Why phone Internet & calling NOT working with 1, 2, 3, 4 or 5 bars?
The number of bars on the cell phones display usually has NO bearing on the performance. When using a cell phone booster system, many times the phones will function better on 1 bar than 3 or 4 because unfortunately that functionality of all smartphones today in 2018 is not perfect. To check signal strength more accurately, check cell signal strength in decibels.
The strength of cellphone signal is measured in decibels (-dB) with -50 decibels roughly equating to full bars and around -100 decibels to one bar and -120 decibels as zero signal or no bars. As there is no industry standard to convert decibels (read as -dB) to bars on the phone, signal strength as represented by bars on a device is very subjective and determined by each carrier.
Decibels are measured exponentially. For example, the difference in signal strength between +7dB gain and +10dB gain is not an increase of +3 but rather two times the strength. If +20dB is attained, that is 100x the signal strength!