Network Communications News (NCN) May 2016 | Page 27

copper cabling systems

however, there is limited space to
effectively add the patch cabling that
would be required. In this type of
situation, 28-AWG patch cabling is an
effective solution to cabling systems
space limitations.
Common patch cabling challenges
include congestion that makes moves,
adds and changes (MACs) a timeconsuming undertaking, as well as the
use of layouts that consume space,
making it difficult to work with patch
cabling bulk.

New challenges
In the past few years telecom rooms
and data centres have witnessed many
new challenges driven by new network
capabilities. These have forced the
industry to consider new ways to best
solve the critical space issues within
racks and cabinets. 28-AWG cabling can
be used immediately in most scenarios
to help solve space challenges by
increasing pathway capacity, enabling
higher-density layouts, facilitating easier
cable management, and ultimately
lowering costs.
One example of the space saving
gained by using 28-AWG cabling can
be seen in the use of a typical vertical
cable manager, which has a finger
opening of one inch (25.4mm). A typical
24 cord bundle of 24-AWG cords has
a diameter of 1.37 inches (34.8mm),
larger than the actual gap in the cable
manager. This then makes the ‘normal’
cable bundle difficult to work with.
In comparison, a 24 cord bundle of
28-AWG cords has a diameter of 0.89
inches (22.6mm), therefore it fits easily
into the cable manager.
If we consider the pathway space
within a typical 4-inch (101mm) vertical
cable manager, the advantages
of using 28-AWG are even more
apparent. Assuming using Category
6 patch cords in a four inch manager,
and using a 50 per cent fill ratio, which
is considered full for working capacity,
a typical four inch vertical manager can
fit either 213 24-AWG cords or 523 28AWG cords, which is more than double
the capacity.
At the patch panel, the use of 28AWG cords results in more open space
between the cords where they are
connected. The typical space between
24-AWG Category 6 patch cords at
the panel is 0.315 inches (8.0mm).
When 28-AWG Category 6 patch
cords are used the space increases to
0.4 inches (10.1mm), or 27 per cent
more open space between cords. This

S P E C I A L F E AT U R E

Category 5e

Category 6

Category 6A

0.215” Diameter

0.235” Diameter

0.275” Diameter

48%

41%

45%

0.149” Diameter

0.150” Diameter

0.185” Diameter

24 AWG UTP
28 AWG UTP

28-AWG cabling offers significantly smaller diameter wire than the ubiquitous 24-AWG copper conductors.

space gain offers: better port number
visibility, especially on high-density
panels; easier cord management
due to space for fingers and plug
access, as well as improved routing of
cords, and better airflow for improved
equipment cooling. It also allows for
new configurations, including the use of
fewer, or no, horizontal cable managers.
The use of high-density panels is more
effective because the patching bulk is
reduced. Even a layout like direct-switch
patching, or port replication is practical
when 28-AWG cabling is used rather
than 24-AWG.

Reduced congestion
A common telecommunications
room or data centre situation that
28-AWG cabling can help solve is the
congestion of horizontal and vertical
cable managers and the overall
amount of patch cabling used. Taking
a typical network rack as an example,
it provides two 8-RU chassis switches
(for redundancy), offering a total of
768 ports and cords. In the 24-AWG
cabling situation, all the cords are
routed to the cross-connect rack via
vertical and horizontal managers.
It uses angled patch panels at a
density of 36 ports per rack unit. In
this layout, patching becomes dense.
Furthermore, due to the cable-routing
layout, driven by the bulk of the
cable, several different cord lengths
are needed. The physical layout of
the cabling requires a significant
amount of patch cabling. In this
common layout there is more than a
mile of patch cords in place.
When 28-AWG cords are used
in the same situation, less space is
occupied, bundle sizes are reduced,

the use of high-density panels fitting
48 ports in 1 RU is accommodated and
horizontal managers are eliminated. This
set-up allows a much more compact
side-by-side layout that reduces the
amount of cord required by 60 per cent.
This reduces costs in terms of material as
well as installation time.
Although 28-AWG falls outside of
the size specification of TIA-568-C.2,
Panduit’s 28-AWG cabling is fully
compliant with the performance
requirements of the standard, including
near-end crosstalk and return loss, when
used with specific length guidelines.
This is an exciting area in copper
patch cabling that offers immediate
advantages in current install scenarios.
With advantages such as increasing
pathway capabilities, achieving
higher-density layouts, easing
cable management and reducing
both initial and ongoing c