Research On Train Real-Time Ethernet Base On OPNET Simulation

In recent years,the operating mileage of Chinese high-speed railway ranks first in the world.In 2017,the operation of ’Fuxing’,which was completely independently researched and developed by China,it indicates that Chinese high-speed train manufacturing technology has reached the world’s leading level.The current train communication network is TCN network,and the maximum bus transmission rate is 1.5mbps.However,with the increasing demand for diversified network services,the traditional TCN network will face huge challenges.In order to solve the problem of high bandwidth requirement of train communication network,International Union of Railways and International Electrotechnical Committee introduced Ethernet technology into the train communication network,and successively promulgated new standards for the Ethernet-based train communication network in 2010.However,the traditional Ethernet communication mechanism has problems such as uncertainty and poor realtime performance,which will affect the train’s network performance and safe driving.Therefore,it is necessary to study the network performance of the train communication network based on Ethernet and improve the network performance of the train network.In this thesis,starting from Ethernet train communication network,on the basis of studying the real-time performance of the Ethernet train communication network,conducts in-depth the link aggregation design of Ethernet train backbone network based on the LACP protocol and conducts an in-depth study on scheduling algorithm of switch based on Ethernet train network.The main research results of this thesis are as follows:(1)This thesis studies the overall architecture of the Ethernet train communication network,deeply analyzes the structure and performance of the Ethernet train backbone network and the Ethernet train composition network,and classifies the data of train communication network.Research the Real-time Ethernet and Train Real-Time Data Protocol,analyze the factors that affect real-time performance of the train Ethernet,and combine literature to propose improvement method for real-time communication of the Ethernet train.(2)A design scheme for link aggregation of the Ethernet train backbone network based on the LACP protocol is proposed.The XOR folding Hash algorithm based on the source IP address is designed in the train level switch port,the link bandwidth is increased,the load balance is realized,and the redundancy dynamic backup between links is effective,which effectively improves the reliability of train network.(3)A hierarchical switch scheduling algorithm SRREDF based on train ECN network is proposed.The mathematical model is used to calculate the upper bound of end-to-end delay of FCFS,PQ and SRREDF algorithms,and the validity of SRREDF algorithm is verified theoretically.(4)The OPNET network simulation software is used to verify the feasibility of the link aggregation design scheme of the Ethernet train backbone network.By comparing the end-to-end delay and jitter of FCFS,PQ and SRREDF algorithms based on ECN,the effectiveness of srredf algorithm is verified.Finally,this thesis summarizes and think about the research content of this thesis,and puts forward the problems that need to be further studied and solved in the future.