Abstract：In wireless sensor networks, low-duty-cycle mode is usually adopted to reduce power consumption of sensor nodes, but lower duty cycle will bring a longer waiting delay. For cluster-based wireless sensor networks, the DA-MAC protocol was proposed to adjust the duty cycle dynamically to achieve lower power consumption and lower transmission delay. A lower duty cycle was taken to make nodes sleep more and save more energy under light load, and a higher duty cycle could make nodes have more time to transmit data under heavy load.Simulation results showed that DA-MAC could improve the network throughput and reduce delay compromising energy consumption.

Keyword：wireless sensor network;MAC protocol;timeslot;energy consumption;