Impact of Rayleigh Fading Channel on IEEE 802.11ah Networks Under Restricted Access Window Mechanism

The Internet of Things (IoT) demands an evolution of current networking protocols to support the requirements of its various application scenarios. One such example is the amendment IEEE 802.11ah (a.k.a. Wi-Fi HaLow) designed to operate in sub-GHz frequency bands and achieve higher signal coverage than typical Wi-Fi. Its Restricted Access Window (RAW) mechanism decreases channel contention by dividing stations into RAW groups that can be further divided into RAW slots. However, few works have addressed the impact of Rayleigh channel fading on IEEE 802.11ah networks. To study this problem, we extend a discrete-time Markov chain model to consider the impact of Rayleigh channel fading on the operation of IEEE 802.11ah networks. We validate the model via ns-3 simulations and propose grouping strategies to measure efficiency in terms of Jain’s fairness index. Additionally, we propose an expression to adjust the RAW slot duration based on the distance to the access point (AP).