Performance evaluation of multi-armed bandit algorithms for Wi-Fi channel access

The adoption of dynamic, self-learning solutions for real-time wireless network optimization has recently gained significant attention due to the limited adaptability of existing protocols. This paper investigates multi-armed bandit (MAB) strategies as a data-driven approach for decentralized, online channel access optimization in Wi-Fi, targeting dynamic channel access settings: primary channel, channel width, and contention window (CW) adjustment. Key design aspects are examined, including the adoption of joint versus factorized action spaces, the inclusion of contextual information, and the nature of the action-selection strategy (optimism-driven, unimodal, or randomized). State-of-the-art algorithms and a proposed lightweight contextual approach, E-RLB, are evaluated through simulations. Results show that contextual and optimism-driven strategies consistently achieve the highest performance and fastest adaptation under recurrent conditions. Unimodal structures require careful graph construction to ensure that the unimodality assumption holds. Randomized exploration, adopted in the proposed E-RLB, can induce disruptive parameter reallocations, especially in multi-player settings. Despite this limitation, E-RLB achieves effective adaptation and learning through lightweight stochastic gradient updates. Finally, decomposing the action space across several specialized agents accelerates convergence but increases sensitivity to randomized exploration and demands coordination under shared rewards to avoid correlated learning.