A new approach to the modeling of wireless propagation in buildings is intr
oduced. We treat the scattering by walls and local clutter probabilisticall
y through either a relaxation-time approximation in a Boltzmann equation or
by using a diffusion equation. The result is a range of models in which on
e can vary the tradeoff between the complexity of the building description
and the accuracy of the prediction. The two limits of this range are ray tr
acing at the most accurate end and a simple decay law at the most simple. B
y comparing results for two of these new models with measurements, we concl
ude that a reasonably accurate description of propagation can be obtained w
ith a relatively simple model. The most effective way to use the models is
by combining them,vith a few measurements through a sampling technique.