IBAC: An Intelligent Dynamic Bandwidth Channel Access Avoiding Outside Warning Range Problem

TL;DR

This paper introduces IBAC, a MAC protocol that intelligently adapts channel bonding levels in IEEE 802.11ax to prevent interference issues during dynamic bandwidth channel access, significantly improving network performance.

Contribution

It proposes a novel Bayesian-based MAC mechanism, IBAC, that dynamically adjusts channel bonding to avoid collision problems in IEEE 802.11ax networks.

Findings

IBAC effectively prevents Outside Warning Range Problem during channel bonding.

Simulation results show IBAC outperforms existing mechanisms in network performance.

IBAC significantly reduces collision rates in dynamic bandwidth scenarios.

Abstract

IEEE 802.11ax uses the concept of primary and secondary channels, leading to the Dynamic Bandwidth Channel Access (DBCA) mechanism. By applying DBCA, a wireless station can select a wider channel bandwidth, such as 40/80/160 MHz, by applying the channel bonding feature. However, during channel bonding, inappropriate bandwidth selection can cause collisions. Therefore, to avoid collisions, a well-developed media access control (MAC) protocol is crucial to effectively utilize the channel bonding mechanism. In this paper, we address a collision scenario, called Outside Warning Range Problem (OWRP), that may occur during DBCA when a wireless station interferes with another wireless station after channel bonding is performed. Therefore, we propose a MAC layer mechanism, Intelligent Bonding Avoiding Collision (IBAC), that adapts the channel bonding level in DBCA in order to avoid the OWRP. We first design a theoretical model based on Markov chains for DBCA while avoiding the OWRP. Based on this model, we design a Thompson sampling based Bayesian approach to select the best possible channel bonding level intelligently. We analyze the performance of the IBAC through simulations where it is observed that, comparing to other competing mechanisms, the proposed approach can enhance the network performance significantly while avoiding the OWRP.