基于分层调度算法的列车通信网络实时性研究

Research on Real-time Performance of Train Communication Network Based on Hierarchical Scheduling Algorithm

针对现有列车通信网络带宽小、实时性不高等问题,提出一种基于优先级的列车通信网络分层调度算法。该算法采用静态和动态优先级相结合的方式,首先,根据列车通信网络数据类型和实时性需求,进行静态优先级分配并进行以太网帧封装;然后利用最小截止期优先算法作为动态优先级调度,确定最终优先级。使用网络演算理论和OPNET建模仿真对该算法的可行性进行验证,结果表明,相较于固定优先级调度算法,分层调度算法可以使优先级较高的监督数据和过程数据的实时性分别提高61.7%和61.9%,可为列车通信网络实时性研究提供理论参考和方法支撑。

In order to solve the problem of low bandwidth and low real-time performance in the existing train communication network,a priority-based hierarchical scheduling algorithm for train communication network was presented.The algorithm combines static and dynamic priority.Firstly,the static priority was assigned according to train communication network data type and real-time requirement,with the Ethernet frame encapsulated.Then the frame data was scheduled by using the Earliest Deadline First Algorithm as dynamic algorithm.Afterwards the final priority was determined by combining the static priority and the dynamic algorithm.The feasibility of the algorithm was verified by network calculus theory and OPNET simulation.The results show that the hierarchical scheduling algorithm,compared with the static priority scheduling algorithm,can improve the real-time performance of high priority supervisory data and process data by 61.7%and 61.9%respectively,which can provide a theoretical and practical reference for the real-time performance of train communication network.