Researches On Information Dissemination In Information-centric Vehicular Network

With the rapid development of related technologies in the fields of wireless communication technology and automotive electronics,Vehicle Ad Hoc Network(VANET),as a key supporting technology of intelligent transportation systems,has the enormous developing potential.In VANET,dynamic vehicle nodes can communicate not only with other vehicle nodes(Vehicle to Vehicle,V2V),but also with roadside facilities(Vehicle to Infrastructure,V2I).This enables the vehicles to collect and perceive information about the surrounding environment,which brings many services for the development of intelligent cities and society.From the point of view of V2V communication proposed by ITU,this paper pays more attention to the formation of ad hoc network between vehicles,then studies information distribution.However,the features of the high mobility of vehicles and the instability of wireless transmission in VANET make that reliable data transmission and content sharing becomes a great challenge.Because of the frequent dynamic topology transformation in VANET,the traditional TCP/IP network architecture cannot work efficiently.Besides,some emerging applications have characteristic of source uncertainty,which is inconsistent with the transmission mechanism of end to end of TCP/IP.Thus,this paper introduces an emerging network architecture-Information-Centric Network(ICN)to facilitate information dissemination efficiently.The main contents are as follows:Firstly,Because of inadaptability between traditional TCP/IP transmission paradigm and application scenarios,according to the characteristics of VANET,this paper integrates some features of Named Data Network into the Vehicle Networking scenario to optimize the performance of information distribution in the network,such as name-based routing,in-network caching.To address source uncertainty,this paper introduces network coding to shield the difference of packets sent by information sources.In order to maximize network transmission performance,network coding mode and chunk size are analyzed and set according to the application scenario.Secondly,although ICN solves the end-to-end transmission mechanism flaws of TCP/IP fundamentally,the data redundancy becomes a serious problem because that vehicle density in urban vehicular network is significantly higher than routers in traditional ICN.In order to solve packet redundancy caused by multiple information sources,this paper draws on the theory of three-phase traffic flow and real data sets to analyze the characteristics of vehicle mobility,further analyzes the connectivity and stability indicators of network,and puts forward the reliability indicators under different flow states,then proposes the selection of information sources on this basis finally.Furthermore,this paper proposes an efficient redundant transmission control algorithm based on network coding for VANET.It is receiver-driven and complete information sources scheduling by collaboration between requester and information source,which uses global parameter expectation deadline(EPATD)to effectively control the total amount of encoding data packets transmitted by different information sources simply and further controls the selection of information sources.Finally,performance simulation and analysis are carried out using NS-3 and SUMO simulation platform.The results show that the proposed mechanism greatly reduces data redundancy and further accelerates information dissemination efficiency.