Design And Application Research On Network Coding-based Reliable Transmission

Recently, improving the channel utilization rate and transmission reliability ofnetwork has become more and more attractive since different users with heterogeneousterminals can access their desired resource at the same time. However, the limitedthroughput, packet loss and unpredictable delay are still the three major challengingproblems for the realization of robust, safety and effective transmission in practice. Toaddress these problems, network coding is proposed since it can improve the throughputof data transmission and is also more resilient to packet loss by generating redundantpackets, but the problems of error diffusion, unpredictable delay after loss packets andlow channel utilization in wireless network in existing network coding algorithm arestill unsolved issues. For designing a network coding algorithm with high reliability androbust, this paper researches NC from the principle, development and applications.In order to reduce the impact of error diffusion and unpredictable delay in generalnetwork coding, a special design for the global coding matrix (GCM) of network codingis proposed to realize reliable transmission, which overcome the shortage that theinsufficient rank in the GCM at the decoder in general NC. The form of the codingmatrix is maintained throughout the NC process and enables unequal error protection,reduces the delay and improves the transmission quality. Simulation results show that,in the same packet loss rate, the method promoted the number of packets of receivercompared with traditional store and forward method and general NC design fortransmission. Especially in video application, the method can provide higherreconstructed quality of video at the receiver and unequal error protection ofH.264/SVC transmission against packet loss effectively.To improve channel utilization rate in wireless network, a path scalable networkcoding (PSNC) algorithm is proposed to realize the effective transmission. It caneffectively increase the average path utilization and the innovative packet ratio overwireless networks through selected the main link and the alternate link in wirelesstransmission. The theoretical analysis reveals the feasibility and effectiveness of theproposed algorithm. In addition, general wireless transmission method is notappropriated for satellites network because satellites available do not have the monitorability which is necessary in these methods and it is also too expensive to monitor insatellites. Simulation results also show that this method could improve the transmission efficiency and utilization rate of satellite network and avoid the need of monitoring.