KR0182983B1 - Method of transmitting a data in video conferencing by ring type connection in an integrated service digital network - Google Patents

Abstract

The present invention relates to a data transmission method for video conferencing in a general information communication network. In particular, a data transmission direction is transmitted in two directions, and a ring type connection is used to transmit a 64 Kbps channel by transmitting in a different direction for audio and video. The present invention relates to a data transmission method in a video conference.

Description

Data transmission method for video conference by ring type connection in general information communication network

1 is an overall system diagram of a color video telephone according to the present invention.

2 is a circuit diagram showing an example of a conventional ISDN network connection.

3 is a concrete circuit diagram of FIG.

4 is a diagram showing a conventional network connection example.

5 is a diagram showing a conventional 2B channel allocation state.

6 is a diagram showing an example of a network connection according to the present invention.

7 is a diagram illustrating a 2B channel allocation state according to the present invention.

8 is a flow chart according to the present invention.

The present invention relates to a data transmission method for video conferencing in a general information communication network. In particular, the present invention relates to a data transmission direction in two directions, and a ring type for transmitting 64 Kbps channels in different directions for audio and video. The present invention relates to a data transmission method for video conferencing by connection.

1 is an overall system diagram of a color video telephone according to the present invention, wherein the input unit 100 acquires color signals R, G, B or Y, RY, BY from the camera 105, and this signal is obtained. Is subjected to A / D conversion to obtain a digital signal, which is then passed to the A / D prefilter 106. This is then formatted by the image formatter 107 as Common Intermediate Format (CIF) or QCIF (Quarter CIF).

Referring to the coding and decoding unit 200 that satisfies the CCITT Recommendation H.261, a block matching algorithm for finding motion information in an image and a source coder 202 for transforming a discrete cosine transform (DCT) for transforming an image and A quantizer 204 for quantizing the data converted into DCT by the source coder 202, and a Hoffman coder 206 for compressing the data quantized by the quantizer 204 by Huffman coding. And the BCH coder 210 for channel coding by adjusting the amount of data by sensing the state of the channel and stacking the data in the memory 208 corresponds to a transmission image codec. The coding / decoding control unit 201 that adjusts the amount of data from the state of the channel may, for example, reduce the amount of data and increase the number of channels by increasing the coefficient of the quantizer when the data is not transmitted on the channel because the data is larger than the reference transmission rate. If empty, the coefficient of the quantizer is lowered to generate a large amount of data and accumulate in the memory 208.

On the other hand, when the picture codec for reception is explained, the picture data input in the opposite direction to the transmitting side is stored in the memory 214 via the BCH decoder 212 which is a channel decoder. This data is decoded by the Hoffman decoder 216. The decoded data is inversely quantized with respect to the quantization by the inverse quantizer 218, and then the IDCT and the BMA are converted into original color signals according to the operation of the source decoder 220.

The network connection circuit 300 generates voices as 8-bit PCM data, voice codecs for generating DTMF signals and various rings and tones, and MUX / DEMUX for processing voice data and video data according to CCITT Recommendation H.221. It has a channel interface that connects to the channels of an integrated telecommunication network.

The output unit 101 post-filters the inversely converted data by the D / A post filter 103 and outputs the data to the monitor 104 after the D / A conversion.

FIG. 2 is a diagram illustrating the network connection circuit 300 of FIG. 1, and FIG. 3 is an embodiment diagram of the network connection unit 400 of FIG. 2. Referring to FIG. 2, the MPU 302 is a color video. It provides total control of the phone's functions, provides clock frequency, address and data in the system signal flow, and outputs various control signals.

The memory unit 306 is used for file storage of software for system operation.

In addition, the OPE unit 304 is a portion in which a liquid crystal display (LCD) and a keymatrix are embedded.

Referring to FIG. 3 to describe the network connection unit 400 in detail, the multi- and demultiplexer sections 310 communicate with 8-bit voice PCM data of the voice codec unit 320 and lines A and B. FIG. The data is multiplexed and demultiplexed and output to the ISAC 330.

The multi and demultiplexer 310 is preferably configured to comply with CCITT Recommendation H.221.

The ISAC 330 controls the D channel, which is a signal channel of the ISDN, and performs line message such as Alternate Mark Inversion (AMI) coding and primitive message exchange with Layer 2 of Open System Interconnect (OSI). do.

In addition, the line coded frame data is communicated with the channel interface unit 340 of the ISDN interfaced to the actual switching network and the HDLC format configuration required for data communication of the B channel, which is the data channel with the multi- and demultiplexer unit 310.

In addition, the channel interface unit 340 converts the voice received through the microphone into 8-bit PCM data and outputs it through the output terminal (SIF), the 8-bit PCM of the output of the multi and demultiplexer 310 After receiving the data through the output terminal (SIF) and converts the original voice and outputs to the speaker.

The voice codec unit 320 also generates necessary dual toml multic frequency (DTMF), various rings, and tones.

In CCITT, Layer 1 is composed of physical lines, so the ISAC 330 is responsible for controlling the D channel of Layer 1, Layer 2, and Layer 3, and provides the configuration of the HDLC format of Layer 2 do.

The ISAC 330 receives the AMI coded signal inputted through the receiver terminal SR2-SR1 of the channel interface unit 340, and transmits the AMI coded signal through the transmitter terminal SX2-SX1 to perform actual physical. Make a path.

Therefore, after the layer 1 is set, the D channel is set by message exchange of each signal bit through the D channel, which is a signal channel, and after the D channel is set, the D channel is entered into arbitration of the B channel through which data is actually exchanged between terminals.

Mediation of the B channel is performed through the multi and demultiplexer 310.

