KR19980027902A - Video Conference System Using Wireless LAN Card - Google Patents

Abstract

The present invention relates to a video conferencing system using a wireless LAN card capable of wireless multi-party video conferencing by incorporating a wireless LAN card into a video conferencing system. The present invention contemplates multiplexing by compressing video and audio data for transmission. A moving picture encoder unit for outputting a signal; A multiplexer / demultiplexer for receiving and multiplexing the multiplexed signal to output transmission data or for demultiplexing the received data to output a distributed signal; By converting the transmission data into the WLAN data format, the embedded processor outputs the data to the system bus so that the embedded processor can interrupt the WLAN controller and take the converted transmission data, or the compressed image data received through the system bus can be transmitted through the processor. A system controller for outputting received data and a control signal; A wireless LAN unit which receives transmission data and control signals from a system bus and transmits transmission data via a built-in modem, or receives received compressed image data; A data overlayer for outputting a monitor output signal for displaying an image; It is composed of a moving picture decoder for decompressing the data outputs a video output signal and an audio output signal, the effect of the present invention is to enhance the data transmission efficiency by compressing and extending the video / audio signal using a video decoder and encoder, respectively, Including a LAN system can transmit and receive high frequencies to extend the transmission distance.

Description

Video Conference System Using Wireless LAN Card

The present invention relates to a video conferencing system using a wireless LAN card, and more particularly, to a video conferencing system using a wireless LAN card that enables wireless, short-range, long-range, and multi-party video conferencing by integrating a wireless LAN card with a video conferencing system. will be.

Telecom service mainly used for the transmission of voices centered on telephones, but the proportion of non-speech communication services that transfer data and images from computers is rapidly increasing. Also, due to the development of integrated circuit technology, terminal devices are inexpensive. As a result of being able to be supplied in the form of a mobile phone, the advancement of a communication line, and the like, still picture terminals such as facsimile and videotex, and moving picture terminal devices such as a television conference have been rapidly spread.

Commonly serviced video communication systems include facsimile, videotex, telewriting, and the like, and these are mainly image transmission services using a telephone line, such as performance of a communication line, price of a terminal, required response time, and the like. In view of limitations, devices and systems with various additional functions are commercially available.

With the development of personal computers, personal computers not only deal with characters, but also images, and the role of personal computers as terminals of video communication is increasing.

With the high performance and low cost of image input devices such as image scanners, recording devices such as integrated circuits and optical disks, and high-precision displays, image communication is rapidly accepted in the world of universal data communication. As a device and a data communication terminal, the exact difference between personal computers is disappearing.

On the other hand, a new communication service has been implemented such as the start of a service of a television conference system for transmitting a moving picture using a communication line. It is difficult to reliably reproduce facial expressions and gestures on the back. In other words, if the image is reproduced to some extent, it is impossible in the current telephone line, and a service is required on a special line to reproduce the moving image.

Therefore, since the line cost is high in a line for transmitting a television image, the introduction of high efficiency encoding technology has led to the practical use in various systems due to the saving of the line, the high performance and the low cost of the terminal apparatus, and the like.

Conventional video conferencing system is generally implemented by using telephone line modem or general communication network by using wired network, but meeting video by wireless in the premises is realized due to problems such as transmission speed and transmission distance. It wasn't.

A conventional telephone line modem using a conventional telephone line transmits data at a transmission speed, that is, at a speed of about 28.8 Kbps, so that an image almost close to a still image can be transmitted. In such a case, a time delay occurred in the image data received at the receiving side, and the screen sent from the transmitting side could be seen by the receiving side a few seconds later. In addition, although the transmitting side compresses the image and sends it, due to the problem of transmission speed, the image seen on the receiving side is mostly incomplete in the middle of the image.

In addition, even in a video conferencing system using a high speed transmission network, each system is networked over a telephone line. Therefore, when data of a large video conferencing data is transmitted, a heavy load is placed on the network. There is a problem to drop.

An object of the present invention for solving the above problems is to use a wireless LAN card in place of the telephone line modem used in the conventional video conferencing system to improve the transmission speed and to reduce the load on the network, short-range, long-distance, multi-party video conferencing It is to provide a video conference system using a wireless LAN card.

1 is a block diagram of a video conferencing system using a wireless LAN card according to an embodiment of the present invention.

2 is a configuration diagram of a WLAN card.

