Hi User! Hope it can help:
The CDU is the interface between the transceivers and the antenna system. All signals are filtered before transmission and after reception by means of bandpass filters. The CDU allows several dTRUs to share antennas.
• CDU-A is a filter combiner intended for high capacity solutions.
• CDU-C can be configured either for high capacity or for high coverage. It is a combiner that can be used for synthesizer hopping.
Thanks!