Reference Manual

Radio Base Station RBS 2206
12 (24) EN/LZT 720 0225 R3A
CDU – Combining and Distribution Unit
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. There
are a maximum of three CDUs in one RBS 2206.
The CDU combines transmitted signals from several transceivers, and
distributes the received signal to several transceivers. The CDU is hardware-
prepared to support EDGE. Two different CDU types are used in the RBS
2206 to support all configurations:
• CDU-F is a filter combiner intended for high capacity solutions.
• CDU-G can be configured either for high capacity or for high coverage. It
is a combiner that can be used for synthesizer hopping.
Number of units: 1 – 3
CXU – Configuration Switch Unit
The CXU cross-connects the CDU and the dTRU in the receiver path. The
CXU makes it possible to expand or reconfigure a cabinet without moving or
replacing any RX cables. The RX inputs/outputs on the dTRU and the CDU
are placed in such positions that they minimize the amount of cable types for
connecting the CXU with the dTRUs and the CDUs. The CXU is configured by
means of software.
Number of units: 1
DCCU – DC Connection Unit
The DCCU handles distribution and connection/disconnection of the incoming
DC power supply voltages to the PSUs. Connection/disconnection is
performed by the main switch. The unit also contains filter equipment.
dTRU – double Transceiver Unit
The dTRU contains two TRXs for transmission and reception of two radio
carriers. It has a built-in combiner with the optional possibility of combining two
TX signals into one TX output. It is also prepared for four-branch RX diversity
for further improvements in sensitivity. This version of the dTRU supports only
GMSK and a later version will support both GMSK and EDGE.
Number of units: 1 – 6
DXU-21 – Distribution Switch Unit
The DXU is the central control unit for the RBS. It supports the interface to the
BSC, and it collects and transmits alarms. The DXU controls the power and