A Low-Complexity Cross-Layer Optimization Algorithm for Video Communication Over Wireless Networks

Recent years have witnessed a rapid increment in video applications over wireless networks including on-demand video streaming and videophoning. This growth has also brought the need to find a good compromise in the conflict between resource limitations affecting mobile devices and the desire for high-quality multimedia services. It is possible to face this problem adopting a cross-layer strategy that jointly tunes the parameters of each layer in the network protocol stack. In this optimization strategy, complexity is one of the most significant issues because of the limited computational resources and power supply. The paper presents a low-complexity cross-layer algorithm that is able to jointly tune the parameters of different protocol layers by adopting simple but effective models. The quality of the reconstructed video sequence, the produced bit rate, and the service class associated to each packet are seen as functions of the percentage of null DCT coefficients. This modeling permits to find a closed-form solution to the joint optimization problem that can be computed with a limited number of operations and grants, at the same time, a good visual quality in the reconstructed sequence.