GoP-level distortion optimization for video quality enhancement in MANETs

Quality of Experience (QoE) enhancement for a transmitted video sequence in Mobile Ad hoc NETworks (MANETs) is a challenging and important issue in networking research community. Intrinsic high levels of packet error probability in MANETs can cause high levels of distortion based on the position of packet loss in transmitted Intra-coded (I), Predicted (P) and Bi-predictive (B) frames. Hence, exact modelling of the impact of packet loss on the video quality and the resulting distortion is an important task. Many conventional distortion modelling techniques simply consider a linear relationship between the packet loss and distortion which is inaccurate. The main contributions of the current work are twofold. At first, an accurate model has been developed which can capture the exact effect of network packet loss on the video distortion (and hence on the QoE) with Group Of Picture (GOP)-level granularity. Then, based on this model, an optimal bandwidth allocation strategy is being developed in MANETs which based on some network-specific constraints, the loss-induced distortion associated with a video sources is being minimized using some cross-layer design techniques. Finally, the resulting optimal rates can be used as rate-feedbacks for on-line rate adaptation of a moderate video encoder such as H.264. Some numerical analysis have been presented to validate the theoretical results and to verify the claims.