Over the last decades, the developments on wireless sensor networks and its application are indispensable on social concerns. Is is mandate to have complete study on wsn and grow the competent group of society which utilizes the same. This book addresses the basic model and working macahnism od wsn.Also it emphasize more about the design considerations on wsn with repect to bateery power of sensor mote and the security of the date that it provides. This is ultimate companion to the beginners. Also it is having significant details about Network simulator(NS2) and its installation flow. Those who are working with small projects and demonstration on WSN, MUST refer this book.