Research On Asymmetric,efficient And Reliable Data Forwarding Mechanism In Named Data Vehicle Network

With the rapid development of wireless communication,mobile communication and other technologies,vehicular networking as a key supporting technology for intelligent transportation system has been widely studied.Nevertheless,vehicular networking has the characteristics of limited communication range,highly changing network topology,intermittent communication and so on.And the traditional TCP/IP network based on host addressing and connection-oriented communication will not be able to meet the needs of low delay and large data transmission.Whereas,Named Data Networking(NDN)has the characteristics of data name-based routing,mobility support,intra-network cache and so on,which naturally matches the spatio-temporal dynamics of vehicle networking.To meet the requirements of ultra-low latency and high reliability when NDN is applied to vehicle networking,this paper focuses on the topic of efficient and reliable data transmission in named data vehicle networking,and works from two aspects: the improvement of symmetrical architecture and data forwarding mechanism of NDN in vehicle networking.The main work and innovation points of this paper are summarized as follows:1.To solve the problem that the reverse path of data packet is easy to be separated in NDN symmetric communication mode in high dynamic vehicle networking environment,an improved new architecture asymmetric NDN(a NDN)is designed and implemented.a NDN supports independent forwarding of interest and data packets by modifying packet format and improving packet processing process,and supports both PULL and PUSH communication modes.In addition,in the VANET environment,three cases of forwarding strategy separation,channel separation and PUSH mode forwarding are used to evaluate the data retrieval and broadcast efficiency of a NDN.The simulation results show that compared with the traditional NDN,the use of a NDN can effectively reduce the redundant data in the vehicle network,improve the success rate of data request in the network,and reduce the time delay by more than half at the same time.2.a NDN still has some problems such as insufficient awareness of network state and high forwarding delay in data forwarding processing.In order to further improve the efficiency and reliability of data transmission in dynamic network,a forwarding strategy called multi-factor network state awareness(MFNSA)is studied and implemented.This strategy combines the network state factors such as network congestion,neighbor node distance and interest packet destination based on the queue length of interest packets to design the forwarding waiting time.a probabilistic forwarding retransmission mechanism based on link utility value is used to ensure the reliable forwarding of interest packets and data packets in dynamic networks.The simulation results show that compared with the traditional NDN,the average complete delay of MFNSA is reduced by about 82.2%,and the request success rate is about 10%higher than that of a NDN.