Research On The Performance Of Train Communication Network Based On Ethernet

The Modern train is developing towords automatization, comfortable and high-speed. The status and role of the train communication network is also increasing, resulting in the higher requirement of network bandwidth. Most of the traditional train communication network use fieldbus network technology, its technology and bandwidth are limited. With extraordinarily rapid development of Ethernet technology, one of the development directions of train communication is use Ethernet as the train communication network. However, domestic studies in train communication networks based on Ethernet are just started, there are many issues are to be further studied and solved. Therefore, there is important significance to research on Ethernet-based train communication network to develop domestic train control product break the blockade of foreign technology.In the thesis, the feasibility of the introduction of Ethernet technology into train communication network is studied. In order to ensure the authenticity and credibility of the simulation results, the business of actual CRH2train communication network system is analysis, the traffic model is built and simulation traffic is generate based on traffic model.Secondly, the performance of the train communication network based on Ethernet is studied based on software simulation methods. The requirement analysis, scheme design, software function modules dividing, detailed design of the functional modules, software coding, system deploying and testing are accomplished. Simulation results show that the data transmission delay of the class of train control meets the requirements of the actual business. The probability of the statistical delay exceeds given delay, the maximum delay and packet loss probability can provide a reference for using Ethernet technology to build EMU actual network control system.Then, OPNET network simulation software is used to study the performance of Ethernet-based train communication network. The performance of transmition of the equipment status data, control command data and fault simulation data in10M and100M Ethernet-based train communication network is studied with simulation. The simulation results show that the10M and100M Ethernet communications network can met the requirement of real time and reliability. The ultimate performance is also studied, and the results show that the ultimate rates of10M and100M Ethernet is5.2Mbps and45Mbps respectively.Finally, to study real-time of switched Ethernet is studied and its upper delay bound is derived based on network calculus tool. With the actual flow of CRH2. the upper delay bound of100M Switched Ethernet is calculated.