User Manual

Table Of Contents
CDU-C Combining and Distribution Unit
1 Product Overview
This section includes a product overview of CDU-C, a combining and
distribution unit used in high-capacity cells where low coverage is needed.
CDU-C+ has replaced CDU-C as a spare part.
Note: Two CDU-Cs for each sector are always used.
1.1 Main Functions
This section describes the main functions of CDU-C:
Combining of two TX signals to one antenna
Distribution of RX signals from one antenna to six receivers
Simultaneous transmission and reception on one antenna (GSM 900
version)
Diversity reception (two CDU-Cs required)
Handling of up to six TRUs in one cell (three CDU-Cs required)
Baseband and synthesizer frequency hopping support
Power and supervision of an external Tower Mounted Amplifier (TMA) via
the receiver (RX) antenna cables (GSM 1800 and GSM 1900 versions)
Note: TMA is optional for GSM 1800 and GSM 1900.
1.2 Variants
CDU-C is available for:
GSM 900
GSM 1800
GSM 1900
The GSM 1800 and GSM 1900 versions are identical, except for the frequency
bands.
CDU-C for GSM 900 is equipped with a duplexer. CDU-C for GSM 1800 and
GSM 1900 are not equipped with duplexers and therefore require separate
antenna feeders for the TX and RX signals in both the A and B signal paths.
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EN/LZT 720 0277 Uen R1A