Propagation of IEEE802.15.4 in Vegetation
Data communications and more specifically wireless data communications have an increasing role in precision agriculture. ZigBee is one of the most widely adopted Wireless Sensor Network (WSN) technology, and it operates on top of IEEE802.15.4 that provides the two lower layers of the OSI model. To optimize the placement of sensors in agricultural explorations (greenhouses, crop fields, etc...), besides placing the sensors the nearer as possible to the process to monitor, also the maximum distance between nodes must be taken into account. The maximum distance between wireless nodes depends on the gain of the antennas, output power of the transmitter and attenuation, either in free-space or due to obstacles. Normally propagation models are used to evaluate the values of attenuation.