R 2 NC: robust inter‐session network coding in lossy wireless networks
Long Hai, Hongyu Wang, Yong Liu, Jie Wang, Zhenzhou Tang · IET Communications · 2014
The robustness of inter‐session network coding is still an open issue in lossy wireless networks. The traditional XOR based network coding cannot work well if the overhearing is unperfect. Especially, the coding node cannot know the overheard information in time. In this paper, we consider a robust network coding method, namely R 2 NC which uses random linear network coding to encode packets together in the inter‐session level, to resist the unperfect overhearing problem. With this method, coding node can always know the solvability of coded packets without the knowledge of overheard information. We analyse the performance of R 2 NC method with both lossy links of output and overhearing in the classic X ‐topology model, and give a necessary condition for the existence of coding gain. Finally, we design an optimal coding algorithm and a relay selection algorithm for R 2 NC to achieve its maximal transmission efficiency. Through ns‐2 simulations, we demonstrate that R 2 NC plays a good performance in terms of throughput, delay and overhead, and is robust against losses on output and overhearing links.