i am getting excellent signal strength and voice/data. i even upgraded to android 7.0. after the update, my android system was using 8%. my battery was lasting almost 3 days. now a week later, i'm back at 23% on android system usage and 14% on android os usage. i am only able to make it through 1 day now. i've seen this issue online from others. maybe i should try a different company besides samsung, but i owe to much on this phone.