Andrew Node C, User Manual

Page: 48 / 62

User’s Manual for Node M and Node C
Network Elements
Page 48 M0121A4A.doc
5.2.10. Digital Channel Module (DCM)
The task of the digital channel module (DCM) is to filter and amplify any signals
passing through it. In addition it takes measurements of the input and output signals
and decodes the air interface to ensure proper setup and operation.
Finally it performs the interference cancellation algorithms, which eliminate the
normal problems associated with isolation, and has an integrated controller (in the DL
part) for the entire Node M/C, which maintains a web server for local and remote
communication. This process is accomplished by both analogue and digital means.
In case the diversity option is equipped, the module receives signals from both the
primary duplexer and diversity filter. Both signals are combined digitally and filtered
before being amplified in the uplink amplifier.
The DCM consists of an DL and UL part.
figure 5-15 Digital channel module,
DL part
figure 5-16 Digital channel module,
UL part
1
2
2
7
3
4 6 4
5
No Explanation
1
1
Vdc and remote (RS232) for modem
2 Debug-connector
3 Fan connector (Node x43)
4 Vdc DL digital channel module
5 Battery backup connector
6 EAC-board connector
7 Internal DCM - DCM interface connection
1
Only one modem can be used at the same time.