My private cell site...

I was a Sprint customer for many years and when I started working for a company that had a metal roof on their building, my phone reception (inside the building) became non-existent. Some of my coworkers were Sprint customers and would stand outside to make calls. This was before phones could switch to Wi-Fi calling.
I purchased a signal booster that had 2 antennas, one outside for picking up the nearest tower signal and the other inside that relayed the phone signal. It worked pretty good for about 50 feet from the antenna. When I switched to T-Mobile, I didn't require the signal booster and gave it to a friend who was having the same trouble in the building he worked at.

Now, I'm at a place with the same problem. All the bars lit outside and inside I often had a 'no signal' error message. Switching to Wi-Fi calling wasn't reliable as I missed lots of calls and text messages weren't outgoing. They would snag and I often had to reboot the phone to get things to work again. Several calls to customer service only had technicians remotely checking my phone telling me to change the settings and make Wi-Fi the main method of communication and not cell service. One tech walked me through the settings to be sure everything was good. Rebooting the phone and trying that for a few days didn't work well. that was enough to call them and complain.

I was lucky to get someone who knew of a low power cell site device that connected directly to the network where I'm located (and not an antenna style booster) so they sent me one and I connected it. Instructions said it could be a few hours before the device would download updates and register with the T-Mobile service. Later that night, I received a text message the unit was online. When I got to the office the next day, I had 'full bars' without having to switch to Wi-Fi.

The new mini-cell site works great and 2 of my coworkers who are also T-Mobile customers are also benefiting from this device. It's just sitting on the corner of my desk right now, but I'll mount it on a wall up high for maximum coverage.

My private cell site...