Re: Do these cellular amplifiers work for all cellphones?

On 10 Apr 2022 at 8:54:09 AM, David Woolley <[email protected]>
wrote:

> On 09/04/2022 21:20, Heron wrote:
>> I wonder how those cellular radio boosters handle that encryption then?
> 
> They will repeat the encrypted signal without understanding it. 

I don't have a cellular booster so am not sure if the vehicular cellular
boosters will repeat any signal other than the registered owner's cellphone
signal given they must be registered with a carrier by FCC regulations (even
the multi carrier ones must be registered to all the carriers I think but I
think that registration happens on the selling side, much like how they
collect taxes for you).

I don't know what happens if you use a non registered vehicular cellular
booster but I saw on the FCC site describing legacy devices which were made
prior to the new ruling that they won't go after you unless they receive a
complaint about interference. That implies at least the older vehicular
cellular boosters work on all carriers without needing to register it.

> One implication is that they won't see the power control signalling, 
> although they might sense that the mobile has reduced power.

The 2022 PC Magazine vehicle cellular boosters review specifically describes
the "uplink" as the "connection that goes first" when you are at "the edges
of cell coverage" which they defined as somewhere around below -110dBm.

Even the cheapest vehicle cell signal booster which is an on-the-dash device
has 23dB of gain, which should theoretically boost that weak -110dBm signal
into a respectable range in the mid eighties for that uplink (assuming they
were honest in their FCC certification, which we have to believe is true).

The gain for a home is gargantuan at 100dB in single carrier boosters, and
even the multi carrier boosters provide prodigious gains of 63dB to 72dB.

For vehicles the limits are 65dB for single carrier registrations and 50dB
for multi-carrier setups, which is still a massive uplink signal gain.

Assuming the FCC isn't being conned by the makers of these vehicular
cellular signal boosters, I have to assume these more than substantial
uplink gains will enable someone at the fringe of reception to be squarely
in the middle of the good reception range.

Of course nothing will work if the signal is too low to amplify but that PC
Magazine 2022 review said they work good when you have spotty coverage.
 
Cheers, Rob