无线局域网中的自适应节能机制

Adaptive Power Saving Mechanisms in Wireless LANs

为节省能量,无线局域网标准IEEE802·11在分布式协调功能(DCF)的基础上定义了节能机制PSM,但该机制在重负载情况下性能严重劣化.为提高该机制在重负载情况下的性能,该文对现有PSM进行研究分析后提出自适应调整接入概率的PSM+和fairPSM+.仿真结果表明PSM+和fairPSM+在轻负载下性能与PSM相当,而在重负载下较大地提高了吞吐量及能量有效性.fairPSM+在PSM+的基础之上考虑了系统的稳定性和公平性,因此具有最好的性能.

IEEE 802.11 specifies power saving mechanism （PSM） under distributed coordination function （DCF） for energy efficiency. However, the performance of PSM degrades seriously when load is heavy. This paper first analyzes the reason of performance degradation, then proposes two adaptive mechanisms： PSM＋ and fairPSM＋. Numerous simulation results have shown that these two mechanisms can achieve high performance with heavy load and still get the same performance as PSM when load is light. Since fairPSM＋ considers stability and fairness on the basis of PSM＋, it can achieve the best performance.