A unified user interface

A general requirement of conferencing systems, at least for relatively small conferences, is that the participants need to know who is in the conference and who is active. Vat is a significant improvement over telephone audio conferences, in part because participants can see who is (potentially) listening and who is speaking. Similarly if the whiteboard program wb is being used effectively, the participants can see who is drawing at any time from the activity window. However, a participant in a conference using, say, vat (audio), ivs (video) and wb (whiteboard) has three separate sets of session information, and three places to look to see who is active. Clearly any conference interface should provide a single set of session and activity information. A useful feature of these applications is the ability to ``mute;SPM_quot; (or hide or whatever) the local playout of a remote participant. Again, this should be possible from a single interface. Thus the conference control scheme should provide local inter-application communication, allowing the display of session information, and the selective muting of participants. Taking this to its logical conclusion, the applications should only provide media specific features (such as volume or brightness controls), and all the rest of the conference control features should be provided through a conference control application.