As a means for achieving the above object, the configuration of the present invention,

A moving picture encoder unit for receiving picture and audio data for transmission, compressing the data, and outputting a multiplexed signal;

A multiplexer / demultiplexer configured to receive and multiplex the multiplexed signal to output transmission data, or to demultiplex the received data for reception and output a distributed signal;

Converts the transmission data received from the multiplexer / demultiplexer into a wireless LAN data format and outputs transmission data and control signals to a system bus so that an embedded processor interrupts the wireless LAN controller to take the converted transmission data; Or a system controller which outputs the received data and the control signal through the processor and the bus controller to the compressed image data received through the system bus for reception;

Receives transmission data and control signals from the system bus, converts them into a wireless LAN packet format according to a communication protocol, and transmits transmission data through a built-in modem through a wireless antenna or received data that is compressed image data received through the wireless antenna. Wireless LAN unit for receiving;

A data overlayer for receiving the received data, the control signal or the video output signal from the system controller and outputting a monitor output signal for displaying an image;

And a video decoder unit for receiving a video input signal, a distributed signal output from the multiplexer / demultiplexer, and receiving data, decompressing the data and outputting a video output signal and an audio output signal.

With reference to the accompanying Figure 1, the configuration of a video conferencing system using a wireless LAN card according to an embodiment of the present invention,

Receives data of an image made from a digital camera or a digital camcorder, and transmits a video / audio signal and an audio-in signal for transmission and monitor output of the image. And an input unit 90 for converting and outputting a video input signal Video-In.

A MPEG encoder 60 which receives image and audio data which is the video / audio transmission signal Video-In2, compresses the data, and outputs a multiplexed signal Mulx and first memory data M1. )Wow;

The first memory data M1 has a built-in memory, and receives and multiplexes the multiplexed signal Mulx for transmission and outputs the data Data2, or demultiplexes the received data to divide the signal. A multiplexer / demultiplexer (Mux / Demux) 30 for outputting Demultx);

It is composed of a built-in processor, a bus controller, a memory and a buffer, and converts the data Data2 received from the multiplexer / demultiplexer 30 into a wireless LAN data format and temporarily stores the data in the buffer for transmission. Outputs the data Data1 and the control signal Control1 to the system bus so as to interrupt the controller and take the data on the buffer, or the compressed image data received through the system bus to receive the processor And a system controller 10 for temporarily storing the data Data2 and the control signal Control2 after temporarily storing them in a buffer through the bus controller;

Receives data (Data4), control signal (Control4) and address signal (Addr) from the system bus and converts them into a wireless LAN packet format according to the communication protocol, and transmits and receives signals (In / Out) through a wireless antenna through an embedded modem. A wireless LAN unit 20 for transmitting or receiving a transmission / reception signal which is compressed image data received through the wireless antenna;

In order to receive the data Data3 and the control signal Control3 from the system control unit 10 and the video output signal Video-Out from the video decoder unit 70, a color (RGB Color) digital / analog is displayed to display an image. A data overlayer 40 for outputting a monitor output signal (Moni-Out) via a converter;

Receives a video input signal (Video-In) output from the input unit 90, a distribution signal Demultx and the second memory data M2 output from the multiplexer / demultiplexer 30, and decompresses the data. A video decoder (MPEG Decorder) 70 for outputting a video output signal (Video-Out) and an audio output signal (Audio-Out);

A video output unit (50) for receiving the monitor output signal (Moni-Out) and displaying it on a monitor such as a television;

The audio output signal (Audio-Out) output from the video decoder unit 70 is converted into an analog signal through a digital / analog converter, or the audio input signal (Audio-In) output from the input unit 90 is output. The audio output unit 80 directly outputs the audio output terminal or the speaker.

By the above configuration, the operation of the video conferencing system using the wireless LAN card according to the embodiment of the present invention is as follows.

Referring to FIG. 1, the input unit 90 receives data of an image made from a digital camera or a digital camcorder, and transmits a video / audio transmission signal for transmitting the image and outputting the monitor. -Audio, an audio input signal (Audio-In) and a video input signal (Video-In) are converted and output.

The MPEG encoder 60 receives image and audio data which is the video / audio transmission signal, compresses the data, and decompresses the multiplex signal Multx and the first memory data M1. The multiplexer / demultiplexer (Mux / Demux) 30 has a built-in memory through which the first memory data M1 is input and output, and receives and multiplexes the multiplexed signal Mulx for transmission. ) Or by demultiplexing the received data to output a distribution signal Demultx.

The system controller 10 includes an internal processor, a bus controller, a memory, and a buffer. The system controller 10 converts the data Data2 received from the multiplexer / demultiplexer 30 into a WLAN data format and temporarily stores the data in the buffer. And outputs the data Data1 and the control signal Control1 to the system bus so that the processor interrupts the WLAN controller and takes the data on the buffer, or receives them through the system bus for reception. The compressed image data is temporarily stored in a buffer through the processor and the bus controller, and then the data Data2 and the control signal Control2 are output. Herein, the system bus refers to an ISA bus, a PCI bus, a PCMCIA bus, or the like.

