Distributed Interactive and Real-time Simulations

In the early days of computer simulation, interactive simulation was a term much favored by analog computer manufactures wishing to emphasize the advantages of their products over digital computers. Analog computers do, in fact, provide a commendable degree of user interaction, especially at run time, and offer many lessons for the designers of interactive digital simulation systems. With Digital systems, on the other hand, the development of interactive simulation facilities has taken many years to gather momentum. However, with the increase in the available processing power, the prospects for interactive simnldion liave been dramatically changed. Indeed, computer interactive simulation is currently undergoing an explosion of innovation and a dramatic increase in its range of applications, that today no one would think of desiging any complex system (an aircraft, a defense strategy, training of complex systems in science and engineering, entertainment, emergencing planning to prepare for earthquakes and other disasters) without creating its simulation first. But simulation is also notoriously expensive. As a result of this, distributed interactive simulation, in which the distributed environment could be both in terms of memory and geographical locations, seems to be a promising solution. Distributed Interactive Simulation (DIS) provides an infrastructure to build large scale-simulations for the simulation of highly interactive activities by interconnecting several types of simulatmrs via a iietworli. This new technology has brought a new set of issues and challenging problems to solve. The new tools of DIS are able to support substantially the solution of highly complex problems of mathematical modelling in physics, engineering, and biology, just to mention a few. This is an important direction of DIS technology applications. Distributed Interactive Simulation is still in its infanty, and despite the fact that research in parallel and distributed simulation (PADS) has been going for some times, DIS and PADS communities have proceeded largely independently of one another. Because of this, techniques developed for one doniitin have not found applications in the other. Complex interactive simulation such as war games and flight simulators are logically good candidates for distributed simulation, however interactive distributed simulation poses special problems to most existing