基于SPN的铁路时间同步网建模与性能分析

Modeling and Performance Analysis of Railway Time Synchronization Network Based on SPN

铁路时间同步网是铁路通信网中重要的支撑子网,该网络为铁路内部各系统提供统一、标准的时间信息,其性能直接关系到故障的快速准确定位,对其进行建模与性能分析具有重要意义。本文根据铁路时间同步网的结构、通信过程以及所选用的网络时间协议NTP,采用随机Petri网建立铁路时间同步网通信模型与故障处理模型,利用随机Petri网性能分析方法计算网络延时,进而计算得到同步周期与绝对守时准确度两个性能指标之间的关系。同时采用TimeNET仿真工具对铁路时间同步网模型进行性能分析并得出相应结论。分析结果表明,铁路时间同步网客户端与服务器具有较高的正确同步成功率。

The railway time synchronization network, an important support network in the railway communication network, provides unified and standard time information for railway system. As its performance is directly related to the rapid and accurate fault location, it is of great significance to carry out modeling and performance analysis on this network. In this paper, the railway time synchronization network communication model and the fault process model were established by using stochastic Petri nets, according to the structure and communication process of the railway time synchronization network, and its chosen network time protocol （NTP）. The stochastic Petri net performance analysis method was introduced to calculate the network delay and to obtain the relationship between synchronizing cycle and absolute punctuality accuracy. At the same time, the TimeNET simulation tool was used to analyze the performance of the railway time synchronization network model and draw the corresponding conclusion. The analysis result proved higher success rate of synchronization with the client and server of the railway time synchronization network.