JP2784534B2 - Multipoint video conference system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to an advanced information communication service network (hereinafter referred to as IS).
Multi-point video conference system using a dedicated line or the like, especially digital exchange (hereinafter referred to as D-PBX) or terminal adapter (T / A), image / voice / video
By constructing an optimal configuration of a data information encoding / decoding device (hereinafter referred to as a codec) and a private branch exchange (hereinafter referred to as a V-TEX) for image / voice / data information signals, image quality degradation, speed delay, etc. The present invention relates to a multipoint videoconferencing system that improves problems and facilitates the progress of videoconferencing.

(Prior Art and its Problems) FIG. 3 shows an example of a network and a system configuration of a conventional multipoint video conference system. In this conventional example, a three-point video conference connecting three venues, Tokyo, Osaka, and Nagoya, on ISDN will be described. In addition, the system configuration at each point consists of two codecs C11 and C12 (Tokyo), C21 and C22 (Osaka), C31 and C
32 (Nagoya) are connected in parallel, each codec is connected to a V-TEX that sends each information of image, audio and data to terminals on the premises, and one terminal connected to the V-TEX ( Monitor, television camera, speaker, microphone, facsimile, personal computer, terminal operation device, etc.).

First, a video conference between, for example, a Tokyo venue and an Osaka venue will be described. On the ISDN, compressed digital information signals of image, sound, and data of the Osaka venue are sent, and at the Tokyo venue, the D-PBX is used to transmit the image, audio, and data of the Osaka venue.
Leading each compressed digital information signal of data into the premises,
The digital information signal is led to V-TEX. The V-TEX determines that the information signal guided by the control section is the information signal of the target Osaka venue, and if the information signal is of the Osaka venue, converts the information signal into an analog information signal by the codec C11 and sends the signal to the terminal in the premises. Send analog information signal, otherwise send back over ISDN through D-PBX. Then, when the information signal of the Osaka venue reaches the premises terminal of the Tokyo venue, the participants of the Tokyo venue view the image of the Osaka venue on the monitor, listen to the sound with the speaker, and output the data by facsimile or the like. Conversely, each information of image, sound and data of Tokyo venue is sent to V-TEX as analog information signal from TV camera, microphone, etc.
The analog information signal sent from the V-TEX to the codec C11 is converted into a compressed digital information signal, and is transmitted in the form of the digital information signal on ISDN by the D-PBX. And a video conference with the Tokyo venue.

Next, a video conference in which the venue of Nagoya participated in addition to Tokyo and Osaka will be described. For example, in the Tokyo venue, as described above, the exchange of information signals with the Osaka venue is performed via the codec C11, and the exchange of information signals with the Nagoya venue is performed via the codec C12. In other words, the number of codecs required at each location is n-1 excluding the venue when the total number of video conference participation locations is n. In addition to displaying the image of only the Osaka venue or the image of the Nagoya venue alone on one monitor of the Tokyo venue, the terminal operation device can also divide the monitor into two and project the images of both venues simultaneously. It is possible by operating.

However, according to the conventional ISDN video conference system described above, no problem occurs when the video conference is performed between three locations as described above, but the following problem occurs when a video conference is performed between four locations or more. Occurs.

Since the structure is as shown in the figure, for example, in addition to Tokyo, Osaka, and Nagoya, the Sapporo venue will participate in the video conference and develop a video conference between the four locations. Will be described. In this case, since there are four points, the route that the information signal of the Osaka venue follows follows first the image, sound,
Each information of the data is sent as compressed digital information signal on ISDN and then to Tokyo via Nagoya venue. However, at the Nagoya venue, the compressed digital information signal is temporarily expanded from the D-PBX in the codec C11 and exchanged for an analog information signal.
It is sent back to 11 and exchanged again for a compressed digital information signal. Therefore, the information signal at the Osaka venue in the Nagoya causes image quality deterioration, sound quality deterioration and speed delay. Also, when the number of participating points increases and the number of waypoints further increases,
There is a problem that image quality deterioration, sound quality deterioration, and speed delay deteriorate in proportion to the number of waypoints. Also, a dedicated line has the same problem as described above.

In a configuration with three or more locations, n-1 codecs are required at each location, and it is difficult to conduct a video conference by connecting a large number of locations.

When storing the information signal at each point, the expanded analog information signal is sent from V-TEX to each information storage terminal device, or is converted again to a digital information signal and then stored in each information storage terminal. In order to increase the amount of information that must be sent to the device and can be stored by the terminal device, there are problems such as the complexity and size of the device.

The present invention solves the above-mentioned problems, and has a simple configuration capable of performing a good video conference by minimizing image quality deterioration, sound quality deterioration and speed delay even when the number of video conference participation points is large, and having a simple configuration. An object of the present invention is to provide a multipoint video conference system capable of storing a large amount of information.

