Alex uses an iPhone 4 on AT&T and over the past couple of months, his reception has gotten so bad it doesn't work where he lives anymore. AT&T sold him a MicroCell to boost his signal but that doesn't help him when he leaves his house. Leo suggests asking people in his area what they use for their carrier, and maybe he could switch to something else.
Leo also suggests asking other people with AT&T if they're having issues with their reception. If they aren't having trouble, then it could be his phone. Leo says it's weird that the signal has degraded over time, and that could be an issue with the nearest cell tower.