Date Added: Jan 2010
Video-conferencing is an efficient means for distributed collaboration especially for people separated by substantial distance. One can identify various paradigms of distributed multimedia collaboration. The interactive video-conference paradigm requires the highest degree of interactivity and scalability. A desirable paradigm for interactive videoconferences requires a number of media channels for video and audio streams from participants. Yet, to achieve good scalability, the number of channels should be limited. Therefore, mechanisms to coordinate the access to the shared channels are required. These tasks are carried out by the conference control protocols. The major functions of a conference control protocol are floor control and session control. This paper presents a conference control protocol intended for an interactive and scalable video-conferencing paradigm. The paper also focuses on description of a collaboration paradigm and the collaboration environment that supports such a paradigm. It also shows how the protocol behaves in a real video-conferencing session. Some examples are interactive video-conferences, video phone, group meetings, and classroom sessions. Experimental results have shown the conference control protocol implemented in the ALX videoconferencing system for high quality video-conferencing over wide area networks. It is used by devising a three-channel rotation scheme for floor control. In an interactive conference paradigm, every participant has an equal opportunity to speak to the other participants, and is able to see the speaker. In this experiment centralized controller was used.