【 Weak current College 】 enterprise-level video conference system five top technical overview (3)

QoS: high-quality transmission security
In the network application QoS is not new technology, but in video hosting online streaming media QoS is a new hot technology.
Business-to-video technology innovation is streaming media technology into the mainstream of the application. Streaming media playback with strict requirements, the requirements of real-time at specific intervals to decode a specific data cell. Currently streaming media business in a number of issues, such as media files playback pause, mosaic phenomenon, there are a large number of users access a top emergency content server processing difficulties, and so on, these issues are related to streaming media QoS guarantee.
Enterprise video because of the mostly applied to business-critical, and the transmission of voice, data synchronization, network quality with higher requirements. Streaming media QoS needs to address two issues, bandwidth and delay jitter.
We all know that video, and voice and unified communications is the most consumed bandwidth in the network application. Bandwidth limit on the one hand, affect the quality of video playback; on the other hand, because the streaming media applications consuming bandwidth, and network with other business in the contend bandwidth on the business impact of normal operation.
In addition, IP network for video data grouping store and forward mechanism determines the latency and jitter is inevitable, therefore convective media transport, the end-to-end delay should be controlled to a certain range. Streaming media QoS with advanced video coding schemes, in improving the efficiency of the video data compression, as far as possible eliminate redundant information in the video, making source code output for as little as possible the amount of data, thereby adapting the minimum transmission bandwidth of the network. At the same time, you can provide flexible video quality rating to best adapt to the dynamic nature of the network, as far as possible, providing users with better video quality.
Scalable coding technology increases the encoded output stream, adapted to network bandwidth, the flexibility of dynamic change, multimedia data compression into multiple streams. One can decode, called basic Bitstream, other stream called enhanced layer. They are not individually decoded, but only with the basic layer and its previous reinforced layer combined with decoding, used to improve viewing.


Enterprise-level video conference system five top technical details (4)
State rendering: implement transparent communication
Reference to presence (Presence), the first thought is QQ, MSN, instant messaging (IM) application. The video is already realized the communication between the face-to-face communication, you also need to get familiar with its state information?
The answer is Yes. Especially in the enterprise business process integration of video communication, Presence technology and video combination will become a new focus on technology. In fact, in the enterprise, individual business processes based on the Unified Communications launch and execution of the process, you can make good use of the State service for dialogue between the transparent communication.
Presence to communicate user status, and the users through a set of devices for communication, such as: online, busy, away, offline, etc. These status information reflects the user to communicate with other users.
A simple Presence as follows: one user (Watcher) subscriptions (SUBSCRIBE) in the interest of another user (Presentity) Presence status, receive subscription request Presentity. Later, when the status of the Presentity changes, he will publish (PUBLISH) your new status, this new status will notify (NOTIFY) to the Watcher.
From a systems perspective, video headend equipment and IM system users have many similarities. For example, the system should always know the front-end device is logged into the system; whether it be user access, and which users access, and so on.
Five protocol compatibility: in the mix in the consolidated
In addition to the video itself a hotspot of technology in the enterprise, in addition to the application and deploy an IP video system, and you want to achieve and speech, data communications platform of "unification", as well as individual enterprise management decision mutual integration of business processes and embedded, faced with cross-network interoperability, cross-functional interoperability and cross-device communication problems.
In theory, the video can provide all aspects of corporate operations provide diverse wealth of services, from the most common meetings, monitoring to broadcast, communications, mobile, and other end-to-end interactive features. To video to promote, in the framework of the unified communications, enterprises can build their own open, performance improvement and powerful information exchange system. But this also brings about another issue, are designed for different applications, may have different protocols and standards, these standards and protocols in a single IP-based unified communications hosting Internet compatibility. Together with the enterprise in the deployment of their video communications systems, hardware and software system has different options, you can build a supporting rich Protocol and is compatible with various standard to achieve in a single network environment to provide more application functionality integrated platform, will become a corporate video deployments are most often in the face of one of the technical difficulties.