Azimuth characteristics of radio wave propagation in a mulberry farm in 920-MHz band

Data collection of the radio wave propagation loss in farm fields is valuable to design a wireless network in a farm. They are used in calculating the link budget to establish a proper and efficient node arrangement. In this study, propagation losses in a 50 × 50 m mulberry field were measured in 920-MHz band with respect to the azimuthal angle of the propagation direction to arrays of bushes. Received signal strength indicators (RSSIs) were measured and they were converted to the path loss. Antennas were placed at a height of 1.5 m while the height of the bush was 3.5 m. Moreover, horizontal and vertical polarizations were measured. The results revealed that the horizontal polarization could be less affected by the direction angle to the ridges than the vertical polarization. These data would be useful for the evaluation of link budgets to design wireless networks in a farm.