Specifications

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Cisco ONS 15530 Planning Guide
OL-7708-01
Chapter 5 Amplified Network Planning
Amplified Network Planning Guidelines
Channel Power Equalization
Amplified networks require that all channel powers be equalized in the network. There are two channel
equalization options for Cisco ONS 15530 and Cisco ONS 15540 networks: per-channel and per-band
equalization.
In the per-channel option, a WB-VOA module is placed between each transmitting ITU laser and the
OADM module. The WB-VOA module attenuation value is set individually so that all channels added
at the OADM module are equal in power on the outgoing trunk.
Alternatively, the added channels can be equalized on a per-band basis. The PB-OE modules and
WB-VOA modules can be used for this purpose. In this case, the added bands are demultiplexed,
separately attenuated, and multiplexed back together by PB-OE modules placed at the OADM module
out-going trunk. The pass through bands can also be attenuated by the WB-VOA modules connected to
the pass through path of the PB-OE modules.
For more information on the PB-OE modules and WB-VOA modules, see the “PB-OE Modules” section
on page 5-3 and the “WB-VOA Modules” section on page 5-5.
Dispersion Limits
Table 5-3 lists the dispersion limits, in the absence of DCUs (dispersion compensation units), of various
components on the Cisco ONS 15530 and the Cisco ONS 15540.
DCUs
DCUs (dispersion control units) can be used in networks that exceed the dispersion limit of the
transmitters. There are three types of Cisco ONS 15216 DCUs that are available: –350 ps/nm,
–750 ps/nm, and –1150 ps/nm. DCUs should be placed where total power is low, for example, at the
input to a preamplifier or just before an OADM module input trunk. DCUs should be placed such that
any span of half the dispersion limit or more should be compensated to a value close to zero, and that
the residual dispersion at the receiver is within the dispersion limit.
We recommend the use of a network design tool, such as Metro Planner, for the validation of DCUs in
amplified network designs for Cisco ONS 15530 and Cisco ONS 15540 networks.
Table 5-3 Dispersion Limits
Card Type Dispersion Limit (ps/nm)
Cisco ONS 15540 SM/MM transponder module 1800
Cisco ONS 15540 extended reach transponder
module
3200
Cisco ONS 15540 10-GE transponder module 1000
Cisco ONS 15530 transponder line card 3200
Cisco ONS 15530 2.5-Gbps ITU trunk card 3200
Cisco ONS 15530 10-Gbps ITU trunk card 1000
OSC module 3200