Propagation Characteristics of A 2.4GHz Wireless Sensor Module with A Pattern Antenna in Forestry and Agriculture Field

This paper describes 2.4 GHz RF peer-to-peer propagation measurements and modeling in forests and a Japonica paddy field. Propagation through vegetation is an important subject for creating a reliable wireless sensor network system. Detailed measurement curves of RSSI (received signal strength indication) against distance indicate the presence of various vegetation types based on the moisture conditions of plants. The SRET (simplified radiative energy transfer-based model fits well depending on leaf density for NLOS (non-line-of-sight) conditions in the forests and the paddy field. In the case of LOS (line-of-sight) conditions of paddy field, a novel model named the "TRPF (two-ray paddy field) model" is proposed in order to express the influence of vegetation for a reflection wave.