基于概率同步算法的计算机外时钟同步系统设计与仿真

Design and Simulation of Computer External Clock Synchronization System based on Probabilistic Synchronization Algorithms

在计算机软件时钟同步系统中 ,网络延迟的测量与建模、同步算法的设计及算法性能的评估是要解决的三个主要问题。该文研究了基于概率同步算法的计算机外时钟同步系统设计。首先研究了基于PC高分辨计数器接口的网络延迟精确测量方法 ,对几种典型网络环境进行了测量 ,建立了网络延迟的对数正态分布统计模型。然后推导了在网络延迟为对数正态分布模型下的同步包数目的计算公式 ,研究了基于该公式的概率同步算法参数设计。最后 ,对单个从节点情况下改进的概率同步算法的性能进行了仿真检验。结果表明 ,基于网络延迟的对数正态模型的推导和设计是正确、可靠的。改进的概率同步算法具有较高的同步效率和同步精度 ,可以用于实际的仿真系统。

In computer software clock synchronization system, the measurement and modelling of network delay, the design of synchronization algorithm and the performance evaluation of the synchronization algorithm are the main problems to solve. The problem of designing computer external clock synchronization system with probabilistic algorithm is studied. Firtstly, the method to precisely measure the network delay is studied, and the actual network delay of typical network environments are measured and modelled, then the formula to compute synchronization package number is deduced from the log-normal model of network delay. The design of synchronization algorithm parameters is studied with this formula. The performance of probabilistic synchronization algorithm with single slave node is tested by simmulation.