Research On Performance Optimization Of Data Service Technology In VANETs

In recent years,with the continuous expansion of cities all over the country,the number of motor vehicles has been increasing,and the rapid growth of traffic has caused tremendous pressure on the urban traffic,which has caused inconvenience to people’s travel,while the pollution caused by vehicles has also greatly reduced the air quality,leading to a continued declining in people’s health.However Intelligent Transportation System(ITS)is expected to be an effective means to deal with this problem.It uses advanced information technology to control urban traffic,optimize resource allocation,and improve the operational efficiency of the transportation system.ITS is an important part of building a smart city,and VANETs(Vehicular Ad-hoc Networks)is an essential technology to construct an ITS.However,the complex wireless communication environment and the high mobility of vehicles bring great challenges on the data service in VANETs.In this paper,two issues are investigated,namely multi-hop routing protocol based on V2 V communication and data service technology based on V2I/V2 V collaborative communications in VANETs.The main contributions are as follows:1)We investigate multi-hop routing protocol based on V2 V communication in VANETs.First,a mechanism for self-evaluation of nodes is established by using fuzzy logic theory,the stability of nodes is quantitatively evaluated.On basis of this,an AOMDV-based routing protocol named AOMDV_NSE is proposed,which aims to ensure the stability of routing in VANETs.Finally,an extensive experiment is carried out to verify the superiority of proposed algorithm in term of packet delivery rate,end-to-end delay,and routing overhead.2)We investigate data service technology based on cooperative V2I/V2 V communications in VANETs.First,based on fog computing and software-defined network,we propose an architecture for data service in VANETs.Based on proposed system architecture,we formulate a new problem called Cooperative Service in Vehicular Fog Computing(CS-VFC),the objective of CS-VFC is to maximize the bandwidth efficiency of Vehicle to Cloud(V2C)communication.Then,we design the encoding-based broadcasting strategy for cloud layer and the cooperative service scheme for fog layer.Simulations with different size of the dataset and the number of caches of vehicles are conducted,results show that the algorithm proposed can effectively improve both bandwidth utilization and service rate,and greatly reduce average service latency.