Mobile data and movement

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pcslookout

Lifer
Mar 18, 2007
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Does 3G or 4G mobile data slow down while you are on the move in a car or bus ?

If so why and is there anyway around it ?
 

who?

Platinum Member
Sep 1, 2012
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Moving towards or away from the antenna? It's electromagnetic energy like light so this is a speed of light question.
 

Mark R

Diamond Member
Oct 9, 1999
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LTE has channel frequency tracking, which is good for about 1 kHz of frequency offset. Given a carrier of 2 GHz, that works out at a Doppler velocity of about 320 mph.

Because of the active channel frequency estimation, Doppler shifts lower than the tracking rate should be accurately handled without signal degradation. Above the limiting Doppler velocity, it is unlikely that the system will work at all.
 

sm625

Diamond Member
May 6, 2011
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My 4G has always worked best on the highway. I guess that is because that's where they put the towers.
 

BarkingGhostar

Diamond Member
Nov 20, 2009
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Moving between towers, or even between radio technologies (3G vs 4G) can have differing collective consumption taking place. Its not a single radio your phone is talking with, but many and as your link hops from radio to radio, both within the same tower and multiple towers, the available performance can easily change. Then there are other aspects that can come into play, like the moron in the car beside you hogging all the bandwidth because they are on the same utran of the same radio tower/carrier. :D
 

John Connor

Lifer
Nov 30, 2012
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LTE has channel frequency tracking, which is good for about 1 kHz of frequency offset. Given a carrier of 2 GHz, that works out at a Doppler velocity of about 320 mph.

Because of the active channel frequency estimation, Doppler shifts lower than the tracking rate should be accurately handled without signal degradation. Above the limiting Doppler velocity, it is unlikely that the system will work at all.


Actually, the sporadic difference in harmonics with the frequency shif, the BFO in the phone and the gravitational pull of the earth and whether or not those tacos from Taco Bell make me pass gas will have a bearing on whether the signal degrades or not. :twisted:
 
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