Energy-Efficient Airtime Allocation in Multi-Rate Multi-Power-Level Wireless LANs

This paper considers the energy-conservation problem in multi-rate multi-power-level wireless local area networks (WLANs). This problem is addressed from a unique angle — the system-level fairness which is significantly different from most of current research that focuses on improving the performance of each individual wireless station. To emphasize fair energy-consumption among contending stations, we introduce a new fairness notion, called energyconservation fairness, in contrast to the conventional throughput fairness and airtime fairness. Another contribution of the paper is an energy-efficient airtime allocation scheme, which allocates airtime shares to contending stations in such a way that the combined airtime and energy-conservation fairness is achieved. Our simulation results show that, when the energy-conservation fairness is considered, both aggregate system throughput and overall system energy-efficiency can be improved significantly with all contending stations consuming a similar amount of energy.