The convergence of computer, telephony, audio, video, and
Internet applications have made high-speed data transmission
imperative for todays local area networks (LANs). Communication
systems designers and integrators need innovative strategies
to cope with constantly changing landscapes within office
buildings, corporate campuses, and other commercial facilities
where continuous moves, adds, and changes are a fact of life.
In these dynamic environments, air-blown fiber-optic (ABF)
cabling technology can provide a cost-effective solution.
ABF offers all of the benefits of conventional fiber-optic
transmission high speed, high bandwidth, and superior
performance but without the high infrastructure and
How ABF Works
The heart of the ABF system is a highway of tube cable
installed in place of conventional inner duct to define the
network topology. Once the infrastructure is in place, lightweight
bundles of single-mode or multi-mode fiber are blown, at speeds
up to 150 feet per minute, through a predefined route, using
specially designed equipment.
Installation is fast and easy, typically requiring only two
trained technicians. Cable runs may exceed 6,000 feet and
the fiber path may traverse outdoor, riser, and plenum tubes
in a single run. Since the fibers are not pulled, installation
damage ceases to be an issue. Moreover, point-to-point connectivity
eliminates splices the most common site of network
In most ABF installations, tube cable is installed with more
cells than are currently required to ensure room for expansion.
Unused cells are capped until needed. Network expansion or
reconfiguration is accomplished by extending tube cables from
the nearest tube distribution unit. Fiber bundles can be upgraded
or replaced by blowing cable through unused cells, or by blowing
out old fiber (which can be reused) and blowing in new
all without disrupting the existing network.
A World of Applications
Because of its inherent flexibility, ABF cabling systems
are ideally suited to LANs deployed in healthcare complexes,
universities, manufacturing sites, resort hotels, corporate
office buildings, and campuses.
The renowned Getty Center in Los Angeles is a prime example.
With construction costs of about $1 billion, the Getty Center
is as enormous in scope as it is stunning in setting and architecture.
The Getty Center is one of the nations largest fiber-to-the-desk
installations, with more than 3 million feet of air-blown
optical fiber. Typical of corporate environments, the Getty
Center network had to be designed for computers, printers,
and other devices, as well as Internet access and videoconferencing.
At the sprawling campus, the state-of-the-art ABF cabling
system paid for itself almost immediately. Huge savings stemmed
from the selection of ABF technology and adoption of a centralized
network architecture (CNA) that eliminates costly communications
The CNA design model takes advantage of the longer transmission
distances possible over optical fiber to eliminate the floor-by-floor
electronics required in telecommunications closets served
by copper wire installations. At the Getty Center, most or
all network electronic equipment is housed in a single computer
room, making TC closets unnecessary. The fiber-optic cabling
systems are fully compliant with industry standards TIA/EIA-568A
for telecommunications cabling and ICEA-S-83-596 for fiber-optic
For the Getty Center, these choices delivered a cost-savings
bonanza. Total cost savings in floor space saved and related
construction costs avoided totaled more than $5 million
more than enough to pay for the entire telecommunications
cabling system. Additional system maintenance and administration
savings were gained through centralized network electronics
and a sophisticated cable management system.
Jim Allen is product marketing manager at Research Triangle
Park, NC-based Sumitomo Electric Lightwave Corp., a leading
supplier of conventional fiber-optic cabling and FutureFLEX®
Air-Blown Fiber-Optic Cabling systems.