Abstract: A connection unit comprising a feeder port for connecting the connection unit to an antenna feeder, a first relay port for connecting the connection unit to a receiving and transmitting port of a first base station, and a second relay port for connecting the connection unit to a diversity receiver port of a second base, wherein the connection unit comprises a directional coupler for separating signals where a signal in the feeder port is divided into a first output signal in the first relay port of the first base station and a second output signal in the diversity receiver port of a second base station. A signal in the first relay port is, however, passed undivided to the feeder port. Diversity may be selectively provided in the receiving direction, but substantially no additional loss is introduced to the main transmission direction.

Abstract: A base station and a method of configuring a base station are provided in a cellular telecommunication system, wherein the base station comprises an electrically tunable duplex filter with a tuning range covering at least two parallel sub-bands used in the telecommunication system. The electrically tunable duplex filter is tunable on site to a sub-band allocated to the base station, thus enabling an increased flexibility in selecting a fixed frequency band to be used in the lower frequency stages in the transceiver and the base band parts of the base station.