Next, the wireless LAN unit 20 receives the data Data4, the control signal Control4, and the address signal Addr from the system bus, converts the data into a wireless LAN packet format according to a communication protocol, and converts the wireless antenna through an embedded modem. Transmit and receive signals (In / Out) through, or receive and transmit signals that are compressed image data received through the wireless antenna.

Herein, the operation of the wireless LAN unit 20, that is, the general wireless LAN card is as follows with reference to FIG. 2.

The MAC controller 21 receives data Data4, an address signal Addr, and a control signal Control4 from the system bus, and receives a clock signal OSC to synchronize the signals. There is no high level signal component in the Radio Frequency area, so it is converted into data of the MAC method suitable for frequency modulation. In this case, the MAC (Multiplied Analog Component (MAC)) time-base compresses the luminance signal and the chrominance signal, which are analog components of the video signal, to 2/3 and 1/3, respectively, to time-sequence the digital audio signal together with the digital voice signal within one horizontal scanning line period. It refers to a communication method of receiving and broadcasting.

The static RAM (SRAM) 22 stores the data converted by the MAC controller 21, and the flash memory 23 stores the address converted by the MAC controller 21.

The synthesizer 27 receives the control signal X1 of the MAC controller 21 and outputs a precise variable frequency by frequency synthesis using a crystal oscillator.

The modem 24 includes a baseband processor and a local oscillator. The modem 24 receives a control signal and data from the MAC controller 21 and outputs a variable frequency (OS2) of the synthesizer 27. ) Is used as a clock, the data is modulated and demodulated, and an antenna selection signal ANTSEL is output. A first band filter (BPF) 25 is passed to pass only alternating current of a constant frequency of the output of the modem 24.

An RF / IF converter 25 uses the variable frequency OS1 of the synthesizer 27 as a clock, receives the output of the first band filter 25 for transmission, To convert, or to convert the high frequency to the intermediate frequency for reception, and passes through the second band filter (BPF) 26 to pass only the alternating current of the intermediate frequency that is the output of the high frequency / intermediate frequency converter 24.

The first selecting means ST1 selects the first antenna ANT1 or the second antenna ANT2 based on the antenna selection signal ANTSEL received from the processor of the modem 24, and the third band filter BPF. 31 passes only alternating current of a predetermined frequency component of the data received by the antenna selected by the first selecting means ST1, and the second selecting means ST2 passes the output of the third band filter 31. Receive and select whether to input to the high frequency / intermediate frequency converter 28, or transmit the output of the high frequency / intermediate frequency converter 28.

In FIG. 1, a data overlayer 40 receives data Data3, a control signal Control3, and a video output signal Video-Out from the video decoder unit 70 from the system controller 10. In order to display an image, a monitor output signal (Moni-Out) is output through a color digital / analog converter.

The MPEG decoder 70 may include a video input signal Video-In output from the input unit 90, a split signal Demultx and a second memory data output from the multiplexer / demultiplexer 30. M2) is received, and the data is decompressed to output a video output signal (Video-Out) and an audio output signal (Audio-Out).

The video output unit 50 receives the monitor output signal (Moni-Out) and displays it on a monitor such as a television, and the audio output unit 80 outputs the audio output signal (Audio-) output from the video decoder unit 70. Out is converted into an analog signal through a digital / analog converter or outputted, or an audio input signal (Audio-In) output from the input unit 90 is directly output through an audio output terminal or a speaker.

In other words, the image data coming from the receiving end is processed as follows.

Compressed image data entered through the wireless LAN unit 20 is temporarily stored in a buffer memory through a processor and a bus controller built in the system control unit 10. Thereafter, the processor converts the audio decoder and the moving picture decoder unit 70 for data extension into the desired data format. Then, the video decoder unit 70 decompresses the data, converts it into an analog signal via the data overlay unit 40, and then converts the video output unit 50 into a desired signal in a computer monitor or in a television format. The signal is converted into a signal and displayed on a monitor or television, and the audio signal component of the received data is converted into an analog signal after passing through a processor through a digital-to-analog converter and output directly to an audio output terminal or a speaker.

On the contrary, the sequence for transmitting video conferencing data made by the transmitting end to the other receiving end is as follows.

