Traffic Classification And Supervision Of Train Control And Service Network

After decades of development,China has made remarkable achievements in the field of high-speed railway construction,high-speed train technology is already world-leading.The "CRH" and "CR" have become synonymous with speed and comfort.Whether long-distance or short-distance travel,more and more people choose to take the high-speed rail.The traditional train communication network can only guarantee the reliable transmission of train control services,cannot provide passengers with a stable and reliable internet service.But today mobile communication technology is highly developed,if passengers cannot be guaranteed effective access to the network during the ride,then it will seriously affect the passenger’s ride experience,and even cause great economic losses.With the popularization of 5G networks,large-capacity vehicle-ground communication is no longer the bottleneck restricting the development of train communication networks.Therefore,the integrated transmission of passenger service business and train control business has become the best solution to solve the above problems.To realize the integrated transmission of the train control business and passenger service business,the key problem to be solved is how to build a complete network traffic management system,on the basis of ensuring priority transmission of key train control services,maximize the use of train idle bandwidth resources to provide better internet service for passengers.This thesis takes the national science and technology support plan topic "train control and service network(TCSN)key technology and system development" as the background,studies key technical issues such as TCSN traffic classification,supervision,scheduling and simulation,and a complete solution for TCSN traffic management is given.First,by analyzing the application scenario of CRH2 train control business and the mechanism of message generation,this thesis establishes a traffic model for train control business.Integrate and classify foreign public data and laboratory capture data to construct a passenger service traffic data set TP-Traffic.After analyzing the traffic characteristics of the passenger service business in TP-Traffic,it is found that the packet arrival interval follows the heavy-tail distribution,which provides important theoretical support for the establishment of passenger service business traffic models.Secondly,according to the TCSN traffic characteristics and transmission service quality requirements,service level agreements(SLA)and traffic supervision agreements(TCA)for TCSN business have been formulated;improve the two-level token distribution algorithm,and design a three-level token distribution algorithm for TCSN traffic supervision.Third,through the integration of seven functional modules of traffic generation,traffic identification,traffic classification,traffic supervision,queue management,traffic scheduling and parameter statistics,a complete solution of TCSN from traffic generation to dispatching is given,and the TCSN simulation system based on discrete events is implemented.Finally,simulation experiments are conducted on application scenarios such as different bandwidth resources,number of concurrent passengers,class processing schemes,delay priority,packet drop priority,supervision algorithm,scheduling algorithm,etc.The validity and practicability of the TCSN traffic management scheme are verified by the analysis of the experimental results,and the optimal parameter configuration scheme of each module in different application scenarios is given.