On the analysis of the application of video conferencing system and its

Paper Keywords: video conferencing systems, teaching and Learning
Abstract: This paper shows the definition video conferencing systems, composition and classification, based on the analysis of the current video conferencing systems commonly used in network applications model, the last of the video conferencing system in Education teaching and influence.



Video conference system is the way people communicate product and technology integration, along with Computer networks, multimedia technology and the gradual development of communication technology is widely used. Which by means of a dedicated physical device, through the transmission channel, such as LAN, Internet , Intranet, wireless or satellite, between two points or more to establish visual communication of image, voice and data communication, completely breaks through the traditional on-site meeting in geographical limitations, is the CSCW Computer Supported Cooperative Work that one typical of the most basic applications. It allows geographically dispersed users in a copolymer, through images, sounds, text and other means to exchange information, to support people with long-range real-time exchange of information sharing, collaborative learning and work, greatly facilitates the collaboration between members of the real, intuitive communication.

First, the definition video conferencing systems and components
Video Conference System (Video Conferencing System) is a subject to geographical restrictions, based on the established two-way broadband networks, multi-point, real-time video and audio interactive system. Video conference system consists of terminal equipment, transmission channel (communications network) and multi- point control unit.


1. Terminal Equipment
Video conference system terminal equipment is the input and output devices. Including audio / video input / output devices, audio / video encoder / decoder equipment, information processing equipment and multiplexing / decomposition equipment, these devices can achieve the the venue was able to clearly see the scene of other venues, and can discuss issues with each other and share data. It is the role of audio, video, data and signaling and other digital signal processing, respectively, the synthesis of the way or multi-channel digital bit stream, and then convert it to data suitable for network transmission format for transmission and sent to the channel.

2. Communication Network
Communication network is the connection terminals, to enable transmission of audio, video and data transmission media of various general, including cable, fiber optic, microwave and satellite, etc., in the transmission mode, it can be a variety of networks based on existing technology, such as LAN, ISDN, Internet, FDDI / ATM and so on. use it to send events or static image signals, voice signals, data signals and system control signals.

However, due to a different principle and structure of communication networks vary widely, resulting in the deployment of video conferencing systems micro-structure (including end-system connection structure, MCU's configuration program structure, etc.) differences.

3. Multipoint control unit (MCU)
Multipoint control unit (MCU) is a digital processing unit, usually set at the central node in the network, available in multiple locations simultaneously meeting the communication between each other, the role of the equivalent switch. Its main function is realized in the digital domain Meanwhile, multiple audio, video, data signaling and other digital signal mixing and switching. it will come from the meetings of the terminal equipment with data aggregation, and synchronous separation of the image, voice, data, signaling and other signal, the venue again the same types of information are mixed, switch, etc., at last, re-combined into a data stream sent to the corresponding conference. It is like the same TV program director, according to the changing needs of the scene to switch to a different screen.

Second, the type of video conferencing systems and its application
In general, the video conferencing system from the perspective of various different categories. According to the different number of nodes in the meeting can be divided into point to point video conference system and multi-point video conferencing system; its communications network to run the points, and into digital data network (DDN) or other type of private network, LAN / WAN (LAN / WAN)-based and public switched telephone network (PSTN)-type three. from the video conference terminal type of the selected points, in general can be divided desktop and conference room for the type of two categories. The meeting room video conferencing systems for larger meeting with the environmental control equipment in the conference room dedicated to one or more large screen device, the system from the screen, camera, microphone and auxiliary equipment and other components, the configuration is fixed, can provide high-quality video and synchronized audio, but expensive. and desktop video conferencing system is a general-purpose personal Computer in some additional equipment, the integrated use of audio and video, and network communication technology, the use of Computer software to achieve between people in different locations communicate with each other, so their use is much lower cost, is the video conferencing system development.

Video conference system is reflected in the exchange of information accessibility and collaboration, can achieve high efficiency, high-quality internal and external communication and collaboration: So, as long as they need more exchange of information between the industry, the system has a useless, it is the products, information, knowledge, joy and friendship spread to every corner of the world. For example, in the following industries and scenarios, the system is capable of:


Third, the video conferencing system is implemented
Currently, video conferencing way to achieve a 3:
1. Broadcasting System (TV) commonly used in television broadcast video conference system
Need to rent a dedicated satellite channel, transmission mode is one-way transmission, you must hire two to two-way channel. Leased satellite is expensive, the longer the higher the cost. Also need professional and technical personnel and approval procedures, only able for some special units such as the television industry to use.

2. MPEG1, MPEG2 compression format VOD video conference system video transmission
As the transmission need to MPEG1 1. 5M bandwidth, MPEG2 need 3M bandwidth, and the image quality will sharply with the network transmission distance is usually used only for high-speed local network segment, and the bandwidth, only with its own network resources functions such as the bureau can establish a dedicated high-bandwidth-based video conferencing system.

3.ITU (ITU) proposed based on H. 261 / H. 263 video compression formats H. 320 / H. 323 standard video conferencing system
The present stage of technological maturity and market share dominance is based on the true H. 320 / H. 323 standard video conferencing systems. H. 323 is the P-based approach to transmission work video conference; H. 320 IP is outside the Other methods for transmission network video conferencing, there is usually work SDN, DDN, Frame Relay, ATM and so on.

