User Manual
Airbridge cBTS3612 CDMA Base Station
System Description
2 Hardware Architecture
2-9
BCKM comprises the following parts:
1) MPU module
MPU controls logic circuits to initialize components. It realizes control and
management over BTS system through system software.
2) Clock module
Clock module is the clock source of BTS, providing working clock for boards. Clock
module is available in two modes: external synchronization mode (locked mode) and
free oscillation mode (holdover mode). The clock module can provide high -precision
oscillation clock (voltage control constant temperature crystal oscillator) or be
synchronized with external clock source (GPS, GLONASS, external synchronization
equipment ).
3) Backplane bus module
The communication port of the Central Processing Unit (CPU) is connected with
other boards of BTS through the backplane bus module, processing or transmitting
O&M signaling from other boards of BTS (BRDM, BCPM and BCIM ).
4) External communication module
External communication module utilizes the multiple communication control ports
provided by the main control CPU to implement functions such as LMF interface,
external monitoring module interface, debugging interface, and out-of-band
signaling serial port.
5) Power supply module
BCKM includes two isolated secondary power supply modules, conv27V
voltage into +5V, +3.3V and +2.5V for various modules of local board.
III. Interface
l
LMF interface (10/100 Base-T)
l
Remote maintenance serial port (RS232)
l
Environment alarm interface (RS485)
l
GPS/GLONASS antenna port
l
2s and 10MHz test port
l
Inter-board interface, and interfaces with other boards in the baseband subrack.
IV. Index
The board size is 460mm
%
233.35mm, powered with +27V, power consumption
<20W.
