| In recent years, we have witnessed a growing interest in the synchronous collaboration based class of applications. Several techniques for Collaborative Virtual Environments (CVE) and Collaborative Haptic, Audio and Visual Environments (C-HAVE) have been designed. However, several challenging issues remain to be resolved before CVE and C-HAVE technologies become a common place.;In this thesis, we propose a hybrid multicast transport protocol, which we refer to as HMTP that aims at meeting the CVE requirements. We describe our protocol, discuss its implementation and report on the performance results we have obtained for two virtual tele-surgery training class of applications.;In this thesis, we focus on applications that are based on closely coupled and highly synchronized haptic tasks that require a high-level of coordination among the participants. Four main protocols have been designed, in the literature, to resolve the synchronization issues in collaborative virtual environments: the Synchronous Collaboration Transport Protocol (SCTP), the Selective Reliable Transmission Protocol (SRTP), the Reliable Multicast Transport Protocol (RMTP) and the Scalable Reliable Multicast (SRM). However, none of these protocols has been able to meet all of the basic CVE requirements, i.e., scalability, reliability, synchronization, and minimum delay. |
