So why not do White Rabbit free space ? Cheers Michael
On Sat, Apr 30, 2016 at 4:04 AM, Paul Boven <p.bo...@xs4all.nl> wrote: > Hi everyone, > > On 04/29/2016 03:28 PM, Magnus Danielson wrote: >> >> Phase/time transfer over fiber is shaping up, but White Rabbit is >> starting to grow up and more reports for long distances is showing up. >> ETFT is one of the placces to check for reports. > > > And the White Rabbit workshops, with the presentations online: > http://www.ohwr.org/projects/white-rabbit/wiki/Mar2016Meeting > > I happen to be working on time transfer via White Rabbit. The White Rabbit > standard proscribes the use of 1000Base-Bx10 (10km reach bi-directional) > SFPs, but it turns out to work just fine with longer reach SFPs. However, > there are several effects that limit the accuracy that you can get on longer > links: > > * Dispersion of the fiber (as the lasers change temperature, their > wavelength changes, and they experience a slightly different index of > refraction, hence propagation speed. > > * Change in index of refraction in the fiber itself. The propagation speed > of both the uplink and downlink wavelength change, in absolute sense but > also their ratio changes. This is something the WR protocol can't > detect/correct for. > > There are several people working on these issues, trying to improve both the > calibration and stability even further. > > Regards, Paul Boven. > > > _______________________________________________ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.