An architecture for a multimedia teleconferencing system

We present an object-oriented architecture for a computer-based, real-time, multimedia conferencing system. This architecture divides the system into five functional areas: a multimedia shared workspace, a user interface, conference management, communications, and an information base. The structure and operation of the first four areas are modeled with object-based concepts that address design requirements identified during the development of a proof-of-concept prototype, that preceded the architecture specification. The shared workspace, the most important component, is thoroughly discussed; the other components support its realization. The modeling of workspace entities emphasizes their aggregation into composed entities and the homogeneous handling of several data media. The user interface manages uniformly the man-machine interaction for both local and remote user actions. Conference management deals with session establishment, participation, and control of multiple media floors. The communication functions replicate user actions over workspace objects in all hosts participating in a conference, matching traffic types with transmission services in the process.