Centralized PSM: An AP-centric power saving mode for 802.11 infrastructure networks

Energy management in a wireless LAN is an important problem, as the viability of wireless devices depends very much on their battery life. In this paper, we propose a centralized power saving mode (C-PSM), an AP-centric PSM for 802.11 infrastructure networks. Having the AP select optimal PSM parameters, such as the beacon and listen intervals, CPSM is able to maximize the total energy efficiency for all clients. Moreover, C-PSM provides a first-wake-up schedule to further increase the energy efficiency by reducing clients' simultaneous wake-ups. Extensive simulation experiments show that C-PSM outperforms the standard PSM by a very significant margin. In our set of experiments, C-PSM reduces power consumption and increases energy efficiency by as much as 76% and 320%, respectively. As a side benefit, C-PSM also decreases the frame buffering delay at the AP by 88%. The wake-up schedule can save clients' energy consumption by 22% at most. Moreover, the improvement increases with the number of clients.