[ScreamingFist]

The principle is not trivial at all. It's impossible, unless you encase a building in mu-metal.

I am sitting in a cell phone proof building as we speak. No signals can be received inside, at all. AM doesn't work either, I do however receive FM. Top of the line government structure?.......No. U.S. Steel metal barn in the shape of a quonset hut, 42'X 36', 17' high, I store my tractor and tools and have my shop in here, I also have a landline for the Internet...NO cell phone calls at all.....am I breaking the law?

[RFEngineer]

".....U.S. Steel metal barn in the shape of a quonset hut, 42'X 36', 17' high, I store my tractor and tools and have my shop in here, I also have a landline for the Internet...NO cell phone calls at all.....am I breaking the law?"

You should call the FCC, just to make sure! ;^)