An Implementation Scheme of Power Saving Mechanism for IEEE 802.11e

U-APSD is the power save procedure defined in IEEE802.11e to improve the QoS performance of multimedia applications. U-APSD is specially suited for bi-directional traffic streams. But in some scenario without synchronized uplink and downlink traffic, defects in U-APSD procedure will result in some problems. In order to address this issue, this paper develops a low power implementation scheme of U-APSD by exploiting the downlink traffic rate estimation algorithm, and using clock gating technique as circuit-level approach to save dynamic power. Our experiments show that the scheme brings significant reduction in power consumption of NIC with little impact to the performance.