A design aid and real-time measurement framework for Virtual collaborative simulation Environment

Distributed Virtual Environment (DVE) has attracted much attention in recent years due to the rapid advances in the areas of E-learning, Internet gaming, human-computer interfaces, and etc. However, the complexity of designing an efficient DVE greatly challenges today´s researchers. Indeed, how to effectively measure a DVE or the design of DVE plays an important role in progressively guiding the DVE design. Meanwhile, the performance of protocols and schemes used in an existing DVE cannot be easily measured straightforwardly. Traditionally, simulation tools are involved to predict the performance of the DVE system or any used protocols; however, existing tools have limited capabilities in terms of accurately capturing the real-world performance. This is due to the statically configured simulations, hard-to-model hardware devices (such as haptic devices, mobile devices), single processor´s execution of the simulations, and etc. Moreover, there exists no integrated simulating and measuring framework that can effectively support model reuse, dynamic reconfiguration of a simulation, real devices in the simulation loop (statically or run-time), and distributed simulation execution, just to name a few. In this paper, we propose and implement an integrative simulation and measuring framework; in particular, we design a generic real-time service oriented virtual simulation system which can effectively measure the real time performance of distributed virtual environments and virtual reality based applications. The main goal of our proposed framework lies in providing accurate and near-real-world measurements of a DVE and any related protocols, so that a highly cost-efficient DVE system design can be achieved. Moreover, our framework uses the Experimental Frame concept to separate simulation services from design models so that model reuses, model formalization and model validation can all be done within one layer. The idea of using experimental frame also makes possible a h- - ardware-in-the-loop type of simulation, which is quite useful in DVE including haptic virtual environment, sensor network based virtual environment, and etc. As a case study, we investigate a QoS-aware adaptive load balance algorithm using our framework; and our real-time simulation results clearly indicate that the algorithm outperforms others in a near real-world scenario.