When these new rollable ribbon
fibers are used, the overall flexibility
of the cable is improved. This allows
for an easier-to-handle fiber optic
cable that is easier to route within
the data center. A standard format
ribbon cable does not have the same
bending performance in all axes,
which makes the fiber difficult to
route within fiber trays and racks.
An easier-to-bend cable also lends
itself to easier slack storage as the
loops can be smaller.
Some studies suggest that a 30
percent reduction in cable weight
while doubling the fiber density
has a direct correlation to
installation savings, especially
when considering rack sizes and
reduced cable tray footprints.
Typical of cloud data centers,
singlemode optical ribbon cables
are used to connect the network
equipment, such as servers, access
switches and routers. Various
internet service providers support
these large-scale data centers with
high-count (up to 3,456) fiber cables.
The providers’ equipment is located
in the entrance room, which
provides a point of demarcation.
From here, the various ribbon fibers
48 I ICT TODAY
are routed/spliced for connection
to routers and then to switches. At
this point, all fiber connections are
ribbon splices with MPO connections
to the network equipment. As the
fiber paths make their way to the
individual racks, the fibers can
be broken down to simplex fibers
by use of fanout cable kits for
connection to discrete network
equipment as necessary. This is
where single fiber splicing would
be needed.
FUSION SPLICING
TECHNOLOGIES
It is important to understand the
evolution and capabilities of splicing
technologies to fully appreciate
the skill set and tools required
to effectively splice ribbon cables.
The first fusion splicers employed
V-groove technology. These
machines have two motors that
push the fiber together when the
splice is initiated and discharge the
electrodes to “melt” the two fibers
together. The alignment occurs
only in the pushing motion and
no optimization is performed
to minimize the splice loss. This
technology is prone to higher
splice losses due to the very high
possibility of actual v-groove
contamination or damage.
Core alignment splicers are
able to align the two fiber cores
to minimize the splice loss.
Typically, this is accomplished by
the use of six motors. Two motors
in the X and Y domains align the
fiber geometries while the focus
motors are able to positively identify
the center of the fiber core. Two
motors then push the two fibers
together for the fiber splice.
Active clad fusion splicers
use four motors to align the two
fibers and often provide similar
performance as the core alignment
splicers when optical fibers of
similar geometries are being spliced.
Luckily, this is predominantly the
case with the fibers that have been
manufactured over the last two
decades, and splice loss results are
similar to the core alignment splicer
for these same-type newer fibers
as well. Core alignment splicers are
more tolerant than V-groove, which
succumb easier to contamination
and damage, but this should not be
considered a license to not properly
clean the splicer. Proper cleaning
is one of the most important
processes that a technician must
routinely do. If not done, the
technician’s days will be filled
with disappointment.
Ribbon splicers, often referred
to as mass fusion splicers, use the
V-groove method. Since V-groove
splicers are prone to contamination
of the v-grooves, the technician
must be extra diligent in cleaning
the splicer. If there is contamination
High-count ribbon cables are needed
to be able to transfer mass amounts
of data, especially between linked
data centers.