KR0151455B1 - Image conference system using a broadband integrated service digital network - Google Patents

Abstract

The present invention relates to a video conferencing system using a broadband integrated telecommunication network for multi-party video conferencing in a broadband integrated service digital network (B-ISDN), comprising: means for receiving a video / audio signal; Means for compressing the video / audio signal; In transmission, the compressed signal is formatted into a first type, the information is partitioned so as to be suitable for the ATM layer, the ATM head information is transmitted to the ATM layer, and the video / audio information is transmitted to suit the type of service to be transmitted and received. First means for establishing a call in two types, outputting a control signal of a predetermined VPI / VCI when setting up a call, and distributing the received data to respective decoders in response to the control signal of the received VPI / VCI; and; In transmission, HEC is created in ATM header to convert into ATM cell.In reception, VPI is determined by receiving the data sent to the received ATM cell, removing ATM header, and determining which display the transmitted data is displayed on. Second means for generating a / VCI control signal; A plurality of decoders connected in parallel to the first means, respectively, for decompressing video / audio data provided in the first type; Multi-party video conferencing is provided by providing control means for providing a signal for control to the first means.

Description

Video Conference System Using Broadband Comprehensive Network

The present invention relates to a system for implementing video conferencing by using a broadband integrated service digital network (BISDN), and more particularly, to a video suitable for implementing video conferencing connected to each other through a broadband integrated communication network. It is about a conference system.

In a conventional video conferencing system using a broadband integrated network, video conferencing can be performed only one-to-one. Therefore, in the related art, when a user conducts a video conference using a broadband integrated communication network, only one-to-one meeting is possible, and thus, there is a problem in that a substantial video conference cannot be obtained at the same time.

Accordingly, an object of the present invention is to provide a video conferencing system using a broadband comprehensive communication network capable of simultaneously realizing multi-party video conferencing using a broadband integrated communication network.

In order to achieve the above object, the present invention generates a user data consisting of video and audio of the user who wants to attend a video conference via a camera and a microphone, respectively, and transmits and receives user data between a plurality of users interconnected through a broadband integrated communication network. A videoconferencing system comprising: an encoder for A / D conversion of the generated user data and compression encoding the converted user data; Reconstruct each received data of the encoded remote multiple users received through the broadband integrated network to the original signal before encoding to generate the video and audio signals for each remote user, and to generate the generated video and audio signals. A plurality of decoders for performing D / A conversion and respectively transmitting the corresponding outputs; Control means for generating a control signal for establishing a plurality of calls corresponding to the number of conference attendees who wish to attend the video conference and a signaling message for call setup; In transmission, the compressed user data is formatted in AAL1 format, the formatted user data is divided, assembled into protocol data unit information by attaching headers and trailers, and generated header information required by each ATM cell. Upon receipt, the header and the trailer of the protocol data unit information from which the ATM cell header information has been removed are extracted to extract the encoded data of the plurality of remote users, and the extracted user data is extracted in response to a selection control signal. First means for communicating to corresponding decoders in the decoder of the first decoder; Combining the assembled protocol data unit information and the generated header information to generate an ATM cell, multiplexing the generated ATM cells to transmit to the broadband integrated network, extracting and analyzing header information of the received ATM cell; Second means for extracting a VPI / VCI signal in header information and providing protocol data unit information from which header information is removed to said first means; Stores respective ID information for the plurality of decoders, decodes and analyzes the extracted VPI / VCI signals provided from the second means, and controls corresponding decoders based on analysis results based on the stored ID information. Decoding means for generating a signal; And analyzing the generated decoder control signal, and generating and providing the selection control signal to the first means according to the analysis result, respectively, and generating and outputting an output enable control signal for operating each corresponding decoder. Provided is a video conferencing system using a broadband integrated communication network comprising decoding arbitration means for providing each decoder.

1 is a block diagram illustrating a multi-party video conference system by connecting a video conference system according to the present invention to a broadband integrated communication network.

2 is a block diagram of a video conferencing system using a broadband integrated communication network according to a preferred embodiment of the present invention.

