Abstract
Users on computer networks can share virtual spaces easily by exchanging their descriptions of Virtual Reality Modeling Language(VRML). Besides, users have to exchange the additional information such as their motion. To achieve the smooth interaction among users, the information must be delivered in real-time. Moreover, to keep the consistency of the virtual spaces of users, the information delivery must be reliable. however, in case of a shared virtual space on the Internet, it is difficult to achieve the real-time and reliable delivery. In this paper, we propose a new delivery mechanism for a shared virtual space, which use the peer-to-peer communication for the reliability and the multicast communication for the realtimeness. To achieve the smooth interaction and the consistency of the virtual spaces, this mechanism chooses the communication method dynamically according to the data type, the user's position, and the system resource availability.
