Communications systems and methods with an evolved packet-switched core network architecture to enable voice services on second- and third-generation wireless access networks. The systems and methods permit unmodified 2G and 3G mobile devices to conduct voice calls using conventional circuit-switched user-plane and control-plane protocols at the air interface while the voice calls are switched at the back-end using a packet-switched core network. The system may include a translation module at a controller component that is configured to provide both user-plane and control-plane translation functions between an unmodified 2G/3G mobile device that utilizes circuit-switched protocols for a voice call and the packet-switched core network that utilizes packet-switched protocols to switch the voice call.