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Cisco ONS 15454 DWDM Installation and Operations Guide, R6.0
August 2005
Chapter 17      Node Reference
17.1.1 Hub Node
A Dispersion Compensation Unit (DCU) can also be added, if necessary. The hub node does not support 
both DWDM and time-division multiplexing (TDM) applications since the DWDM slot requirements do 
not leave room for TDM cards. Figure 17-1 shows a hub node configuration with 32MUX-O and 
32DMX-O cards installed. 
Note The optical add/drop multiplexing (OADM) AD-xC-xx.x or AD-xB-xx.x cards are not part of a hub node 
because the 32MUX-O and 32DMX-O cards drop and add all 32 channels; therefore, no other cards are 
necessary.
Figure 17-1 Hub Node Configuration Example
Figure 17-2 shows the channel flow for a hub node. Up to 32-channels from the client ports are 
multiplexed and equalized onto one fiber using the 32MUX-O card. Then, multiplexed channels are 
transmitted on the line in the eastward direction and fed to the Optical Booster (OPT-BST) amplifier. 
The output of this amplifier is combined with an output signal from the Optical Service Channel Modem 
(OSCM) card and transmitted toward the east line. 
Received signals from the east line port are split between the OSCM card and an Optical Preamplifier 
(OPT-PRE). Dispersion compensation is applied to the signal received by the OPT-PRE amplifier, and 
it is then sent to the 32DMX-O card, which demultiplexes and attenuates the input signal. The west 
receive fiber path is identical through the west OPT-BST amplifier, the west OPT-PRE amplifier, and the 
west 32DMX-O card.
OPT-BST W
OPT-PRE W
32MUX-O
DCU
Air ramp
DCU
32DMX-O
32DMX-O
TCC2/TCC2P
OSCM W
OSCM E
TCC2/TCC2P
32MUX-O
OPT-PRE E
OPT-BST E
AIC-I
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