As the field of communications networks continues to evolve, a very interesting and challenging area — wireless sensor networks — is rapidly coming of age. A wireless sensor network consists of a large number of sensor nodes that may be randomly and densely deployed. Sensor nodes are small electronic components capable of sensing many types of information from the environment, including temperature; light; humidity; radiation; the presence or nature of biological organisms; geological features; seismic vibrations; specific types of computer data; and more. Recent advancements have made it possible to make these components small, powerful, and energy efficient and they can now be manufactured cost-effectively in quantity for specialized telecommunications applications. Very small in size, the sensor nodes are capable of gathering, processing, and communicating information to other nodes and to the outside world. Based on the information handling capabilities and compact size of the sensor nodes, sensor networks are often referred to as "smart dust.1'