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228 P P a r t V : a r t V : T T h e G r e e n i n g P r o c e s sh e G r e e n i n g P r o c e s s

Installing high-performance cable not only saves you money, but copper, aluminum, and
other natural resources are conserved. Further, the discarded cable doesn’t have to be recycled
or disposed of, thus saving some environmental impact.

Other Savings
Although optimization of airflow with proper cable planning and routing will save energy,
there are other energy saving opportunities within the cable infrastructure.
For example, if you move to a higher performing class of cabling, you will reduce noise
on the cabling channel, thus resulting in a significant power savings in the equipment by
eliminating Digital Signal Processing (DSP) complexity used to reduce noise levels. In fact,
using fully shielded cabling could save 20 percent in the overall power budget in 10BASE-T
deployments.
Alien crosstalk (shown in Figure 11-7) happens in 10GBASE-T deployments when
signals from neighboring cables bleed into other cables.

LEED Considerations
If you are concerned with LEED, good cabling practices can help propel you toward your
certification goal. Buildings registered under the LEED system are awarded “credits” for
reaching certain environmental goals, and are assigned a rating within the LEED system
based on the following scale:

• Platinum 52–69 credits
• Gold 39–51 credits
• Silver 33–38 credits
• Certified 26–32 credits
Table 11-1 lists some design considerations, what they accomplish, and which LEED
credits they can help you earn.

Affected cable

Disturbing cables

FIGURE 11-7 Alien crosstalk occurs when signals bleed from one cable to another.