Performance Analysis Of Communication Network Based On Vehicles Assistance In The Parking Lot

In urban vehicular networks,Road Side Units(RSUs)can improve the performance of the network as content distribution nodes and relay forwarding nodes.However,deploying RSUs often requires a large amount of investment and elaborate design,which keeps these units from widespread deployment.There are a large number of parking vehicle in urban areas,and these parked vehicles can be regarded as static nodes to assist communication in urban vehicular networks,becoming a new type of RSU.Despite parked vehicles are characterized by large number,long-time staying and so on,for a single vehicle,it can leave at any time and is energy-limited.In order to better integrate the resources of parked vehicles into the existing vehicular network architecture,what impacts on performance of network based on the assistance of parked vehicles that parked vehicles can leave any time and be energy-constrained take need to be studied urgently.In order to take the mobility of parked vehicles into consideration in the performance analysis of networks based on parked vehicles assistance,first,we built a system model based on the vehicle-assisted communication network architecture in the parking lot.With the vehicle arriving time model and parked duration model in the parking lot,the distribution function of the vehicle leaving probability is given,and the power consumption of the parked vehicle is briefly analyzed.On this basis,the outage probability,channel capacity and energy efficiency of the vehicle-assisted communication link in the parking lot are derived.Comparing to the situation where parked vehicles cannot leave any time and are not energy-limited,network performance such as outage probability is more fluctuating in one day,which caused by the mobility of the parked vehicles.As the signal-to-noise ratio threshold increases,the influence of vehicle departure behavior will gradually decrease.For relay node selection problem of communication network based on parked vehicles assistance,the thesis then studied the impact of vehicle arrival time and vehicle duration on the network performance in the flow model of parked vehicles in the urban parking lot.Through the analysis of Monte Carlo simulation results,the vehicle arrival time has a greater impact on network performance,and it can be understood approximately that selecting parked vehicles which arrived easier to assist communication can reduce the outage probability of this link.The duration of the vehicle has little impact on the network performance,which can almost be neglected.Based on the above conclusions,the paper improved the maximum and minimum criteria algorithm,and proposed a relay selection strategy based on vehicle departure probability and remaining battery.And comparing with the random selection strategy and the selection strategy based on the instantaneous signalto-noise ratio,it has a better effect in reducing the outage probability of communication system.