Steel frame homes are often sided with a metal siding of some kind. But there are doors and windows that allow openings through the metal. These homes act as giant Faraday cages. Cell reception is often weaker inside them. If the roof is metal, there can be a lot of interference. But, just as a test...
Stick your cellphone inside a microwave oven, at the back, standing up, so you can see the face/screen of the phone. Make sure the screen on the phone is lit up so that you can see how much service is available. Usually, once you have activated the screen, it will stay lit up for several seconds before it goes black.
Now close the door on the microwave oven.
ABSOLUTELY DO NOT TURN THE MICROWAVE OVEN ON! Notice that you will lose service in a few seconds. Apply what you have learned to making this kind of Faraday cage for yourself and where you live.
Perhaps out in public you can wear a microwave oven as a helmet.
