1. A method of interfacing in a base station in a mobile communication system, the base station comprising radio units and at least one controller unit for controlling the radio units, different types of the radio units including at least one radio equipment unit coupled to at least one antenna and at least one radio equipment controller unit for controlling the radio equipment unit, the radio units having a common public radio interface for streaming data samples and control data arranged in lanes corresponding to antenna signals and a serial interface for transferring packets separate from the common public radio interface, the method comprising:transferring, between a first radio unit and a further unit, selected control data arranged in packets via the serial interface, the selected control data corresponding to control data streamed between the first radio unit and a preceding radio unit via the common public radio interface;
in the first radio unit, arranging in packets the selected control data to be transmitted via the serial interface to the further unit, bypassing processing of the control data in the first radio unit;
receiving an interrupt packet by an interrupt unit in the first radio unit or the further unit, the interrupt unit triggering further processing of the selected control data upon receipt of the interrupt packet; and
in the further unit, processing the selected control data arranged in packets received via the serial interface.