  Exploiting multi-antenna technologies for robust beamsteering to overcome the
effects of blockage and beam misalignment is the key to providing seamless
multi-Gbps connectivity in millimeter-wave (mm-wave) networks. In this paper,
we present the first large-scale outdoor mm-wave measurement study using a
phased antenna array in a typical European town. We systematically collect
fine-grained 3D angle-of-arrival (AoA) and angle-of-departure (AoD) data,
totaling over 50,000 received signal strength measurements. We study the impact
of phased antenna arrays in terms of number of link opportunities, achievable
data rate and robustness under small-scale mobility, and compare this against
reference horn antenna measurements. Our results show a limited number of 2--4
link opportunities per receiver location, indicating that the mm-wave multipath
richness in a European town is surprisingly similar to that of dense urban
metropolises. The results for the phased antenna array reveal that significant
losses in estimated data rate occur for beam misalignments in the order of the
half-power beamwidth, with significant and irregular variations for larger
misalignments. By contrast, the loss for horn antennas is monotonically
increasing with the misalignment. Our results strongly suggest that the effect
of non-ideal phased antenna arrays must be explicitly considered in the design
of agile beamsteering algorithms.
