I live in 28110 area and i am having the same problem.  I've noticed a drastic change over the last couple of weeks.  I disconnected my landline because i get such a good signal at home and now i can barely make a call.  Multiple calls have been dropped and text message bounce back.  Is there something going on in my area...upgrades to towers?  Something?  I've always had fantastic service but now i can barely use my phone.