 24 hours in a day and 360 degrees of longitude around the earth, it is obvious that the world could have 24 time zones with the average single hour time zone covering longitude of 15 degrees (360 / 24). With this scheme, various governments around the world could adopt one or more of the time zones (or even quarter- and half-hour time zones) that worked for their situation. The result was that all clocks within a time zone were aligned to the same time reference rather than being locally defined. That way, local communities could have a common understanding of scheduled events like train timetables. Larger countries could adopt more than one time zone SO that the local time did not di- verge too far from the daily movement of the sun. 1.2 What Is Synchronization and Why Is It Needed? Time synchronization is simply a mechanism to allow coordination and alignment among Processes, such as robots in a factory working on a single widget. Clocks that are running independently of each other, such as wall clocks across a railway net- work (including changes for summertime or daylight saving time). Computers that should process information in the correct time order, such as executing trades on a stock trading system. Multiple streams of information that should be presented in a strict sequence or coordinated with each other-a good example is audio and video in a TV signal. Events observed at multiple locations. Observers can determine the location of an event (for ex- ample, tracking storms via lightning strikes) if several lightning detectors can all record the de- tection time with closely aligned time clocks. Sensors monitoring real-world processes. If an accurate timestamp is logged against an event, operators can determine the correct sequence in a chain of events leading up to a critical situ- ation (such as monitoring the stability of the power grid). Accurate timing is also a critical attribute of a modern mobile network. These networks require a well-designed and implemented synchronization system to maximize th