Conference TV Network Technology Comparison and Analysis

With the information and communication network in China's sustained and rapid development, the current level of our communication has greatly improved the exchange of information for businesses and industries provide a reliable guarantee. In many communication services, meeting more and more TV shows good momentum of development. Video Conference is a benefit Electricity As the technology and equipment, through a communications network meetings multimedia communications. When the video conference held, in two or more different locations of the participants, not only can hear each other's voices, and can see each other's image, while the other room to see a scene and displayed at the meeting physical, pictures, forms, documents, etc., "shortened" the distance between the participants and enhance the atmosphere of the meeting, so we like to participate in the meeting in one place, significantly enhancing efficiency. 

Our public meetings through public meetings television business is the backbone network television achieved. Backbone network from the public meetings television conference terminal equipment (including codecs), Digital Channel ( Cable , Satellite), multi-point control device (MCU) form. Thus, the meeting venue and communications television system by the transmission channel composition. Video conference system is usually divided into the main hall of the venue and the sub-venues, the main venue for the conference system's control center, the main control device, image or sound distribution and switching equipment are configured in the main venue. Video conference system of communication commonly used fiber optic cable transmission channel (known as ground-conference system), satellite (known as satellite video conference system) and cable and satellite channels and use (known as hybrid video conference system). Its main role is to be the main venue for the live video signals, voice signals and the user's data signal acquisition, compression, multiplexing is sent to channel. Meanwhile, the channel received from the conference television signals to demultiplex, video and audio decoding, restore the venue of the video component, audio signals and data signals. 

Most current broadband intelligent network, IP technology, ATM network video conferencing capabilities, the following three areas are discussed in this narrative. Intelligent network-based broadband network in the two programs In the broadband intelligent network TV, there are two options to achieve the meeting: Add-on Type TV and Meet-me Conference Type Conference TV. Add-on type session, requested the meeting coordinator television (CFC) to join, CFC by a participant to act as. CFC has the following privileges: the list of participants for input; responsible for activation of the Conference Television; the right to release the business; responsible for supervision of all participants; any time the right to exclude participants. Add-on-based video conference needs the support of SNR, SNR in Package With two broadband intelligent network (BIN) feature entities: Broadband - Service Switching Function (B-SSF) and broadband - Special Resource Function (B-SRF). Meet-me type not videoconference CFC intervention. This type of meeting is equivalent to an open forum, participants can open and free exchange. Most of the meeting by a special network element functions?? Server ?? Completed. Comparing the above two programs known, Meet-me type the required information flow videoconferencing less easy to achieve; Add-on based videoconferencing needs the support of SNR, the control process is complex, requiring more and more information flow, but more flexible conference control. Integrated Intelligent Network and broadband multimedia services to a variety of architecture provides a unified, so that multimedia services become more flexible and convenient.

Network based on IP technology prospects As the rapid development of Internet in the world, IP applications have become a trend. Can make use of the Chinese public in China have built multi-media networks to build IP-based videoconferencing systems across provinces (also available across the country Internet TV conference system, but under the current export of China's Internet bandwidth is inadequate constraints). Head office and branch offices around the nearest access to the local communication network, recommend the use of ADSL access mode or wireless spread spectrum access, rate of 1Mbps ~ 2Mbps, with data communications network to share the same network line, line of low cost, monthly fee also low. However, IP-based real-time communication is not guaranteed QoS, while communication network can not guarantee at all times have enough bandwidth available, so the quality of both image quality and sound effects. In short IP-based videoconferencing system is a promising direction of development. ATM-based network can provide QoS network ATM technology as the biggest feature is a QoS guarantee, as long as the increase in the existing ATM Internet access ATM25M Switch V-Switch, the same time, as long as the increase in ISDN videoconferencing gateway device V-Gate, can be realized based on ATM-based ISDN videoconferencing systems and interoperability of Video Conference System. 

Features of this program is a very good image quality (up to MPEG image quality), Zu Wangfang it (not all video conference terminals to the MCU on the line all together), and high reliability. However, the high cost of equipment, and the ATM network should be. In summary, three methods have different features, broadband intelligent network method can break through the limitations of the existing ATM network, ATM network is very easy to complete the video conference can accomplish some of the features; achieve media control of information transfer and business separation, the system has good compatibility and scalability. Trend from the network technology, IP technology is the development of multimedia networks, in particular IPv6 Technology further extends the IP address space, a dynamic distribution network address and support the real-time business functions, enhanced IP layer security mechanism. ATM port speed with high throughput, latency, connection-oriented, and many other advanced features, and can meet the needs of multimedia communications. Which way to achieve the specific use of video conference system, to consider how to improve the efficiency and management and reduce administrative costs, it is necessary to consider the practical needs and current situation of the national network infrastructure, but also consider future scalability.