An energy-efficient power control approach for WLANs

In this paper we consider the problem of reducing energy consumption during the transmission phase in WLANs. We found that for a given network configuration, channel characteristics, and packet length, an optimum RF transmission power level exists which assures a minimum energy expenditure for the actually transmitted bit of information. Based on this observation, we present a packet length dependent power control mechanism. We performed discrete event simulations of an IEEE 802.11 LAN in ad hoc mode using a two state Markov channel model. The achieved simulation results indicate a significant potential for energy saving. We also present a workable approach for choosing the most energy-saving RF transmit power level which is based on the perceived packet error rate of a single mobile.