In accordance with a first aspect, a communication device is provided, comprising: a transmitter configured to transmit one or more radio frequency signal pulses to an external communication device; a receiver configured to receive one or more response signals in response to the radio frequency signal pulses transmitted by the transmitter; a signal analyzer configured to detect one or more characteristics of the response signals, to compare the detected characteristics with predefined reference characteristics and to generate an output indicative of a result of comparing the detected characteristics with the predefined reference characteristics; a processing unit configured to determine at least one category to which the external communication device belongs based on the output generated by the signal analyzer. In accordance with a second aspect, a corresponding method of operating a communication device is conceived. In accordance with a third aspect, a corresponding computer program is provided.