Adaptive power saving algorithm for 802.11 mobile access points

IEEE 802.11 standard defines PSM(Power Saving Mode) such that stations can save their energy by entering sleep states if there is no data to send or receive. On the other hand, the PSM is not defined for AP(Access Point)s as they are assumed to run on fixed power sources not on batteries. Recently, however, the widespread use of Wi-Fi tethering and wireless LAN mesh networks requires battery-powered MAP(Mobile Access Point)s. In this paper, we develop an adaptive method which enables the MAPs to entering sleep states such that delays or losses experienced by stations are minimized. Our algorithm dynamicallly adjusts the sleep durations according to the traffic pattern of uploading and downloading data. Using simulations, we show that our algorithm considerably reduces the energy consumption of MAPs while the delay experienced by stations are minimized.