Particle Filtering of the Number of Competing Stations to Support Combined Access Modes in IEEE 802.11 Networks

This paper proposes a new method to estimate the number of competing stations in IEEE 802.11 networks. Due to nonlinear nature of measurement model, a nonlinear filtering algorithm, called the particle filter (PF), has been employed. PF provides better alternative to the conventional extended Kalman filter (EKF) for nonlinear filtering since it avoids errors associated with linearization, has both high accuracy as well as prompt reactivity to changes in the network occupancy status and specifically gives better results in non-saturated conditions. From this method, we propose the combined access mode to maximize the system throughput by switching between basic access and RTS/CTS access mode.