This book provide the most current and comprehensive coverage of wireless sensor network specially Power Conservation in wireless Sensor Network, Localization Process, Deployment, or Data forwarding rules (Protocols). Energy is most precious resource in wireless sensor network. Current expectation on sensor node in terms of size, cost and energy efficiency have led to several limited design space in hardware and software. We explore the capabilities at the network edge aiming to reduce the energy consumption with the help of software & system model approach for sensor node.