A method of calibrating coexistence of several wirelessly communicating sub-systems within a wireless device wherein the wirelessly communicating sub-systems comprise several transmitters and several receivers which are interconnected through one or more interfaces, the method comprising:—activating one of the transmitters while maintaining the other transmitters off by causing said transmitter to transmit a first signal with a known set of characteristics;—measuring unwanted signal received at each receiver and originating from a coupling of said receivers with the activated transmitter;—storing coupling data derived from each of the measured unwanted signals in relation with the set of signal characteristics of the first signal and/or a set of unwanted signal characteristics, whereby forming a calibration database for adjusting operation of one or more transmitters and/or receivers to manage the coexistence of the plurality of wirelessly communicating sub-systems during normal operation of the wireless device.