A probability-based wake-up mechanism for radio-on-demand wireless LAN

In order to reduce energy wastefully consumed by access points (APs) in wireless LAN (WLAN), Radio-On-Demand (ROD) WLAN has been proposed, which offers wireless access only when and where it is needed in an on-demand manner. Each AP in ROD is equipped with a wake-up receiver, which transits a state of AP from sleep to active by receiving a wake-up signal from a station (STA). However, if there are several APs having the same wake-up ID around a STA, a wake-up request from STA causes more than one AP to wake up though STA only needs a single AP. In this paper, in order to reduce the number of APs redundantly woken up in such a situation, we propose a probability-based wake-up mechanism. With the proposed mechanism, each AP does not always wake up after receiving the wake-up request. Instead, each AP decides whether it should wake up or not based on the wake-up probability. This probability is adjusted in such a way that only APs suited for serving the corresponding STA have the higher probability to wake up while the other APs maintain a lower probability. By computer simulations, we show that our proposed mechanism can significantly reduce the number of redundant wake-up while keeping the adverse impact on their usability and quality of service (QoS) small.