This book describes how to build wireless sensor networks, from the layers of communication protocols through the design of network nodes. It summarizes the multiple applications of wireless sensor networks, then discusses network device design and the requirements that foster the successful performance of these applications. The book discusses factors affecting network design, including the partitioning of node functions into integrated circuits, low power system design, power sources, and the interaction between antenna selection and product design. It presents design techniques that improve electromagnetic compatibility and reduce damage from electrostatic discharge. The text also describes the design features of the wireless devices.