  The geometry-based stochastic channel models (GSCM), which can describe
realistic channel impulse responses, often rely on the existence of both {\em
local} and {\em far} scatterers. However, their visibility from both the base
station (BS) and mobile station (MS) depends on their relative heights and
positions. For example, the condition of visibility of a scatterer from the
perspective of a BS is different from that of an MS and depends on the height
of the scatterer. To capture this, we propose a novel GSCM where each scatterer
has dual disk visibility regions (VRs) centered on itself for both BS and MS,
with their radii being our model parameters. Our model consists of {\em short}
and {\em tall} scatterers, which are both modeled using independent
inhomogeneous Poisson point processes (IPPPs) having distinct dual VRs. We also
introduce a probability parameter to account for the varying visibility of tall
scatterers from different MSs, effectively emulating their noncontiguous VRs.
Using stochastic geometry, we derive the probability mass function (PMF) of the
number of multipath components (MPCs), the marginal and joint distance
distributions for an active scatterer, the mean time of arrival (ToA), and the
mean received power through non-line-of-sight (NLoS) paths for our proposed
model. By selecting appropriate model parameters, the propagation
characteristics of our GSCM are demonstrated to closely emulate those of the
COST-259 model.
