A mobile ad hoc network (MANET) is a collection of two or more nodes equipped with wireless communications and a networking capability without central network control. Nodes in a MANET are free to move and organize themselves in an arbitrary fashion. Energy-eficient design is a signiJicant challenge due to the characteristics of MANETs such as distributed control, constantly changing network topology, and mobile users with limited power supply.

The IEEE 802. I1 MAC protocol includes a power saving mechanism. Howevel; it has many limitations. A new energy-eficient MAC protocol (EE-MAC) is proposed in this paper. This protocol elects master nodes which keep awake and act as a network backbone to transfer data. The other (slave) nodes sleep to conserve energy and wake up periodically to communicate with the masters. To balance energy consumption, a rotation mechanism of masters and slaves is used, It is shown that EE-MAC per$ornw better than IEEE 802.1 1 power saving mode and exceeds IEEE 802.11 with respect to balancing network throughput and energy savings. The performance of EE-MAC is considered with respect to network load, node density and network mobility.