Re: Do these cellular amplifiers work for all cellphones?

On Tue, 12 Apr 2022 at 21:01:56, Alan Browne <[email protected]> 
wrote: (my responses usually follow points raised):
>> How could new cars be sold in GB with cellular boosters as Martin Brown 
>> said
>> they were if those cellular boosters are illegal in GB in the first place?
> 
> I never said they were.  I was clarifying that just because a car has a 
> sharkfin on it, and even with the requisite electronics and antenna, it 
> does not mean the phone in the car is actually using it.

Right. It could be that you're not connecting to the internal car antenna.

Or it could be a single user booster instead of a multi user booster (if 
they make both).

Or even it could be a single carrier booster instead of a multi carrier 
booster (I know they make both but I don't know the difference other than 
the FCC limits drop in decibels when you go from single carrier boosters to 
multi carrier boosters (why? what's the difference?).

>>>>> I called UberSignal who said they work fantastically for all carriers.
>>>>> https://www.ubersignal.com/vehicle-signal-boosters.html
>>>>
>>>> Well they would, wouldn't they! What they don't say is that it also 
>>>> messes up phone reception for anyone else in your vicinity (and quite 
>>>> likely radiates sidebands into other protected frequency bands).
>>>
>>> This is why the system still has to meet compliance.  US has its 
>>> standard, the UK its own.  Usually manufacturers know and publish what 
>>> countries they are compliant to.
>> 
>> If they messed up reception as much as Martin Brown said they do then how
>> could they be approved by the FCC and by all the cellular companies then?
> 
> Because Martin's assumptions are likely wrong or incomplete.
> 
> Facts:
> 1) They work[1]

I'm sure they work. Otherwise there would be a lot of unhappy people.
 
> 2) They are meant for areas where cell towers are sparse - so you're not 
> going to be interfering - there is no one close by to interfere with. 

The FCC and carriers wouldn't have approved them if they were interfering.

> (Competitor antennas are probably on the same tower).  Power output from 
> the device is likely controlled as commanded by the receiving tower 
> (reduces saturation at the receiver).

The home boosters are allowed 100 decibels but they stay in place.
The mobile boosters are only allowed 65 decibels.
That they move is maybe why mobile is lower?

> 3) They are compliant (at least in the US per FCC rules).
> 
> To be clear, Great Britain is less than 1/3 the size of Texas. 
> There are lots of areas in the US that have sparse, poor or no coverage 
> at all.

Maybe that's why cellular boosters are outlawed in GB.
Because they're not needed in such a small area.

> It could be in GB that there is adequate coverage almost everywhere. 
> Certainly not in the US.

I don't know but I think the laws on radios are more free in the US.
But I don't know that for sure.

> [1] To be sure, user expectations need to be managed, most esp. for the 
> mobile case.

Even the lower maximum of around 50 decibels for multi carrier mobile 
cellular boosters seems indicate that they must work when there is enough 
signal to boost.

Would be nice to read a real world test.