Information Technology Reference
In-Depth Information
cordage was 30% higher than for the same manufacturer's Category 5e plenum cop-
per cable. You can draw your own conclusions from these cost comparisons.
The third question asks whether your application requires some of the special
characteristics that make fiber shine. For example, in an industrial plan with long
distances, lots of electromagnetic field interference, and potential grounding prob-
lems, fiber cabling makes lots of sense. Fiber is immune to electrical interference,
eliminates ground loops, and can transmit much longer distances than copper. If
your network equipment has existing fiber interfaces or, if you require very large
data bandwidths, fiber is again the obvious choice for your use. And fiber is an
appropriate choice for backbone and campus cabling.
But what about the future? Will technology make copper cabling facilities obsolete
in a few years? Should you install an all-fiber facility now so that doesn't happen? What
about your current equipment that may not have fiber interfaces? Can you afford new
network adapters and hubs that support fiber, or can you even upgrade your existing
equipment? Wow, what a mess! How can you decide between the two types of cabling?
If relative expense is not an issue, must one really choose fiber
or
copper?
Why not install both? Install Category 5e copper for today's applications and
fiber for the future. In fact, most telecommunications outlet manufacturers have
outlet modules that can easily accommodate both a fiber duplex connection and two
or more twisted-pair cable jacks. It is certainly less expensive to install both tech-
nologies in a new facility than it would be to go back in 5 or 10 years and add fiber.
The best advice, if the budget allows, is to put in twin fiber and copper facilities.
Several variations of cable construction are available, as shown in Fig. 5.5. The
cable may use either a tight or loose buffer construction. A tight buffer closely sur-
Tight-Buffer
Loose-Buffer
Two strand
(zip cord)
Single strand
FIGURE 5.5
Several variations of fiber-optic cable construction are available.
