Novel AP association and fair channel access in high throughput WLAN for energy efficiency

Abstract

Distribution of wireless stations (STAs) becomes skewed towards a few groups of wireless access points (APs) due to the dense deployment of APs in a single hotspot and the signal strength based AP association mechanism in IEEE 802.11. Such a skewed distribution of wireless STAs may result in severe energy wastage, where a few APs could go to the sleep state if AP association is maintained optimally. This wastage increases in high throughput wireless extensions over IEEE 802.11, such as IEEE 802.11n/ac, where wider channels are used for communication (by channel bonding). Wider channels consume more power but do not necessarily provide high throughput under all different channel conditions. In this paper, we develop a joint management framework for energy-efficient AP association along with channel-width selection for active APs. Exploring the interdependency between these two objectives, we develop an optimization framework leading to GreenAP for AP association and channel width selection in high throughput wireless local area networks. We evaluate the performance of GreenAP using both simulation experiment and testbed implementations. We show that it is capable of saving significant energy without any loss in network performance parameters, compared to other competing schemes available in the literature.