Research On Error Control Of Network Video Communication Based On Network Coding

With the development of multimedia technology, mobile communication technology and network technology, video communication is becoming more widely used. However, data loss caused by network congestion, failure of data reception caused by channel interference, or delay caused by retransmission strategy will affect the fluency of video playing. Therefore, the appropriate strategy should be taken to control network congestion, and the retransmission strategy should be improved to reduce the retransmission rate. In addition, the studies on network coding emerging in recent years have shown that network coding can balance the network load, enhance network throughput. Thus, it can control network congestion perfectly.Firstly, theory and current research status of network coding and video transmission are described.Secondly, a retransmission strategy combined with network coding: Network Coding ARQ is put forward. Three dimensional double cater-corner line redundancy code is constructed for error detection, considering the sensitivity of network coding to error. Erroneous packets are discarded, instead of being involved in coding. After that, in response to the principle that overall loss probability is much larger than the localized loss probability in multicast, a retransmission mechanism fit for network coding is proposed to reduce the waste of network resources caused by retransmission effectively. This mechanism determines the structure of retransmission packets according to the minimal rank of the sink nodes. Subsequently, the encoding way based on this retransmission mechanism is described. The results of experiment show that NCARQ can reduce the rate of retransmission, and improve the efficiency of information transmission.At last, the existing deficiencies of error control in network video transmission are analyzed. Video transmission strategies combined with network coding according to the characteristics of video transmission are put forward. The specific transmission strategy of video sever and client with applying NCARQ to video transmission is described. Theoretical analysis shows that this method of error control in video transmission has obvious advantages.