Contraction and Expansion

By Claire Swedberg | Apr 15, 2011




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With the convergence of low-voltage systems into one Internet protocol (IP) network for commercial or industrial buildings, cabling multiple disparate systems may become a thing of the past. The Ethernet cable standard Category (Cat) 5 cable cannot support the bandwidth necessary for such solutions.

To meet the structured cable needs of their clients, contractors will increasingly be working with Cat 6 and 7 cable and more shielded systems with very high performance to resist noise. At the same time, with data centers expanding to increase the load of servers and data in one system, there is a need for contractors who can build out existing Cat 5 cable solutions to accommodate the upgrades.

Many electrical contractors and their customers continue to consider Cat 5 and Cat 5e “good enough,” and that may be a short-sighted attitude, said Valerie Maguire, vice-chair of the Telecommunications Industry Association (TIA) TR-42.7 Copper Cabling Systems Subcommittee and global sales engineer for Siemon.

The challenge is building an infrastructure that can support multiple applications on a single cable.

“Suddenly, all these disparate systems and disparate cabling plans are being managed together,” said Brian Duvall, marketing communication manager, Siemon. Some companies are finding there is a cost savings in renovating old systems, creating a more energy-efficient system, he said.

When it comes to renovation cabling, vendors such as Siemon recommend Cat 7a—which is backward compatible to Cat 5 and Cat 6 cable—fully shielded cable encased in metal. Using Cat 7 will eliminate any interference coming from within the cable and shield against interference from adjacent cables. The cable supports frequencies up to 1,000 megahertz (MHz) as opposed to Cat 6a’s 500 MHz.

William Tao & Associates (WTA), a St. Louis engineering firm, installed a Cat 7a converged system. The company uses a unified building technology platform with a single structured-cabling infrastructure to support voice, data, video, surveillance and access control. The system includes a single Cat 7a cable as part of the Siemon TERA cabling system, which features cable sharing and high bandwidth. The system allows sharing of cable with hybrid patchcords that can accommodate up to 4-pair plugs terminated to Ethernet plugs. The system can also offer a bandwidth of 1,000 MHz.

For WTA, the company and its installers first built models of the existing structure, then designed new systems to fit around it. The design included determining the layout of the low-voltage cabling infrastructure and pathways and placement of surveillance cameras, access control units and additional drops of voice and data. The layout of cable pathways and telecommunication closets as well as network infrastructure products, such as racks, cable management and patch panels, can be designed using building information modeling.

Data center growth and change
The market for data center network equipment grew about 67 percent in 2010 over 2009, reaching a total of $7.6 billion worldwide, according to a study by market research and consulting company Infonetics Research.

The way the centers are being cabled is changing with that growth. Traditionally, contractors installed raised-floor systems, which provided cold air distribution channels and space to run power and data cables underneath the IT equipment. This met users’ needs for data centers with a small number of large IT devices, which rarely were changed out.

On the other hand, modern data centers have more IT devices in the same space, so the number of branch circuits per square foot is greater. In addition, devices are swapped around regularly. The necessary increase in cabling can then create congested and inefficient cooling channels that are more difficult to access. The weight of equipment per square foot is higher, and that causes capacity problems for raised floors, which might require special reinforcing. So, here’s another potential cost in material and design planning.

So not only are solutions moving away from raised floors, the cable being used is shifting as well. Twinlinx cables are a popular way to upgrade from Cat 5 to Cat 6 without pulling out all the Cat 5 cable. In addition, copper cables are replacing optical fiber for 10 gigabit Ethernet on twisted-pair cabling. By 2013, according to an Intel study, 44 percent of 10 gigabit links in data centers will be copper. With the cost of copper driving the price of cable, Maguire speculates that waiting for prices to come down to invest in higher bandwidth cable, such as Cat 7, may not be beneficial.

“We’re in a bit of a jam with copper pricing,” she said.

Recouping the cost of research and development of new cable products may not apply if copper prices, as some predict, continue to rise.

SWEDBERG is a freelance writer based in western Washington. She can be reached at [email protected].

About The Author

SWEDBERG is a freelance writer based in western Washington. She can be reached at [email protected].

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