G stands for Generation
Originally there was just cellular data services, but it wasn't called 1G, just like OBD(on board diagnostics) wasn't called OBD1 until there was OBD2, lol
2G is 2nd Generation, and faster than "1G"
For 2G to work the Cell tower needs to have 2G software and electronics and your phone needs to have 2G software and electronics
Then there was 3G
And then LTE, LTE's full name is 3GPP LTE, and should be called 3.9G really since it not quite 4G but you would never notice much difference between LTE and 4G
Now 5G is coming
Each generation is faster or better in one way or another that previous generations or it wouldn't be implemented by wireless providers or phone makers
5G is suppose to offer more bandwidth VS more speed, but shorter range, which really only matters in big city highrise areas or sports arenas , when there are 50,000+ people all with a cell phone, lol, more band width means more people can be using the local towers for data without as much speed loss.
And in traffic jams, lol, local towers get jamed up and drop data connection(and phone calls) when handing off to the next tower or you can't connect at all
2G, 3G, LTE, 4G signals can travel as much as 100miles from the tower, but...........................Your cell phone battery and antenna can't, lol
And that 100miles is flat barren ground, any building, hills, trees, ect...........lessens the signal
And then there is interference, "like frequencies cancel each other out", so cell towers need to be placed and powered only enough to not interfere with the next tower, N, S, E and W
In cities cell antennas are usually angled down to limit the range while keeping power higher
What the closest cell phone tower has 2G, 3G, LTE, or 4G is what is available, assuming you have all of these on your phone
At the edge of the cell towers range the faster signals may drop out, data bits go missing, so your phone may switch to 3G, or even 2G if available, better to get the WHOLE signal slower than only bits and pieces of faster signal
A booster has the advantage of a larger Directional antenna and higher voltage, plugged in to 110ACv, or larger battery pack
The directional antenna is what helps the most
The signal level on your phone is YOUR signal level NOT the towers level
When your phone is on, it is constantly "pinging" the tower(s), the tower sends back YOUR phones signal level received at the tower
The tower has way more power and directional antennas so its never the towers signal you see its YOURS
That's why some brands/models of phones work better in areas where other phones lose the signal, if it was the towers signal then both phones would lose signal at the same time at the same spot, there is more to it than this but thats enough, lol
Cell phones usually broadcast/ping at 0.6 watts, some can jump to 2 watts others to 3 watts as needed
The booster's directional antenna is pointed in the towers direction so your phone signal can now "ping" it with higher strength and you get higher Bars back.
Directional antenna and booster may work where your phone has "no bars", line of site to tower would be best, and no guaranties.
But if there is any bars the booster will for sure help
But 2G, 3G, or 4G speed won't be known until tested
You can rent satellite phones, about $50/week, but $1.50/minute for calls