Patent ID: 7697902

Claim:
A method for transmitting a control signal wirelessly from a first radio communication unit of a portable communication device to a second radio communication unit, wherein the portable communication device is provided for radio communication over a first radio communication frequency band using a first type modulation technique, comprising: determining whether the first radio communication unit is idle; generating a control signal; switching off the first type modulation of a carrier signal having a frequency within the first radio communication frequency band for the first radio communication unit responsive to determining that the first radio communication unit is idle; shifting the frequency of the carrier signal from the first radio communication frequency band to a second radio communication frequency band for the first radio communication unit; switching on a second type modulation of the carrier signal having a frequency within the second radio communication frequency band, wherein the carrier signal is modulated with the control signal; and transmitting the control signal modulated carrier signal wirelessly over the second radio communication frequency band to the second radio communication unit so that the control signal can be used for controlling a second communication device comprising the second radio communication unit.