Abstract: A base station (10) for mobile radio telecommunications systems comprises a radio frame set (11), an amplifier frame (12) and an antenna interface frame (13) connected to transmit and receive antennas (22 and 23). The radio frame set (11) comprises a radio channel frame (14) including a radio control complex (31), a plurality of radio channel units (54) and a plurality of digital interface circuits (57) for interconnecting the base station to a remote mobile telephone switching office. A time division multiplexed bus (53), connected to the radio control complex (31), the radio channel units (54) and the interface circuits (57), is used for selectively connecting, under the control of the radio control complex (31), any radio channel unit (54) to any digital interface circuit (57). Such a radio channel arrangement is capable of handling analog, as well as, digital radio channel units while exhibiting greater capacity, easier maintenance and upgrade, and substantially increased flexibility (FIG. 3).