The Centre for metrology and accreditation in Finland (MIKES,
http://www.mikes.fi ) is evaluating White Rabbit for time & frequency
Long distance time transfer
MIKES has set up a White Rabbit link between two PCs that are connected
with a 1000 (one thousand!) kilometer link. This work is a
collaboration between MIKES and CSC (http://www.csc.fi) - IT Center for
Science Ltd that operates FUNET (the Finnish University Network.
The White Rabbit console reports a mean round-trip-time (RTT) delay of
10.4 ms with a daily variations of ca +/- 40 ns.
10.4 ms corresponds to a ca 2000 km round trip, assuming a refractive
index of 1.5.
The WR protocol is compensating for the daily variations, but this could
not yet be verified as both points are physically spaced at a 567 km
This experiment shows that the White Rabbit hardware and protocols are
much more flexible than the original design goal for use at maximum
distance of ten kilometer. Also the fact that the designs are "Open",
made that MIKES could easily replace the original SFP lasers by longer
Sample text - to be replaced>*
Link distance: 1000 km link sending UTC (MIKES) from A to B