Like most wireless Internet service providers, JAB Broadband relies on unlicensed spectrum to get its service out to sparsely populated areas where there's only dial-up service.

The open airwaves are plentiful, spanning the 900 MHz band, 5 GHz band and heavily populated 2.4 GHz band, but JAB Broadband has to share them with federal users, Wi-Fi routers and other devices. Signals sent at the higher frequencies also have a difficult time getting through obstructions like leaves, trees and walls, making them even less attractive.

This leaves certain customers out of reach because WISPs simply can't get a signal to them.

So you might think that a company like JAB Broadband would jump at a chance to get its hands on more spectrum, especially 700 MHz spectrum prized for its propagation characteristics: the television white space spectrum opened by the FCC in September 2010.

The white spaces spectrum is comprised of the empty bandwidth located between channels used for broadcast television, and it's abundant in sparsely populated areas of the country where television stations are few and far between.

Signals sent over the white space bands can penetrate obstacles impervious to other spectrum, making it possible for wireless ISPs to serve a whole new segment of formerly unreachable customers.

But JAB Broadband co-founder Jeff Kohler isn't banking on the technology to usher in the next wave of connectivity for rural areas of the country just yet.

"It will be another spectrum tool in our bag," he says. "We're sticking with equipment that gives us the greatest speeds at the best price."

White space spectrum has potential, but like any new technology, it also has challenges.

Not only is the equipment more expensive because there are no economies of scale on the amount being currently produced – Kohler says right now it's "very, very expensive" and costs about four times more than JAB Broadband's current gear – it also offers slower speeds because the FCC has deep restrictions on the amount of each 6 MHz white space channel that can be used.

"It won't deliver anywhere near the level of speeds we get with current unlicensed spectrum," Kohler says.

White space-based broadband will be faster than the snail's pace of dial-up service, but it won't compare to high-speed DSL lines. U.K.-based white space startup Neul says its gear can realistically offer average speeds of 1-2 Mbps for multiple users in a single cell.

"Obviously, people prefer 10-20 Mbps, but if you're looking at dial-up speeds of about 100 kilobits, 1-2 Mbps seems like a big step forward," says Neul Chief Technology Officer William Webb.

Even so, higher cost and lower performance aren't exactly the attributes most companies look for in new technologies. So does that mean white space technology is dead in the water for rural broadband? No.

White Space's Awkward Adolescence

Wireless ISPs long had their eyes on white space spectrum, so the FCC's decision to finally make the channels available without having to apply for an experimental license was seen as a victory for rural broadband providers.

The opening of the airwaves last year marked the largest release of unlicensed spectrum since 1985, a move which led to the creation of today's Wi-Fi technology.

TV white spaces were touted as ushering in a new era, with FCC Chairman Julius Genachowski claiming they would "enhance our economy and strengthen our global competitiveness, lead to billions of dollars in private investment and to valuable new products and services."

Sharing Genachowski's enthusiasm were companies like Google that want to use white space frequencies to boost the performance of Wi-Fi routers, the so-called "Super Wi-Fi" everyone's been talking about.

Rural broadband providers and companies serving the machine-to-machine space also saw ways to use it to serve difficult-to-reach customers.

But as is so often the case with new technologies, there's still a long way to go before white space service will be commercially viable.  

ERF Wireless CEO Dean Cubley says white space technology could eventually allow the company to serve customers it couldn't otherwise reach because of economics, but the technology isn't anywhere near the maturity it needs to be at for wide-scale deployment.

"We want to see performance that matches the theory. We want to see a cost-effective supply of equipment," he says. "Right now neither of those has been proven. The equipment is extremely expensive compared to what it has to be for wide market acceptance."

The company is using pre-production equipment from Carlson Wireless Technologies to test out how white space technology compares to services running on the spectrum it currently uses, which includes both licensed and unlicensed bands. Results from the field trials are expected in the coming weeks.

Jim Carlson, president and CEO of Carlson Wireless Technologies, confirmed that its white-space-compatible customer premise equipment (CPE) is more expensive than its legacy microwave products, and for good reason: Its microwave gear has been on the market for about 15 years, providing plenty of time for prices to come down.

Carlson's equipment is so new it hasn't even filed for FCC approval yet. The company did proof-of-concept testing in August and plans to submit the resulting gear to the FCC through white space database administrators Spectrum Bridge and Telcordia next month.

Carlson says its white space gear will have the same pricing as its microwave equipment in about a year and a half. "Affordability is big with WISP's," Carlson says.

A single CPE for white space service currently runs about $600. Carlson expects that price to drop to $460 within two years as it ramps up production.

WISP Association Executive Director Rick Harnish is a proponent of white space technology and says it has huge potential for the WISP industry. He concedes the cost of white space equipment is still more expensive than the legacy gear used by wireless ISPs, but for reasons that are typical.

"It's brand new technology and there are no economies of scale yet on the quantity that's being manufactured," he says.

But even with prices at the point they're at now, Harnish says demand is great enough that WISPA's members will invest.

"Given the demographics of our membership, I'd estimate that 10 percent will invest early in the technology regardless of the price," Harnish says. "There will be a lot of customers taking a 'wait and see' attitude – they're waiting for second- or third-generation equipment to come out, waiting to see how the performance is before investing in it."

Even at this early stage, the WISP industry is "excited" about the technology's ability to allow providers to reach currently unserved customers, Harnish says.

There is still some uncertainty on the legislative front. TV white spaces almost met a premature demise last month when Congress introduced a measure to repack television stations into a smaller swath of spectrum, cutting down on the number of empty channels available for white space devices. The bill failed to pass, but could be revived.

