Cellular network doesn't switch to proper signal iPhone 5

I have an iPhone 5 with iOS 6.0.2 (latest update) and AT&T as my carrier. I rarely get a signal while at home due to my house being a tri-level townhome, but I'm fine with that because I use Google Voice. My issue just started happening very recently. When I leave the house and head to work, where my LTE signal is super strong, my phone doesn't automatically connect to LTE, but instead goes to Edge. At home, my status bar usually has a "No Service" or 1 bar LTE/4G message.  I have to reboot the phone in order to pick up the signal. I've done the typical software restore from backup and as a new phone, but the problem still persists. Again... This just started happening for the past two weeks, but was fine before. No software update coincided with my problem as it was updated long before my issue started happening.

Is anyone having this issue?