VIDEO DATA MULTIPARTY TRANSMISSION IN COOPERATIVE DESIGN TOOL

The video tool is one of the essential means in cooperative design environment．In order to support group work，the video tool should possess the characteristics of multiple parties and multiple views．This feature will enlarge very much the problem for the occupation of large volume network bandwidth resource，which exists originally in ordinary video tools．Based on multicast transmission，a hybrid data processing and transmission method is put forward，which makes the occupation of network bandwidth for video data decreased distinctly．And an adapted control engine is introduced for source video stream，which can adjust the size of video data stream according to the load on network in order to compromise between the quality of video and the allocation of network bandwidth．Besides，we adopt the centralized strategies to allocate and reserve the network bandwidth resource and to make the video data higher priority，in order to guarantee the transmission of the real-time video continuously on LAN．