Influence of leaves, branches and trunks on the propagation loss in 920-MHz on a mulberry farm

Radio wave propagation characteristics were measured in 920-MHz band on a mulberry farm, and influence of leaves, branches and trunks was investigated by analyzing the measured data in three different environments and in two polarizations. RSSIs (Received Signal Strength Indicators) were measured at two propagation distances and converted to path losses. And, then they were compared among maturity stage, deciduous stage, and the case without plants. As a result, it was found that horizontal polarization was mainly influenced by leaves and that vertical polarization was mainly influenced by branches and trunks. The obtained radio wave propagation characteristics are useful for building a farm sensor network.