Energy efficiency research trends-A study based on IEEE 802.11B DCF system

The proliferation of mobile computing devices including portable computers, PDAs and handheld devices has created a tremendous demand for wireless local area networks (WLANs). One of the greatest limitations of contemporary WLANs is the finite energy resource of mobile computing devices. As a result, energy-efficient protocol design for WLANs has recently become the focus of many research efforts. To design energy-efficient protocols, it is indispensable to thoroughly investigate the energy consumption of WLANs. In this article, we propose an analytical framework to study the energy consumption and energy efficiency of IEEE 802.11b WLANs. Our framework models the energy consumption by jointly considering the interactions between IEEE 802.11b PHY and MAC layers. Extensive simulations are conducted to validate the theoretical analysis. It is shown that the theoretical model is accurate in predicting the energy efficiency over a wide range of scenarios. In addition, the impacts of different PHY layer and MAC layer parameters on energy efficiency of IEEE 802.11b WLANs are examined. Insights into the effects of different parameters on energy efficiency are provided as well.