Free space optics technology evolves to higher speeds, broad deployment

FSO’s value proposition remains steady and worthwhile for many users.

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FSO’s value proposition remains steady and worthwhile for many users.

By Patrick McLaughlin

Deployed primarily as a high-speed connection for enterprise users who are unable to run cable from one point to another, free-space optics (FSO) technology has matured over the past decade. A handful of equipment providers did not survive the 2001 dot-com crash, but those that remain provide systems with data-rate increases and price stabilization.

Peter Schoon is president of System Support Solutions (www.systemsupportsolutions.com), an integrator of

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Post-production company The Post Group in Hollywood, CA installed a rooftop-to-rooftop 10-Gbit/sec free-space optics system (top) with a 1-Gbit/sec radio-frequency backup (bottom).

FSO and other wireless-connectivity systems including radio-frequency (RF)-based products. System Support Solutions has been installing FSO and RF systems for approximately 10 years and says it has made more than 400 link deployments in that time.

We interviewed Schoon about the recent history, current state, and potential future direction of the FSO marketplace. A broad look at FSO technology, including quotes and specifications from some providers of FSO systems, can be found on our Web site, www.cablinginstall.com. For now, here are relevant excerpts from our interview with System Support Solutions’ Peter Schoon.

CI&M: Is the basic value proposition for FSO the same as it has been for some time—an affordable high-speed option when running cable from point to point is either not possible or not economical?

Schoon: It is. FSO is one of many tools in a bag. Users look at their options and sometimes find that even a single trenched fiber is cost-prohibitive. The telco might say it’s going to take six months [to get the connection made] and it will cost $20k per month. The user tries to find another option.

FSO fits best when the bandwidth requirement is high, 100-Megabit minimum, and distances are shorter. FSO systems definitely max out at 2 kilometers. Links between 1 and 2 kilometers probably make up about 10% of what we install now, and hops up to 500 meters make up about 70% of our installations. Once the link distance gets to 500 meters, it can make sense to pay more money and go with an RF link.

CI&M: Fog has historically been the enemy of FSO. Is that still the case?

Schoon: Yes, it’s fog. Snow, ice, and rain are not so much an issue. Fog is. I try to explain it simply to potential customers: If you can see from one point to the other, your FSO link will work. Some links may be a little farther than the eye can see, but the point is if the physical conditions allow line-of-sight vision, you’ll have a working FSO link. If not, like in the case of fog, you won’t.

CI&M: How have current economic conditions affected the industry?

Schoon: The recession has actually been good for the industry. Manufacturers have right-sized and they are all doing well financially. Integrators specializing in point-to-point are lean, mean, and profitable.

CI&M: The FSO market’s dynamics have evolved over the 10 years you have been installing these systems,

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FSO systems, like this one at The Post Group, most often reside in unglamorous positions atop roofs. Nevertheless, they provide critical connectivity.

haven’t they?

Schoon: One thing that applies to a lot of industries, including this one, is that we lost some companies that burned through cash. Those that made it through have streamlined and economized. Product improvements are customer-driven. A lot of the smoke-and-mirrors are gone, which is nice. Ten years ago some in the industry were incorrectly setting expectations. That’s half the battle in any business: don’t overpromise, but make sure you overdeliver.

CI&M: What are some of the more recent customer-driven product improvements?

Schoon: One is a Web-based management interface. Customers really do want that. Lightpointe has added it to some of their equipment and MRV Communications has it across the board.

Power over Ethernet is also very popular, especially for 100-Megabit links. Typically a 100-Mbit link is installed in a lower-cost environment. And using PoE over a Category 5 cable can save three or four, sometimes up to six thousand dollars on an install.

Another feature is adding an RF feature as a backup to lasers. It gives a dual-path hybrid link at little [additional] cost. This type of feature had been bundled and sold as part of a more-expensive package. But in the enterprise industry what’s important are low cost and simplicity. With this backup feature, the link is 100% available. If you put this in, you have 100% redundancy and the telco doesn’t.

CI&M: How can systems without this integrated-backup feature achieve redundancy?

Schoon: Use lasers [FSO] for shorter distance or RF for longer distance. Putting redundancy in is inexpensive. We have a lot of hybrid [FSO as the primary and RF as the backup] sites running, and I’ve never had someone call and say the performance has failed or is slow because they’re on the RF setup. The RF backup is a 20-Mbit link. When it activates it is for minutes, not days. Users don’t notice [the difference in transmission speed].

CI&M: FSO and RF remain competitive technologies to some extent, depending on distance and uptime requirements, as well as cost. Is there a sweet spot for FSO?

Schoon: There are a lot of cost-competition issues. Bridgewave sells a lot of their SLE100 products with 802.3at PoE. That’s a hot item from the leader in the RF industry and provides true 100-Meg transmission. The list price is $9,995. I tell the FSO providers their real target market over the next five years is going to be 500-meter links, Gigabit speed at a 10K list. There are some FSO systems at that price point that do Gig speeds. They offer 10 times the throughput of Bridgewave’s SLE100 for the same price, but with a little bit lower availability.

CI&M: What about super high speeds like 10-Gigabit? Is there any demand for that?

Schoon: The biggest news in the industry is probably MRV’s 10-Gig product. 10-Gig is getting requested now. When MRV first started work on that product two years ago, I didn’t get many requests for that speed. But now I do. The big home for FSO continues to be a company that has a 10-Gig environment and is expanding across a campus.

The Post Group [a post-production company in Hollywood, CA] installed a 10-Gig link and backed it up with 1 Gig of RF. It added between $16,000 and $17,000 to the project cost, but to have dual paths on a rooftop … their telco option was very expensive.

MRV’s 10-Gig design uses an erbium-doped fiber amplifier, which solves amplifying issues.

CI&M: After 10 years installing FSO systems do you find them durable?

Schoon: Some of our early links are still running flawlessly. The second install I ever did is nearby [in Minnesota]. I call him every year and he says everything’s good; his only question is when I’m going to take him to lunch. We offer three-year on-site support and maintenance, and we don’t think twice about renewing those agreements. With some customers we are on our third agreements, which will take them to nine years of coverage.

Patrick McLaughlin is chief editor of Cabling Installation & Maintenance.

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