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6 Reasons To Use Fiber On Your Next Project

Connecting the right cable in the right place is obviously essential for pro AV systems integrators, but choosing the right type of cabling for the job can be just as important. We've all heard the s 9/22/2005 6:51 AM Eastern

6 Reasons To Use Fiber On Your Next Project

Connecting the right cable in the right place is obviously essential for pro AV systems integrators, but choosing the right type of cabling for the job can be just as important. We've all heard the stereotypes, as the fiber versus copper debate has been raging for more than a decade.

Connecting the right cable in the right place is obviously essential for pro AV systems integrators, but choosing the right type of cabling for the job can be just as important. We've all heard the stereotypes, as the fiber versus copper debate has been raging for more than a decade.

For most, the main argument against using optical fiber is straightforward: It's just too expensive. But cost isn't the only factor to consider in selecting the right cable for specific AV applications. Sometimes the additional advantages of using fiber can justify the extra initial cost. Here are six reasons why you should consider choosing fiber on your next project.

1 Fiber can cover longer distances.

Distance is fiber's No. 1 advantage, says David Hall, manager of marketing plans and systems at Corning Cables Systems, a division of Corning Inc., in Corning, NY. “That's probably the main reason people are forced into going with fiber,” he says. “We always get called in for the longer distances.”

Of course, distance doesn't always matter. Michael Laiacona, president of Whirlwind Music Distributors, an audio equipment manufacturer in Rochester, NY, points out that if you want to install many drops throughout a facility and will never need to run more than 330 feet — a distance to which Cat5 cabling is limited between switches or repeaters — then copper works as well as fiber. For short cable runs, either will do.

Size, one of the advantages of fiber over copper, speaks for itself."/>

Size, one of the advantages of fiber over copper, speaks for itself.

On the other hand, for a broadcast crew covering a golf tournament or downhill ski event, for example, distance can be important, says Joe Commare, vice-president of sales and marketing at Telecast Fiber Systems Inc., in Worcester, MA. Hall says cable runs to surveillance cameras may justify fiber, depending on their locations, and many media events call for cable runs that make fiber the logical choice.

True, it's not that copper cable can't be made to work over longer distances. But doing so requires switches or repeaters at intervals. That adds significantly to the cost compared to a single fiber run, and each one of those creates a potential point of failure, Hall adds.

2 Fiber offers greater bandwidth.

Comparing the bandwidth of fiber and copper cables is trickier than it seems because bandwidth increases as distance decreases, and there are different types of fiber and copper cabling. While data-transmission standards are in the works that might allow high-quality twisted-pair copper cable to carry 10 Gb of data more than 300 feet, single-mode fiber can carry the same load a couple of miles. For short distances, fiber's capacity is practically unlimited.

More bandwidth means it takes fewer fibers to carry the same information. That means when conduit is required, you can use smaller conduit, says John Lopinto, president and chief executive officer of Communications Specialties Inc., located in Hauppauge, NY. It may reduce installation costs as well. For instance, union rates for installations are sometimes based on length times number of strands times a fixed amount. Fewer strands means lower labor costs.

Carrying several different signals over copper usually means running separate cables, Hall explains. “With fiber, if you run a bunch of different devices into a multiplexer, then you can drop in one single fiber,” he says.

Even if current requirements don't make a compelling case for fiber, there's the future to consider. Expanding video applications, such as videoconferencing and surveillance systems, are likely to increase capacity needs in the future, and replacing cable can be costly and disruptive.



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6 Reasons To Use Fiber On Your Next Project

Connecting the right cable in the right place is obviously essential for pro AV systems integrators, but choosing the right type of cabling for the job can be just as important. We've all heard the stereotypes, as the fiber versus copper debate has been raging for more than a decade.

In digital video applications, copper cables that are adequate today won't be up to carrying higher-resolution signals that will come with tomorrow's standards, says Steven Barlow, president of DVIGear in Chapel Hill, NC. Future standards for high-definition television will raise bandwidth requirements from 742.5 Mb/s to 1.545 Gb. A 50-foot copper cable could handle the former, but not the latter. Barlow says this is his major reason for recommending fiber to DVIGear customers. “If you want to be sure the pipeline is going to be future-ready, you should consider fiber,” he says.

One technique involved in fiber installations offers added insurance against future needs. It involves installing conduit with space to spare and then blowing in fiber using compressed air. If you need more capacity in the future, you can blow in additional fibers. Commare says this has been done in the Notre Dame Cathedral in Paris to minimize future work in the historic building. Air-blown fiber is also used in the White House, he says.

3 Fiber has installation advantages.

Some people think fiber is harder to install than copper. It's true that terminating fiber in the field used to be tricky. “Up until about three years ago, I'll be honest with you, it was a major pain,” Lopinto says. But no more. “Today there are field termination kits where you can put a connector on in three minutes or less.”

That's down from 10 or 15 minutes a few years ago, and is comparable to the amount of time it takes to terminate coax. Meanwhile, fiber is also thinner and lighter than its copper counterpart. “The big disadvantage of having copper cabling is that it's very heavy and very bulky,” says David Caidar, president of Opticomm Corp. in San Diego. Not only does that mean copper cable takes up more space — sometimes a critical issue — but it also makes it more work to install.

Reduced bulk eliminates a number of headaches, especially in rental & staging jobs. A copper snake can be a bulky, intrusive beast that's difficult to route without causing annoyance and hazards to the audience. A fiber snake is much less bulky. “I have many more ways that I can route it and sneak it into places,” Lopinto says.

For those who worry fiber is more fragile and prone to damage, Lopinto disagrees. “Just because optical fiber is made of glass doesn't mean it's easy to break,” he says.

