Wireless sensor network (WSN) is a new family of networks that collects information by the help of the collaborative work of several sensor nodes. In this book, a new WSN for military monitoring (MILMON) is proposed. MILMON monitors its environment and reports the sensed events as soon as possible to the sink. WSNs are application specific and all design considerations are different for each application. Especially, military application requirements are very special. Design considerations of MILMON are energy consumption, delay and fault tolerance. Time synchronization, data indicator slot and time scheduling mechanisms are essential parts of the new system. SyncHRT which is a new synchronization schema is proposed to minimize energy consumption and to maximize precision. Newly proposed data indicator slot mechanism (DISM) helps to reduce energy consumption. A new time slot distribution mechanism, ft_DTSM is also proposed for the new military monitoring system. Although there are WSN systems that perform better than our system for only energy consumption or for only delay, new proposed sensor network realizes an optimization on energy, delay and fault tolerance.