Fundamentals of Time Synchronization

Abstract

Communication infrastructure that enables today’s connected digital economy relies on synchronization of clocks. Improper synchronization of clocks may render serious network issues from performance degradation to catastrophic failure depending upon applications. Synchronization is categorized based on frequency, phase, and time for which oscillator serves as the core clock source. Atomic clock or atomic frequency standard remains to be the most sought-after yet expensive proposition for primary clock source. There are different atomic clock standards such as hydrogen maser, rubidium, cesium, and quantum. However, these clocks are bulky and may not be suitable for most environments. The chip-scale atomic clock (CSAC) is an effort undertaken by DARPA and NIST to miniaturize atomic clock. For worldwide coordination of these clocks, a unit of time is important and thus UTC was defined to regulate clocks and provide a standard time for coordination.