A control signal is wirelessly transmitted from a first radio communication unit of a portable communication device to a second radio communication unit. The portable communication device is provided for radio communication over a first radio frequency band using a first modulation technique. The control signal is transmitted by generating a control signal, switching off the first modulation of a carrier signal, shifting the frequency of the carrier signal from a first radio frequency band to a second radio frequency band for the first radio communication unit, switching on the second modulation of the carrier signal having a frequency within the second radio 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 frequency band to the second radio communication unit.