Content deleted Content added
resolved duplicate references |
|||
Line 7:
But if the connection to the reference is lost then the base station will be on its own to establish what time it is. The base station needs a way to establish accurate frequency and phase (to know what time it is) using internal (or local) resources, and that’s where the function of holdover becomes important.
Two independent clocks, once synchronized, will walk away from one another without limit.<ref name="smartclock">{{cite paper|url=http://tf.nist.gov/general/pdf/988.pdf |title=Smart Clock: A New Time |publisher=[[IEEE]] |date=1992-12-06 |accessdate=2012-10-21}}</ref> To have them display the same time it would be necessary to re-synchronize them at regular intervals. The periods between synchronizations is referred to as '''Holdover''' and performance under Holdover relies on the quality of the reference oscillator (usually an [[OCXO]]), the PLL design and the correction mechanisms employed.<ref name="analog1">{{cite web|url=http://www.analog.com/static/imported-files/application_notes/AN-1002.pdf |title=AN-1002 (Rev. 0) |format=PDF |date= |accessdate=2012-09-28}}</ref>
==The Importance of GPS Derived Timing==
| |||