The video and audio data of the input unit 90 produced by the videoconferencing camera passes through the moving image encoder unit 60 for data compression, and then is converted into a multiplex signal (Multx) by the multiplexer / demultiplexer 30, and a processor and a bus controller. Is sent to the built-in system control unit 10. At this time, the processor converts the transmission data, which is the multiplex signal (Multx), into a data format desired by the wireless LAN unit 20 and temporarily stores it in a buffer. The processor then interrupts the Mac controller 21 of the wireless LAN unit 20 and requests the data on the buffer to be taken. Then, the MAC controller 21 reads this data, converts it into a wireless LAN packet format determined by the communication protocol, passes through the modem 24, converts the radio frequency, and then transmits the data to the outside through the wireless LAN antenna of the transmitter. do.

As a result, the features of the present invention are as follows.

First, a transmission speed problem occurs in a telephone line modem using a general telephone line. That is, the image data of the data sent from the transmitting side can be seen with a delay of several seconds when viewed from the receiving side. By using a LAN card, the problem of time delay of image data having a large data size can be solved.

Also, in order to improve the data transmission efficiency, data compression algorithms such as MPEG, MPEG II, and MPEG IV can be used to solve the problems caused by the data transmission speed.

Second, even in the conventional videoconferencing system using a fast network, each system is networked by telephone line. Therefore, when videoconferencing data with a large data size is transmitted, a heavy load is placed on the network. By using a wireless LAN system to solve this falling problem, data transmission is possible not only in a general network but also in a wireless network itself, so that video conferencing is not heavily loaded.

Third, conventional videoconferencing cannot be performed at the same time because a telephone line modem using a telephone line must allocate a separate telephone line or use its own telephone line when the videoconferencing system is mainly connected by a wired telephone line. However, the present invention can be freely multi-party video conferencing even near or remote offices, schools, factories, buildings, department stores, etc. by replacing the telephone line with a high-frequency wireless.

Accordingly, the present invention is expected to be an important technology for high-speed wireless data communication, which is expected to emerge in the future of wireless data communication, in particular, a personal communication system (PCS).

The effect of the present invention is to enhance the data transmission efficiency by compressing and extending the video / audio signals using a moving picture decoder and encoder, respectively, and to carry out multi-party video conferencing by including a wireless LAN system to transmit and receive high frequency to extend the transmission distance. A video conference system using a wireless LAN card can be provided.

Claims (10)

In a wireless video conferencing system, A moving picture encoder unit for receiving picture and audio data for transmission, compressing the data, and outputting a multiplexed signal; A multiplexer / demultiplexer configured to receive and multiplex the multiplexed signal to output transmission data, or to demultiplex the received data for reception and output a distributed signal; Converts the transmission data received from the multiplexer / demultiplexer into a wireless LAN data format and outputs transmission data and control signals to a system bus so that an embedded processor interrupts the wireless LAN controller to take the converted transmission data; Or a system controller which outputs the received data and the control signal through the processor and the bus controller to the compressed image data received through the system bus for reception; Receives transmission data and control signals from the system bus, converts them into a wireless LAN packet format according to a communication protocol, and transmits transmission data through a built-in modem through a wireless antenna or received data that is compressed image data received through the wireless antenna. Wireless LAN unit for receiving; A data overlayer for receiving the received data, the control signal or the video output signal from the system controller and outputting a monitor output signal for displaying an image; Using a wireless LAN card characterized in that it comprises a moving picture decoder for receiving a video input signal, the distribution signal and the received data output from the multiplexer / demultiplexer, decompresses the data to output a video output signal and an audio output signal Video conferencing system. The image and audio data received by the encoder unit, A video conferencing system using a wireless LAN card, which is input from a digital still camera. The image and audio data received by the encoder unit, A video conferencing system using a wireless LAN card, which is input from a digital camcorder. The method according to claim 1, wherein the moving picture, A video conferencing system using a wireless LAN card, characterized in that the MPEG system video. The method according to claim 1, The system bus, A video conferencing system using a wireless LAN card, which is an I / S bus. The method according to claim 1, The system bus, A video conference system using a wireless LAN card, characterized by a PC-I bus. The method according to claim 1, The system bus, A video conferencing system using a wireless LAN card, characterized in that the PCM IC bus. The method according to claim 1, The system control unit, And a buffer for temporarily storing transmission and reception data input and output to and from the system bus. The monitor output signal of the data overlay unit, A video conferencing system using a wireless LAN card, characterized by being converted into an analog signal by a color digital / analog converter. The audio output signal of the moving picture decoder unit, A video conferencing system using a wireless LAN card, characterized by being converted into an analog signal by a digital to analog converter.