this ones worth reading note what it states "tunable" and its wireless
http://v3.espacenet.com/textdes?DB=EPODOC&IDX=US2007111709&F=0&QPN=US2007111709
Abstract of US2007111709
A combination of a radio receiver with a detachable controller that determine sends either reduced or enhanced metadata about received programming to the detachable controller based upon periodic authorization. A connection from the detachable control device to the radio receiver carries commands to the radio receiver and carries only the reduced set of metadata, such as tuned channel and tuned channel name, from the radio receiver to the controller. The controller is authorized by sending a radio identifier from the radio receiver to the control device, determination of an authentication code at the controller and communication of the determined authentication code back to the controller for validation. Upon validation, an enhanced set of metadata, including song title and artist, is sent to the controller. The enhanced metadata, the reduced metadata, or both, are optionally able to be encrypted. The radio receiver periodically performs this authorization processing.
28. The method of claim 27, wherein the determining: determines that the control device is of the first type in response to receiving an authentication signal generated at the control device, and determines that the control device is of the second type in response to not receiving the authentication signal.
29. The method of claim 27, further comprising the step of generating a time window at the tunable radio receiving set, and wherein said step of determining: determines that the control device is of the first type in response to receiving, within the time window, an authentication signal generated by the control device, and determines that the control device is of the second type in response to not receiving, within the time window, the authentication signal.
30. The method of claim 27, further comprising the step of generating, at the tunable radio receiving set, an identification signal uniquely indicative of the tunable radio receiving set, and wherein said step of determining:
determines that the control device is of the first type in response to receiving, from the control device, an authentication signal that is indicative of the identification signal, and determines that the control device is of the second type in response to not receiving the authentication signal that is indicative of the identification signal.