Time synchronization in a local area network

In this article we examine the problem of synchronizing the time-of-day clock in one node of an automation network system with a reference clock. The emphasis of this article is on switched, highly loaded networks, where unpredictable delays introduce excessive synchronization noise. PC clocks are accurate enough when connected within a network, but a new requirement is for them to be synchronized, which means that they should show the same time at the same instant. The most prominent timesynchronization method is the network time protocol proposed by Mills and Internet engineering task force group. A complete solution of the highprecision time-synchronization problem must reduce the randomness associated with the RTOS. The methods discussed in this article can help determine the frequency and time offset of a local time-of-day clock. The next challenge is to construct a local time-of-day clock and apply the synchronization information to it.