| Because CSCW adapt the characters of work modes in the information society, such as group, interactive, distributed, cooperative, it has a multitudinous application market with great potential, a very strong developmental tendency. In recent years, the research about CSCW acquires quiet great progress. Its application field expands so quickly, and its level improved so much.The multimedia conference system (MMCS) takes the great part in the CSCW system. So taking the MMCS as one of the application of CSCW, we deeply research key techniques of CSCW including multimedia, concurrency control and synchronism.The multimedia technique is very important in CSCW system. In order to support cooperative work among people, the communication of audio and video must be needed. We do our research according to audio and video respectively, analyzing and comparing the existing techniques, then choose the right techniques and apply in MMCS. At the same time, we research synchronism of CSCW in deeply, and present the method of synchronism which based on RTP/RTCP.In CSCW system, sharing of information is the foundation of collaboration, and support a group of users to work together more effectively. So the concurrency control is very crucial. Some kinds of concurrency control algorithms have been invented to guarantee the concurrency of the document, but only the operational transformation based algorithm can prove users to do editing operations freely and to satisfy short response time. This algorithm is firstly proposed in the GROVE system, but the GROVE system can not guarantee the consistency of result document in some cases. Several independent research groups have deeply analyzed this algorithm, we analyze these algorithms, then choose the SOCT3 in our system.According to these researches above, we design and realize MMCS, which can solve concurrency control and synchronism problems greatly. At last, we present a experiment of multimedia communication based on IPV6. |
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