Throughput and Energy Efficiency Analysis of the IEEE 802.11ah Restricted Access Window Mechanism

Abstract

Internet of Things (IoT) is an emerging technology, which enables the interconnection of computing devices through Internet. IEEE 802.11ah is introduced as an amendment to IEEE 802.11 standard to provide ubiquitous connectivity, scalability and to reduce the energy consumption in dense networks like IoT. IEEE 802.11ah implements Restricted Access Window (RAW) mechanism to reduce packet collisions and improve energy efficiency. RAW reduces contention among the devices by dividing them into several groups and channel time into various slots. In this article, we have developed an analytical model to evaluate the performance of RAW mechanism in terms of throughput and energy efficiency in a dense IoT network. We have also analyzed the performance of RAW mechanism for different Modulation and Coding Schemes (MCS) proposed in the draft standard. The analytical model has been validated through the simulation studies. The results show that, the RAW mechanism outperforms the legacy DCF in a dense IoT scenario.