JPH01180153A - Transmission speed control system for video conference - Google Patents

Abstract

PURPOSE:To attain efficient connection control by monitoring the operating state of a network, controlling a picture coder and a picture decoder of each television conference unit at a transmission speed allowed for the network and assigning the transmission speed in response to the operating state of the network. CONSTITUTION:When a transmission controller 150 monitoring each digital multiplexer receives a conference open request to video conference units B154, C156 from a video conference unit A152, the transmission capacity of incoming lines 161, 163, 165 and that of outgoing transmission lines 152, 164, 166 are discriminated. Then the unit 150 collects the information to calculate each transmission capacity. The unit 150 allocates each transmission capacity of picture decoders of the units A152, B154 and C depending on the combination of TV conference units and the operating state of the network so as to obtain an optimum transmission speed.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a transmission rate control system for video conferencing, and in particular to a transmission rate control method for video conferencing that controls the transmission rate of image information in a video conferencing service conducted via a network. Regarding the method.

[Conventional technology]

FIG. 4 is a block diagram of an example of a conventional transmission rate control method for video conferencing, and FIG. Network 403 with reference to Figure 4
The video conference device 401 connected to the video conference device 4
The operation of connection control when holding a video conference with 02 will be explained.

The video conference devices 401 and 402 each have image encoding means 404 and 407 that convert analog image information into digital image information at a prefixed transmission rate of Hbit/s.
, image decoding means 405, 406 for converting digital image information at a prefixed transmission rate of t [Hbit/s] into analog image information, and terminals 408, 409 having analog image information input/output functions and call control functions. It is configured with

The video conference device 401 that requests a conference with the video conference device 402 first sends the request to the connection control means 400 via the communication path 410.

The connection control means 400 monitors the usage status of the workpiece 403 via a control line 411.

The connection control means 400 shown in FIG.
The usage status of each link 503, 504 between the node 3 and the node 3 is monitored.

The connection control means 400 of the network example shown in FIG.
Monitor the usage status of 0. As a result, for example, Fig. 5 (at
In the example network, link 503 between node 1 and node 2 in the path between video conferencing devices 501 and 502
Suppose that the node is the most congested, and the usable transmission capacity (in the following description, it is synonymous with transmission speed) between node 1 and node 2 is Fbtt/s.

Now, as shown in FIG.
Considering the video conference devices 401 and 402 in FIG. 4, the allowable transmission capacity from the video conference device 401 to the video conference device 402 is Fbit/s. Depending on the usage state of the network, Fi, F < H may hold, and the network cannot tolerate the amount of image information from the video conference device, so this conference holding request is rejected. In this case, either request to hold the conference again or encode the images of each video conference device 401 and 402.
Resetting the transmission speed of the decoding means to Fbit/s,
Request another meeting.

[Problem that the invention seeks to solve]

The above-mentioned conventional transmission rate control system for video conferences controls connection of video conferences between video conference devices equipped with image encoding means and image decoding means that process image information at a pre-fixed transmission rate. In this case, when a request to hold a conference is rejected due to the usage status of the network, the transmission rate between the video conference devices is reset to the one allowed by the network, and the request to hold a conference is sent. 9. It is not possible to hold a conference between video conferencing devices set to different transmission speeds, even if the transmission speed is fixed in advance. There were always nine problems if we were not able to respond flexibly.

[The tth way to solve the problem]

The transmission rate control method for a video conference according to the present invention includes (1) an image encoding means and an image decoding means each having a variable transmission rate; The apparatus further includes a transmission rate control means for controlling the transmission rate of the image encoding means and the image decoding means in accordance with the permissible transmission capacity obtained from the usage state of the network according to the request for holding the image.

(2) At least one image encoding means with variable transmission speed;
a digital multiplexing device that multiplexes image information from a plurality of the video conferencing devices and connects it to a multipoint connection device via a communication path; Transmission for controlling the transmission speed of the image encoding means and the image decoding means according to the allowable transmission capacity obtained from the usage state of the digital multiplexing means in response to a request to hold a video conference notified from the video conference device. and speed control means.

[For production]

In the video conference transmission speed control system of the present invention, the video conference device is equipped with an image encoding means, an image decoding means, and a metal fitting for processing image information at an arbitrary transmission speed, and when holding a conference, the trap is configured to meet the requirements. , to the transmission rate control means, which monitors the usage status of the network and controls the image encoding means and image decoding means of each video conference device at a transmission rate that is permissible on the network. By doing this, it is possible to efficiently control connections because the transmission speed is allocated according to the usage status of the network.

〔Example〕

Next, embodiments of the present invention will be described with reference to the drawings.

Figures 1 (al and b) are block diagrams of an embodiment of the first and second inventions, Figure 2 is a ninth detailed block diagram explaining the second invention in detail, and Figure 3 is a block diagram of an embodiment of the second invention. It is a connection diagram of the 9th video conference device which explains in detail the invention of 2.

First, an embodiment of the first invention will be described with reference to FIG. 1(a). In FIG. 1(a), a video conference device 104 connected to a network 106 is connected to a video conference device 10.
5 shows how the image information transmission speed is controlled when holding a video conference.

