Performance Evaluation of Centralized and Distributed Control Methods for Efficient Registration of Massive IoT Devices

Abstract

The IEEE 802.11ah Wi-Fi HaLow allows thousands of devices being connected to a single access point (AP) with several improved functionalities compared to existing WiFi, such as restricted access window (RAW), target wake time (TWT), and traffic indication map (TIM). However, such functionalities are applicable only after successful registration process (exchanges of authentication and association information). In the registration process, a large number IoT devices are simultaneously trying to connect to a single centralized AP and inevitably imports severe contentions that bring a long registration time. In IEEE 802.11ah standards, the problems have been addressed through Centralized Authentication Control (CAC) and Distributed Authentication Control (DAC) protocols. Both CAC and DAC are proposed to reduce severe contentions by allowing an optimal number of devices requests for the registrations. However, the standard does not define the way to select the optimal operational parameters. In this paper, we evaluate and compare the performances of CAC and DAC protocols and provide two modified CAC-based algorithms that achieve substantial improvement overall existing IEEE 802.11ah schemes to reduce the registration time.1