Recently I began noticing that my iPhone 5 doesn't have data coverage when leaving my home. I first noticed it one day when I was driving and needed Siri to get me turn by turn navigation guidance and she said no data connection. I work from home so am connected to my WiFi sometimes days at a time without leaving. While at home I know I'm on LTE because my signal strength is 3 bars opposed to 5 bars on HSPA+. I know this because I tested it by turning WiFi off seeing 3 bars on LTE then turning LTE off and getting 5 bars. Lately I've been seeing 5 bars more frequently on my phone. When I turn WiFi off, I have no data connection. I can only get data back by turning the phone off and back on. Turning Airplane mode off/on doesn't fix it, turning Cellular Data on/off doesn't fix it, and turning LTE on/off doesn't fix it. Is it my iPhone 5 or is the problem with at&t's network? Any suggestions how to correct this problem? I'm tempted to turn WiFi off for a few days (on unlimited plan) to see what happens. FYI my WiFi network is from an AirPort Extreme if that matters.