[time-nuts] lightsquared test in las vegas

Hal Murray hmurray at megapathdsl.net
Thu Jun 9 21:32:08 UTC 2011


> Does the GPS world really have much to say about the interference if
> LightSquared keeps their transmitters clean and out of the GPS spectrum? 

I think the key idea is that the receiver can't build a brick-wall filter.  
Even if the transmitter stays within their assigned band, a strong enough 
signal near enough to the receiver channel will leak through the filters.

At the FCC level, there has to be coordination between the frequency 
allocations, the signal power the receiver is expected to work with, and the 
expected signal power at the receiver from the transmitters on nearby 
channels.

If the Lightsquared frequency assignment were farther away from the GPS 
frequency we wouldn't be having this discussion.  Some other users might be 
complaining, but if their application used stronger signal levels at the 
receiver it might be easier to find a workable solution.



-- 
These are my opinions, not necessarily my employer's.  I hate spam.






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