On 2/7/2013 2:17 AM, Terje Mathisen wrote:
Most (GSM/3G/4G) cell towers make do with OCXOs/TCXOs, but very good
ones, rated at a few ppb/day in drift rate.
...
The interesting part here is that the actual requirement is for
_frequency_ synchronization, not absolute time sync!
You're probably not familiar with CDMA systems, which absolutely MUST be
synchronized in both time and frequency.
http://www.cdg.org/technology/cdma_technology/a_ross/systemtime.asp
Hence the appearance of surplus GPSDOs, like the HP Z3801A, which was
part of a Nortel CDMA BTS.
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