The video conference devices 104 and 105 each include image encoding means (G) 101 and 112 for converting analog image information into digital image information having an arbitrary amount of information, and image encoding means (G) 101 and 112 for converting analog image information into digital image information having an arbitrary amount of information, and converting digital image information having an arbitrary amount of information into analog image information. It consists of image encoding means 102 and 111 for conversion, and conference terminals 103 and 113 having analog image information input/output functions and call control functions.

The video conference device 104 that requests a conference with the video conference device 105 first transmits the request to the transmission rate control means 10.
0 via the communication path 116. The transmission rate control 100 monitors the usage status of the network 106 via a control line 117.

For example, in the network example shown in FIG. 5(a), the usage status of the bus connecting the video conference devices 501 and 502, and the links 503 and 504 between node l, node 2, and node 3, is monitored. In the network example shown in FIG. 5(b)K, a link 53 between digital multiplexing devices 521 and 522 in which video conference devices 511 and 512 are accommodated is shown in FIG.
Monitor the usage status of 0.

As a result, for example, in the network example shown in FIG. The possible transmission capacity (synonymous with transmission speed in the following explanation) is 012 bit/s, and the usable transmission capacity in the direction of node 2 and node 1 is C21 bit/s.
Suppose that s. Now, the video conference device 501 shown in FIG.
502t-1 Figure 1 (Al's video conference device 105,1
04 respectively, the video conference device 1
The allowable transmission capacity from 04 to the video conference device 105 is C2.
At 1 bit/s, the allowable transmission capacity in the opposite direction is Cl2b
it/s. Based on this information, the transmission rate control means 100 controls the image encoding means 01 of the video conference device 104.
101 and the image decoding means 111 of the corresponding video conference device 105 are controlled by control lines 109 and 114 so that their transmission capacity becomes 021 bit/s.

Control lines 115 and 110 are used to control the image encoding raw stage 112 of the teleconference device 105 and the corresponding image decoding means 0102 of the video conference device 104 so that the transmission capacity becomes Cl2 bit/s. As a result, the analog image information from the conference terminal 103 is input to the image encoding means qlo1, where it is converted into digital image information with an information amount of F12 bit/s, and transmitted through the network through the communication channels 107 and 117 to the video conference equipment. [10
The hole diameter is converted into image information by the image decoding means No. 5 and inputted to the conference terminal 113.

Conversely, analog image information from the conference terminal 113 is input to the image encoding means (G) 112, where it is
It is converted into digital image information with an information amount of 1 b+t/s, and is transmitted via the network to the image decoding means ID) 102 of the video conference device 104 via the communication path 118.108i.
The information is input into the conference terminal 103 after being converted into analog image information.

Next, an embodiment of the second invention will be described with reference to FIG. 1 (bl). FIG. Video conference device 154 connected to 159
This shows how the image information transmission speed is controlled when a video conference is held between three points: the video conference device 156 connected to the digital multiplexing means 160, and the video conference device 156 connected to the digital multiplexing means 160. At this time, video conference devices 152, 154, which conduct a video conference between three points,
156 is realized by the configuration shown in FIG. 2, for example.

That is, each video conference device has an image encoding means 201 that converts analog image information into digital image information having an arbitrary amount of information, and two image encoding means 201 that converts digital image information having arbitrary information t into analog image information. It consists of decoding means 202 and 203, and a conference terminal 204 that provides input/output functions for analog image information and call control functions.

By having two image decoding means, it is possible to receive image information from two other locations.

Now in Figure 1 (bl), 154 video conference equipment B.

The 152nd videoconferencing device A that requests a conference with the 156th videoconferencing device C first sends the request to the transmission rate control means 150 via the control network through the control line 17.
Send with 0.

The transmission rate control means 150 is connected to each digital multiplexing means 15.
The usage status of 8,159,160 is monitored by a control line 176 via a control network. For example, the digital multiplexing means 158, 159, 160 also accommodates video conferencing equipment 153, 155, 157, and depending on their operating status, the usable capacity of each digital multiplexing means 158, 159, 160 is Although the transmission capacity changes, the transmission speed control means 150 monitors the change.

10,000, the point-to-long point connection means 151 connects the video conference device 1
52, 154, and 156, connection control is performed as shown in FIG. 3. In FIG. 3, video conference devices 301 and 304 are the same video conference device Ai and video conference device 302. , 305 represent the same video conference device B, and video conference devices 303 and 306 represent the same video conference device C, respectively.

Image information is sent to the long point connection means 300 via the image information network of the communication path 311 to the video conference device, and the image information is transmitted from the long point connection means 300 to the long point connection means 300 via the image information network of the communication path 314. I! Receive information from 1B and C.

The video conference device B sends image information from itself to the long point connection means 300 via the communication path 312, and transmits information from the video conference devices A and C from the long point connection means 300 through the communication path 315. Receive via. Furthermore, the video conference device C sends image information to the long point connection means 300 via the communication path 313, and receives information from the video conference devices A and B from the long point connection means 300 via the communication path 316. .