As pressure mounted on Capitol Hill, the FCC approved Spectrum Bridge as the technology's first database administrator – white space devices must check with the database for open channels in their area – and Koos Technical Services became the first company to release an FCC-approved white space device. Telcordia is set to become the second database administrator to get FCC approval after trials conclude this month.

So far, so good.

Finagling at the FCC

Part of the solution to boosting the broadband speeds offered by white space technology lies in the equipment – still in pre-production phases – but a larger part of the fix requires the FCC to loosen up restrictions on power limits and out-of-band emissions.

White space devices operate in spectrum adjacent to incumbent services like wireless microphones and television broadcasts, so their signals could present major interference problems if not managed correctly. This issue prompted the FCC to put rigid regulations in place to protect the band's pre-existing users.

The limits on out-of-band emissions for white space technology – or "adjacent channel attenuation" in FCC lingo – are stricter than for other technologies like Wi-Fi and WiMAX, cutting into the amount of the already narrow 6 MHz white space channels that can be used.

The inevitable result: slower speeds.

Motorola Solutions estimates that the FCC's spectrum mask for white space bands will reduce the amount of usable bandwidth in a given 6 MHz channel by 25 percent. Not only does this affect data rates, it increases the number of access points needed to provide coverage. The result: an estimated 33 percent increase in network deployment costs for WISPs and a 65 percent increase in the cost of customer premise equipment.

The concerns were echoed by a group of broadband companies led by the WISP Association, which warned the FCC in documents filed last year that "the increased costs that would result from tightening the OOBE (out-of-band emissions) mask would have a chilling effect on fixed white space broadband deployment."

Despite the pleas from equipment vendors and broadband providers, the FCC ultimately denied requests to relax the stringent restrictions on out-of-band emissions set out in its original white space plan and left the limits in its final order.

The FCC also denied petitions to raise power limits on fixed white space devices like the type used for broadband, but indicated it may consider easing the limits on power levels in the future – it said in its final order that "we could re-visit the issue of higher power levels for TV bands devices on a licensed or unlicensed bases at some point in the future as may be appropriate."

Like the restrictions on out-of-band emissions, the limits on higher power levels will reduce the range of the service and increase infrastructure costs.

The FCC may consider relaxing the regulations if early white space trials are successful and don't knock out signals from existing users like broadcasters.

"Once things get started and they develop a track record of non-interference, the television stations will have a much weaker argument and we'll likely see those spectral requirements relaxed," says Philip Leigh, contributing analyst at Diffusion Group.

A few municipalities signed up for experimental licenses and have been conducting trials of white space devices, including a smart city application in Wilmington, N.C., a rural broadband project in Claudville, Va., and a smart grid trial in Plumas County, Calif.

Boiling it Down to Economics

Aside from the technical and regulatory challenges facing the still-nascent white space market, basic issues of economics could prove to be a major hurdle for getting the technology into the mainstream.

Analyst Chetan Sharma points out that there simply aren't enough potential residential customers for rural white space deployments to make the technology profitable for most companies. Even when it reaches maturity, the market for white space technology in rural broadband will pale in comparison to the consumer market for super-fast Wi-Fi routers.

"The market as a whole for rural broadband is really not that big," Sharma says.

In fact, it's miniscule.

Though the FCC estimates that 18 million Americans largely in rural areas don't have access to broadband Internet, target market for residential white space service is much smaller.

The Diffusion Group estimates that the number of rural residents that can't be reached by current WISP technology is under a million – about 600,000 people. Compare that to the country's total population of about 312 million people, and you don't exactly have a huge market.

Neul shares the Diffusion Group's meager estimate about the number of U.S. homes that could benefit from white space technology. Webb pegs the potential residential customers for white space service in the hundreds of thousands.

"It's not anywhere as near as big as M2M, which is our longer term goal," he says.

That doesn't mean Neul thinks white space technology lacks potential for rural broadband, but it has other things in mind. Like many other companies developing white space technology, Neul has its sights set on vertical markets, namely the booming machine-to-machine market.

It could be cheaper to run M2M modules on white space service than on operators' cellular networks, and white space technology may work better for modules located in areas that can't be reached by signals on higher-frequency unlicensed bands, such as the inside of buildings.

ERF Wireless has staked its business model on vertical markets and thinks white space technology could open new channels of revenue from business customers that need connectivity in hard-to-reach areas.

"The WISP business is a break-even business at best. If that were the only business we had, we'd be struggling," Cubley says. "But when you overlay that with other verticals, that's when it really gets interesting."

ERF Wireless provides fixed wireless broadband connectivity in rural markets and it also provides connectivity to companies in the lucrative oil and gas industries. Oil and gas exploration often occurs in remote areas of the country where cell towers are practically an endangered species, making white space technology an attractive fit.

"There's not a cost-effective way to hook up the hundreds of thousands of older producing wells," Cubley says. "If this works and can be made cost-effective, the market is almost endless. Where you can't reach them with any other technology, it may be the only solution other than laying out a fixed line."

And that's where white space technology fits in the rural broadband market. For now, it's slower and more expensive than services running on unlicensed spectrum. But it could find a niche getting connectivity out to areas where other signals can't reach and it's too expensive to run a fixed line.

Back at JAB Broadband, Kohler says the company expects to conduct small scale trials of white space technology some time later this year, but has "no major plans" to deploy it en masse any time soon.

But like other wireless ISPs with reservations about the technology, that doesn't mean JAB is dismissing TV white spaces altogether. "Any solution that allows us to take advantage of additional spectrum is welcome," Kohler says.

Equipment will become less expensive as the market advances and more spectrum could come in handy, especially given the rising data use of JAB's customers.

Data consumption is up 66 percent over last year and JAB Broadband is planning for 50 percent increases in data use every year, forcing the company to essentially rebuild its network to keep up with demand.

It's that kind of demand that will help television white space technology find a home in rural America.