Sorting through cables and connectivity options could be a
frustrating exercise. It's hard enough working through the categories
and levels of copper networking cables, where most cables end with
similar connector. What happens when you start looking at fiber cables?
This is where things can definitely get confusing! This article tells
you how to select the right kind of fiber cables.
Let's move on
off by saying that fiber optic cables can be used in a huge variety of
applications, from small office LANs, to data centers, to
inter-continental communication links. The information lines that
connect between North America and Europe, for example, are constructed
with fiber optic cable strung underneath the ocean. Our discussion in
this article will focus mainly on the kinds of cables present in those
small-scale networks closer to home, and in particular to pre-terminated
cables which may be designed for installation, called "patch cords",
"pre-terms", or any other similar nicknames like fiber patch cables. Prior to you buying, you should make clear the following parameters.
Multimode and Single mode
One of the first things to determine when selecting fiber optic cables
is the "mode" of fiber that you'll require. The mode of a fiber cable
describes how light beams travel within the fiber cables themselves.
It's important because the two modes aren't compatible with each other,
which means that you can't substitute one for that other.
There's
really not much variety with single mode patch cords, but there's for
multimode. You will find varieties described as OM1, OM2, OM3 and OM4
(OM means the "optical mode"). Basically, these varieties have different
capabilities around speed, bandwidth, and distance, and the right type
to make use of will be based mostly upon the hardware that is being used
with them, and any other fiber the patch cords will be connecting to.
Fiber Optic Cable Jackets
Pre-term fiber can be used in a variety of installation environments,
and as a result, may need different jacket materials. The standard
jacket type is called OFNR, which means "Optical Fiber Non-conductive
Riser". This can be a long-winded way of saying, there's no metal in it,
so it won't conduct stray electrical current, and it can be installed
in a riser application (going in one floor up to the next, for
instance). Patch cords are also available with OFNP, or plenum jackets,
which are ideal for use in plenum environments for example drop-ceilings
or raised floors. Many data centers and server rooms have requirements
for plenum-rated cables, and also the local fire codes will invariably
have the final say in what jacket type is required. The ultimate choice
for jacket type is LSZH, which means "Low Smoke Zero Halogen", that is a
jacket produced from special compounds that provide off very little
smoke with no toxic halogenic compounds when burned. Again, seek advice
from the neighborhood fire code authority to be certain of the
requirements from the installation before making the jacket selection.
Simplex and Duplex
Simplex and duplex have only the difference between one fiber or two,
and between one connector at each end of the cable, or two connectors
each and every end. Duplex patch cords are the most common type, because
the method in which most fiber electronics work is they need two fibers
to speak. One is used to transmit data signals, and the other receives
them. However, sometimes, just one fiber is required, so simplex patch
cords may be essential for certain applications. If you aren't sure, you
can always be on the safe side by ordering duplex patch cords, and just
one of these two fibers.
Fiber Optic Cable Connectors
Remember what we should said at first about copper category cables? No
matter what level of twisted pair you were coping with (Cat 5, 5e, etc),
you always knew you would be dealing with an 8-position modular RJ-45
plug around the end from the cable. Well, with fiber patch cords, there
is a few possibilities when it comes to connectors. The common connector
types are FC, LC, SC, ST and MTRJ etc..
These are the most
typical selections that you will find when choosing amongst patch cords.
If you're able to determine which of these characteristics you need, it
is highly likely you will make the right choice when custom fiber optic cables with suitable parameters.
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