Fiber Optic Cabling For Beginners
By Brandon Michael
Everyone knows that a structured cabling system is the foundation of every business network,
providing connectivity between servers, computers, and other network devices and allowing both
voice and data to be sent worldwide. When it comes to data cabling, there are different mediums
available to carry that data, transferring it from point A to point B.
Traditionally, twisted pair copper cable has been and is still currently used as the most
common form of structured data cabling, transmitting data through copper wires. As technology
continues to advance however, and the demand for faster, more advanced methods of networking grows,
fiber optic cabling is quickly on its way to becoming the next generation standard in data cabling.
Benefits of fiber optic cabling include:
• Longer distances - Signals carried through fiber optic cable can go up
to 50 times longer than those using copper wires due to low attenuation (signal loss) rates,
without requiring a signal repeater to maintain the integrity of the signal over long distances
as copper wire cables do.
• Intrusion prevention - With copper wire cable systems, it is possible to
remotely detect a signal being broadcast over the cable, which can present unwanted security
loopholes. This is not an issue with fiber optic cable as its dielectric nature makes remote
detection impossible, and gaining access to the fiber itself would require a physical intervention
that would be easily thwarted by a well placed surveillance system.
• Installation improvements - Longer lengths, smaller diameter, and lighter weight
of fiber optic cable make installation and upgrades easy and less costly than with copper cables.
• Higher bandwidth and data transfer rates - With wider bandwidth, more data
is able to be transferred at a much faster speed. This allows for shorter download times and
increased network efficiency.
• EMI Immunity - Fiber optic cables can be installed in areas with high Electromagnetic
Interference (EMI), as the absence of metallic wiring makes the cable completely immune to EMI.
Depending on your specific data cabling requirements, there are two different types of
fiber optic cable available to meet your needs:
• Multi-Mode fiber - Multi-mode fiber has a large core diameter, where light
may be broadcast through multiple paths on its way to its destination. This gives multi-mode
fiber high transmission capacity, but only retaining reliability over short distances generally
less than 8 miles, limited by modal dispersion.
• Single-Mode fiber - Single-mode fiber has a much smaller core diameter
than multi-mode, allowing only one path for light to be broadcast through. Single-mode is used
for long distance transmission, well exceeding the limits of multi-mode, and is not limited
by modal dispersion.
Different environments also require different types of cabling systems to ensure the
fiber stays in good condition. Depending on where you are installing the cable, there are two
basic types of fiber cabling systems that can be used:
• Inside plant - Inside plant fiber cabling systems are designed for use
inside a building where they generally have no contact with environmental variables. In a typical
fiber inside plant cable system, individually coated fibers are positioned around a dielectric
strength member core, and then surrounded by a subunit jacket. Aramid yarn(Kevlar) surrounds
the individual subunits within the cable, reinforcing tensile strength.
Some inside plant fiber cabling systems have an outer strength member as well, meant to
provide protection to the entire cable. For inside plant installation, fiber ribbon-cable
systems are also frequently used. Ribbon cables have a flat ribbon-like configuration that
allows installers to conserve conduit space as they install more cables in a particular conduit.
• Outside plant - When installing fiber optic cable either outside or underground,
an outside plant fiber optic cabling system is used. Outside plant fiber cabling systems are
composed of individual gel-filled subunit buffer tubes which are placed around a central core
strength member. Within each subunit buffer tube, buffer coated fibers are placed around a strength member.