Assessment of the adaptive routing performance of a Wireless Sensor Network using smart antennas

Wireless sensor networks are built from nodes which have at least one sensor attached to them. To increase robustness and capacity, a signal from one node can be routed through many different nodes before it reaches its destination node (i.e. a base station). A smart antenna with a steerable beam has the potential, compared to a monopole, to increase the signal-to-noise ratio between nodes and hence provide more reliable communication paths. In this study, the data routing and link performance of a rhombus-shaped mesh network using four IEEE 802.15.4 compliant MICAz sensor nodes (motes) is assessed using both monopole and smart antennas. Both reflectionless and multipath-rich environments are used. It is shown that the electronically steerable parasitic array smart antenna offers a superior performance to a monopole antenna in both environments, while still consuming a similar amount of input power.