JPH06284218A - Communication transfer control method, communication transfer system and device thereof - Google Patents

Abstract

PURPOSE:To facilitate transfer during communication by using a terminal equipment reaching finally a communication enable state so as to make communication when plural terminal equipments set in the communication enable state are in existence. CONSTITUTION:When a signal is transferred from a video telephone set 1a to a video telephone set 1b and the user hooks off a handset of the video telephone set 1b or makes a request of transfer by using a key board, a CPU 10 informs of the arrival to a communication enable state to a communication transmission equipment 13 through a D channel. Then a CPU 15 of the communication transfer equipment 13 detects it that both of the video telephone sets 1a, 1b reach the communication enable state, and since the video telephone set reaching finally the communication enable state is the video telephone set 1b, a B channel changeover circuit 14 connects B channels of communication control circuits 9a, 9b. Thus, the communication is transferred from the video telephone set 1a to the video telephone set 1b.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a communication transfer control method for transferring communication to another terminal during communication, and more particularly to communication transfer between terminals using the same network termination device in a service integrated digital network. The present invention relates to a preferable communication transfer control method, communication transfer system, and device thereof.

[0002]

2. Description of the Related Art In the comprehensive service digital network, CCI issued by the Japan ITU Association on January 31, 1990
As described in pages 225 to 235 of the TT Blue Book I Series Recommendation (Part 1), a communication transfer control method for transferring the communication to another terminal during communication is defined as an international recommendation as a transfer additional service during communication. Has been done. According to this recommendation, when the communication is transferred from the terminal A to the terminal C during the communication between the terminal A and the terminal B and the communication is performed between the terminal B and the terminal C, the user of the terminal A performs the following procedure. Is required. First, the terminal A designates the terminal C by the telephone number and the sub address and requests the transfer during communication. As a result, the terminals A and C can communicate with each other. Next, the user of the terminal A releases the communication of the terminal A after confirming that the terminal A and the terminal C can communicate with each other by communicating with the user of the terminal C, for example. As a result, the terminals B and C can communicate with each other.

[0003]

The above-mentioned communication transfer control method allows transfer during communication between arbitrary terminals connected to the integrated service digital network, but between terminals using the same network terminating device. Then, there was no consideration in the point of performing transfer during communication.

In the case of a conventional telephone connected to an analog network, for example, when it is installed in an office, two phones are connected to the same line and installed at a distance of about several meters. After receiving the call, verbally transfer the call to the other phone without going through the phone, visually confirming that the handset of the other phone is off-hook, and communicating by hooking your handset on-hook Could be transferred.
However, in the communication transfer control method for the integrated service digital network, even if a videophone, which is an example of a terminal, is installed at a distance of about several meters using the same network termination device, the videophone is transferred to the other videophone. At times, it is necessary to specify the telephone number and sub-address of the other videophone to request transfer during communication, resulting in a problem of reduced usability.

A first object of the present invention is, for example, a communication which can be easily transferred during communication, such as a telephone connected to a conventional analog network, between terminals using the same network terminating device of an integrated service digital network. It is to provide a transfer control method.

A second object of the present invention is to provide a communication transfer system using the above communication transfer control method, and a communication control device and a terminal used in the system.

[0007]

In order to achieve the first object, when there are a plurality of terminals in a communicable state,
Communication is performed by using the terminal which is finally in the communication enabled state.

In order to achieve the second object, the communication for detecting that the terminal is in the communicable state is made to the connection control means for controlling the connection between the line control means connected to the communication line and the plurality of terminals. Among the terminals in the communicable state, the terminal which is in the communicable state at the end is connected to the line connecting means.

[0009]

When an incoming call is received, one of the plurality of terminals connected to the line control means is set in a communicable state, so that the line control means can make the only one of the terminals through the communication possible detection means. It is determined that the terminal is in the communicable state, that is, the terminal that has finally become in the communicable state, and the terminal is connected to the communication line. This allows the terminal to communicate with the calling terminal. Next, in the case of transferring to another terminal connected to the line control device, by making the transfer destination terminal in a communicable state, the line control means causes the terminal to operate via the communicability detection means. Finally, the terminal is determined to be in the communicable state, and the terminal is connected to the communication line.
Therefore, the user can easily perform the transfer during communication by simply setting the communication destination terminal in the communicable state, and the operability can be improved.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below by taking a videophone that uses a comprehensive service digital network (hereinafter referred to as ISDN line) as a terminal. In each drawing, the same components are denoted by the same symbols, and duplicate description will be omitted.

