User Manual
Airbridge cBTS3612 CDMA Base Station
System Description
2 Hardware Architecture
2-39
exception of transmit signal power of antenna can be monitored in real time. LNA
status monitoring circuit monitors the voltage and current of the 4 LNAs inside
RLDU. It gives alarm when fault t is found.
III. Interface
RLDU is the reverse link function module of the BTS, which interfaces with
CDU/DFU and BTRM in both input side and output side through the two sets of 8W8
D-type combination blind mate connectors on the backside of the module.
1) Interface signals between RLDU and CDU/DFU/DDU are:
l
Main/diversity path receiving RF signals outputted from two CDU/DFU/DDU
receive filters. They are amplified and distributed by RLDU.
l
CDU/DFU/DDU coupling RF signal, which are used for antenna VSWR
monitoring and forward power detecting.
2) Interface signals between RLDU and BTRM are:
l
Main/diversity path receiving RF signals transmitted to BTRM after being
amplified and distributed.
l
Antenna VSWR, LNA status monitoring alarm signals and forward power
detecting voltage signals, which are outputted to BRCU by RLDU through a
DB15 interface on the front side of the module and transferred to BIFU for
processing.
3) The +27V DC power is necessary for RLDU. It is provided directly by the
secondary power supply module in the BTS through a MOLEX power connector on
the front side of the module.
IV. Index
l
Supported frequency band: 450MHz band, 800MHz band, 1900MHz band
l
Power supply: +27VDC
l
Power consumption <50W
l
Module size: L
%
W
%
H= 450mm
%
180mm
%
50mm
2.3.9 BTS RF Fan Module (BRFM)
BRFM mainly consists of BBFM, BBFL and fans. The following is the introduction to
BBFM and BBFL.
I. BTS BTRM FAN Monitor (BBFM)
1) Overview
BBFM collects and analyzes the temperature information of BHPA module and
adjust the fan speed in real time to lower the system noise, so as to prolong