Fiber snakes its way closer to the desk

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SPECIAL REPORTS: Installing Networks

A unique solution deploys fiber cable through ceilings and floors to the head of a workstation cluster, where active networking components reside.


Since mainframe computing burst onto the scene in the 1970s, supporting tens of thousands of "dumb terminals" by connecting them with thousands of tons of copper data-communications cabling, an explosion of voice and data cabling has snaked its way through virtually every commercial building in this country for the better part of 30 years. In North America alone, some 150,000 miles of copper cable-enough to circle the earth about six times with plenty left over-sits on the shelves of distribution facilities coast to coast, ready for overnight deployment into North America's voice- and data-network infrastructure.

Today, powerful LANs, incorporating shoebox-sized servers with a million times more computing power than the '70s mainframe, reside in a fraction of the space once reserved for round reel data tapes. Ironically, today's small, powerful, high-tech servers usually exchange information, albeit faster, with their users the same way they did back in the days of mainframe computing. It's still done by snaking heavy, bulky, and expensive copper cabling through the ceilings, floors, and office furniture to each end-user workstation.

Today, it is common to find three or four voice and data cables running to each workstation. When tenants move, cable is cut-usually left abandoned in the ceiling or floor. A new tenant means new cable-upgrade your network, pull new cable; install a new phone system, pull new cable; troubleshooting, pull new cable; moves, adds, or changes; pull new cable. Cabling moves, adds, or changes combined with new network upgrades cost corporate America more than $15 billion each year. Th 74191

Photo 1. This "active" enclosure provides a fiber zone cabling solution that eliminates any technological risk while providing all the advantages of fiber-to-the-desk at a very low cost. Workgroup switches and hubs-now confined to telecommunications closets-are strategically deployed to each workgroup, extending the fiber "backbone" horizontally to an "active" enclosure, where short, effective copper patch cords run to each workstation appliance.

In 1991, Anixter, a communications products distributor, quietly coined the phrase "fiber-to-the-desk," as a better approach to in-building communications infrastructure. Why fiber? The benefits are numerous, but bandwidth, weight, and reliability are key. Imagine a scenario where 200 workstations are located on a floor with three voice and data "drops," or connections, per workstation or office. Twenty-five pounds of optical fiber in the horizontal link from the server to the workgroup can accommodate significantly more data than a ton or more of Category 5 copper and save a nightmarish mess in the pathways.

Fiber has the largest bandwidth of any media available. It can transmit signals over the longest distance at the lowest cost with the fewest repeaters and the least amount of maintenance. Fiber is immune to network performance bandits-electromagnetic interference and radio-frequency interference-which are critical issues with copper cabling as network data speeds and bandwidth needs increase. Fiber transmission systems are highly reliable. Fiber cannot be tapped, so it is very secure. Network downtime is limited to catastrophic failures such as cut cables, instead of wasting time on "soft" failures such as overloading. There are no "crosstalk" issues with optical fiber, since it is impervious to lightning strikes and doesn't conduct electricity.

While there's no question why fiber is the superior choice for today's high-speed network demands, there has been one barrier to implementing all-fiber networks: cost. Ideally, there is no reason to even use copper cabling in the communications infrastructure, but fiber network interface cards (NICs) are still very expensive. Without a fiber NIC, there's no way to make the final connection at the end user's desktop in an all-fiber network. Therefore, most businesses still use the traditional homerun copper cabling method.

But there are emerging solutions that allow the end user to run fiber out to the desktop while providing huge savings over traditional homerun cabling methods. This solution maximizes the power of horizontal fiber in the workspace while blending it with the economies of a short copper segment to the desktop appliance (PC, telephone, fax machine, printer).

A unique solution, fiber zone cabling runs fiber-optic cable through ceiling or floor pathways, terminating the fiber connection at the head of a workstation cluster, where an enclosure houses active networking components (switches and media converters). From that point, a very short, low-cost copper segment runs from the "active" enclosure directly to the end user's desktop appliance.

This solution provides a clear, easy-to-implement migration path to higher-speed technologies. Using copper the last 20 ft minimizes copper's run-length distance and maximizes copper's bandwidth characteristics, providing a viable answer to expensive fiber NIC cards. The end result is a high-speed network at a fraction of the cost with all the benefits, including easy fault isolation and testing, new network overlays without interruption to existing operations, futureproofing for emerging technologies, and no-hassle moves, adds, and changes (see Photo 1).

