Robust wireless transmission of scalable coded videos using two-dimensional network coding

With the rapid increase in the popularity of wireless devices (e.g. smartphones and tablets) and watching videos over the Internet, delivering high quality videos to mobile users over wireless links is becoming an important application. Diversity of the receivers is a main challenge of multicasting in wireless networks, where variant channel conditions of end users lead to different packet delivery rates. In order to handle these heterogeneous channel conditions, multi-resolution videos can be used to deliver videos at multiple quality levels. The recent research studies on multi-resolution codes show that triangular network coding can increase the quality of the received videos by the users. In this paper, considering the dependencies among different temporal and spatio (resolution) layers of a video, we propose the concept of two-dimensional triangular network coding that performs network coding between the temporal and spatio layers. We also propose the concept of coding speed, which realizes difference balances between video playback smoothness and resolution. We evaluate our proposed two-dimensional coding schemes through simulations using two video sequences. (C) 2015 Elsevier B.V. All rights reserved.