Directional antennas for angular diversity in wireless sensor networks

In this paper, multiple directional antennas are implemented on sensor network motes to create angular diversity in wireless sensor networks. Wireless sensor systems deploying directional antennas can establish angular diversity to cope with uncertainties in wireless channels. These systems also have improved bandwidth utilization and energy conservation. From our experiments, the degradations of the link quality under the fading channel are observed, and the proposed angular diversity increases the mean received signal strength, reduces the variance of the received power, and decreases the threshold-level crossing rate. Therefore, with a simple switching network and multiple directional antennas, the infrastructure of the wireless sensor network is enhanced.