Abstract: A power controll MAC (medium access control) protocol based on IEEE 802.11 is presented.Transmission power and the permitted receiving power of messages are comprised in the control packets.Through exchange of control information between a pair of communication nodes transmission power of the data packet is determined, and the neighbor nodes' transmission power is restricted, which can effectively reduce interference between hidden terminals and exposed terminals.The protocol also allows neighbor nodes to transmit messages during data receiving.In simulation the protocol is compared with the IEEE 802.11 MAC protocol.The results indicate that, in mobile ad hoc networks, the powercontrol protocol can improve the network throughput performance, while significantly reduce power consumption of mobile nodes and improve energy utilization efficiency of mobile terminals.Moreover, it can reduce energy consumption of the system by more than 93%.

Key words: mobile ad hoc network (MANET), IEEE 802.11, MAC protocol, power control