A multicast network architecture for large scale collaborative virtual environments

This paper introduces a multicast based architecture for supporting large scale Collaborative Virtual Environments (CVEs). The paper begins by defining CVEs, discussing the motivations behind their development and identifying some of the key challenges that they pose to network developers. The paper then reviews a so-called spatial model of interaction which defines a number of general mechanisms (awareness, focus, nimbus and third party objects) for structuring virtual worlds and for managing mutual awareness between their inhabitants. Finally, the paper shows how this model may be mapped onto an underlying multicast network architecture and defines new techniques for managing the membership of multicast groups and for introducing aggregated flows of information between different levels of a multicast hierarchy.