Research On Data Content Delivery And Caching Technology In Internet Of Vehicles

Data traffic has increased dramatically in the era of big data,thus resulting unprecedented challenges and opportunities in wireless communication.As a product of mobile internet,the internet of vehicles(IoV)has posed some essential challenges,such as fast and reliable data transmissions between vehicle-to-vehicle(V2V),Vehicle-to-Road Side Unit(V2R)and Vehicle-to-Human(V2H).Caching is one of the most effective ways to deal with massive data transmission.This thesis focuses on the data content delivery and caching technology in two common scenarios(V2R and V2V)of Internet of Vehicles.First,this thesis proposes a collaborative caching scheme for multiple road side units in a highway scenario.Then through system mathematical modeling,simulation platform in MATLAB is built,and the related performance parameters including RSU storage,vehicular speed,gradient of content popularity and RSU download rate are analyzed based on this simulation platform.It is verified that the multi-RSUs cooperative caching scheme can reduce the average download delay of vehicles compared with population-based caching scheme.In addition,based on the collaborative multi-RSU caching model,the system performance and complexity of traversal algorithm,greedy algorithm and substitution algorithm are analyzed and compared.Meanwhile,an improved simulated annealing algorithm is proposed,and it is shown by MATLAB simulation that the improved simulated annealing algorithm has a significant reduction in the complexity without excessively sacrificing the system performance.Furthermore,a distributed probabilistic caching scheme is proposed based on ContentCentric Network in the scenario of crossroad.The thesis gives the detailed algorithm,and proposes a dynamic popularity calculation method.Based on this distributed probabilistic caching scheme,the thesis analyzes traffic situation of the intersection scenario through MATLAB simulation.It is shown through simulation and analysis that the distributed probabilistic caching scheme has certain performance improvement in cache collision probability,cache utilization,average delay and average hop of system.