Control unit, system and method for sending and receiving radio signals in several frequency ranges

A distributed antenna system for transceiving radio signals in several frequency ranges, comprising:

• a control unit for forwarding first radio signals and second radio signals;
• and
• a plurality of remote units for mobile communication, the plurality of remote units being connected to the control unit via a distributor network;
• wherein the first radio signals are received via a first line at a first port of the control unit and the second radio signals are received via a second line at a second port of the control unit, the control unit being connected to said distributor network and remote units and antenna elements via a third port, wherein the first line and the second line are bidirectional lines and therefore can transmit respectively the first radio signals and the second radio signals also in the reverse direction,
• wherein the control unit comprises:
• at least one first port for forwarding the first radio signals in a first frequency range and one second port for forwarding the second radio signals in a second frequency range,
• wherein the first frequency range lies in a frequency range available in the distributor network, and the second frequency range lies at least partially in a frequency range unusable in the distributor network;
• a third port connectable to the distributor network;
• a sensor for recognizing available frequency ranges in the distributor network;
• and
• a modulator/demodulator in order to convert, upon transmission of the second radio signals via the distributor network, the second radio signals to or from a further frequency range, said further frequency range being different from the first frequency range, and which contains at least partially at least one of the available frequency ranges;
• wherein the remote units have at least one further demodulator/modulator for converting the second radio signals from the further frequency range to a different frequency range.