Fractional order proportional integral controller for active queue management of wireless network

A new active queue management (AQM) algorithm named fractional order proportional integral (FOPI) controller was proposed, which was used for congestion control of networks with traditional wired backbone and wireless terminal user supporting Internet TCP flows. First, the small signal theory was introduced to linearize the dynamic model for the congestion control of wireless networks in the steady state. Second, for meeting the system stability and robustness requirements, the parameters of FOPI were presented based on the frequency specifications concerned with the phase and the gain of the system open-loop transfer function. Simulation results show the excellent robustness performance of FOPI with system parameter variation and external disturbance experiments respectively.