CommScope® Enterprise Data Center Design Guide - Public ...

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Interlocking Armored Cable
Loose Tube Cable
Tight Buffered
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Trunk Cables
Trunk cables are a subset of distribution cables that run in the data center between the Entrance
Facility, MDA, HDA and EDA. Commonly trunk cables are factory-terminated with MPO or LC
connectors. Although trunk cables could contain tight-buffered or ribbon fibers, today the best
option is to use loose-tube fibers. Loose tube fibers typically have the lowest attenuation because
they are not encumbered by an over-coating (900 μm) or stressed due to their attachment to the
other fibers within a ribbon. Loose tube cable designs also provide the lowest density for the
fiber counts most commonly seen in today’s data centers runs (12 – 144 fibers).
Interlocking armored cables
Distribution cables can be overlaid with interlocking aluminum armor that provides protection
against damage due to extreme conditions. This eliminates the need for installing conventional
conduit or innerduct, thus reducing the overall time and cost of the installation. Interlocking
armor offers superior protection combined with excellent installation flexibility.
Interlocking armored cables are NEC & CEC compliant for OFCR, OFCP and OFCR-LS
(Low Smoke) applications.
Indoor/Outdoor Fiber Optic Cables
Indoor/outdoor cables may be plenum or riser-rated yet are tough enough for use outside.
A water- blocking technology swells on contact with water to arrest moisture ingress and
eliminate the need for a gel outside of the buffer tube. In loose tube cables, water-blocking
technologies (either gel or gel-free) may be inside of the tube as further protection against
moisture ingress.
Distribution (tight buffer)
Indoor/outdoor distribution cables are based on 12-fiber subunits, supported with a central
dielectric strength member and protected with strength yarns impregnated with water blocking
materials, cabled around another central strength member, then jacketed with a UV-resistant
compound. The riser rating eliminates the need for a splice point at the building entrance.
These cables are available in versions of 4 to 72 fibers. Composite multimode/single-mode
versions are available. Distribution cables can be used for risers and backbones.
Stranded Loose Tube
Stranded loose tube cable contains multiple buffer tubes laid around a central strength member.
Yarn adds tensile strength. The buffer tubes contain up to twelve (12) individual fibers. Multiple
tubes are stranded in a reverse-oscillating lay to reduce fiber strain and this allows easier ‘midsheath’
entry. In other words, if some fibers are going to be ‘dropped’ along the route, the
separate buffer tubes permit access to only the dropped fibers while the remainder stay
protected within their own buffer tubes.
Central Loose Tube
These are small diameter cables with a single tube that is thicker and stronger than a traditional
buffer tube. That strength is augmented with several dielectric strength members embedded in
the UV-resistant jacketing material. At some fiber counts, the central tube cable may have a
smaller diameter compared to a similar loose tube design, although with some loss in
manageability.
Interlocking armored cables
Armoring is available on all indoor/outdoor cables except for central loose tube.