[ntp:questions] UK report on GPS vulnerabilities seems to overlook NTP

Q .. at ..
Wed Mar 9 01:11:54 UTC 2011


"Chris Albertson" <albertson.chris at gmail.com> wrote in message 
news:AANLkTimwu-EZZXv9pp-GBg9MfT1yLhSf9EDrDzLKjnD0 at mail.gmail.com...

> I can't defend the design of CDMA cell technology.  But I'm sure a lot
> of it was driven by trying to get as many calls as possible into a
> limited bandwidth.      Another requirement for precision timing comes
> from the need to measure the signal's speed of light delay.  They use
> this to locate a phone by noting the differences in the delay to
> several towers   A uS is about 1000 feet so they need to do this far
> better than to a uS.

There are lots of other systems that will break as well that people didn't 
think of;

Clustered microwave links
Clustered WiMAX and point to multi point data access points
TETRA
P.25 (I think depending on the configuration)
Motorola SmartZone & SmartNET (Depending on configuration)
Digital Quazi/Simulcast radio networks (Mototurbo)

Some of those platforms accept any valid clocking source but most depend in 
there default setup on GPS.

So far as time of day goes - The people's systems I deal with have S0 GPS 
and MSF or DCF77 inputs to there S1 devices so that will be fine - Alas we 
don't have any proper caesium clock sources.





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