  Communications using frequency bands in the millimeter-wave range can play a
key role in future generations of mobile networks. By allowing large bandwidth
allocations, high carrier frequencies will provide high data rates to support
the ever-growing capacity demand. The prevailing challenge at high frequencies
is the mitigation of large path loss and link blockage effects. Highly
directional beams are expected to overcome this challenge. In this paper, we
propose a stochastic model for characterizing beam coverage probability. The
model takes into account both line-of-sight and first-order non-line-of-sight
reflections. We model the scattering environment as a stochastic process and we
derive an analytical expression of the coverage probability for any given beam.
The results derived are validated numerically and compared with simulations to
assess the accuracy of the model.
