The characterization of path loss in indoor environments has been the subject of extensive research and many models have been proposed to make accurate predictions. Statistical models are easy to obtain when a lot of measurement data are available, but their validity is limited to the category of buildings in which the measurements are performed. Ray-tracing tools on the other hand take into account the geometry of the building and the used materials. However, the results appear to be very dependent on geometrical details of the ground plan, which force the user to work with very accurate plans. Also, the selected number of interactions (transmissions, reflections, and diffractions) has a huge influence on the predicted path loss [1]. Finally, for a high number of interactions, calculation time of ray-tracing tools may be very long.