Adaptive transmit power control in IEEE 802.11a wireless LANs

Transmit power control (TPC) has been recognized as one of the effective ways to save energy in wireless devices. In this paper, we demonstrate the energy-efficient distributed coordination functions (DCF) operation of IEEE 802.11a wireless LANs (WLANs) via TPC and physical layer (PHY) rate adaptation. The key idea is to enforce an RTS/CTS frame exchange before each data transmission, and then select the most energy-efficient combination of the PHY mode and the transmit power level for the subsequent data frame transmission to save energy. The performance of the proposed scheme is evaluated via simulation in the ns-2 simulator.