The application of remote sensor technology to assist the recovery of rare and endangered species

We describe a wireless sensor network designed for the long-term study of rare and endangered species of plants. We wish to monitor plants and their environment via high-resolution cameras and temperature, humidity, rainfall, wind, and solar radiation sensors. Our units must be "invisible" (camouflaged), very low energy, and must allow distributed local computation. Data rates are 1 to 100 bytes/second per node, but networks can be large an early prototype had 60 nodes. Failures are expensive and we must exploit redundancy whenever possible. Nodes are stationary but for energy reasons may decline to participate in transmissions. We have designed two wireless routing protocols that satisfy these constraints. Multipath On-demand Routing (MOR) computes multiple optimal routes to avoid depleting the energy at any given node. Geometric Routing scales to large networks, relying on Geographic Routing when possible and on selected global information otherwise. We have simulated and are implementing both protocols. © 2002 Sage Publications.