[Soekris] Time keeps on slippin into the future... (was net4501 + FreeBSD losing time?)

Darryl Okahata darrylo at soco.agilent.com
Tue Feb 4 19:17:23 UTC 2003


Chuck Yerkes <chuck+soekris at 2003.snew.com> wrote:

> Now given that GPSs are fairly cheap, at the consumer level
> and at the chip level, and given that you can start to see
> early consumer GPSs on the used market becuase they don't meet
> current consumer needs (a display of your Lat/Long/Alt isn't
> as useful as the current models that can put you on a map),
> what's the state of pulling a serial line of THOSE to get time
> and be Stratum 1?
> 
> Can the first gen Garmins be used for this and is it practical?

     Not if you need accuracy.  The consumer GPSs have only serial
ports, which introduce jitter.  While it can be used to get passable
accuracy for an home network, people who have tried it report accuracies
of around +/- 100ms (that's 0.1 sec!).

[ Of course, a lot of that is probably introduced by not taking into
  account the character transmission delays, etc..  ]

     For some viewpoints, see:

	http://groups.google.com/groups?hl=en&lr=&ie=UTF-8&threadm=up0ogq3rdlm9b4%40corp.supernews.com

	http://groups.google.com/groups?hl=en&lr=&ie=UTF-8&threadm=fa.no5t0ov.pk6gqd%40ifi.uio.no

	http://groups.google.com/groups?hl=en&lr=&ie=UTF-8&threadm=3AF6D6E4.49C88CB4%40udel.edu

-- 
	Darryl Okahata
	darrylo at soco.agilent.com

DISCLAIMER: this message is the author's personal opinion and does not
constitute the support, opinion, or policy of Agilent Technologies, or
of the little green men that have been following him all day.



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