User Manual
Airbridge cBTS3612 CDMA Base Station
System Description
2 Hardware Architecture
2-8
l
Perform operation and maintenance via the backplane bus for other boards in
the baseband subrack, realizing in-band signaling communication.
l
Connected with Local Maintenance Function (LMF) through the 10/100M
compatible Ethernet interface.
l
The active/standby asynchronous serial port serves as a path for out-band
signaling backup. MPU functions as the main node and other boards function
as the standby nodes. When a fault occurs to the in-band signaling path,
signaling communication can be maintained with this standby path.
l
Provide an interface connected with Modem in compliance with RS232 serial
communication standard, realizing remote maintenance and monitoring in case
of OML link failure.
l
Connected with an external monitoring module in compliance with RS48 5
standard, collecting and processing the equipment room environment
information (such as fire alarm/water soaking/temperature/ humidity).
l
CLK unit is the clock source of BTS system, providing working clock for all
boards. It provides high precision oscillation clock and can be synchronized
with an external clock (such as GPS clock).
l
BCKM provides active/standby switchover function, working in active/standby
mode in the system. When a fault occurs to the active BCKM, the standby
BCKM is switched to active status under the control of specific software. A fault
occurring to either MPU or CLK module of the BCKM will result in the
switchover of the whole BCKM.
II. Structure and principle
The structure of BCKM module is as shown in Figure 2-4.
Power supply
module
External
communication
unit
Clock module
Backplane bus
module
Other
functional units
MPU module
BCKM
CBKM
...
Backplane
bus
Figure 2-4
Structure of BCKM module
