[time] GPS Time Server Survey

Tim Shoppa tshoppa
Fri Apr 25 12:55:50 UTC 2008


KE5NGX writes:
> I am designing a system with a GPS module, and started looking at all of
> the things it could do, including time.

> Since you folks are all interested in time, I was wondering which of two
> products would be of interest to you.

> 1. A GPS module with the ability to expand the serial port to more than
> 10 to allow you to use the NTP NEMA driver. The time pulse would be
> accurate to about 30 nS RMS. Retail cost about $100.

> 2. A time server with 2 Ethernet ports, with GPS time reference, to
> directly support between 50 and 100 users using GPS. Retail Cost about
> $200

> Both would be Stratum 1 by using the GPS (and later Galileo also)
> Satellites.

I personally feel that the Stratum 1's way way way over-rely on GPS
and do not have enough diversity in terms of other traceable time
sources.

CDMA is, IMHO, too closely tied to GPS.

Getting Galileo too would be a good step. Are Galileo receivers
available off-the-shelf already in preparation for deployment?

But an even better step would
be to diversify the very much inbred Stratum 1 population and have
a deeper and wider variety of Shortwave, Longwave, Atomic, etc. clocks
represented.

Tim.




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