We need what kind of video conferencing system? First, moderate price, to bear for most industrial users and the use of video conferencing systems is the real meaning of the video conferencing system. Followed by the technical indicators, to achieve high quality images / voice transmission, but the bandwidth the lower the better; two-way interaction, the need to support the work start time (low power); simple operation, without professional knowledge, operational errors and no damage; should be no operating system, virus attacks are not afraid, not afraid of sudden power, should have a variety of network interfaces (ISDN, Public P, V.35, E1/T1, etc.), adaptive function, fully intelligent, reliable, low repair rate. reposted elsewhere in the Research Papers Download http : / / www.hi138.com four video conferencing systems in Education
Full use of network video conference system, information transmission vivid, the establishment of audio-based multimedia technologies, interactive channels of dialogue, is the value of existing network platform for a rise. Video conferencing system in the main application field of Education in distance Education , local Education offices conferencing, distance teacher training, distance education, campus. at all levels of the education authorities and schools, through the video conference system, a variety of regular or random work conference convened to carry out various forms of training and teaching, distance learning can also save a lot of resources and costs, because a teacher can teach to the thousands of people, and a good curriculum can be for weeks, months, in different regions. As experts and senior limited number of teachers, teaching techniques that allow them to play a greater role in addressing the school division participants will be able to accept the best teachers to teach problem. distance learning can make teaching across a large geographical area, which for the remote areas of China education will be of great value.

Video conferencing system provides not only smooth voice, clear video images, while providing document sharing, WEB sharing, collaborative browsing, whiteboard, desktop sharing and remote collaboration, data processing, using the Internet to students through the different parts of the audio and video real-time interactive communication, such as exposure to being in the same classroom.

1. Video Broadcasting
Can broadcast video to students, for students to class, both heard and have seen their faces.

2. Multiplayer mix
Using the industry's leading multi-channel mixing technology to support 4 to 16 mix, to achieve audio and video interaction. Can be realized without delay of audio and video transmission, to ensure synchronization of audio and video.


3. Desktop sharing and remote control
Using desktop sharing feature, you can display your Computer screen in real time to remote users, allowing them to see their every move. By remote control, you can let your machine directly to the remote operation, the same as operating the local machine convenient.

4. Whiteboard
Students can freely draw on the whiteboard, writing any visual information to facilitate the exchange of all the members.

5,. Document sharing, Web sharing and co-browsing
Through document sharing and Web sharing, members can discuss all of the Office, PDF, AutoCAD, PowerPoint and other forms of documentation; co-browsing so that all members can simultaneously browse the Web, to achieve a more direct communication.

6. Written communication and text whisper
All members can take advantage of a common language platform for effective exchange and communication of text; text private chat function provides a point between members of the private space, between the two members of the private chat function through the text between the two communication.

7. File Transfer
Participants can transfer files at the same time meeting the members to a conference or transfer files to all members of the Conference, which send and receive real-time remote file online.

8. Audio and video recording capabilities
Real-time audio and video record your own local or remote user audio and video. You can use the popular video players such as Media Player, to play; use of common video editing software, such as Movie Maker for editing. Capable of recording the meeting, the meeting information is completely recorded, more than any client of a sub-venue or a synchronous simultaneous recording, video display, including the meeting notes documents, graphics and label the contents of such exchanges.

Fifth, video conferencing system of distance education
1. Helping to train and stimulate the motivation of learners
In distance learning, learners can maintain a high degree of attention and motivation, whether positive and be prepared to take the initiative to adjust their own learning pace, ability to monitor their own learning, testing, revision and evaluation, networked learning guarantee. through video conferencing system to a certain extent, ease the distance education students, life and play down the role of teachers due to separation and weakening of teaching management, and to overcome the learner access to online resources produced by the "information Trek" and "information overload "phenomenon.

2. There will help guide and strengthen the learner's self-monitoring
Traditional education, learners used to learn under the supervision of teachers, resulting in a lack of learner autonomy, independence, lack of self-monitoring of learning ability, and in such an open network, autonomous learning environment for learners Self-monitoring requirements are greatly enhanced the need of external control of the learner step by step process of learning from the self-control to change the learning process, this transformation entirely on students to "natural" form is unrealistic, and video conferencing systems provide for this change an intermediate link, making the experience of teachers, learners complete control - part of the monitoring - self-monitoring of the change process, and gradually adapt to distance learning.

3. To strengthen the emotional exchanges between students and teachers to improve learning initiative
Distance education to today's Internet-based learning model age students because of its quasi-state separation, mainly limited to verbal communication, exchange of knowledge-based level, emotional communication is relatively scarce. And have a real, efficient, real-time characteristics of video conferencing systems can solve this problem to some extent, real-time interaction information including text, sound, images, face to face to achieve a similar effect. In this way, learners in distance learning can be immediate help, in real time observed their progress and lack of timely adjustment of learning required, greatly enhances the learning initiative. the traditional classroom [that can guide teachers to the living knowledge of Enlightenment desire the image of cultural groups of learners, and learners can trigger groups perception of knowledge and cultural self image of teachers in distance education through video conferencing systems can be achieved.

VI Conclusion
The purpose of the development of modern communications technology is to meet each person at any time, anywhere information access and to express a variety of requirements. Although there are video conference technical problems and limitations, high cost, not to universal stage. But with the video conferencing technology and other new technologies such as the combination of virtual reality technology, the base of a distance education conference in the video will be more perfect, which undoubtedly lead to even broader distance learning development, to the role of distance education and bring tremendous to far-reaching impact. Links http://www.hi138.com Research Papers Download