JPH02179186A - Video conference system - Google Patents

Abstract

PURPOSE:To efficiently operate a circuit and to curtail the circuit royalty by providing a function for processing video information, voice information and facsimile information, etc., received from other station by a video conference device of the own station, and also, transferring each received information to a third station. CONSTITUTION:The system is constituted of a transmission control part 10 in an A spot, a video conference device 13 in the A spot, a transmission control part 11 in a B spot, a video conference device 14 in the B spot, a transmission control part 12 in a C spot, a video conference device 15 in the C spot and transmission lines 1, 2, 3 and 4 for connecting each spot, etc. That is, for the purpose of a video conference in the B spot, signals are reproduced by each device, and also, these video information and voice information or facsimile information return to the transmission control part 11 in the B spot through a path 7, pass through the transmission line 2 and reach the C spot. In such a way, in the case of executing a video conference between plural spots, it will suffice that even a station of a terminal bears the circuit royalty only to the relaying spot, and the royalty can be curtailed remarkably.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a TV conference system that transmits and receives video information, audio information, etc. between TV conference devices connecting remote locations.

(Prior Art) Conventionally, video conference systems have been known in companies in which remote locations such as a head office and a branch office are connected via communication lines. This T
V-conferencing systems are becoming increasingly popular for the purpose of saving time and transportation costs for traveling to remote locations.

A TV conference system is usually used to connect two points, but sometimes three or more points can be connected simultaneously for a conference. In the case of such a system that connects three or more points, a system is used in which one point connects each other point with a separate communication line to send and receive video information, etc. from the other point. For example, three-point ASB as shown in FIG.

In the case of a conference system based on the combination of C, three communication lines are required: points A and B, points A and C, and points B and C. Here, 10°11.12 are the transmission control units at point A, point B, and point C, respectively, and 20°
25 are communication lines.

(Problem to be solved by the invention) In the above-mentioned three-point video conferencing system, the local station and two other stations are connected through separate lines for communication, but the charging system depends on the distance. In such cases, there is a problem in that the above-mentioned line connection form is not necessarily optimal.

[Structure of the Invention] (Means for Solving the Problems) In order to solve the above problems, the present invention provides a TV conference system capable of reproducing and relaying video information received from other stations, It is characterized by having a function of processing voice information, facsimile information, etc. with the TV conference device of its own station, and transferring each of the above-mentioned received information to a third station.

It is also characterized by having a function of processing video information, audio information, facsimile information, etc. received from other stations with the TV conference device of the own station, and processing and transmitting each of the above received information to a third station. do.

(Function) Based on this configuration, when holding a video conference between multiple points, even the terminal station only has to pay the line usage fee between the relay points and the usage fee can be significantly reduced. I can figure it out.

(Example) Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a schematic diagram of a TV conference system connecting three points, A point, B point, and C point.

This TV conference system includes a transmission control section 10 at point A,
TV conference device 13 at point A and transmission control unit 11 at point B
, a TV conference device 14 at point B, a transmission control unit 12 at point C, a TV conference device 15 at point C, and transmission lines 1, 2, 3, 4, etc. connecting each point.

In the example shown here, the effect is expected at point B.

That is, video information, audio information, facsimile information, etc. from point A reach point B via transmission path 1.

The signal received by the transmission control unit 11 at point B is passed through the path 6 to the TV conference device 14, where processing for the TV conference is performed.

For example, video information is displayed on a TV, and audio information is reproduced as audible sound by a predetermined decoding means. Furthermore, in the case of facsimile information, the information is sent to a facsimile receiving device and reproduced on a predetermined sheet of paper.

As described above, signals are reproduced by each device for the TV conference at point B, and the video information, audio information, and facsimile information are transmitted to the transmission control unit 11 at point B via path 7. It returns to point C, which is the third point, via transmission path 2.

Video information, audio information, facsimile information, etc. that have reached point C are processed by the TV conference device 1 in the same way as they were done at point B.
5, and a TV conference is carried out.

On the other hand, video information, audio information, facsimile information, etc. from point C follow the route in exactly the opposite direction as described above.
Needless to say, it is transmitted to point A and point A. That is, from point C, via transmission path 4, to transmission control section 11 at point B, and then back to transmission control section 1 via path 8 and path 5.
Return to 1. During this time, video or audio is played back on the TV conference device 14, as described above.

The signal leaving the transmission control unit 11 reaches point A via the transmission line 3, and reaches the TV conference device 13 via the transmission control unit 10, where video information, audio information, and facsimile information are reproduced.

As mentioned above, the video information, audio information, facsimile information, etc. of points A and C are respectively between point B and point C or between point B and A.
Although we have described the case where information is transmitted to a point, in a TV conference, information from point B, which plays the role of reproducing relay, must also be transmitted to points A and C. In this case, a method of transmitting to point A and point C using a channel different from the transmission path described above may be considered.

Now let's talk about channels. Figure 3 is CCITT
(International Telegraph and Telephone Advisory Committee) Recommendation I.

