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 time-synchronization method is the network time protocol proposed by Mills and Internet engineering task force group. A complete solution of the high-precision 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.