ZXC10-BTS (V5.4) Installation Manual
12-2
4. RIM
RIM (Radio Frequency Interface Module)
implements the interface between
BDS and RFS. The forward link first sums the baseband data sent from CHM as
per different sectors, multiplexes the summation result, HDLC signaling and
PP2S from GCM, and then sends them to RMM. Then the reverse link receives
the reverse baseband data and HDLC signaling, selects them according to the
signaling sent from CCM, then sends the selected data by broadcasting to the
CHM and the HDLC data to the CCM for processing. RIM lies in the BDS
frame and supports active/standby configuration.
5. SAM
SAM
(
Site Alarm Module
)
monitors the running status of the PM and fans, as
well as access control, flood, temperature, humidity, and smog signals. It will
then report the results to the OMC console via CCM. In addition, it provides
RS232 and RS485 interfaces for the connections with external monitoring
devices.
6. GCM
GCM (GPS Control Module) provides reliable and high-stability clock source
for various modules of BTS. The major clocks include TOD (UTC timing
message), system clock (16CHIP and PP2S), circuit clock (2MB and 8K) and
RF reference clock (30M).
7. SNM
SNM lies in the BDS and implements STM-1 downlink and uplink functions for
BTS.
8. CDM
CDM (Clock Distribution Module) distributes the clock of GCM in BTSB to
TRX. The RF reference clock in BTSB is transmitted as the 30M MLVDS clock,
while TRX needs the 10M/12M analog clock. Therefore, CDM is used to
convert the 30M MLVDS clock sent from GCM to TTL signals and generate the
10M/12M analog clock needed by TRX in HIRS through the phase-lock loop.
9. RFE
