Resource and Energy-Efficient Configuration of IEEE 802.11ah Networks under Rayleigh Channels

The Restricted Access Window (RAW) mechanism included in the IEEE 802.11ah standard is one of the promising solutions to meet the requirements of Internet of Things (IoT) applications. It splits channel time into RAW slots and limits channel access to only a group of stations at a time. In this paper, we consider an IEEE 802.11ah network operating under Rayleigh fading channel with capture effect, and we develop efficient schemes to optimize the gain of the RAW mechanism. We propose an algorithm to identify the best cases for the RAW slot duration. Then, we deploy this result to develop a resource-efficient scheme to reconfigure a RAW consisting of several RAW slots. The new configuration eliminates the extra time wasted during the RAW period, resulting in higher throughput and energy efficiency. We present numerical results and simulations to validate our findings and analyze the impact of several parameters. The proposed RAW reconfiguration scheme significantly increases RAW performance by up to 21% for throughput and up to 8% for energy efficiency. It further optimizes the channel allocation resources, providing a channel gain ratio of up to 19%.