GPS as a source of timing is a key component in not just [[Synchronization in telecommunications]] but to critical infrastructure in general. <ref>http://www.dtic.mil/cgi-bin/GetTRDoc?AD=ADA503921</ref>. Of the 18 Critical Resource and Key infrastructure (CIKR<ref>http://training.fema.gov/EMIWeb/IS/IS860a/CIKR/sectorMenu.htm</ref>)sectors, 15 use GPS derived timing to function correctly. <ref>http://www.swpc.noaa.gov/sww/SWW_2011_Presentations/Wed_830/GPS-PNTTimingStudy-SpaceWeather4-27.pptx</ref>
A key application for GPS derived timing is to provide synchronization in wireless basestations. andBase instations depend on timing to operate correctly, particularly for the handoff that occurs when a user moves from one cell to another.<ref>http://www.gmat.unsw.edu.au/snap/publications/khan&dempster2007b.pdf</ref> In these applications Holdoverholdover is used in base stations to ensure continued operation while GPS is unavailable and to reduce the costs associated with repairs <ref>http://www.eetimes.com/design/communications-design/4213947/Understanding-the-concepts-of-synchronization-and-holdover</ref>
1usSome forof the most stringent requirements come from the newer generation of wireless base- stations, where phase accuracy targets as low as 1us need to be maintained for correct operation. <ref>http://www.telecom-sync.com/pdf/2008/Day1/WCDMA_and_LTE_Synchronisation_Aspects_(Stefano_Rufini,_Ericsson).pdf</ref>▼
Base stations depend on timing to operate correctly, particularly for the handoff that occurs when a user moves from one cell to another.<ref>http://www.gmat.unsw.edu.au/snap/publications/khan&dempster2007b.pdf</ref>
▲1us for base-stations <ref>http://www.telecom-sync.com/pdf/2008/Day1/WCDMA_and_LTE_Synchronisation_Aspects_(Stefano_Rufini,_Ericsson).pdf</ref>
Search for reliable timing based on something other than $3k Rubidium spurred on by the need for CDMA to compete. <ref>http://www.4timing.com/SyncGPS.pdf</ref>
