Abstract: Wireless sensor network is applied to greenhouse agriculture more and more widely, and needs higher requirements on the quality and reliability of network communication. In greenhouse, the wireless signal decays with density,height and distance of middle plants, so it causes to recede the network performance. I3y measuring the power of receiving signal with CC2430 chip under different conditions, the relationship of attenuation of 2. 4GHz signal and distance between the plant obstacles and the signal source were studied. hhe results can provide designing basement for efficient distribution of wireless nodes and optimization of network topology.

Key words: Wireless sensor network, Signal attenuation, Network topology