GSM clock and phones

This is merely a historical archive of years 2008-2021, before the migration to mailman3.

A maintained and still updated list archive can be found at

Harald Welte laforge at
Thu Jul 12 14:08:54 UTC 2012

On Thu, Jul 12, 2012 at 03:41:52PM +0200, Dario Lombardo wrote:
> If yes, my question is: how can a phone determine that the clock given
> by the network is precise enough? I'm a bit confused: how can the
> phone say that's not good, if it doesn't have a precise clock itself?

The phone will trim it's oscillator against the first network it is
trying to register.  So it is not absolute accuracy that you need, but
relative accuracy.  If the first cell the phone registers to is wrong,
then it will only find other cells with an equally wrong clock.
- Harald Welte <laforge at> 
"Privacy in residential applications is a desirable marketing option."
                                                  (ETSI EN 300 175-7 Ch. A6)

More information about the baseband-devel mailing list