Phone Problems

I love my android. It's the second smart phone I've bought since smartphones came out. My very first one was an old iPhone which I loved also. Too bad AT&T practically doesn't exist in our house. I bought an iPhone upgrade one time, only to return it a couple of hours later because I realized it doesn't have a signal inside the house. What's the use of having a phone that doesn't have signal? I am now with T-Mobile because they work fine at least. It's also 3G which I do enjoy. My only gripe? It doesn't work inside metal buildings. What gives? I don't understand. But oh well, I can use it most of the time. You can never have it all.