An apparatus and method including attaching a user equipment to a long term evolution system and simultaneously registering the user equipment attached to the long term evolution system to a circuit switched domain, is disclosed. The user equipment is simultaneously registered based on an interface between a mobility management entity and a mobile switching center server. For a mobile originated call from the user equipment attached to the long term evolution system, an enhanced call control is carried via the mobility management entity to the mobile switching center server. For a mobile terminated call, an enhanced call control is carried via the mobility management entity to the mobile switching center server, after the mobile switching center server pages the user equipment. The user equipment is offered existing circuit switched domain services while connected to the long term evolution system.