Abstract: An apparatus for controlling the representation of at least one data stream in a multi-participant application, comprising a server and a client, comprising: transmitter for transmitting a plurality of data streams from a server to a client across a communications network, each data stream being associated with a participant in a multi-participant video application; processor for determining a data stream ranking associated with at least one of the plurality of data streams; and, processor for selectively controlling the representation of at least one of the plurality of the data streams at the client in dependence on the data stream ranking.

Abstract: A method for controlling the quality of a displayed video image to meet the perceptual requirements of a viewer, comprising the steps of determining the location and orientation of a viewer with respect to a video image and varying the quality of the video image in dependence on the location and orientation of the viewer.

Abstract: A method for transferring data between computing systems, comprising the steps of for a plurality of computing systems, dividing the plurality of computing systems into at least two virtual zones, and, for each of the plurality of computers within each virtual zone, utilizing an algorithm to determine the manner in which the computers should be linked.