JP2000184344A - Multi-point conference system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase transmission reception speed of, especially image data between terminals. SOLUTION: A plurality of terminals are connected in a loop. Two line interfaces 10, 11, a demultiplexer section 60 that demultiplexes transmission image data into two, a multiplexer section 30 that multiplexes two received image data, an input and an output of the two line interfaces are selected and two transmission image data demultiplexed by the demultiplexer section are transmitted from the two line interfaces and the two reception image data received respectively by the two line interfaces are sent to the multiplexer section by changeover devices 70, 71.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multipoint conference system using a video conference, a video phone, or the like.

[0002]

2. Description of the Related Art Conventional multipoint conference systems generally include:
As shown in FIG. 1, each terminal is connected in a star configuration centering on a multipoint conference unit (MCU), and the MCU selects and adds images and sounds sent from each terminal and sends out the signals to each terminal. .

[0003]

However, the video conference terminal connected in a star configuration has an upper limit in design, and M
The transmission path speed by the CU has been reduced.

Japanese Patent Application Laid-Open Nos. 1-2241959 and 5
-221321, JP-A-7-288792,
As disclosed in JP-A-8-32950,
A multipoint conferencing system in which terminals are connected in a loop type has also been proposed, but there is no system that speeds up transmission and reception of image data between terminals in particular.

It is an object of the present invention to increase the speed of transmission and reception of image data between terminals in a multipoint conference system in which terminals are connected in a loop.

[0006]

According to the multipoint conference system of the present invention, a plurality of terminals are connected in a loop type, and each terminal has two terminals.
One line interface, a demultiplexing unit that divides transmission image data into two, a multiplexing unit that multiplexes two reception image data, and a demultiplexing unit that switches input and output of the two line interfaces And a switching unit for transmitting the two pieces of transmission image data divided by the two line interfaces from the two line interfaces and transmitting the two received image data respectively received from the two line interfaces to the multiplexing unit. I do.

That is, the transmitting terminal divides the transmission image data into two parts, one of which transmits the loop counterclockwise, and the other transmits the clockwise clockwise. Multiplexes image data from both left and right.

Each terminal is provided with a delay adjuster in order to compensate for the difference in transmission delay between the lines, and adjusts the amount of delay of the two pieces of received image data received from the two line interfaces, respectively, and sends them to the multiplexing unit.

In order to encode and transmit an image, each terminal is provided with an image coder that encodes the image and sends it to a demultiplexing unit and an image decoder that decodes the image data from the multiplexing unit.

[0010]

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

The multipoint conference system according to the present invention is shown in FIG.
As shown in (1), terminals are connected to each other in a loop by a circuit network. In the figure, three terminals 1 to 3 are connected. FIG. 3 shows the configuration of each terminal.

Each terminal has a line interface 10 connected to the first line, a line interface 11 connected to the second line, two delay adjusters 20 and 21 for correcting the delay amount of each line, A multiplexing unit 30 for multiplexing the image data received by the two line interfaces 10 and 11; an image decoder 40 for decoding the multiplexed image data into an image; and an image coder for encoding an image from the camera 50, a demultiplexing unit 60 that divides the encoded image data into two, and outputs one of the two divided image data from the output of the first line interface 10 to the input of the second line interface 11 A first switch 71 for switching and sending the other of the two divided image data from the output of the second line interface 11 to the first line interface. A second switch 70 to send switch to the input face 10, line interface 10
・ Retrieving switching information from 11 and switching device 70
A control unit 80 for controlling the controller 71;

Next, the operation will be described. A case where image data is transmitted from the terminal 1 will be described as an example. In terminal 1,
An image captured by a camera is encoded by an image decoder 50 and then divided into two image data by a demultiplexer 60. One of the image data is switched to a switch 7
At 0, the image data is sent to the line interface 10 and transmitted counterclockwise to the line network.
Is sent to the line interface 11 and transmitted clockwise to the line network.

The terminal 2 and the terminal 3 receive the two divided image data at the line interfaces 10 and 11, respectively, and switch the input and output of the two line interfaces 10 and 11 at the switches 70 and 71. , And relays the two received image data at the same time as the delay adjuster 20.
After being sent to 21 to adjust the difference in line delay, the multiplexing unit 20 multiplexes the signals. Then, the multiplexed image data is decoded into an image by the image decoder 40 and displayed on a monitor.

Here, the control of the switches 70 and 71 is performed by the control unit 80 so that the terminal transmits only one point.
Is controlled by

[0016]

According to the conventional multipoint conference unit (MCU), there is an upper limit in design for a video conference terminal which can be connected.
According to the present invention, there is no limit on the number of terminal connections for loop connection. In addition, since the loop can be constructed twice, the transmission path speed of the conventional MCU can be doubled, and a special device such as an MCU is not required.

In particular, in the present invention, the transmitting image data is divided into two by the terminal on the transmitting side, one of the image data is transmitted counterclockwise through the loop, and the other image data is transmitted clockwise. Since the receiving terminal multiplexes the image data from both the left and right, the speed of transmitting and receiving the image data between the terminals can be increased.

[Brief description of the drawings]

FIG. 1 is a conventional system configuration diagram in which each terminal is connected in a star configuration around a multipoint conference device (MCU).

FIG. 2 is a system configuration diagram of the present invention.

FIG. 3 is a block diagram illustrating a configuration example of a terminal according to the present invention.

[Explanation of symbols]

 10.11 Line interface 20.21 Delay adjuster 30 Multiplexer 3 40 Image decoder 50 Image coder 60 Demultiplexer 70.71 Switcher 80 Control unit

Claims (3)

[Claims] 1. A plurality of terminals are connected in a loop type, each terminal has two line interfaces, a demultiplexing unit for dividing transmission image data into two, and a multiplexing unit for multiplexing two reception image data. And the input and output of the two line interfaces are switched so that the two transmission image data divided by the demultiplexing unit are transmitted from the two line interfaces, and are received from the two line interfaces, respectively. A multi-point conference system comprising: a switching unit that transmits two pieces of received image data to the multiplexing unit. 2. The terminal according to claim 1, wherein each terminal is provided with a delay adjuster for adjusting a delay amount of two pieces of received image data respectively received from two line interfaces and sending the same to a multiplexing unit. Multipoint conference system. 3. Each terminal is provided with an image coder for coding an image and sending it to a demultiplexing unit, and an image decoder for decoding image data from the multiplexing unit.
Or the multipoint conference system according to 2.