A reliable multicast framework for distributed virtual reality environment

Sharing a virtual space by many users, a Distributed Virtual Reality Environment (DVE) provides the high level communication and cooperative design facilities. In the construct of the large scale DVE in the wide area network, a reliable and efficient multi-cast protocol on the Internet is necessary. Since almost of the existing reliable multicast protocols aim to send a relatively large data (e.g. a file) from a few source sites, it is not suitable to apply the DVE because it has many source sites and the size of the data is relatively small and the number of data is large. In this paper we propose a new multicast protocol that is suitable to the DVE. This protocol provides a fast retransmission management and an efficient retransmission buffer management based on a local Mutual Aide Region (MAR). In this method, the source site does not have the responsibility of the receipt of all sites, and the retransmission management is distributed in the regions.