Interference Analysis and Transmit Power Control in IEEE 802.11a/h Wireless LANs

Reducing the energy consumption by wireless communication devices is perhaps the most important issue in the widely deployed and dramatically growing IEEE 802.11 WLANs (wireless local area networks). TPC (transmit power control) has been recognized as one of the effective ways to achieve this goal. In this paper, we study the emerging 802.11a/h systems that provide a structured means to support intelligent TPC. Based on a rigorous analysis of the relationship among different radio ranges and TPC's effects on the interference, we present an optimal low-energy transmission strategy, called MiSer , which is deployed in the format of RTS-CTS( strong )-Data( MiSer )-Ack. The key idea of MiSer is to combine TPC with PHY (physical layer) rate adaptation and compute offline an optimal rate-power combination table, then at runtime, a wireless station determines the most energy-efficient transmission strategy for each data frame transmission by a simple table lookup. Simulation results show MiSer's clear superiority to other two-way or four-way frame exchange mechanisms in terms of energy conservation.