The Research On Network Coding For TCP-Reno In Ad-hoc Networks

The traditional TCP protocol is mainly care about the research design for reliable channel, in the cable network it can show the good performance. However, in Ad hoc network, the performance of the TCP protocol will drop because of the packets loss. Therefore, researchers improve the TCP protocol from the link layer to end-to-end design. But these solutions are to change traditional TCP congestion control scheme, and destroyed the TCP/IP protocol of the original control strategy. Therefore, the pipeline coding is used to replace the original random linear codes in this thesis, the new coding control strategies are used to get the new TCP-Reno/NC protocol in order to improve the performance of the TCP-Reno.In this thesis, we introduce the current situation and problem of the TCP protocol in wireless network. And we study in the theory and characteristics of the pipeline coding. Based on the studying, the TCP-Reno/NC protocol which combine the pipeline coding and network coding has been proposed. It gives the buffer management strategy which based on the ACK. In order to compare the performance of TCP-Reno protocol and TCP-Reno/NC protocol, we experiment them in the same wireless topology.TCP Reno/NC protocol has been simulated in the typical chain of Ad-hoc wireless network in the NS2.The result shows that the TCP-Reno/NC protocol can shield part of the link loss and the throughput is obviously higher than the TCP protocol. From the transport layer, the sliding window of the TCP-Reno/NC protocol changes placidly in high packet loss network. But the sliding window of the TCP protocol changes tempestuously. It conforms to the original intention that we want the sliding window of the TCP-Reno/NC will not change tempestuously.