A consensus approach to PI gains tuning for quality-fair video delivery

Abstract : In this paper we provide necessary and sufficient conditions for the quality-fair delivery of multimedia contents to mobile users. We control the encoding rates and the transmission rates of the video streams, delivered through a limited capacity channel. This problem is cast into a problem of consensus among identical discrete-time linear systems, connected through a network with fixed and fully connected topology. The information exchanged over the communication network is the measure of the quality of the encoded videos. Based on a consensus result for identical linear systems, we reduce the problem of designing the Proportional and Integral (PI) gains of the encoding rate and transmission rate controllers to a linear static output feedback. We propose an iterative design technique based on linear matrix inequalities to solve the corresponding nonconvex problem, thereby providing a constructive optimality-based approach to the PI gains tuning problem. We demonstrate the effectiveness of our method in simulations, where we compare it to pre-existing approaches.