The glass core is well protected, and according to Lopinto, fiber is less sensitive to damage than coax, which can produce ghosting on a video image if the cable is crushed.

Citing a specific example, Commare claims broadcast crews covering professional golf matches have been able to cut four days off their time onsite because of the simplicity of setting up with fiber (see photo, left). “They go from having a bundle of cable that's probably 18 inches to having one bundle of fiber probably as big as your pinky.” And weight is important to broadcasters for another reason — fiber costs a lot less to transport. “They made their money back in the first year just on labor and accommodations and the weight of their trucks,” Commare says.

Installing the cable itself isn't the whole story. With copper cabling, Lopinto says, a series of steps are necessary to ensure a good signal — equalization, gain adjustment, and de-skewing. Fiber requires none of this. “You basically put the product in and that's it,” Lopinto says. “It either works perfectly, or it doesn't work at all.”

4 Fiber is immune to electromagnetic interference.

Neither radio-frequency interference (RFI) nor electromagnetic interference (EMI) affects fiber, notes Caidar. This means you can run fiber right alongside electrical cables without worrying about noise. Electric motors, fluorescent light ballasts, and other environmental variables that can cause problems with the signal on a copper cable have no effect on the photons flowing through fiber. That means there are more options for routing fiber. “We have people that run fiber through elevator shafts, which are notorious for being very noisy because of the high-induction motors there,” Lopinto says.



6 Reasons To Use Fiber On Your Next Project

Connecting the right cable in the right place is obviously essential for pro AV systems integrators, but choosing the right type of cabling for the job can be just as important. We've all heard the stereotypes, as the fiber versus copper debate has been raging for more than a decade.

“With fiber, run it with the power cable — it just doesn't matter,” Commare says. “Where you run it doesn't become an issue unless you put it somewhere where a door can slam on it.”

Fiber can even be run in the same conduit with a low-voltage electrical line. For instance, Caidar notes, the wires carrying power for a projector bulb can be packaged with the fiber carrying the video signal to that projector, making for simpler installation without causing any crosstalk problems. In many parts of the United States, fiber can also be run without conduit, simplifying installation and reducing cost. (Check with local codes for specific conduit requirements in your area.)

This immunity to interference, coupled with fiber's ability to carry signals greater distances without loss of quality, means more consistent results, maintains Lopinto. With copper connections, he says, “you may have 10 plasmas all showing the same image, but they all look different.”

Interference and distance from the source may affect brightness, color balance, and clarity. With fiber, “you get absolute consistency from one display to the next, regardless of what the length is back to the source,” he says.

But Al Keltz, general manager of Whirlwind, adds a qualifier to this. While analog signals over copper wire are highly vulnerable to interference, Keltz says, digital signals are less so, even when transmitted over copper. Keltz says he wouldn't run any copper AV cabling parallel to electrical cables for any distance, but other than that few environmental factors would have much effect on a digital signal.

5 Fiber doesn't radiate signals like copper cable.

“Fiber cable, because it's not electrical, doesn't act like an antenna and radiate a signal,” Lopinto says. That makes fiber communications more secure than transmissions over copper cabling. “It's very hard to tap into fiber-optic cable,” Caidar says. “It's very easy to tap into coax and very easy to tap into twisted pair.”

Does this security matter in AV applications? Not always. If you're carrying audio signals from a stage to a mixer, or a video image of a conference speaker on stage from a camera to a projector that will display a large image on a screen above the speaker's head, you're not dealing in sensitive information. But consider video from surveillance cameras being transmitted back to a bank of monitors or a private videoconference. Caidar says fiber is especially popular in government and military installations for this reason.

The fact that fiber doesn't radiate a signal can be important for another reason — running fiber alongside copper cabling won't be subject to interference from the adjoining copper; nor will it cause any interference on the nearby cable. This could also be important where fiber runs close to sensitive electronics, such as in a hospital, suggests Barlow.

6 Fiber doesn't cost as much as you think.

In bulk, fiber costs about eight cents a foot. Cat5 twisted-pair cable costs about five cents a foot. The copper cable is cheaper — but fiber has greater capacity. Therefore, it can be cheaper when bandwidth requirements are high.

The bills for fiber start mounting when you look at the supporting electronics, which to date have cost more than their counterparts for copper. But that cost is coming down. The need to convert signals from electronic to optical is even being eliminated in some cases. In fact, some manufacturers have begun including optical outputs in video cameras, Hall says. And in longer-distance installations, the need for more switches or repeaters to enable copper to go the distance can make fiber the cheaper alternative.



6 Reasons To Use Fiber On Your Next Project

Connecting the right cable in the right place is obviously essential for pro AV systems integrators, but choosing the right type of cabling for the job can be just as important. We've all heard the stereotypes, as the fiber versus copper debate has been raging for more than a decade.

Laiacona says the benefits of fiber show up not on small jobs and short runs but on major installations, such as wiring stadiums. “In a large project like a baseball stadium or something of that magnitude, you can easily spend $750,000 on hanging conduit, pulling wire, and terminating it,” he says.

In many cases, fiber will cost more than copper —and in a significant number of those cases, copper is therefore the better choice. But as Barlow points out, you have to consider the big picture. In a home theater system, for instance, a 50-foot fiber cable might cost $700 versus $200 for the same length of copper cable. But the fiber will be able to handle the higher resolution of future video standards and deliver a better signal. Given the fact that cable is typically three to five percent of the total system cost, he says, why save money on cheaper cabling that becomes “the weakest link in the chain” and prevents you from getting the full benefit of the other components?

Based in Kingston, Ontario, Canada, Grant Buckler is a freelance writer and editor who has been covering information technology and communications for 25 years. He can be reached at gbuckler@cogeco.ca.



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