(Means for Solving the Problems) An ISDN in which digital high-speed transmission is performed, a digital exchange connected to the ISDN for transmitting digital information signals to the premises, and a remote place via the ISDN and the digital exchange In a multipoint video conference system for mutually transferring voice, image, text data, and the like between a plurality of video conference terminals, the digital exchange, the information input / output terminal device, the information storage terminal device, and a plurality of codecs are directly connected. In addition, a visual terminal exchange for exchanging information such as image, voice, data, etc. between these devices and codecs, and respective bridges provided in the visual terminal exchange for exchanging signals with digital exchanges, codecs and information input / output terminal devices. A matrix circuit,
A control unit for performing each control of the signal exchange and the information storage terminal device, wherein the control unit is a compressed digital signal directly transmitted from the visual terminal exchange based on an identification signal transferred from the video conference terminal. Is transmitted via the digital exchange.

(Operation) With the above configuration, the compressed digital information derived from the line such as ISDN according to the above 1) is directly converted to V-TE
X can be sent to, and the compressed digital information that is converted to analog information is sent to a codec, converted to analog information by the codec and then led back to V-TEX and sent to a premises terminal such as a monitor, In addition, since the information storage terminal device or the like can transmit the compressed digital information signal from the V-TEX as it is, a large amount of information can be stored without increasing the complexity and size of the device. Further, according to the above 2), the bridge matrix circuits and the information storage terminal device can be controlled independently, and the processing speed can be increased. According to the above 3), at the time of a video conference between three points or more, the D-PBX or the compressed digital information signal derived from the T / A is converted from the V-TEX to the D-PBX or the It can be sent over ISDN or dedicated line via T / A.

Embodiment An embodiment of the present invention will be described below with reference to the drawings. 1 and 2 are diagrams for explaining an embodiment of the present invention. FIG. 1 is a basic configuration diagram of a multipoint video conference system at each point, and FIG. 2 is Tokyo and Osaka on ISDN. FIG. 1 is a configuration diagram of a four-point video conference system between Nagoya, Nagoya and Sapporo.

First, the basic configuration of the multipoint video conference system at each point will be described with reference to FIG. The symbols and numbers given in Fig. 1 are D-PBX (digital exchange), V-TEX
(Private branch exchange), C11-C1m (codec), S11,
S12 (information storage terminal equipment such as optical disk drive) T11 ~
T1k (information input / output terminal equipment such as monitor and facsimile), 1 (control unit), 2 (buffer memory and signal processing unit), 3 (channel bridge matrix),
4 (codec bridge matrix) and 5 (terminal bridge matrix).

The D-PBX is connected to the ISDN, and guides compressed digital information signals such as images, voices, and data on the ISDN to the premises. next
The compressed digital information signal derived from D-PBX is sent to V-TEX. According to the judgment of the control unit 1, the V-TEX sends the compressed digital information signal to the codecs C11 to C1m to convert the compressed digital information signal into an analog information signal, and then guides the analog information signal into the V-TEX, and the information storage terminal devices S11, S12, Alternatively, the information input / output terminal device T11 to T1k is sent, or the compressed digital information signal is sent to the information storage terminal device S11, S12 or the information input / output terminal device T11 to T1k, or a video conference participation point. If there are three or more points, control such as sending the compressed digital information signal back to the ISDN via the D-PBX as it is is performed. The control unit 1 is sent to V-TEX
The number of video conference participation points is determined from an identification signal assigned to each venue included in the information signal of the image, sound, data, and the like on the SDN. Further, when transmitting image / voice / data information on the ISDN from the information storage terminal devices S11 and S12 or a television camera, a microphone,
Facsimile, image scanner, personal computer, information input / output terminal equipment such as terminal operation device
When sending data information over ISDN, if the image / audio / data information is a compressed digital information signal,
TEX, sent to ISDN via D-PBX, if the image, audio, data information is an analog information signal, to V-TEX to codec C11 ~ C1m to convert to compressed digital information signal,
It is sent to ISDN again via V-TEX and D-PBX.

The signal exchange to the D-PBX, the information storage terminal devices S11 and S12, and the information input / output terminal devices T11 to T1k performed by the V-TEX is performed by the channel bridge matrix 3, the codec bridge matrix 4, This is made possible by each bridge matrix circuit of the terminal bridge matrix 5.

In this embodiment, the video conference system is connected on the ISDN, but it can be applied to any line such as a dedicated line, satellite communication, VAN (value added communication network). In this embodiment, the D-PBX is used, but a T / A (terminal adapter) may be used.

Next, a four-point video conference between Tokyo, Osaka, Nagoya and Sapporo on ISDN will be described with reference to FIG.

The symbols and numbers given in Tokyo, Osaka, Nagoya and Sapporo in FIG. 2 are as follows.

