remote radio unit (BBU) (RRU)
The Remote Radio Unit (RRU), functionally similar to the Remote Radio Head(RRH), is a radio module that performs radio transceiver functions in 4th and 5th generation cellular networks.
The RRU unit is a remote RF processing unit with antennas and computing functions. It is connected via fiber to the central baseband unit in the radio base station. To minimize attenuation by the antenna cable, remote radio units are attached to the antenna mast, usually directly next to or below the radio antenna. RRU units communicate with the baseband unit via the CPRI interface and with the subscriber unit via the air interface.
The remote radio unit is controlled by the radio networkcontroller. Both units, the RRU unit and the controller form the radio base station.