First, a first embodiment will be described with reference to the drawings.

FIG. 2 shows a block diagram of an example of the videophone used in the first embodiment. In the figure, reference numeral 1 is a videophone, which is conventionally connected to an ISDN line (not shown) via a network terminating device 2. 3 photographs the user, for example N
A camera that outputs a TSC video signal, and a camera 3
, A video codec circuit for encoding and decoding the video signal, 5 a monitor of the decoded video signal, 6 a handset for inputting and outputting the audio signal, 7 an audio codec circuit for encoding and decoding the audio signal, 8 is a hang-up switch that detects on-hook / off-hook of the handset 6;
Reference numeral 9 denotes a communication control circuit, which is a bidirectional data channel (hereinafter referred to as Bch) for information communication such as a coded signal of a video signal and a coded signal of audio, and a bidirectional data channel for line control of an ISDN line. (Hereinafter referred to as Dch)
Separate / mix. Reference numeral 10 is a CPU for system control of the videophone 1, which performs line control through the Dch and the communication control circuit 9, 11 is a keyboard for inputting a telephone number or operation, and 12 is a bell for notifying an incoming call.

FIG. 3 shows a block diagram of a first embodiment of the communication transfer system of the present invention using the videophone 1 shown in FIG. In the figure, the videophones 1 a and 1 b are connected to the same network terminating device 2 via a communication transfer device 13. Reference numeral 14 is a Bch switching circuit separated by the communication control circuits 9a and 9b, and 15 is a system control CPU of the communication transfer device 13, which performs line control via the Dch and the communication control circuit 9c.

Next, an example of the operation of the communication transfer device 13 for transferring an incoming call received by the videophone 1a to the videophone 1b will be described with reference to FIG.

When the CPU 15 of the communication transfer device 13 detects an incoming call by Dch, the CPU 15 of the videophone 1a and 1b sends a D
Notify the incoming call using ch. As a result, the CPUs 10 of the videophones 1a and 1b ring the bell 12 to notify the user of the incoming call. When the CPU 10 detects by the hang-up switch 8 that the user has hooked the handset 6 of the videophone 1a off, the CPU 10 communicates that an incoming call has been received, that is, the communication is enabled, using Dch. Notify the device 13. CPU of communication transfer device 13
Reference numeral 15 detects by Dch that the videophone 1a is in a communicable state, uses Dch to notify the videophone 1b of cancellation of the incoming call, stops the bell 12 of the videophone 1b, and causes the Bch switching circuit 14 to operate. The Bch of the communication control circuits 9a and 9c are connected. Next, Dch is used to notify the ISDN line that an incoming call has been received. As a result, communication is started in the videophone 1a.

After that, when the communication is transferred to the videophone 1b, the CPU 10 causes the CPU 10 to either off-hook the handset 6 of the videophone 1b or request the transfer from the keyboard 11 thereafter. The communication transfer device 13 is notified that communication is enabled using Dch. As a result, the CPU 1 of the communication transfer device 13
5 detects that both of the videophones 1a and 1b are in the communicable state, and since the videophone that has finally become communicable is the videophone 1b, the Bch switching circuit 14 causes the communication control circuits 9b and 9c. Bch of is connected. Thereby, the communication is transferred from the videophone 1a to the videophone 1b, and thereafter, even if the videophone 1a is on-hook, the communication on the videophone 1b is continued.

When the hang-up switch 8 detects that the handset 6 of the videophone 1b has been hooked, the CPU 10 uses Dch to notify the end of communication. As a result, the CPU 15 of the communication transfer device 13 detects that both the videophones 1a and 1b are not in the communicable state, and notifies the ISDN line of the end of communication using Dch.

According to this embodiment, the videophones 1a to 1 are
The transfer of the communication to b can be performed easily by off-hooking the handset 6 of the videophone 1b, or by thereafter requesting the transfer from the keyboard 11, and the usability can be improved. Further, in this embodiment, the communication control circuit 9 for communicating with the videophone 1 is made the same as the network terminating device 2 so that the ISDN is conventionally provided via the network terminating device 2.
The videophone 1 connected to the line can be directly connected to the communication transfer device 13.

