Research On Routing Mechanism Of Vehicle Network Based On UAV

In recent years,with the advent of special network scenarios such as vehicle ad hoc networks,interstellar networks,and sensor networks,an emerging research field has been formed for such long-latency and easily interrupted networks.Kevin Fall in 2003 proposed a new network architecture-Delay Tolerant Network,which is applied to the above special network scenarios.DTN network is a kind of mobile ad hoc network with long delay,intermittent links,and high bit error rate.There are unstable end-to-end transmission paths for a long time,so the traditional TCP / IP protocol is not suitable for DTN networks..In order to achieve efficient communication in this special network environment,DTN adds a bundle layer to the traditional Internet 5-layer protocol stack,which is called a bundle layer.The bundle layer is mainly responsible for the custody transfer of messages,accepting replies,custody delivery notifications,bundle forwarding and notifications,classification of delivery priorities,and authentication of the sender’s identity.Although the DTN’s carry-forward mechanism can provide efficient communication,it is extremely easy to form a message island in an environment such as a hard-hit area,military war,or emergency rescue,that is,a domain that cannot send messages to and receive external messages.Unmanned aerial vehicles(UAV)are gradually being widely used in search and rescue,aerial photography,reconnaissance and other fields due to their high maneuverability,good line-of-sight communication,and rapid deployment.In this paper,a UAV assisted cluster-based hybrid router(UCHR)is designed based on a vehicle-mounted DTN network in an urban environment.UCHR clusters in-vehicle networks based on connection reliability,and uses UAV as a message carrier to transfer messages between clusters.To this end,the following research is carried out:1.First of all,in the research,this paper understands the development of DTN networks in detail and the characteristics of network construction,and clarifies the architecture principle and advantages and disadvantages of several conventional DTN networks in a comparative way,and studies the control algorithms of these networks.2.Designed the UCHR routing protocol for urban vehicle DTN network environment.The protocol divides the message transmission into intra-cluster message transmission and inter-cluster message transmission by clustering the ground network.The cluster head is used to maintain the communication between the members in the cluster and ensure the transmission of messages in the cluster.Use drones to transmit messages between different clusters,and use ant colony algorithm to optimize the drone path selection and consider the social attributes between the cluster head node and the destination node.When the current cluster or the destination node and the cluster head node of the current cluster have a higher probability of encounter,the drone delivers the message to the cluster head,and the cluster head delivers the message to the destination node.3.Aiming at the phenomenon of network congestion during message transmission due to the limited node cache capacity in DTN networks,the cache management algorithm was improved,and a unified cache management strategy UCBM(UCHR Based Buffer Management)based on the UCHR protocol was given.),That is,in a congested state,discard messages with smaller survival values calculated with the ucbm algorithm.Finally,the Opportunistic Network Simulation Environment Simulator(ONE)was used to simulate and analyze the UCHR protocol and UCBM cache management strategy and compare it with several typical routing protocols and management strategies.this paper uses three performance metrics: message delivery rate,network overhead and average transmission delay to evaluate routing protocols and cache management policies.Simulation results show that the UCHR protocol and UCBM cache management strategy are improved on three performance indicators.