A method and apparatus for wirelessly communicating data that receives electromagnetic (“EM”) radiation incident upon an antenna of a mobile device from a base station is described. The antenna is an element of the mobile device that serves an additional purpose than just as a reflective antenna for backscatter communications. A radar cross-section of the antenna is modulated between two or more states using a backscatter tag coupled to the antenna. Data is encoded onto a backscatter channel of the EM radiation via the modulating. The data is transmitted to the base station over the backscatter channel.