Research On Delay Of Internet Of Vehicles Based On Fog Computing

In recent years,due to the rapid increase in the number of smart devices and vehicles and the rapid growth of traffic information services,more and more problems have been caused in the service capacity and information processing in the Internet of Vehicles(Io V),which has a potential negative impact on traffic safety.In order to meet the increasingly stringent delay requirements,Io V communication often uses fog computing to process related data information.Fog computing can not only solve the problems of limited storage capacity and calculate ability of a base station effectively,but also reduce the transmission delay of information to cloud and solving the problem that cloud does not support high mobility.Therefore,in this paper,based on fog computing,we propose a hierarchical service architecture and analyze the total system service delay under different scenarios.In this paper,we first study the communication scene between pedestrians and base stations and that between vehicles and base stations in typical urban areas.Considering information reliability,Automatic Repeat-re Quest(ARQ)technique is used to increase the reliability of information,we model the transmission probabilities of pedestrian signal and vehicle signal,simulating and analyzing the relationship between different parameter factors and transmission probability.The simulation results show that the denser the pedestrian/vehicle,the smaller the success probability of signal transmission and the more the number of signal retransmissions.While studying the service delay of a base station,we also study the power consumption of a base station.In order to evaluate the trade-off between power consumption and delay of a base station,we use base station sleep mode operation to process information in Io V.We derive the theoretical model between power consumption and delay of a base station under different parameter factors.In the simulation,we compare and analyze the power consumption and service delay of a base station under different situations.The simulation results show that the power consumption and the service delay of a base station are inversely related to each other.Finally,based on fog computing,we propose a hierarchical service architecture,which includes base station layer,fog layer and cloud layer.Based on load-sharing strategy,we derive the service delay model of fog layer and cloud layer,and then derive the total service delay model of the whole system.In the simulation,we analyze and compare the relationship between different parameter factors and the total service delay of Io V system under different processing schemes.The simulation results show that the layered service of the hierarchical service architecture can reduce the total service delay of the whole system,which provides a theoretical basis for optimizing the Io V system service delay study.