CALL CONTROL IN VIDEO CONFERENCING ALLOWING ACCEPTANCE AND IDENTIFICATION OF PARTICIPANTS IN A NEW INCOMING CALL DURING AN ACTIVE TELECONFERENCE

摘要

A multimedia collaboration system that integrates separate real-time andasynchronous networks--theformer for real-time audio and video, and the latter for control signals andtextual, graphical and otherdata~in a manner that is interoperable across different computer and networkoperating systemplatforms and which closely approximates the experience of face-to-facecollaboration, while liberatingthe participants from the limitations of time and distance. These capabilitiesare achieved by exploitinga variety of hardware, software and networking technologies in a manner thatpreserves the quality andintegrity of audio/video/data and other multimedia information, even afterwide area transmission, andat a significantly reduced networking cost as compared to what would berequired by presently knownapproaches. The system architecture is readily scalable to the largestenterprise network environments.It accommodates differing levels of collaborative capabilities available toindividual users and permitshigh-quality audio and video capabilities to be readily superimposed ontoexisting personal computersand workstations and their interconnecting LANs and WANs. In a particularpreferred embodiment, aplurality of geographically dispersed multimedia LANs are interconnected by aWAN. The demandsmade on the WAN are significantly reduced by employing mufti-hoppingtechniques, includingdynamically avoiding the unnecessary decompression of data at intermediatehops, and exploiting videomosaicing, cut-and-paste and audio mixing technologies so that significantlyfewer wide areatransmission paths are required while maintaining the high quality of thetransmitted audio/video.