A reliable multicast framework for distributed virtual environment

Sharing a virtual space by many users, a distributed virtual environment (DVE) provides high level communication and cooperative design facilities. In a large scale DVE in a wide area network, a reliable and efficient multicast protocol on the Internet is necessary. Since most of the existing reliable multicast protocols aim to send 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 amount of data is large. We propose a new multicast protocol that is suitable for DVE. This protocol provides 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.