دانلود رایگان مقاله انتقال بی سیم قوی فیلم کد شده با برنامه نویسی شبکه دو بعدی

Abstract

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.

7. Conclusion

As a result of the rapid increase in the popularity of wireless devices, such as smartphones and tablets, and video streaming over Internet, wireless video multicasting is becoming an important application. However, the diversity of users’ channel conditions is a challenge to video multicasting to multiple receivers. Multi-resolution video coding, in which a video is divided into a set of base layer and enhancement layers, is an efficient method to address this challenge. In the previous works, it has been shown that a triangular network coding scheme can increase the quality of the received videos by the users. In this work, we propose a two-dimensional network coding method to further increase the users’ experience. In our coding scheme, we combine both temporal and spatio layers together, and we introduce a search algorithm to find the optimal distribution of the transmissions to different coded layers. Through simulations results, we show the effectiveness of our two-dimensional coding scheme, as compared to the one-dimensional network coding scheme. Our future work is to analyze the effect of spatio and temporal layers on the video quality, and to find a mechanism to select the appropriate coding strategy based on the characteristics of the videos.