FIG. 4 shows a processing flow executed within the hardware when the terminal becomes a destination terminal.A program for executing the processing flow shown in FIGS. 3 and 4 is stored in the ROM 24 of FIG. This ROM2
A CPU 22 that executes the program in 4 and a RAM 26 that is used for executing the program correspond to the communication mode control section 10 in FIG. Each TV phone terminal device itself is configured to be able to independently set either a voice call mode or a TV phone mode, which is determined according to call mode information given under a known method.

:□: In Figure 2 and Figure 6, ROM24, ROM
A CPU 22 for executing a known program for call control in each of the above-mentioned call modes stored in the CPU 24 and a RAM 26 used for executing the program also run a system for the voice call mode shown in FIG. Constituent audio C0DEC
The image CODEC 30 and display interface 28, which constitute the system for the TV telephone mode, also constitute the terminal control system for the display interface 28 in that mode. Further, the switches SWI to SW5 shown in FIG. 6 are configured to be turned on/off under the control of the communication mode control section 10 described above, but are not used in the terminal control system described above in the voice call mode or in the TV telephone mode. The configuration may be such that equivalent control is produced by the control by the terminal control system described above.

The call mode switching control in the ISDN terminal as described above will be explained below.

When a call is made to the TV telephone terminal device, the originating T
ISDN between the V telephone terminal device and the receiving TV telephone terminal device.
A connection in which one of the B channels is established between the originating terminal device and the terminating terminal device using the D channel of the 2B+D channels as a communication mode setting processing (negotiation) channel for the call. Control procedure 210,2
12°214.216 are produced sequentially as shown in FIG. The connection control procedure itself in this case is a known procedure.

Using the B channel, a call mode setting processing sequence 300 is sequentially generated between the originating TV telephone terminal device and the terminating TV telephone terminal device in the following manner. In this embodiment, it is assumed that the call mode setting processing sequence 300 is performed under the known HDLC format.

When the call mode setting process starts (300 in Figure 3)
, the communication mode control unit 10 (see FIG. 1) controls the communication line interface 32 to transmit the SNR to the terminating TV telephone terminal device via the B channel formed between the originating and terminating terminals.
Send the M command (302 in Figure 3 (Part 1)),
The terminating TV telephone terminal device (4th
No. 2 in Figure (Part 1) returns the UA response to the originating TV phone terminal via the B channel (Figure 4 (Part 1)).
) NO4).

When the originating TV phone terminal device receives the UA response (504 in Figure 3 (Part 1)), the originating TV phone terminal device transmits its own terminal mode initial value via an HDLC I frame (Figure 3 (Part 1)). Part 1), 306), when the calling terminal mode initial value is received by the receiving TV phone terminal device (
No. 6 in Fig. 4 (Part 1)), and in response, an RR response is returned to the originating TV telephone terminal device (No. 4
RO8 in Figure (Part 1)). The originating TV phone terminal device that received the RR response (808 in Figure 3 (Part 1))
Send the R command to the destination TV telephone terminal (see Figure 3).
310) in Part 1), and 310 in Figure 3 (Part 1), also activates the timer of its own terminal and starts counting.
2).

The terminating TV phone terminal device that has received the RR command transmits its own terminal mode initial value in the HDLC ■ frame as described above (R11 in FIG. 4 (part 1)), and performs the following processing. The initial value of the received calling terminal mode is in the TV telephone mode (Yes in R13 in Fig. 4 (Part 1)),
If the initial value of the own terminal mode is also in the TV telephone mode (Yes in R15 in Figure 4 (Part 2)), then the terminal mode is set to the TV telephone mode (Yes in R15 in Fig. 4 (Part 2)), then the terminal mode is set to the TV telephone mode. The operation mode of the terminating TV phone terminal device is set to TV phone mode. Conversely, if the initial value of the calling terminal mode is the TV phone mode, but the initial value of the own terminal mode is not the TV phone mode (NO in R15 in Figure 4 (Part 2)), or if the initial value of the calling terminal mode is is not in video phone mode (Fig. 4 (So(7) 1) (7) R13 (7) No)
, the operation mode for telephone calls of the terminating TV telephone terminal device is set to the voice telephone call mode (R19 in FIG. 4 (part 2)).

By setting one of the above operation modes, the call mode setting process on the called terminal side ends (Fig. 4 (Part 2) R20
).

In parallel with this call mode setting process on the destination terminal side, call mode setting process on the calling terminal side is performed as follows.

Before the activated timer times out, the HDLC ■ frame is received via the B channel (the third
S16 in Figure (Part 1). Yes in S14), and the initial value of the destination terminal mode is set as the TV phone mode in the information section (Yes in 318 and 5-20 in Figure 3 (Part 2)).
s), and if the initial value of own terminal mode is also set to TV telephone mode (Y of 322 in Figure 3 (Part 2)
es) Then, the operation mode of the originating TV phone terminal device for a call via the B channel to be established is set to the TV phone mode (324 in FIG. 3 (part 2)).

