Re: Do these cellular amplifiers work for all cellphones?

On 9 Apr 2022 at 3:24:46 AM, Wilf <[email protected]> wrote:

>> How are you going to do consistent wifi calling while driving in a car?
> 
> With difficulty?

Depends on whether there is signal or not from your provider where you are.

A strong signal would be above -90dBm (like -80 or -70) and a weak signal is
when it gets below -110dBm. Below -120dBm and you likely can't use a phone.

This map shows cellular signal coverage for every provider in the world.
https://www.cellmapper.net/map

When you're at the edges of cell coverage it's most often the uplink
connection that goes first. Your phone isn't able to broadcast as much power
as the cell tower which means uplink power is what usually matters most.

The FCC limits single carrier cellular signal boosters to 100 dB maximum.
The multi-carrier boosters can have up to between 63 dB to 72 dB gain.
For vehicles in motion FCC limits reduce to 65 dB & 50 dB respectively.

The FCC allows 4G & 5G bands for AT&T & Verizon but only 4G T-Mobile bands.
If you're on T-Mobile you might have to use a 4G LTE or 5G hotspot instead.

These four companies are the biggest - CelFi, HiBoost, SureCall & WeBoost. 

Cheers, Rob