Improving the IEEE 802.11 power-saving mechanism in the presence of hidden terminals

Abstract

Due to its low cost and popularity, the IEEE 802.11 WLAN (wireless local area network) is considered as one of the most promising wireless technologies for IoT (Internet of Things). 802.11 WLAN also provides a PSM (power saving mechanism), by which the devices that have no data to transmit are enabled to turn into doze mode where much less power is consumed. However, the 802.11 PSM is known to be inefficient because of its contention-based mechanism, i.e., it suffers from the performance degradation due to hidden terminals, especially in a network with a large number of devices. In this paper, in order to improve the performance of the 802.11 PSM, we propose a BC (backoff counter) reservation scheme that is combined with a neighbor polling solution. By building analytic models and performing extensive simulations, we show that our proposed scheme provides a much improved performance.