FIGURE 3: Comparison of 200 μm and 250 μm ribbon fiber.
April/May/June 2020 I 9
CABLE TYPE
Loose Tube Cable
FIBER COUNT
144F 288F 432F 864F 1,728F 3,456F
Ribbon Loose Tube Cable
Flexible Ribbon Cable Example
16.0 mm 18.9 mm
19.8 mm
12.0 mm
21.0 mm
19.8mm 25.1 mm 35.4 mm
13.5 mm 17.5 mm 23.0 mm 30.0 mm
13.9 mm
10.5 mm
all fiber cross-section. This translates to the ability to support
higher density, less overall weight, and a smaller
bend radius that supports an overall easier installation.
Choosing a ribbon solution that maintains a 250 μm
pitch enables backward compatibility to existing infrastructures
built on 250 μm SMF with 250 μm pitch
(Figure 3).
This is most important within the data center facilities
where the need to maximize connections is pitted
against the need to minimize overall infrastructure size.
The smaller diameter cabling translates directly into
the benefits of ribbon and loose tube designs. Choosing
a gel-less ribbon solution removes the typical mess associated
with gel-filled cable solutions. This, alone, can
remove hours from installation time. These modern, flexible
cable designs enable the fiber to be pulled together
easily in groups of 12 and as individual fibers.
Because size reduction is one of the greatest differentiators,
cable manufacturers know that it is critical to reduce
the size and weight of the cabling infrastructure. As shown
in Figure 2, today’s flexible ribbon solutions can provide
864-fiber cable in the similar space once required for 144-
fiber loose tube or 288-fiber traditional ribbon solutions.
With these new innovations, 100 to 200 percent density
increase in the same space can be reached. This translates
to less used space in ladder racking, less weight for easier
handling and installation, and smaller holes and conduits
between data center halls and campus buildings
due to the smaller diameter cable. Without these breakthroughs
in optical fiber and cable manufacturing, the
demands of tomorrow’s data center could not be achieved.
New flexible ribbon designs, the technical enabler
of 200 μm singlemode fiber (SMF), has allowed for the
significant breakthrough in density-per-square-inch. The
200 μm fiber provides over a 35 percent reduction in over-
FIGURE 2: Cross-section comparison of different cable technologies.