Hybrid Roadside Node Placement And Data Download In VANET

With the rapid development of mobile communication and wireless access,Internet of vehicles has become the most important part of the intelligent transportation system.VANET(Vehicular Ad-hoc Network,VANET)is actually a Mobile Ad Hoc Network,frequent interruption,high mobility and low contact rate and other characteristics,has a significant impact on content download of vehicles when accessed Internet by roadside units.At the initial stage of deployment in VANET,due to the number of roadside units is limited within the scope of roadside network,the information carrying capacity and the number of data requests of vehicle nodes is far greater than the range of the roadside units.To solve these problems,we propose a hybrid node deployment solution based on the roadside advertising scene in Vehicular Cyber-Physical System,which target to maximize the benefits of deploying roadside units.The purpose of this solution is to optimize the hybrid roadside unit for merchants to maximize their benefit from advertisement dissemination when given the budget constraint and the distribution of traffic conditions.We establish models of merchant's benefit and detour behaviors by users,and determine the goal to maximize overall benefit for merchants.Meanwhile it ensures that the cost of roadside node deployment is under the budget limit.At the same time,according to the problems existing in data downloading on vehicle by the roadside units and 4G cellular network: when vehicles download data through the 4G network,there is no time and place restrictions,and the download rate is high,but it is more expensive;when vehicles download data through the VANET,it is with high download speed and low cost of content download.This paper presents a hybrid transmission mode download scheme combined with VANET and 4G networks.This solution gives an optimized slot algorithm based on this two download mode,and it solves the problem like long time delay of download data in VANET,intermittent channel scarce resources and vehicle nodes of short links etc.The simulation results show that the proposed hybrid deployment of roadside access node scheme has higher deployment revenue when compared to the previous single type of roadside access node deployment scheme.Meanwhile,by comparison and analysis of the simulation experiment about hybrid data download from multiple dimensions,it is confirmed that the slot algorithm is better than using a single download mode on the effect of data download cost minimization.