Sensor networks have many interesting applications with great utility; however, their actually deployment and realization rely on continuous innovations and solutions to many challenging problems. Thus, sensor networks have recently attracted the attention of many researchers and practitioners. The compilation of the Handbook on Sensor Networks will meet the demand of the sensor network community for a comprehensive reference and summary of the current state of the area. The Handbook on Sensor Networks is a collection of approximately 40 chapters on sensor network theory and applications. The book spans a wide spectrum and includes topics in medium access control, routing, security and privacy, coverage and connectivity, modeling and simulations, multimedia, energy efficiency, localization and tracking, design and implementation, as well as sensor network applications.