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Discussion of precise time and frequency measurement

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Striking change in iPhone time accuracy with 8.2

P
Paul
Fri, Apr 3, 2015 2:58 AM

On Wed, Apr 1, 2015 at 4:41 PM, Oz-in-DFW lists@ozindfw.net wrote:

The phone has to keep synch within a few microseconds of the network.

I suspect only the so-called baseband system needs to  maintain any
synchronization with the RF network and the "alarm" clock is only loosely
coupled. I have an LTE radio in my iPAD and according to Emerald Time the
alarm clock varies from .5s to .005s error. I'm sure a signifcant fraction
of that is server error but it doesn't seem worth it to do more careful
testing given how fussy Emerald Time can be.

On Wed, Apr 1, 2015 at 4:41 PM, Oz-in-DFW <lists@ozindfw.net> wrote: > The phone has to keep synch within a few microseconds of the network. > I suspect only the so-called baseband system needs to maintain any synchronization with the RF network and the "alarm" clock is only loosely coupled. I have an LTE radio in my iPAD and according to Emerald Time the alarm clock varies from .5s to .005s error. I'm sure a signifcant fraction of that is server error but it doesn't seem worth it to do more careful testing given how fussy Emerald Time can be.