Sam Moore is senior industrial engineer at Siemens Electrocom (Arlington, TX), a manufacturer of high-technology equipment. Siemens has six buildings in Arlington totaling 700,000 sq ft. The costs of cabling workstations using the traditional homerun method ranges from $200 to $250 and as high as $500 per cable, depending on the pull distance. Moore, with more than 20 years' experience in the cabling and facilities environment was looking for a more cost-effective and efficient way of delivering connectivity to the end user.

When it came time to replace the Arlington branch's 900 stations of furniture, Moore realized he would have to spend millions of dollars to replace systems furniture with newly styled panels. Moore was interested in implementing a fiber-to-the-desk solution because he could reap the benefits of broadband connectivity while saving money. He accomplished that by using his existing furniture, which was in good condition, with a top-cap raceway system running along the spine of systems furniture combined with the "active" enclosure. Less wiring congestion results in reduced troubleshooting time. Th 74192

Photo 2. Siemens Electrocom's telecommunications room is shown before implementation of fiber-to-the-desk solutions and after the unique distributed LAN architecture was installed.

Moore reports that the implementation of this solution reduced network-cabling costs to just 10% of the traditional homerun copper cable system. With just a portion of the network cabling removed from the main terminals, Siemens' technicians significantly cut troubleshooting time and installation time was cut in half (see Photo 2).

Another user of a fiber-to-the-desk solution is the U.S. Department of Defense Commissary Agency (DECA), which is responsible for the management of the worldwide network of U.S. military commissaries-the retail outlet for active and non-active military personnel and their families. DECA includes about 100 international commissaries as well as an additional 200 facilities on U.S. soil.

DECA's communications infrastructure consisted of a vertical fiber backbone from which traditional homerun copper cabling ran out to each end user. To manage information effectively, the agency needed high-speed bandwidth that would allow quick access and the transfer of large volumes of data. When the decision was made to move headquarters into a state-of-the-art facility in Fort Lee, VA, the requirement was for fiber to all data connections.

The agency decided to deploy a solution combining new systems furniture with a "passive" enclosure and top-cap raceway system (see Photo 3). This solution met all requirements of the project: flexibility, economy, and sensitivity to fiber-optic cabling. Four floors and 278 employees of the new headquarters are now served by this system.

A "passive" enclosure resides at the head of an eight-person workgroup. The enclosures, which are EIA/TIA standards-compliant, hang from a furniture panel and are fed by cable distribution routed through the floor. Inside each enclosure is a 24-port multi-user telecommunications outlet assembly (MUTOA) that is the flexible consolidation point in DECA's fiber/copper communications system. Each end-user receives three drops, or connections-one fiber for data and two copper Category 5E for voice and fax. The fiber data drop required the agency to use fiber NICs to accommodate the connection at the computer. From the "passive" enclosure, the top-cap raceway carries the 24 cables along the spine of the systems furniture to each end user and uses a vertical wire manager to seamlessly route cabling from the raceway to each desktop appliance. Th 74193

Photo 3. This top-cap raceway system runs along the spine of systems furniture and keeps communications cabling separate from the harsh environment of furniture panels. It provides a pathway for either copper or fiber cabling-ideal for high-performance networks.

To support DECA's unique requirements, the passive enclosure and top-cap raceway system, combined with the new furniture, enable delivery of optical fiber to each workstation in an efficient and economical manner. The economy of the system enables moves, adds, and changes at 50% less cost to the agency.

The next phase of the fiber-to-the-desk solution involves a unique approach to communications cabling within a building. This system is a communications infrastructure that becomes a permanent amenity of the building, not unlike a building's plumbing, electrical, and HVAC systems-essentially a fourth utility. No longer will tenants need to build and reconfigure their own network infrastructures. Buildings will be "pre-wired," with runs of optical fiber on each floor and sub-runs to each cluster of workstations. Tenants can simply lease the infrastructure from the building owner, "plug in" each of their end users at the desktop, and begin to work.

Communications infrastructure is evolving to accommodate the needs of today's high-speed, constantly connected work environment. The best way to increase bandwidth and maximize the network is to extend fiber horizontally to within whispering distance of each end user. Who could imagine how much progress would be made in such a short time, from huge mainframes and discos in the '70s to mini-LANs and cell phones today.

Chuck Sinks is senior vice president of marketing at Holocom Networks (Carlsbad, CA). He can be reached at the company's Website, Jennifer Balch is Holocom's communi cations manager.

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