How to strengthen the cellular network signal?

Question

Iron

Tell me how to strengthen the signal of the cellular network, if only 2G is confidently catching, and then not all the strips.
You need a confident reception of a 4G signal, it catches it as confidently as possible 400-500 meters from the building on the street.
As far as I understand - you need a broadband antenna - how much dB gain? 4G modem (USB) and router to distribute Wi-Fi.
Actually the question is, what kind of antenna do you need? can it be strengthened? and what about in general?
Installation of everything and everyone is supposed to be in the attic of the house (there is a 220V output there).

Answer 1

need a broadband antenna

We need a narrow-band antenna for the LTE frequency, well, 2band is also possible, but the characteristics are already lower - due to compromises.
directional
turn out
We buy an antenna, connect it to the modem, turn it around, focusing on the maximum signal, and test it.
And what kind of antenna, it's up to you to choose - according to your finances and allowable dimensions.
Radio communication is such an unpredictable thing that poking at antennas and saying "take this one, everything will take off" is just stupid.

Answer 2

For connecting the antenna to the modem, as well as choosing the type of antenna here: https://bitconnect.ru/blog/antenna-4g-modem/