Abstract: Contraposing the problem of energy saving in MANET，propose a graded power control method based on signal strength operated at MAC layer，by adding processing functions for incoming packet at physical layer and MAC layer，it can start communication with appropriate transmit power according to specified channel condition and communication condition，and force node into sleep mode when interference between two ongoing communication occurs，so that maintains the reception power at a suitable level and guarantees proper performance.The experiments analyses the availability of the method for energy saving and performance promotion in NS-2.

Key words: power control, collision avoidance, MANET, signal strength

摘要： 针对移动自组网的节能问题，提出基于接收信号强度的链路层分级功率控制方法，通过在通信双方的物理层和链路层添加针对接收数据包的处理功能，应对特定的信道状况和通信状况采用合适的发送功率进行通信，使数据包的接收功率处于合理的范围，并采用睡眠机制应对同步通信之间的干扰，确保实现良好的通信性能。通过NS-2环境下的仿真实验，分析了该功率控制方法在能量节省和网络性能提升上的有效性。

关键词: 功率控制, 冲突避免, 移动自组网, 信号强度