Low Delay Mix-flows Scheduling Strategy For VANET

In recent years,the reliable transmission of data in VANET(Vehicular Ad-hoc Network)has attracted interest in both academia and industry.Among them,VANET applications such as vehicle collision avoidance,driving path optimization,traffic information,and available parking spaces are faced with serious challenges of transmission reliability.Aiming at the reliable transmission requirement of different data streams in VANET,we design a low delay mix-flows scheduling strategy for VANET,which can improve the performance and efficiency of VANET system.With the research background in both coexistence of different priority data streams in VANET applications and the needs of corresponding transmission requirements respectively,we propose a low delay mix-flows scheduling strategy for VANET,which considers the bandwidth limitation.Therefore,our proposal successfully solves the problem of resource and rate allocation in mixed data streams,i.e.,this strategy not only meets the need of different data flow transmission,and improve the user experience,but greatly reduces the system delay.The specific research contents include:1)We proposed a mix-flows scheduling strategy for VANET.In order to meet the transmission requirements of mixed data streams with different priorities in VANET,this paper takes the factors such as transmission revenue,storage cost and packet loss into account,and models it as the V_MFS model,and proves that the problem is an NP-hard problem.Then the solution of the optimization problem is transformed into 0-1 knapsack problem and using the TESA algorithm which is proposed by using the simulated annealing algorithm to solve the problem.Thus,the data flow resource and rate allocation problem of VANET with different priority are solved successfully.By analyzing the TESA algorithm,Time complexity is O(log?(1/T)×L).2)A joint optimization strategy of mix-flows scheduling and path selection in VANET is proposed.Aiming at the real-time transmission problem of delay sensitive data stream in VANET,in this paper,based on the V_MFS model,the path selection condition is added and modeled as V_MFSPS model to meet the need of mix-flows scheduling,as well as the reliability and real-time transmission for both delay sensitive data and original data.We prove the NP-hard property of the V_MFSPS model,and prove that the link capacity is the basis of the path selection through the rigorous mathematical analysis.The PS&TESA algorithm is therefore used to solve the model.The time complexity of the algorithm is O(log?(1/T)×L×n2).In order to verify the validity of the proposed algorithm,this paper has carried on a lot of simulation.The simulation results are analyzed from the aspects of problem scale,CPU running time,transmission delay and objective function,and the final results show that the proposed algorithm is efficient and feasible.