User Manual
Airbridge cBTS3612 CDMA Base Station
System Description
2 Hardware Architecture
2-6
High-speed
data bus
BCIM
BSC
BRDM
BCKM
BCPM
BTRM
Other functional
units
E1
Optical fiber
Clock bus
Backplane bus
Emergency serial port
...
Figure 2-2
Structure of baseband subsystem
Baseband subsystem is connected with BSC through Abis interface provided by
BCIM. The transmission in this subsystem is performed through E1 trunk (The
coming version will provide STM-1 optical transmission ). BRDM and BTRM are
connected by optical fiber to support RF module extended afar mode.
Baseband subsystem also provides some other interfaces through BCKM:
l
LMF interface: 10/100 Base-T interface, connecting Local Maintenance
Function (LMF).
l
Remote maintenance serial port : The interface is an RS232 serial port,
connected with PSTN via an external Modem. When OML between OMC and
BTS is interrupted, maintenance can be performed through telephone line
dial-up connection.
l
GPS/GLONASS antenna interface: It is used to receive clock signal from
GPS/GLONASS.
l
System external synchronization interface: When GPS/GLONASS is not
available, it makes the system clock synchronized with external clock.
l
Fan module interface: It is connected with fan module through RS485 serial
port, monitoring the fan module.
l
Environment alarm interface: It is connected with an external environment
alarm collection box, providing environment monitoring alarm information of the
equipment and monitoring information of the primary power supply.
l
Power monitoring interface: It is connected with power supply module, reporting
various alarm information of the power supply.
l
Test interface: It is an interface for BTS test, providing 10MHz and 2s signals.