Hi Somnath,

The main clock on the Telos motes runs on an internal DCO which has a
lot of frequency error (could be on the order of 10%), unless the
error is corrected through periodic recalibration with the crystal.

I believe the timers are run off the 32KHz crystal in TinyOS, which
would lead to a worst case of 40ppm freq error.

The clock drift is essentially (in sec), drift =
(time_since_last_sync)*(freq_error_in_ppm)/1e6.

This means that if you don't resync periodically, your clock drift
could be unbounded.
Hope this answers your question.

Zainul.

On Sat, Oct 18, 2008 at 1:17 PM, Somnath Mitra <[EMAIL PROTECTED]> wrote:
> Hello ,
>
> People who have worked on time synchronization, can anyone please tell me
> that -
>
> Can we say that there is a maximum upper bound on the amount of drift of the
> clocks of Telos like platforms ?
>
> Thanks,
>
> Somnath Mitra
>
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