Optimizing controllability of an interactive videoconferencing system with Web-based control interfaces
With the rapid advances in computing and communications technologies, interactive multimedia applications, such as videoconferencing, over wide-area networks are becoming feasible. We developed an ATM-based multipoint videoconferencing (AMV) system, which can support continuous presence with high-quality audio/video and provide Web-based control interfaces for conferees to conduct interactive videoconferences in wide-area networks. On the basis of a well-developed multimedia distribution platform, we developed an application development platform, on which we can prototype videoconferencing applications quickly. Through running a prototype AMV system, we obtained many valuable experiment results. This paper reports the practical experience and studies the controllability of the AMV system on basis of a proposed videoconference model. Since there is unpredictable delay in transmitting conferees' interaction requests, in general, we cannot simultaneously achieve high controllability and high interactivity. To gain more insight into this issue, we develop an approach which can dynamically adjust, according to network conditions, the interval for collecting interaction requests to achieve either high controllability or high interactivity. We conduct experiments to validate and evaluate the approach and, moreover, determine the proper parameter values that achieve optimum tradeoff between controllability and interactivity.
videoconferencing systems web-based control atm networks performance evaluation