Tokyo: PBX1 (D-PBX) V-TEX1 (V-TEX) C11-C1m (codec) S11, S12 (information storage terminal equipment such as optical disk drive, magneto-optical disk drive) T11-T1k (monitor, TV camera, facsimile) , Information input / output terminal equipment such as terminal operation devices) Osaka: PBX2 (D-PBX) V-TEX2 (V-TEX) C21-C2m (codec) S21, S22 (information storage terminal equipment) T21-T2k (information input / output) Terminal equipment) Nagoya: PBX3 (D-PBX) V-TEX3 (V-TEX) C31-C3m (codec) S31, S32 (information storage terminal equipment) T31-T3k (information input / output terminal equipment) Sapporo: V-TEX4 ( V-TEX) C41-C4m (codec) S41, S42 (information storage terminal equipment) T41-T4k (information input / output terminal equipment) For example, in the Tokyo venue, each of the video, audio, and data at the Osaka venue, Nagoya venue, and Sapporo venue Information signals can be transmitted and received at the same time, without causing problems such as image quality deterioration, sound quality deterioration, and speed delay. In this case, the information signal at each venue in Nagoya and Sapporo can reach the Tokyo venue without passing through other video conference participation points, but the information signal at the Osaka venue is the PBX3, V at the Nagoya venue.
-Reach the Tokyo venue via TEX3. Conventionally,
Although the compressed digital information signal was once expanded and converted into an analog information signal after passing through the codecs C31 and C32, it was converted back to the compressed digital information signal and returned on the ISDN. Because the compressed digital information signal sent from the Osaka venue was sent back to ISDN again without passing through, the picture quality deteriorated at the waypoint,
Sound quality deterioration, speed delay, etc. are reduced to the maximum. Therefore, the information on the Osaka venue, which is stored and output to the terminal devices T11 to T1k at the Tokyo venue and stored in S11 and S12, is very good and facilitates the progress of the video conference.

Also, since the optical disk drive, magneto-optical disk drive, floppy disk drive, etc. of the information storage terminal equipment S11, S12 are directly connected to the V-TEX1, the compressed digital information signal sent to the V-TEX1 is stored as it is. It is possible to store a large amount of information with extremely high density.

Further, the control unit in the V-TEX1 is adapted to the respective specifications of the information input / output terminal devices T11 to T1k and the information storage terminal devices S11 and S12, for example, an information signal to be transmitted to a terminal device operated by an analog information signal is a codec C11. ~ C1m to convert to an analog information signal and send it to the terminal device.Also, it is easy to control such as sending the information signal as it is to the terminal device operated by the digital information signal.
T11 to T1k, S11 and S12 can be of various specifications.

It should be noted that the same effect as in Tokyo can be obtained in each of the points of Osaka, Nagoya, and Sapporo. In this embodiment, only one V-TEX is installed at each point.
The information input / output terminal devices T11 to T11 are not limited to only one device, and only need to be connected in series to the one V-TEX.
By connecting a plurality of V-TEXs in the same way as the 1k connection, a large number of terminal devices can be connected in one premises.

(Effects of the Invention) According to the present invention, despite the simple system configuration, image quality degradation even in a multipoint video conference,
Since video quality deterioration and speed delay can be prevented to the utmost, video conferences can proceed smoothly, information storage terminal devices can store large amounts of information at high density, and various terminal devices can be easily connected. Means that the number of codecs installed at each location is n-1 where n is the number of video conference participants
Although a table was required, according to the present invention, the effect is great, for example, it can be freely configured.

[Brief description of the drawings]

FIG. 1 is a basic configuration diagram of a multipoint video conference system at each location, and FIG. 2 is a configuration diagram of a four point video conference system of four locations on ISDN: Tokyo, Osaka, Nagoya, and Sapporo. FIG. 3 is an explanatory view of a conventional example. D-PBX, PBX-PBX4: Digital exchange V-TEX, V-TEX1-V-TEX1: Private terminal exchange C11-C1m, C21-C2m, C31-C3m, C31-C3m: Codecs S11, S12, S21, S22, S31, S32, S41, S42: Information storage terminal equipment T11 to T1k, T21 to T2k, T31 to T3k, T41 to T4k: Information input / output terminal equipment 1: Control unit 2: Buffer memory and signal processing unit 3: Channel bridge Matrix 4: Codec bridge matrix 5: Terminal bridge matrix

Claims (1)

(57) [Claims] An ISDN for performing digital high-speed transmission, a digital exchange connected to the ISDN for transmitting digital information signals to a premises, and a plurality of video conference terminals located at remote locations via the ISDN and the digital exchange. In a multipoint video conference system that mutually transfers voice, image, text data, and the like, the digital exchange, the information input / output terminal device, the information storage terminal device, and a plurality of codecs are directly connected and these devices and A visual terminal exchange for exchanging information such as image, voice, data, etc. between codecs, a digital exchange provided in the visual terminal exchange, a bridge matrix circuit for exchanging signals with a codec and information input / output terminal equipment, Control for signal exchange and control of information storage terminal equipment Wherein the control unit transmits a compressed digital signal transmitted directly from the visual terminal exchange via the digital exchange based on an identification signal transferred from the video conference terminal. Point-to-point video conference system.