  Future dense small-cell networks are one key 5G candidates to offer outdoor
high access data rates, especially in millimeter wave (mmWave) frequency bands.
At those frequencies, the free space propagation loss and shadowing (from
buildings, vegetation or any kind of obstacles) are far stronger than in the
traditional radio cellular spectrum. Therefore, the cell range is expected to
be limited to 50 - 100 meters, and directive high gain antennas are required at
least for the base stations. This paper investigates the kind of topology that
is required to serve a suburban area with a small-cell network operating at 60
GHz and equipped with beam-steering antennas. A real environment is considered
to introduce practical deployment and propagation constraints. The analysis
relies on Monte-Carlo system simulations with non-full buffer, and ray-based
predictions. The ray-tracing techniques are today identified as a relevant
solution to capture the main channel properties impacting the beam-steering
performance (angular dispersion, inter-link correlation); and the one involved
in the present study was specifically enhanced to deal with detailed vegetation
modeling. In addition to the user outage, the paper evaluates the evolution of
the inter-cell interference along with the user density, and investigates the
network behavior in case of local strong obstructions.
