Well At&t runs on a GSM network and Alltel runs on an CDMA network. Where I live you either have Alltel or Verizon(CDMA). Now that Verizon has bought Alltel it has to sell the towers where Verizon and Alltel overlap. So if we were to resign our contract with Alltel and At&t changes the tower the GSM what would happen? or should we just sign a contract with Verizon, but the reason we switched from Verizon to Alltel is because Verizon does not have service where my dad needs it for work. So.............what will happen and what should I do?