Next, a second embodiment will be described.

FIG. 4 shows a block diagram of an example of a videophone used in the second embodiment. In the figure, 16 is a video telephone, 17 is a video signal from the camera 3, a voice signal from the handset 6 and a line control signal from the CPU 10 are frequency-multiplexed with a radio frequency band signal (hereinafter referred to as an RF signal), for example. RF input after being modulated and output
An RF signal modulation / demodulation circuit that demodulates a signal and separates each signal,
Reference numeral 18 is an RF signal detection circuit that detects the presence or absence of an input RF signal by, for example, frequency detection or envelope detection.

FIG. 5 shows a block diagram of a second embodiment of the communication transfer system of the present invention using the videophone 16. In the figure, videophones 16a and 16b are connected to the same network terminating device 2 via a communication transfer device 19. Reference numeral 20 is an RF signal switching circuit.

Next, an example of the operation of the communication transfer device 19 for transferring an incoming call received by the videophone 16a to the videophone 16b will be described.

When the CPU 15 of the communication transfer device 19 detects an incoming call via the communication control circuit 9, it outputs an RF signal to the videophones 16a and 16b via the RF signal modulation / demodulation circuit 17 and the RF signal switching circuit 20. Videophone 1
The CPUs 6a and 16b are the RF signal detection circuit 18
When the RF signal is detected by, the bell 12 is sounded to notify the user of the incoming call. When the CPU 10 detects by the hang-up switch 8 that the user has hooked the handset 6 of the videophone 16a, the CPU 10 enters a communicable state, and the RF signal modulation / demodulation circuit 17 starts outputting the RF signal. The CPU 15 of the communication transfer device 13 detects that the video telephone 16a is in the communicable state by detecting the RF signal by the RF signal detection circuit 18a, and the RF signal is detected.
The signal switching circuit 20 stops the RF signal output to the videophone 16b, stops the bell 12 of the videophone 16b, and connects the videophone 16a and the RF signal modulation / demodulation circuit 17. Then, the IS is passed through the communication control circuit 9.
Notify that the incoming call has been received by the DN line. This allows
Communication is started in the videophone 16a.

After that, when the communication is transferred to the videophone 16b, the user takes the handset 6 of the videophone 16b off-hook, or thereafter, the keyboard 11 is used.
By requesting more transfer, the CPU 10 causes the RF signal modulator / demodulator circuit 17 to output an RF signal to the communication transfer device 19. Thereby, the CPU of the communication transfer device 19
15 detects that both of the videophones 16a and 16b are in the communicable state, and the videophone 16b which is finally in the communicable state is the RF telephone 16b.
The signal switching circuit 20 connects the videophone 16b and the RF signal modulation / demodulation circuit 17. Thereby, the communication is transferred from the videophone 16a to the videophone 16b, and thereafter, even if the videophone 16a is on-hook, the communication on the videophone 16b is continued.

When the hang-up switch 8 detects that the handset 6 of the videophone 16b is on-hook, the CPU 10 causes the RF signal modulation / demodulation circuit 17 to perform RF.
Stop signal output. CPU 15 of communication transfer device 19
The RF signal detection circuit 18 detects that both the videophones 16a and 16b are not in the communicable state, and notifies the ISDN line via the communication control circuit 9 of the end of communication.

Also in this embodiment, as in the first embodiment,
Transfer of communication from the videophones 16a to 16b can be easily performed by off-hooking the handset 6 of the videophone 16b, or by simply requesting the transfer from the keyboard 11 after that, improving operability. can do. Further, in the present embodiment, since relatively expensive circuits such as the video codec 4, the audio codec 7, and the communication control circuit 9 can be shared by the respective videophones, there is an advantage that the communication transfer system can be constructed at a low cost.

Further, in the present embodiment, the presence or absence of the RF signal is used to detect whether or not the videophone 16 can communicate, but it is also possible to use a line control signal in which this RF signal is frequency-multiplexed, for example. Absent. Further, it goes without saying that the connection with the videophone 16 and the communication transfer device 19 may be performed wirelessly. In addition, FIG.
As shown in the block diagram of the third embodiment of the communication transfer system, the communication transfer device 21 using a baseband signal switching circuit 22 may be used instead of the RF signal switching circuit 20. In this example, the signal switching circuit 22 does not switch all signals by switches, but only the video signals from both RF signal modulation / demodulation circuits 17 are switched by the switch 23 as shown in FIG. Signal and audio signal from audio codec 7 are buffer 2
It is also possible to supply it to both RF signal modulation / demodulation circuits 17 at 4, and add the audio signals from both RF signal modulation / demodulation circuits 17 by the adder 25.

