I have an AT&T Samsung Note 2 SGH-I317. For the first year I had great reception and recently it's been really poor. Other AT&T phones in my neighborhood work just fine. While not at home I get between full reception and no reception so it doesn't seem to be just one area or tower. I tried a full wipe and this week upgraded to Android 4.3 but nothing seems to help. Any idea what I can do? Could it be physically the antenna??