ASPROC: Adaptive smith predictor-based rate oscillation cancellation

The paper presents a control-theoretic approach to the design of a rate oscillation cancellation module. The main objective was to develop an effective method applicable to an audiovisual streaming system operating in an IP network. The proposed discrete-time nonlinear model represents functions of a real stream adaptation system based on the widely used RTP/RTCP protocol set. The paper demonstrates how the model had been transformed into a linear time-invariant (LTI) form and used in analysis of the system´s dynamic characteristics. The criteria for the optimal system configuration refer to representation of the transfer function´s roots on the Z-transform plane. It has been demonstrated how the proposed optimization method enables development of a stable rate control module which effectively cancels oscillations in the most demanding test scenario.