  We are interested in the assessment of electromagnetic Path-Loss in complex
environments. The Path-loss is the attenuation function $P$ of the
electromagnetic power at a distance $d$ of an antenna. In free-space, $P(d)
\propto 1/d^2$, in complex environments like cities, wave trajectory is altered
by successive reflections and absorptions, the path-loss is not theoretically
known and engineering rules postulate that $P(d) \simeq 1/d^{\gamma}, \,
\gamma>2$. We place in a stochastic geometry context to answer the problem
statistically. We present random models of 3D-city. These models reproduce main
real cities' features, can be calibrated with simple mean formulae and can be
fast simulated. For collections of random cities with the same mean morphology,
we estimate by Monte-Carlo ray tracing techniques their attenuation maps. By
averaging these maps, we show that the power expectancy actually follows a
function $\sim 1/d^{\gamma}$ with $\gamma$ depending on the environment
morphology.