4 shows a transmission line format of a primary rate interface defined in 431. Here, the transmission path format includes an F bit for embedding synchronization and maintenance data, and B channels B1 to 823 bits each consisting of 8 bits.
It consists of signals for 23 channels leading to 8 bits and an 8-bit D channel signal used for call control information. The signal from this F bit to the last bit of the D channel is
Since it is repeatedly transmitted at a rate of 125 μs, each B channel and D channel has an information transmission rate of 64 kbps.

Furthermore, FIG. 4 shows the configuration of an HO1 channel in which six B channels are bundled. Since the B channel has a transmission rate of 64 kbps, the HOI channel 40, HO2 channel 41 and HO3 channel 42 each have a transmission rate of 384 kbps.
The transmission speed is s. Note that the D channel is also 64 kbps in this case.

In TV conferencing systems, the 384k mentioned here is often used.
This is sometimes done using the BPAS transmission speed.

Further, the primary rate interface described here is provided in a four-wire system with separate upstream and downstream lines, so full-duplex communication is possible. Therefore, to sort out how to use channels, the HOI channel is assigned as an information channel from point A to point B to point C, and the HOI channel in the opposite direction is assigned as an information channel from point C to point B to point A.
I channel can be used. Next, the HO2 channel can be used as a channel for transmitting video information, audio information, etc. from point B to points A and C, respectively.

Therefore, transmission line 1 only supports the HOI channel, and transmission line 2
HOI and HO2 channels, and HOI and HO2 channels in transmission line 3.
and the HO2 channel, and only the HOl channel is used in the transmission path 4.

The above is an example in which information is transferred to points A and C without being processed when the information is regenerated and relayed at point B, but below is an example in which information is processed and transferred during regenerative relay. this is,
This is because in the above example, only the HOI channel is used to realize a TV conference. HO2 channel and HO3
When attempting to use a channel, it is possible that it is already being used for other communication, so the method described here may be effective.

Regarding the processing of information, here is an example of information compression, that is, information that was transmitted at 384 kbps is compressed to 1/2 and transmitted at 192 kbps. To this end, the processing at the reproduction relay point differs depending on how the video information is compressed and received. Generally, the amount of code generated by information compression is not constant over time, so after decoding to source data, it must be re-encoded to match the speed to 192 kbps and then transmitted. At this time, a buffer memory is usually used to smooth out information generation. If the memory overflows, speed matching measures such as omitting one frame's worth of information may be taken.

On the other hand, information compression methods reduce the generation of time-fixed information to one
In the case of an independent encoding method for each scanning line or each field, information can be transmitted by simply transmitting information for one scanning line for two scanning lines or for one field for two fields. The speed can be halved.

FIG. 5 shows an example of channel usage when 384 kbps information is processed into 192 kbps information and transferred to a third station using the above-described means. That is, this is an example in which the HOI channel is divided into 1/2 and transferred. In terms of the B channel, it is a configuration in which three channels are bundled. Here, the information from point A is processed and inserted into the first half (50) of the HOI channel as 192 kbps information, and
HOI with point information as 192kbps information
This shows that the signal is inserted into the latter half of the channel (51) and transmitted to point C.

Further, FIG. 6 shows an example in which information from point A and information from point B are sent alternately every other frame. In other words, in FLI, the information from point A is processed to 192 kbps and inserted into HOI (60), and in FL2,
HO information processed from the point to 192kbps
This is to be inserted into I (61). In FL3, the information from point A is set to 192kbps again as HOI (6
2) and repeat the above method.

As described above, the case where information going from point A to point C is processed at point B has been described, but when going from point C to the entry point, processing at point B can be performed in the same way.

In addition, although the above example was a video conference between three points, it is obvious that it can be applied to a TV conference system that connects even more points, and the transmission speed of the transmission path is also shown as an example of 384 kbps. It is also clear that is possible at other transmission speeds.

[Effects of the Invention] As explained above, according to the TV conference system of the present invention, since it has a regenerative relay function in a TV conference between multiple points, the line can be operated more efficiently than the method of connecting all the points with lines. At the same time, line usage charges can also be reduced.

[Brief explanation of the drawing]

FIG. 1 is a conceptual diagram of a TV conference system according to an embodiment of the present invention, FIG. 2 is a conceptual diagram of a conventional TV conference system, and FIGS. 3, 4, 5, and 6 are transmission frames, respectively. FIG. 1.2.3.4...Transmission path, 5,6,7.8...Route, 10,11.12...Transmission control unit, 13,14°15-TV conference device, 20, 21, 22, 23゜24
．． 25... Communication line, 40, 41.42 43...
channel.

Claims (2)

[Claims] (1) In a TV conference system that connects remote locations, video information, audio information, facsimile information, etc. received from other stations are processed by the TV conference device of the own station, and each of the above received information is transferred to a third station. A TV conference system characterized by having a function to. (2) In a TV conference system that connects remote locations, video information, audio information, facsimile information, etc. received from other stations are processed by the TV conference device of the own station, and each of the above received information is processed and a third A TV conference system characterized by having a function of transmitting data to a station.