Consistency in Large Scale Distributed Virtual Training Environments

Principal Investigator: Prof Cai Wentong

Co-PI(s): Prof Stephen J. Turner, Ast/P Zhou Suiping

Starting Date: 2002-01

Duration: NIL

Funding Source: Defence Science and Technology Agency

Overview:

Quality of Training (QoT) is very important in large scale distributed virtual training environments (e.g., virtual battlefield simulations). A bad QoT may result in loss of money invested on the training system, loss of time of the military personnel who underwent the training and, worst of all, wrong decision-making. As a fundamental problem for all distributed systems, consistency is especially important for large scale distributed virtual training environments. This research supports the development of distributed virtual training environments that offer an improved QoT by minimizing inconsistencies in the simulation applications. In a large scale distributed virtual training environment, due to message transmission delay over the network and clock asynchrony among different simulation nodes, a consistent view among different participants is not guaranteed automatically, and various inconsistencies may thus occur. In this project, two types of consistency problems are studied: causality violation and time-space inconsistency � a unique consistency problem of large scale distributed virtual environments. To eliminate causality violations, a causality-based Time Management TM mechanism will be developed. To tackle the time-space inconsistency problem, a metric, a model and the protocol associated with the model will be investigated. In addition, a middleware solution for implementing the TM mechanism and the protocol will also be developed.