Performance Study of the PRAW Mechanism with Slots of Arbitrary Duration in Wi-Fi HaLow Networks

Abstract—The rapid growth in the number of smart devices capable of exchanging data within a single network leads to the emergence of mechanisms that allow adapting data transmission technologies to the Internet of Things networks. One of them is the mechanism of the periodic restricted access window (PRAW) presented in the 802.11ah standard. A competent choice of parameters of the PRAW mechanism allows a large number of sensors to transmit data quickly and energy-efficiently, but the 802.11ah standard itself does not give recommendations on their choice. This article solves the following optimization problems: minimizing (a) the average delay, (b) the average energy consumption per transmitted packet when the average delay limit is met, and (c) the share of channel time consumed by the PRAW mechanism when the restrictions on both metrics are met. Based on the results of solving these problems, we give recommendations on the choice of PRAW parameters for different network loads determined by the intensity of packet generation and the number of stations.