In the embodiment of the present invention, two multi and demultiplexers 311 and 312 are used, one assigning image data to a B1 or B2 channel, and the other assigning voice data to a B1 or B2 channel, according to CCITT Recommendation H.221. Followed multi and demultiplexing.

Data transmission and reception between the multi and demultiplexer 310 and the ISAC 330 is performed by a ping-pong method through one data line, and the ISAC 330 is the multi and demultiplexer. The framer (FSC) and the data clock (DCLK) are provided to the lexer 310.

When two video phones described in FIGS. 1-3 are connected to each other in a ring type as shown in FIG. 4 to implement video conferencing through an ISDN network, two video phones of different BRI2B channels are provided. By connecting only one channel to each other. However, as shown in Fig. 4, after the connection is established, a certain data transmission direction is determined, and audio (A) and video (V) data are transmitted only in this direction. The generated data is added to the next video telephone terminal. In this case, all terminals connected in a ring type can share data with each other, and can use this to implement audio mixing and video separation.

However, conventionally, as shown in Figs. 3 and 4, audio (A) and video (V) data are put together in one channel, that is, audio and video are sent in a channel of 64 Kbps. There is a problem that can not use efficiently the transmission capacity of the transmission path.

Accordingly, an object of the present invention is to provide a method and a circuit in which data is transmitted in two directions, audio data in one direction and video data in the other direction so that audio and video data can be used in a channel of 64 Kbps. .

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

6 is a diagram illustrating a network configuration and connection example according to the present invention, starting from terminal A 101 and connecting to terminal B 102, terminal C 103, and terminal D 104 in that order. FIG. 7 illustrates an example in which a connection is terminated from the terminal A 101 to FIG. 7. FIG. 7 is an exemplary diagram of a 2B channel allocation state according to the present invention, and reference numerals 7a and 7b denote a terminal B 102 from the terminal A 101. ) Shows an example in which transmission is video (V: Video) and reception is audio (A: Audio) data through the B1 channel, and (7c, 7d) is the terminal D (at terminal A 101). 104) is configured to transmit audio (A) and video (V) data through the B2 channel.

8 is a flowchart of a call processing procedure according to the present invention, which comprises a first step of completing a connection by an ISDN call processing procedure according to a B channel number from a call connection message and a calling party, and the connection is ringed in the first step. If it is not type, if it is returned and if it is a ring type connection, the second process of confirming whether there is an initial call connection by assigning a predefined use to the connected channel is started; When the call is not connected, the third process starts the call connection procedure on another B channel after checking another terminal in the terminal list, and completes the connection by the ISDN call processing procedure on the B channel in the third process The fourth step of assigning a predefined use to the completed channel to put the conference on standby.

Therefore, a specific embodiment of the present invention will be described in detail with reference to FIGS. 1, 3, and 8. First, in FIG. 6, the ISDN network 600 is connected to the terminal A 101 to the terminal B 102. If you want to connect through the control of the MPU 302 of the network connection circuit 300 through the MUX / DMUX 310 and ISAC 330 to allocate one B channel, and connected through the channel interface unit 440 do. At this time, if it is confirmed whether the ring type or ring type connection is confirmed according to the B channel number, the calling party number in the process (8b) through the call message of (8a), the terminal connected in the process (8e) List is defined and assigned in order, and in step 8f, the MPU 302 checks whether the first call connection is started. Here you have a conference call. That is, each terminal 401-404 of FIG. 4 communicates by catching a transmission / reception channel through operations of the MPU 302, the ISAC 330, and the MUX / DMUX 310 as described above. As described above, if one channel is connected in the terminal B 102, the MPU 302 checks whether the connection is a ring-type connection procedure (8d), and then moves the other terminal to the next terminal located in the terminal list. Start connection to channel B. In this way, the terminal D 104 confirms that it is the end of its list, and performs a connection to the terminal A 101 located first, and the terminal A 101 disconnects from the terminal of the list that was originally sent. If it tries, it ends the ring-type connection process and starts the meeting. At this time, there should be predefined rules in using the channel. As an example, the channel started to be connected from the other side is used for video (V) transmission and audio (A) reception. In this way, the audio (A) and the video (V) is transmitted in a different direction in a different direction, it is possible to share the data of all terminals, and obtain a channel assignment as shown in FIG.

However, when the call connection is not started for the first time in the terminal in step (8f) (8g), after checking the next terminal in the terminal list and starting the call connection procedure to another B channel, the ISDN call in step (8h) The connection is completed by the processing procedure, and a predetermined use is allocated to the connected channel in step (8i) and then waited.

As described above, by connecting to the BRI of the ISDN network in the form of a ring, it is possible to maximize the transmission capacity when implementing video conferencing and the like, there is an advantage that can realize high-quality video transmission and the like.

Claims (3)

A data transmission method in a general information communication network, comprising: a first process of completing a connection by an ISDN call processing procedure according to a B channel number and a calling party from a call connection message of the general information communication network; If it is not this ring type, it is returned and if it is a ring type connection, the second process of confirming whether there is an initial call connection by assigning a predefined use to the connected channel is started, and the conference starts when the first call connection is started in the second process. And if the first call is not connected, the third process starts the call connection procedure on another B channel after checking the other terminal in the terminal list, and completes the connection by the ISDN call processing procedure on the B channel. And a fourth step of assigning a predefined use to the completed channel to put the conference on standby. Data transmission method during a videoconference. The transmission method of claim 1, wherein the audio (A) transmission channel is divided into an audio channel and a data channel during data transmission. In the ISDN data transmission method, the channel assignment is asymmetrically assigned when implementing video conferencing by connecting to the ISDN BRI network in a ring type.