The nodes in a mobile ad hoc network also form its routing infrastructure. Previous researchrnshows that the idle power consumption in the nodes is significant, as the network interfaces onrnthem is always on in order to maintain the routing fabric. As mobile nodes are dependent onrnbattery power, there is a need for protocols that minimize energy consumption. In this thesis, thernDynamic Source Routing protocol used for on-demand routing in an ad hoc network is modifiedrnto reduce the power consumption in nodes by adaptively putting their interfaces to sleep.rnIn an ad hoc network, it is impossible to predict accurately when it is all right for a node to put itsrnnetwork interface to sleep, using only its own information. In the approach presented, the timernslot during which the interface is on is alternated with a time slot during which the interface isrnput to sleep. The duration of the on period depends only on indigenously available informationrnabout the number of packets the interface receives during this time slot. In the absence of anyrnnetwork activity in the on slots, the sleep period is linearly increased up to a maximum. Thernreport explains all the factors that can affect the performance of the modified routing protocolrnand its influence on the energy consumption in the network. The penalty of increase in delay andrnpacket loss is unavoidable and the levels of the factors are identified to minimize the penalty.rnThe modified protocol is implemented in the Ns-2 network simulator. A linear equation is usedrnto model the energy consumption for each node in the network. Simulations are conducted to testrnthe modified protocol and the factors varied to study their impact. The results are compared withrnthose obtained from the simulations using the unmodified DSR protocol. The results showrnaverage energy savings per-packet of up to 25% with an average of 2-3ms per-packet increase inrnthe delay. The packet loss is comparable to the unmodified DSR protocol.