In each of the above embodiments, the number of videophones that can be connected to the communication transfer device is two in order to simplify the description, but it goes without saying that the number of videophones can be easily expanded to three or more. Further, although the operation at the time of calling is not particularly described, it is clear that the communication transfer device can perform the same control by off-hooking the handset of the videophone for calling. Of course, the calling side can also perform transfer during communication in the same manner.

[0029]

According to the present invention, when the communication is transferred to another terminal during communication, it can be easily performed only by setting the terminal of the communication destination to the communicable state. In particular, when the terminal is a videophone, between the videophones that use the same network termination device on the ISDN line, the transfer of the videophone of the transfer destination is the same as the transfer between the phones connected to the same line of the conventional analog network. Since the transfer during communication can be easily performed only by taking the handset off-hook, it is possible to improve the usability of the videophone placed at a distance of several meters in an office or the like.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing an example of a communication transfer operation.

FIG. 2 is a block diagram of an example of a videophone used in the first embodiment.

FIG. 3 is a block diagram of a first embodiment of the communication transfer system of the present invention.

FIG. 4 is a block diagram of an example of a videophone used in the second embodiment.

FIG. 5 is a block diagram of a second embodiment of the communication transfer system of the present invention.

FIG. 6 is a block diagram of a third embodiment of the communication transfer system of the present invention.

7 is a block diagram of an example of the signal switching circuit 22 of FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Videophone of 1st Example, 2 ... Network termination device, 3 ... Camera, 4 ... Video codec circuit, 5 ... Monitor, 6 ... Handset, 7 ... Voice codec circuit, 8 ... Hangup switch, 9 ... Communication control circuit, 10 ... CPU of videophone, 11 ... Keyboard, 12 ... Bell, 13 ... Communication transfer device of first embodiment, 14 ... Bch switching circuit, 15 ... CPU of communication transfer device, 16 ... Second Video telephone of the embodiment, 17 ... RF signal modulation / demodulation circuit, 18 ... RF signal detection circuit, 19 ... Communication transfer device of the second embodiment, 20 ... RF signal switching circuit, 21 ... Communication transfer device of the third embodiment , 22 ... Signal switching circuit.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Sakae Nemoto 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Stock company Hitachi Image Information Systems (72) Inventor Hitoshi Aoki 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa In Hitachi Image Information System (72) Inventor Shigeru Tsuchida 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Stock Company Hitachi Image Information System (72) Inventor Soichi Sugimoto 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Hitachi, Ltd. In the image information system (72) Inventor Koji Kusuda 216 Totsuka-cho, Totsuka-ku, Yokohama-shi, Kanagawa Hitachi Information & Communication Division (72) Inventor Koji Saraku, 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Hitachi Image In the information system

Claims (4)

[Claims] 1. A first terminal issues a communication request to a second terminal (hereinafter referred to as a call), and after the second terminal detects the call (hereinafter referred to as an incoming call), A method for controlling communication transfer to a terminal which starts communication by setting a communicable state, wherein when there are a plurality of the second terminals in the communicable state, the second communication terminal finally becomes the communicable state.
A communication transfer control method, characterized in that communication is performed between said terminal and said first terminal. 2. A terminal system having line connection means for connecting to a communication line, a plurality of terminals, and a connection control means for controlling connection between the plurality of terminals and the line connection means, wherein the terminals can communicate. Of the terminals in the communicable state, which is equipped with a communicable detection means for detecting that the state is
A communication transfer system, characterized in that a terminal which is finally in a communicable state is connected to the line connecting means. 3. The system according to claim 2, wherein the line connection means for connecting to the communication line, the connection control means for controlling the connection between a plurality of terminals and the line connection means, and the terminal are communicable. A communication transfer device comprising a communication possible detecting means for detecting, and connecting a terminal which is in a communicable state and which is finally in a communicable state to the line connecting means. 4. A terminal equipped with notifying means for indicating that the apparatus of claim 3 is in a communicable state.