* Explanation of symbols for main parts of the drawings

102, 202: Camera and microphone 104, 106, 204, 206, 208: Monitor

108, 218: encoder 110, 112, 220, 222, 224: decoder

114, 223: AAL 1st layer 116, 234: AAL 5th layer

118, 236: ATM layer 120, 240: physical layer

130: broadband integrated network 210: A / D converter

212, 214, 216: D / A converter 226: CS sublayer

228 SAR layer 230 ATM header register

232: SAAL layer 235: ATM block

238: VPI / VCI decoder 239: AAL arbiter

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

1 is a block diagram illustrating a multi-party video conferencing system by connecting a video conferencing system according to the present invention to a broadband integrated communication network.

As shown in the figure, a plurality of video conferencing systems 100 are connected to each other via a broadband integrated network 130, and when performing video conferencing, each video conferencing system 100 is connected to such a broadband integrated network 130. Through the video and audio signals required for the conference are transmitted and received between each other.

Here, each video conferencing system 100 includes a camera microphone 102, a monitor 104, 106, an encoder 108, a decoder 110, 112, an ATM adaptation layer (AAL) layer 1, 114, AAL 5 Layer 116, ATM layer 118, and physical layer 120, wherein the camera and microphone 102 capture user (or conference participant) voice while simultaneously capturing (or required) the image of the video conference. In addition, each monitor 104, 106 is for displaying each image (i.e., a remote participant image) transmitted from another video conference system at a remote location.

As is well known, ATM (Asynchronous Transfer Mode) is a special type of packet type message transfer method using Asynchronous Time Division Multiplex (ATDM) as a communication method for implementing a broadband integrated network.

On the other hand, in BISDN, information is transmitted by a continuous flow of packets having a certain size. The packets of fixed size are called ATM cells. More specifically, the ATM cell is a packetized information obtained by dividing a plurality of inputted service information into short-length cells of fixed length and attaching 5 bytes of header information to each cell. Byte (data information 48 + header information 5), each of these ATM cells is multiplexed and transmitted through a transport channel.

In addition, the ATM cell as described above is a connectivity method, and establishes a virtual channel (VP) to deliver service information. When a virtual channel is established, a number (identification number) for connection is given and a connection is established. When released, this number is also released.

Meanwhile, the ATM communication scheme as described above defines a layered protocol reference model for systematic information transfer. The protocol layer includes a physical layer, an ATM layer, and an ATM adaptation later (AAL).

Here, the AAL layer provides user service information of the upper layer into protocol data units, and cuts the protocol data unit into a predetermined size to form a user information section of an ATM cell. It provides functions such as control of network access and information flow, translation of virtual path number and virtual channel number, connection with service access points, multiplexing and demultiplexing of cells, and physical layer. Functions such as generation and confirmation of control bytes and detection of cell boundary points are provided.

On the other hand, each video conferencing system 100 generates a variety of messages necessary for communication with the user information (video, audio, etc.) to be transmitted to the broadband integrated network 130, and also delivers the broadband integrated network 130 It provides a function of decomposing and interpreting various messages and actual information received through each of these functions, which will be described in detail with reference to FIG. 2 showing a detailed block of a video conferencing system.

2 is a block diagram of a video conferencing system using a broadband integrated communication network according to a preferred embodiment of the present invention.

As shown in the drawing, the video conferencing system 100 of the present invention is a means for inputting data necessary for video conferencing, that is, user data (video, audio, etc. of a conference participant) to be transmitted to a remote video conferencing system. Camera and microphone 202, A / D converter 210 and encoder 218, and also as a means of restoring and displaying compressed data for remote users (meeting participants) received via the broadband integrated network. Decoders 220, 222, 224, multiple D / A converters 212, 214, 216, and multiple monitors 204, 206, 208.

In this case, although not shown in the diagram, each monitor may include a speaker for outputting the voice of the attendees of the remote meeting, and each monitor may be configured as a separate monitor, or multiple windows on the multi-screen. It can also be configured.

