  When signals propagate through forest areas, they will be affected by
environmental factors such as vegetation. Different types of environments have
different influences on signal attenuation. This paper analyzes the existing
classical propagation path loss models and the model with excess loss caused by
forest areas and then proposes a new short-range wireless channel propagation
model, which can be applied to different types of forest environments. We
conducted continuous-wave measurements at a center frequency of 605 MHz on
predetermined routes in distinct types of forest areas and recorded the
reference signal received power. Then, we use various path loss models to fit
the measured data based on different vegetation types and distributions.
Simulation results show that the proposed model has substantially smaller
fitting errors with reasonable computational complexity, as compared with
representative traditional counterparts.
