Front Panel; Figure 3-4 Cdu Structure - Huawei BTS3 Series Hardware Description Manual

M900/M1800 BTS3X Series Base Transceiver Station
Hardware Description Manual

Figure 3-4 CDU structure

RXD-OUT
Besides the basic combining and dividing function, the CDU also has the following functions
for alarm tests:
!
!
!
!

3.3.3 Front Panel

Figure 3-5
Issue 01 (2006-11-18)
TX1
Combiner
TX2
TX-COM
TX-DUP
RX1~4
Divider
HL-OUT
RX5~8
Divider
HL-IN
Standing wave test
Monitors the status of the antenna and feeder system:
When the standing wave exceeds the preset threshold, that is, 1.5:1, the CDU reports
−
a minor alarm, and the indicator on the front panel is in ON status.
When the standing wave exceeds the preset threshold, that is, 2.5:1, the CDU reports
−
a critical alarm, and the indicator on the front panel is in ON status. Then the
transmitting signals are closed one minute later.
Low-noise amplifier faulty alarm
The fault signals are from the power supply current of low-noise amplifier. The alarm is
generated when the current exceeds a certain range or no current is detected.
TMA alarm
When the TMA works, the CDU judges the working status of the TMA based on its
working current. The alarm is generated when the current exceeds a certain range or no
current is detected.
Control function
The CDU performs power attenuation control of the main receiving channel and
−
diversity receiving channel (dynamic range: 15 dB, step: 1 dB).
The control function realizes powering on and powering off the TMA feeding. The
−
TMA feeding can be powered off automatically in TMA alarm.
shows multiple types of CDU front panels.
Huawei Technologies Proprietary
Duplexer
LNA
LNA
Filter
3 Board
TX/RX-ANT
RXD_ANT
3-7