Research On TCP Cross-Layer Transmission Method Based On Network Coding In Vehicle Networking

The wireless vehicle network is an important application scenario of the 5th generation mobile communication system(5th Generation,5G),it has attracted great attention from academia and industry.It not only has the characteristics of dynamic network topology and unpredictable channel quality,but also has the characteristics of frequent changes in network topology and fast movement of nodes.At the same time,the requirement of delay and throughput is also high.Therefore,reliable transmission of wireless in-vehicle networks is critical,designing its TCP protocol is a great challenge.Network coding(NC)has obvious advantages in reducing the energy consumption of wireless transmission,improving network throughput and enhancing network transmission reliability.A networking coding TCP protocol that combines with TCP protocol,which provides a new way to improve network performance.Nowadays,there are few studies on network coding TCP protocol in wireless vehicular networks,at the same time,the multi-layer cross-layer optimization has not been given attention.First of all,we analyze the research of laccase at home and abroad.On this basis,we simulate the traffic simulation scene and network simulation scene in the vehicle network,and make theoretical analysis.Then we analyze the performance of TCP and TCP/NC in the vehicle network through simulation experiments.The experiments show the reason of existing TCP congestion control algorithm and TCP/NC algorithm are not suitable for the vehicle communication network.Secondly,according to the characteristics and reliable transmission requirements of wireless vehicular network,we bring cross-layer optimization ideas based on network coding.A cross-layer joint optimization method based on random linear network coding is proposed,which named VC-TCP/NC.This method adds a network coding layer between the transport layer and the network layer,use unused VC bits in the TCP header to indicate the status of the channel.The sending strategy of the sender in the network coding layer is redesigned,and theoretical analysis shows the advantages of VC-TCP/NC in terms of delay and network throughput.Finally,the advantages of VC-TCP/NC in delay and throughput in the vehicle communication network are verified by simulation.At last,because the single-path transmission of TCP does not meet the needs of the vehicle communication network.Based on the characteristics and requirements of multi-path TCP transmission in the vehicle communication network scenario,we propose a multi-path TCP network coding transmission scheme for packet loss differentiation.Because multi-path TCP can be transmitted between nodes by using multiple paths,our scheme optimizes the transmission on different sub-streams.The simulation results verify that the performance of our scheme is optimized in terms of throughput and delay.