Although the interest in Wireless Sensor Network research is increasing, and new concepts and applications are being demonstrated, several fundamental issues remain unsolved. While many of these issues do not require to be solved for proof-of-concept designs, they are important issues to be addressed when referring to the long-term operation of these systems. One of these issues is the systems lifetime, which relates to the lifetime of the nodes, upon which the system is composed. This book focuses on node lifetime extension based on energy management. While some constraints and results...