Research on Distributed Time Synchronization in Expressway Toll System

Expressway toll system is a complex distribution network, the synchronization of individual clock in the system is the basis of toll system and expressway management. This paper analyses the hierarchical architecture of time synchronization in the computer network of expressway toll system, and explores the characteristics and applicable conditions of several useful methods of time synchronization. Furthermore, three simple and reliable methods of distributed time synchronization are proposed to ensure the synchronization of individual clock according to their utility in expressway toll system. Finally, the arithmetic method of clock synchronization of the algorithm is offered. The application of the toll system indicates that the synchronization accuracy of network clock not only satisfies the requirement of the expressway toll system, but ensures accurate, efficient and automatic operation of the toll system as well, which also gives guidance to the computer network requiring time synchronization.