Computer Graphics and Knowledge Visualization, Graz University of Technology, Austria
The CARPET project (CAlculation of Radio Propagation Employing a Threedimensional model) investigates whether and how modern methods of computer graphics can be employed to improve existing simulation models for radio wave propagation in the GHz band. While the frequency of light is almost a million times larger, there are some common features:
Yet the different wave lengths and applications prevent a direct transfer of the results:
Thus solutions from computer graphics have to be adapted and new algorithms have to be developed to meet the requirements. On the other hand methods of geometric modeling and ray intersection computation can be used with little or no modifications.
By improving the simulation model and employing modern rayacceleration techniques the simulation speed has been brought to a point where a usual PC can compute the field strength distribution for a typical citymodel in a few minutes. With the antenna below the average roof top -- which is a usual case in reality -- computation times are in the near-interactive rates.
On top of that the gain in simulation speed allows for a larger number of propagation paths to be considered, which often eliminates the need to supplement the results with a less exact, two-dimensional approximation model as it is used in most existing solutions.
The modular architecture makes CARPET a tool box that significantly simplifies the improvement of the simulation model and the realization of new methods. Though important goals have already been reached, CARPET is first of all a starting point -- a base has been designed for future ideas to build upon.
Nevertheless together with our project partner T-Mobile we have sucessfully applied for a patent and CARPET is currently a part of the widely used Mobile Radio Network Planning System Pegasos.