Research On The Deployment Of Roadside Units In The Internet Of Vehicles

Nowadays,the number of vehicles increases dramatically,and the increase speed has exceeded that of constructing transportation infrastructure.This has brought great pressure to traffic.The Internet of Vehicles,one of the most important contents of intelligent transportation,can solve the social problems effectively.Vehicle-to-Infrastructure is an important communication method in the Internet of Vehicles.Vehicles exchange messages by using the infrastructure called Roadside Units（RSUs）,and the global efficiency of the VANET may be largely improved.However,since it is usually very expensive to install the RSUs,it is necessary to determine the amount and the location of RSUs appropriately.The problem of roadside unit deployment in VANET has attracted considerable attention in recent years.In this thesis,the problem is studied,and the main research work is as follows:Because the"false high"relative contact time of vehicles at urban cells might play a negative effect on decision-making,the concept useful contribution is presented,and an algorithm for deploying RSUs is devised based on the concept.The method corrects the relative contact time of vehicles at urban cells,i.e.,avoids the negative effect of“extra”contact time by retaining only the useful relative trip duration of a vehicle at an Urban cell.In terms of the characteristics of different vehicle agglomeration degrees,a dynamic useful contribution method is proposed based on the static one,and the Delta-uc algorithm is devised by combining both the static and the dynamic one.Compared with algorithm Delta-r,the Delta-uc algorithm required fewer RSUs to achieve the same（35）_?^?1₂-Deployment,which were proved by a number of experiments on the realistic mobility trace of Cologne,Germany.Based on the Delta-uc algorithm,an effective recombination operator is designed,and a parthenogenetic algorithm UCPGA is proposed to solve the deployment problem.The recombination operator produces new offspring chromosome based on Useful Contribution to construct a new search area.Firstly the operator randomly removes some grids that have been selected from the individual.Secondly,select grids by using the greedy algorithm Delta-uc based on Useful Contribution so that the requirement of QoS is met.Experiments were conducted with the same data set.The results showed that under the same requirement of QoS,the UCPGA algorithm obtained fewer roadside units than the Delta-GA and the Delta-uc algorithms.Based on the Delta-uc and the UCPGA algorithms,an application software is designed for deploying roadside units.The software is developed in Java language,and includes such main functions as deployment design,document storage,brief introduction,and product.Deployment design function module,integrating algorithms Delta-uc and UCPGA to obtain the roadside unit deployment scheme,is the core part of the software.Document storage function module is in charge of recording related operations and saving deployment results.Brief introduction functional module introduces relevant usage and precautions.Product function module describes the information and contact way about the development team to facilitate later maintenance.In summary,the roadside units deployment problem is studied in this thesis.Two effective algorithms Delta-uc and UCPGA are proposed,and a related application software is designed.These studies will offer theoretical support for further improving road traffic.