In this manner, the point-to-long point connection means 300 shown in FIG. 3 has the function of multiplexing image information from two points and transmitting it to the remaining one point in a video conference between three points.

Therefore, for example, the transmission capacity of the communication path 314 is
This is the sum of the transmission capacities of 12 and 313.

In the following description, the communication path to the long point-to-long point connection means 300 will be called an uplink, and the communication path from the long point to long point connection means 300 will be called a downlink.

As mentioned above, the transmission rate control means 150 monitoring each digital multiplexing means in FIG.
When receiving a request to hold a conference with the video conference device C of 6, the available transmission capacity of each of the uplinks 161, 163, 165 and the available transmission capacity of each of the downlinks 152, 164, 166 is determined. That's what we understand.

These available transmission capacities are now represented by the following symbols. That is, the usable transmission capacity of uplink 161 is t-C bit/s, and the usable transmission capacity of 163 is CR15b.
i t/s, CRcb the available transmission capacity of 165
The usable transmission capacity of the lower blade line 162 is expressed as t-cDcbit/s, and the usable transmission capacity of the CDA bit/sll 64 is expressed as the usable transmission capacity of the CDB bit/s 1166, t-cDcbit/s.

The transmission rate control means 150 collects this information and calculates CD person' = CRa' + CRo'CDB
' = CRA' + CRo'CDo':
Calculate each transmission capacity as C'+CRB'. Here, ODA'≦CD, CRA'≦OR, CDB'≦CD
B, CRB'≦CRB1CDo'≦CDo1CRo'
≦CRo.

I have completed nine. From these values, transmission speed control means 1
50 is the transmission capacity of the image encoding means of the 152 video conference apparatuses t-CRA'1C1 The transmission capacity f of the two image decoding means of the 152 video conference apparatuses B Add the transmission capacity of the two image decoding means to the transmission capacity f CRa'. and C
Do' K, 156 (D Control the transmission capacity tCRc' of the image encoding means of the video conference device C, the transmission capacity 't-CRλ' and CDB' of the two image decoding means, and control these information The multipoint connection means 151 is also controlled to perform the connection control described above.

〔Effect of the invention〕

As explained above, the present invention provides a video conference device that includes an image encoding means and an image decoding means for processing image information at an arbitrary transmission speed, and transmits a request when holding a conference to control the transmission speed. The transmission speed control means monitors the network usage status and controls the image encoding means and image decoding means of each video conference device at a transmission rate that is permissible on the network, depending on the network usage status. Ninth, the transmission rate Kt-allocation has the effect of preventing a connection request from being rejected because the image transmission rate from a conventional video conference device cannot be tolerated by the network.

Also, when holding a video conference at three or more locations, the transmission speed control means can grasp the transmission speed of image information from each video conference device, so it can determine the optimal speed based on the network usage status and the combination of each video conference device. Another advantage is that transmission speed Kk can be assigned to each video conference device and connection control can be performed efficiently.

[Brief explanation of the drawing]

Figure 1 (al, (bl) is a block diagram of an embodiment of the first invention, Figure 2 is a detailed block diagram for explaining the second invention in detail, and Figure 3 is a block diagram of an embodiment of the second invention. The connection diagram of the ninth video conference device that explains the invention in detail, t44 is a block diagram of an example of the conventional transmission speed system for video conferences,
FIG. 5 (al, (bl) is a configuration diagram of a network to which connection control of the transmission speed control method for television conferences can be applied. 100.150...Transmission speed control means, 101
゜112.201,404,407... Image encoding means, 102,111,202,203,405゜406... Image decoding means, 103,113゜204.408,409・・・・・・Conference terminal, 104
゜105.152,153,154,155,156゜157.301,302,303,304,305゜3
06.401,402,501,502,511゜51
2...Teleconferencing device, 106,403...
...Network, 151...Multipoint connection means, 158°159.160,521,522...
... Digital multiplexing means, 400 River... Connection control means, 109゜110.114, 115, 116, 11
7,170°171.172,173,174,175
, 176°177.410.411...-control line,
107°108.117,118,161,162,1
63°164.165, 166.311.312,31
3314.315, 316, 503, 504... seal/communication channel. Agent Patent Attorney Otoiko Uchihara \Y) Figure 5 (-fr'.

Claims (2)

[Claims] (1) A plurality of video conference devices equipped with image encoding means and image decoding means with variable transmission speeds, and permission obtained from the network usage status based on a request to hold a video conference notified from the video conference devices. A transmission rate control system for a video conference, comprising a transmission rate control unit that controls the transmission rate of the image encoding unit and the image decoding unit according to transmission capacity. (2) At least one image encoding means with variable transmission speed;
a digital multiplexing device that multiplexes image information from a plurality of the video conferencing devices and connects it to a multipoint connection device via a communication path; Transmission for controlling the transmission speed of the image encoding means and the image decoding means according to the allowable transmission capacity obtained from the usage state of the digital multiplexing means according to a request to hold a video conference notified from the video conference device. 1. A transmission speed control method for video conferencing, comprising speed control means.