Method for operating a communication arrangement, - said communication arrangement comprising a plurality of PLC modem devices (10, 20, 21, 22), - wherein for each of said PLC modem devices (10, 20, 21, 22) - a presence of interferences caused by at least one of operating other PLC modem devices, a communication line used for own power line communication and operating radio services is monitored and - in the case that interferences from at least one of said operating other PLC modem devices, said communication line used for own power line communication and said operating radio services are detected power line communication is performed only on communication channels or communication spectra where said interferences from other PLC modem devices or from radio services are not detected, - thereby simultaneously avoiding interferences to and from other PLC modem devices and radio services. - wherein a pre-defined reference signal is generated by at least one PLC modem device (10, PLC) and transmitted via at least one available communication channel (31, 32, CC), - wherein all participating modems (20, CP) measure said pre-defined reference signal via a wireless channel by means of a terrestrial antenna, each participating modem is equipped with, and analyze the respective measurement data, - wherein based on said measurements communication quality data, communication spectrum data, communication channel data, a communication spectrum and/or said communication channel (31, 32, CC) are chosen or selected, said communication quality data being descriptive for at least one of communication capabilities, communication quality and communication features of at least one of said participating modems (20, CP) and said at least one communication channel (31, 32, CC), and said communication spectrum data and communication channel data being descriptive for at least one of at least one communication spectrum for said PLC modem device (10, PLC) and for said at least one communication channel (31, 32, CC), thereby avoiding and de-allocating at least one of communication spectra and communication channels (31, 32, CC) associated with at least one of amateur, AM and DRM radio services. - said communication arrangement comprising a plurality of PLC modem devices (10, 20, 21, 22), - wherein for each of said PLC modem devices (10, 20, 21, 22) - a presence of interferences caused by at least one of operating other PLC modem devices, a communication line used for own power line communication and operating radio services is monitored and - in the case that interferences from at least one of said operating other PLC modem devices, said communication line used for own power line communication and said operating radio services are detected power line communication is performed only on communication channels or communication spectra where said interferences from other PLC modem devices or from radio services are not detected, - thereby simultaneously avoiding interferences to and from other PLC modem devices and radio services. - wherein a pre-defined reference signal is generated by at least one PLC modem device (10, PLC) and transmitted via at least one available communication channel (31, 32, CC), - wherein all participating modems (20, CP) measure said pre-defined reference signal via a wireless channel by means of a terrestrial antenna, each participating modem is equipped with, and analyze the respective measurement data, - wherein based on said measurements communication quality data, communication spectrum data, communication channel data, a communication spectrum and/or said communication channel (31, 32, CC) are chosen or selected, said communication quality data being descriptive for at least one of communication capabilities, communication quality and communication features of at least one of said participating modems (20, CP) and said at least one communication channel (31, 32, CC), and said communication spectrum data and communication channel data being descriptive for at least one of at least one communication spectrum for said PLC modem device (10, PLC) and for said at least one communication channel (31, 32, CC),