Look at the white rabbit project and you could also rebroadcast the GPS signal into the cave.
brent On Tue, May 12, 2015 at 7:00 PM, Tucek, Joseph <joseph.tu...@hp.com> wrote: > I'm looking for information on non-GPS time sources. > > For background, I need to provide PTP to a cluster where we don't have > line of sight to the sky, and are unlikely to get roof-rights without a > fight. There are CDMA solutions that would work (e.g. Endrun > Technologies), but I was wondering if there were any other options. I > either need an indoor capable PTP, or an indoor capable PPS. Microsemi > claims to have an indoor capable "GNSS" system, but I've yet to find a > sales rep to talk about it; if anyone has a link to one who can, I'd love > to find out the problems^W^W^W^W talk to them about it. > > For an example of something that almost but doesn't quite work, Beagle > Software has a CDMA NTP server, but they do neither PTP nor PPS in the CDMA > version. Similarly, Meinberg will sell a PTP unit that freeruns (if you > override the config), but they have no solution to discipline via CDMA. > > I'm also curious if anyone has any idea about non-GPS time sync after CDMA > gets turned off (can I get time from 4G?). > > My endgame worst case is to just do PPS from a stratum 2 NTP (or even a > freerunning oscillator) and lie to my PTP server; hard sync to UTC is a > secondary concern so long as the cluster agrees with itself. Endrun is > looking pretty good, but I'd really like to have a second option to compare > against. > > -Joe > _______________________________________________ > 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.