Long
Distance Signal Transmission
Large Bandwidth, Light Weight,
and Small Diameter
Long Lengths
Easy Installation and Upgrades
Non-Conductivity
Security
Designed for Future Applications
Needs
Optical fiber systems have many advantages over metallic-based
communication systems. These advantages include:
Long Distance Signal Transmission
The low attenuation and superior signal integrity found in optical
systems allow much longer intervals of signal transmission than metallic-based
systems. While single-line, voice-grade copper systems longer than a couple of
kilometers (1.2 miles) require in-line signal repeaters for satisfactory performance, it
is not unusual for optical systems to go over 100 kilometers (km), or about 62 miles,
with no active or passive processing. Emerging technologies promise even greater
distances in the future.
The optical fiber cable in the foreground has the equivalent
information-carrying capacity of the copper cable in the background.
Large Bandwidth, Light Weight, and Small Diameter
While today's applications require an ever-increasing amount of
bandwidth, it is important to consider the space constraints of many end-users. It is
commonplace to install new cabling within existing duct systems. The relatively small
diameter and light weight of optical cables makes such installations easy and practical,
and saves valuable conduit space in these environments.
Long Lengths
Long, continuous lengths also provide advantages for installers and
end-users. Small diameters make it practical to manufacture and install much longer
lengths than for metallic cables: twelve-kilometer (12 km) continuous optical cable
lengths are common.
Multimode cable lengths can be 4 km or more, although most standards
require a maximum length of 2 km or less. Multimode cable lengths are based on
industry demand. (Single-mode and multimode fibers will be covered in detail later in
this text.)
Easy Installation and Upgrades
Long lengths make optical LAN installation much easier and less
expensive. Optical fiber cables can be installed with the same equipment that is used
to install copper and coaxial cables, with some modifications due to the small size
and limited pull tension and bend radius of optical cables.
Optical cables can typically be installed in duct systems in spans of
6000 meters or more depending on the duct's condition, layout of the duct system, and
installation technique. The longer cables can be coiled at an intermediate point and
pulled farther into the duct system as necessary.
System designers typically plan optical systems that will meet growth
needs for a 15- to 20-year span. Although sometimes difficult to predict, growth can
be accommodated by installing spare fibers for future requirements. Installation of
spare fibers today is more economical than installing additional cables later.
The dielectric nature of optical fiber can eliminate the dangers found in areas of
high lightning-strike incidence.
Non-Conductivity
Another advantage of optical fibers is their dielectric nature. Since
optical fiber has no metallic components, it can be installed in areas with
electromagnetic interference (EMI), including radio frequency interference (RFI).
Areas with high EMI include utility lines, power-carrying lines, and railroad tracks.
Another advantage of optical fibers is their All-dielectric cables are also ideal for
areas of high lightning-strike incidence.
Security
Unlike metallic-based systems, the dielectric nature of optical fiber
makes it impossible to remotely detect the signal being transmitted within the cable.
The only way to do so is by actually accessing the optical fiber itself. Accessing
the fiber requires intervention that is easily detectable by security surveillance. These
circumstances make fiber extremely attractive to governmental bodies, banks, and
others with major security concerns.
Designed for Future Applications Needs
Fiber optics is affordable today, as electronics prices fall and optical
cable pricing remains low. In many cases, fiber solutions are less costly than
copper.
As bandwidth demands increase rapidly with technological advances, fiber
will continue to play a vital role in the long-term success of telecommunications.
