Energy-based rate adaptation for 802.11n

Rate adaptation (RA) has been used to achieve high goodput. In this work, we explore to use RA for energy efficiency in 802.11n NICs. We show that current MIMO RA algorithms are not energy efficient for NICs despite ensuring high throughput. The fundamental problem is that, the high-throughput setting is not equivalent to the energy-efficient one. Marginal throughput gain may be realized at high energy cost. We propose EERA, an energy-based RA solution that trades off goodput for energy savings at NICs. Our experiments have confirmed its energy savings at NICs while keeping the cost at the device level and across clients acceptable.