In addition, the video conferencing system 100 provides functions such as call setup, call release, message generation and translation, and cuts and multiplexes control information and data provided from an input means into an ATM cell and transfers the multiplexed data to the broadband integrated communication network 130. And a plurality of data processing means (ie, 223, 232, 234, 235, and 240) and a controller 242 that provide functions such as disassembling and analyzing ATM cells received through the broadband integrated network 130. do. Here, the AAL 1 layer 223 includes a convergence sublayer (CS) 226, a segmentation and reassembly (SAR) 228, an ATM header register 230, and an AAL arbiter 239. The ATM block 235 also includes an ATM layer 236 and a Virtual Path Identifier / Virtual Channel Identifier (VPI / VCI) decoder 238.

First, when the user initializes the video conferencing system to conduct a video conference, the control unit 242 generates a control signal for setting up a call corresponding to the number of conference attendees who wish to attend the video conference to generate a signaling AAL (SAAL). Layer 232 and AAL 5 layer 234, and SAAL layer 232 and AAL 5 layer 234, the message required for call setup (e.g., setup messages, connection messages, etc.) to the ATM block 235 ) Is transferred to the ATM layer 236. That is, the SAAL layer 232 and the AAL 5 layer 234 perform various functions for delivering signaling messages required to perform functions such as call setup.

In this case, the AAL 1 layer 223 includes a convergence sublayer (CS) 226, a partition and reassembly layer (SAR) 228, an AAL arbiter 239, and an ATM header register 230. The layer (CS) 226 converts the compressed user service information provided from the encoder 218 into protocol data units at the time of transmission (formatted in AAL 1), and includes error processing, sequence number processing, cell loss processing, and insertion. It performs functions such as cell processing, passes CS-protocol data unit information to the partitioning and reassembly layer (SAR) 228, and is provided from the partitioning and reassembly layer (SAR) 228 upon reception. After analyzing the header and trailer of the assembled and recovered CS-protocol data unit, if there is no error, only the user service information is extracted and transmitted to the corresponding decoder among the corresponding plurality of decoders, that is, the selection control signal provided from the AAL arbiter 239. Compression with the corresponding decoder according to User service information (ie, video, audio, etc.).

In addition, the segmentation and reassembly layer (SAR) 228 divides (for example, divides into 47 bits) CS-protocol data unit information provided from the above-described convergence sublayer (CS) 226 at the time of transmission. Later, the header and trailer are reassembled to generate SAR-protocol data unit information and delivered to the ATM layer 236, and upon receipt, the header and trailer of the received SAR-protocol data unit information provided from the ATM layer 236 are received. The data is collected, and the SAR-protocol data unit information is collected, reassembled (combined) into CS-protocol data unit information, and then transferred to the convergence sublayer (CS) 226 described above.

Meanwhile, the AAL arbiter 239 analyzes the decoder selection signal provided from the VPI / VCI decoder 238 which will be described later, and generates a selection control signal based on the analysis result to the convergence sublayer (CS) 226. At the same time, an output enable control signal (dctr1, dctr2 or dctrn) is generated to enable the corresponding decoder. That is, as a result of analyzing the decoder selection signal, when the current input data is data to be output to the decoder 220, a selection control signal for outputting user data information to the decoder 220 is generated to converge sublayer CS. At the same time, the decoder 220 generates a dctr1 control signal to enable the decoder 220.

Thus, upon reception, the remote user's data (i.e., compressed user data) processed by the convergence sublayer (CS) 226 may be restored to the original signal respectively via a corresponding decoder and then displayed on each monitor and speaker. will be.

Here, the ATM header register 230 generates various header information attached to the ATM cell at the time of transmission and provides it to the ATM layer 236.

Next, the ATM layer 236 in the ATM block 235 sets up a call for data transmission and reception with a remote video conferencing system to communicate, that is, sets up a virtual path VP and a virtual channel VC. The virtual path number (VPI) and the virtual channel number (VCI) and the identification number (ID) of the decoder corresponding to the remote conference participant when the VP and VC are set are stored in the VPI / VCI decoder 238. In this case, each time a virtual channel (VC) for service information is established, a connection identification number is assigned, and when the connection is released, the identification number is also released, and the order between ATM cells in a certain virtual channel (VC) is the ATM layer. By the function of 236, signaling information for connection establishment is carried through a separate ATM cell.

