Research On Communication Model And Cache Strategy Based On NDN-IP In Internet Of Vehicles

With the popularization and development of the Internet,the main demand for users to access the Internet is to obtain data resources,the focus of users from "where to get data" to "what kind of data is needed",and the Internet of Vehicles environment has the characteristics of high-speed mobility,frequent changes in network topology and easy disconnection of wireless connections,etc.The traditional TCP/IP network based on "end-to-end" communication exposes insecurity,poor reliability and poor mobility to the Internet service performance.Therefore,the researchers propose a "revolutionary" technical route for the development of the future Internet,namely Information Center Network,in which the Named Data Network（NDN）is a specific implementation of the Information Center Network paradigm.However,in the process of evolution from the existing TCP/IP network to the NDN network,there will be a period of convergence and interoperability of two networks,so it is of great significance to study the integration and interoperability of the two network systems in the environment of the Internet of Vehicles.Aiming at the problem of reducing the high delay for end users to obtain data resources in the Internet of Vehicles environment,and can improve the node cache hit rate and reduce the cache redundancy,the problem of caching strategy for data resources in the Internet of Vehicles based on the NDN-IP communication model is studied.The main work of this paper is as follows:1.Aiming at the characteristics of high-speed mobility,frequent changes in network topology and easy disconnection of wireless connections in the Internet of Vehicles environment,an NDN-IP converged communication model is proposed.The communication model not only makes use of the characteristics of NDN PIT aggregation,in-network caching and mobility support,but also considers the reality of IP network as the current backbone network,so it builds a terminal-edge-cloud three-layer structure,with the vehicle node as the terminal user,which is in the NDN network,using the content-centric communication mode;RSU node as the edge gateway,by designing the NDN and IP conversion functions,to achieve communication between the NDN network and the IP core network;and the cloud central server as the cloud,which owns all the resources requested by the user,deploys a mapping mechanism between the request name and the data resource,and can return responses to the user’s requests.2.Aiming at the problem of high delay in NDN-IP communication network architecture based on Internet of Vehicles,a two-stage cache strategy based on cluster structure is proposed.The cluster structure takes the RSU nodes located at the edge layer as the cluster head,and the vehicle nodes within its coverage area as the members of the cluster.The first stage of the cache strategy is a probabilistic caching strategy based on global content popularity and local preference at the cluster head node.The second stage is a collaborative caching strategy based on the activity of the nodes in the cluster,the global popularity of the content and local preference of the node in the cluster,and the results of the first stage of caching at the members of the cluster.The global popularity of the content and the local preference of the node are clustered using the BRICH clustering algorithm,which is represented by the ratio of the category to which the content belongs to and all the content received,and the determination of the content cache probability weight is calculated according to the similarity of content name.3.In order to analyze the proposed NDN-IP communication model and the two-stage caching strategy under this communication model,the NDN-IP communication model is first analyzed by using the ndn SIM simulation platform to simulate the nodes at the terminal node and the edge layer,and the NDN network is used for communication,and the performance of the NDN-IP communication model is evaluated by using Alibaba Cloud Server as the cloud central node,which can provide all data resources.Experimental results show that compared with the Internet of Vehicles communication under the pure IP network,the Internet of Vehicles based on the NDN-IP communication model has better performance in terms of latency.Then,the performance evaluation of the proposed two-phase caching strategy under the NDN-IP communication network architecture of the Io V network was evaluated using the ndn SIM simulation platform,and compared with the LCE（Leave Copy Everywhere）,Prob Cache（Probabilistic Caching）and Betwe-based caching strategies,and the simulation results showed that the two-stage caching strategy could reduce the latency of users to obtain data resources.And improve the cache hit ratio of the content.