28 GHz millimeter-wave measurements and models for signal attenuation in vegetated areas

This paper presents 28 GHz channel measurements in vegetated areas using a directional channel sounder. The measurement campaign was conducted in areas lined with trees similar to a vegetated residential environment on the campus of Korea Advanced Institute of Science and Technology (KAIST) in Daejeon, South Korea. It was found that excess loss in vegetated areas is associated with a saturating trend with upper-bounded foliage attenuation at 28 GHz. From the measurement results, we presented 28 GHz foliage propagation models which are based on the ITU-R terrestrial model and the FITU-R-like frequency-dependent model. In addition, the proposed models were compared with several existing attenuation models which are applicable at 28 GHz. These results can be used when predicting path loss results through vegetated areas at 28 GHz. It is anticipated that by conducting and analyzing measurements in even more locations and environments it is possible to further understand the 28 GHz foliage propagation channels for future communication systems.