A radio base station (20) has an internal interface (26) which connects a radio equipment (22) and a radio equipment controller (24). At least one and preferably both of the example radio equipment (22) and radio equipment controller (26) comprises a framer (50, 70) which can be controlled for transmitting samples of different protocols over the internal interface. The framer (50, 70) facilitates (1) time multiplexing of N number of frames of a first protocol over the internal interface; (2) inserting L number of samples of a second protocol into M number of the frames of the first protocol, and (3) inserting a padding sample into each frame of the first protocol which does not include a sample of the second protocol. The first protocol has a frame rate; the second protocol has a sample rate which is different from the frame rate of the first protocol, and N is greater than L and M. In any of plural example modes, the padding sample can comprise either of uninterpreted information or information related to the second protocol. For example, the padding sample can comprise a parity value for the L number of samples of the second protocol. In another embodiment and method of operation, in a distributed radio base station a radio equipment controller (REC) sums different carriers and transfers a wide band signal over the internal interface.