The ATM layer 236 also controls user-to-network connections and information flows, translates virtual path numbers and virtual channel numbers to connect with service access points, multiplexing and demultiplexing of cells, for example, at transmission. For example, an ATM cell including header information such as Header Error Control (HEC) and payload information is generated, the generated ATM cell is multiplexed and transmitted to the physical layer 240, and multiplexed upon reception. Demultiplex the ATM cells, extract header information from the demultiplexed ATM cell, and analyze it, and pass the virtual path number (VPI) and virtual channel number (VCI) obtained as a result of the analysis to the VPI / VCI decoder 238. The header information is removed from the received ATM cell, and then cell data (ie, SAR-protocol data unit information) is transmitted to the segmentation and reassembly layer (SAR) 228.

At this time, the VPI / VCI decoder 238 decodes the VPI and VCI information provided from the ATM layer 236 and determines the decoder output of the corresponding received data based on the decoded VPI and VCI signals, that is, decoded. The output decoder is determined based on the pre-stored decoder IDs corresponding to the VPI and VCI signals, and the decoder selection signals idc1, idc, and idcn are generated and transmitted to the AAL arbiter 239 based on the determination result.

Accordingly, according to the control from the AAL arbiter 239, the encoded remote user data (video, audio, etc.) transferred from the convergence sublayer (CS) 226 to each decoder is restored to the original signal, respectively, Each user picture and sound will be output through the corresponding monitor and sprinkler.

Finally, although the detailed illustration in FIG. 2 is omitted, the physical layer 240 is composed of a transmission convergence sublayer and a physical medium sublayer to separate cell rates, generate and confirm header error control bytes, and determine cell boundary points. By performing a detection function or the like, the multiplexed ATM cell delivered from the ATM layer 236 is transmitted through a transport channel, not shown, and the multiplexed ATM cell received through the transport channel is transferred through the ATM layer 236. To pass.

Therefore, the video conferencing system according to the present invention having the above-described configuration transmits its own data (video, audio, etc.) in the video conference to other conference participants at remote locations connected through the broadband integrated network, and located at the remote location. A plurality of different user data (video, audio, etc.) can be reconstructed and displayed by the respective decoder using the assigned decoder ID, respectively, thereby implementing an effective multi-party video conferencing.

As described above, according to the present invention, there is provided a technique for selecting each data provided from a plurality of conference attendees and a number of decoders corresponding to the plurality of conference attendees. Video conferencing can be effectively realized.

Claims (1)

A video conferencing system for generating video and audio user data of a user who wants to attend a video conference via a camera and a microphone, and transmitting and receiving user data between a plurality of users interconnected through a broadband integrated communication network. An encoder for performing A / D conversion on the converted user data and compression-coding the converted user data; Reconstruct each received data of the encoded remote multiple users received through the broadband integrated network to the original signal before encoding to generate the video and audio signals for each remote user, and to generate the generated video and audio signals. A plurality of decoders for performing D / A conversion and respectively delivering the corresponding outputs; Control means for generating a control signal for establishing a plurality of calls corresponding to the number of conference attendees who wish to attend the video conference, and a signaling message for setting up; In transmission, the compressed user data is formatted in AAL 1 format, the formatted user data is divided, assembled into protocol data unit information by attaching headers and trailers, and generated header information required by each ATM cell. Upon reception, the header and the trailer of the protocol data unit information from which the ATM cell header information has been removed are extracted to extract encoded data of the plurality of remote users, and the extracted user data is extracted in response to a selection control signal. First means for communicating to corresponding decoders in the plurality of decoders, respectively; Combining the assembled protocol data unit information with the generated header information to generate an ATM cell, multiplexing the generated ATM cell to transmit to the broadband integrated network, extracting and analyzing the received ATM cell header information; Second means for extracting a VPI / VCI signal in header information and providing protocol data unit information from which header information is removed to said first means; Stores respective ID information for the plurality of decoders, decodes and analyzes the extracted VPI / VCI signals provided from the second means, and controls corresponding decoders based on analysis results based on the stored ID information. Decoding means for generating a signal; And analyzing the generated decoder control signal, and generating and providing the selection control signal to the first means according to the analysis result, respectively, and generating and outputting an output enable control signal for operating each corresponding decoder. Video conferencing system using a broadband integrated communication network consisting of decoding arbitration means provided to each decoder.