[time-nuts] Distributed DDS
javier.serrano.pareja at gmail.com
Mon Jan 31 08:49:41 UTC 2011
On Sun, Jan 30, 2011 at 11:08 PM, ehydra <ehydra at arcor.de> wrote:
> I'm not sure if I overview the problem correctly. Hm, why not run the cable
> back and measure the round time? Half this time und you know the delay of
> one way. Then you can shift this with a PLL away.
> This is (kind of) what White Rabbit does. In our case, we use a single
fiber with bi-directional transceivers (one wavelength for TX, another one
for RX) and apply a suitable correction factor to account for the difference
in group velocities between the two wavelengths. We could do what you
suggest with each RF to be broadcast, but there are many of them so it would
be wasteful in terms of cabling.
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