! A frame was received, but there was no initial value of the destination terminal mode in the information section (318 in Figure 3 (Part 2)).
(NO), there was an initial value for the destination terminal mode, but it was
Not in the mode initial value (No. 320 in Figure 3 (Part 2)
) or the initial value of the own terminal mode is not the initial value of the TV mode (
In the case of No at 322 in FIG. 3 (Part 2), the connection of the originating TV telephone terminal to the subsequently established B channel is set to voice communication mode (FIG. 3 (Part 2) 326). Setting to this voice call mode is possible even if an I frame is not received from the destination TV phone terminal within the timer interval (Yes in 316 in FIG. (Yes in S-2 in FIG. 3 (Part 1)).

By setting one of these operating modes, the call mode setting process on the calling terminal side also ends.

When the call mode setting processing at the originating and receiving terminals is completed, the known release control procedure (400, 402, 404, 406 in FIG. 5) for the B channel occupied for this purpose is completed.
, 408, 410) are also generated sequentially using the D channel.

And the last step of the release control procedure (release completion)
is completed on the originating terminal side, a known connection control procedure 200, 202° 204, 206, 5 establishes the B channel for communication.
00, 502, and 504 are generated sequentially as shown in FIG. At this time, if the set call mode is a voice call, the B channel will be used as the voice, and if the set call mode is the video call mode, the B channel will be used as the image/audio (CCIT
(see TI series recommendations).

At the end of the connection control procedure, communication via the B channel is established between the originating TV telephone terminal device and the terminating TV telephone terminal device, for example, if the setting in the above-mentioned call mode setting process is the TV telephone mode. Communication under TV phone mode (
600) in FIG. 5 is performed. The switch SW is controlled by the call mode control unit 10 in the TV phone mode.
I and SW4 are off, switch SW2. SW3 and SW
5 is turned on.

Further, when the voice call mode is set, switches SWI and SW4 are on, and switches SW2 . SW3
and SW5 is turned off.

After the above communication is completed, the known release control procedure for the B channel (700, 702, 704, 706, 7 in FIG.
08,710) is generated using the D channel, and upon its completion, the B channel used for the above-mentioned call is also finally released for the above-mentioned originating and terminating TV telephone terminal.

Examples of call formats in these various call modes are shown in the table below.

Note that in the above embodiments, a video telephone terminal device that can operate in a video telephone mode or a voice call mode has been described, but the present invention can also be implemented with respect to a terminal device that can operate only in a voice call mode. .

〔Effect of the invention〕

As described above, according to the present invention, even if the initial value of the call mode in the originating and receiving terminal devices is set to the same value or different values, the signal format transmitted and received via the ISDN channel for re-establishment is consistent. The signal format for the selected call mode is automatically set prior to the call. Therefore,
There is no error in setting the call mode, and as a result, it is possible to prevent the occurrence of a call failure state, and to freely set a good call system.

[Brief explanation of the drawing]

Fig. 1 is a principle block diagram of the present invention, Fig. 2 is a hardware configuration diagram of a TV telephone terminal device according to an embodiment of the present invention, Fig. 3 is a diagram showing the processing flow on the calling terminal side, and Fig. 4 is a diagram showing the processing flow on the calling terminal side. Figure 5 is a diagram showing an example of a control sequence; Figure 6 is a diagram showing a circuit section for establishing an audio/image interface according to the call mode; Figure 7 is a diagram showing a conventional TV. FIG. 2 is a hardware configuration diagram of a telephone terminal device. 1, 2, and 6, 2 is a system for voice communication mode (CPU 22, ROM 2
4, RAM 26, bus 20, audio C0DEC 34, communication line interface 32, switch SWI, SW4. and a handset and a program therefor in the ROM 24), 4 is a system for the TV telephone mode (CPU 22
, ROM24, RAM26, bus 20, image/audio C0
DEC30, display ink face 28, display device 36, TV camera 38, switch SW2. S
W3. 6 is a communication line control unit (communication line ink face 32, C
PU 22, ROM 24, RAM 26, and a program for sending and receiving initial values for communication mode for mode setting in PU 22, ROM 24, RAM 26, and ROM 24); 8 is a mode register; 10 is a communication mode control unit (CPU 22, ROM 24, R
This is a program for controlling call mode settings in the AM 26 and ROM 24. Figure 4 (!Φ1) 14 Tree side processing 70- Figure (I7+2)

Claims (1)

[Claims] (1) A communication line control unit (6) for connecting either the system (2) for the voice call mode and/or the system (4) for the TV phone mode in the terminal device to the ISDN.
An ISDN terminal device that has an ISDN terminal device and makes a call to a partner terminal device is provided with a mode register (8) for registering call mode information and a call mode control unit (10), and when making a call, the host terminal Sending call mode information, the system (
2 or 4) is connected to the communication line control unit (6), and a call in the call mode is performed via a call channel established between both terminal devices. .