Time Synchronization in Networks: A Survey

With the development of network communication, time synchronization plays an important role in various network application scenarios. However, different network scenarios exist different characteristics and complexity. Therefore, in order to meet the needs of different application scenarios, various time synchronization schemes are proposed. The Internet is the most common application scenario, and wireless sensor networks(WSNs) are applied under condition-limited scenarios with less nodes. This paper analyzes the existing time synchronization protocols under these two kinds of network from the aspects of accuracy, resource consumption and so on. NTP protocol and PTP protocol are introduced in detail for their outstanding advantages. Time synchronization protocols in WSNs have their own advantages in different aspects, and distributed synchronization mechanisms are mostly better than centralized synchronization mechanisms. We also explore accuracy and security due to importance of them in time synchronization.