It doesn't matter whether you're a telco, a cable company or a software giant with designs on the ISP market, everyone is hoping that new wireless solutions will cut the cost of providing broadband to large sections of the country. The big question is: How much juice does new wireless tech actually have? And is it enough to make rural broadband deployments cost effective?

Service provider GeoLinks and technology vendor Mimosa Networks Inc. , two partners on the fixed wireless frontier, are very bullish on the technology's promise. How bullish? In working with the Schools, Health & Libraries Broadband Coalition (SHLB), GeoLinks CEO Skyler Ditchfield says he believes fixed wireless technology can be used to reduce the amount of money needed to connect underserved anchor institutions across the US by up to 70%. That could go a long way to helping close the digital divide, and it could even kick off new competition in some markets where service providers traditionally haven't cared to venture.

"[We're] working on doing the cost analysis on doing fixed wireless instead of fiber," says Ditchfield, referring to a program SHLB is working on to get federal funds for rural broadband deployments. "We think we can probably reduce the total cost in the build ask by about 65% to 70%."

Mimosa gear shown in fixed wireless deployments

As partners, GeoLinks and Mimosa have experience in delivering broadband to far-flung places. For example, Ditchfield notes that GeoLinks has built out service to a couple of dozen rural schools in the last 18 months, and that many of these deployments rely on solar- and wind-powered telecom relay stations with wireless links that range from 25 to 58 miles.

"These were schools that weren't able to complete state testing. The students were being bussed out because they had to go do the state testing at another facility and that's obviously very costly and time consuming," says Ditchfield. "So we were able to come in and solve that geographical issue with fixed wireless."

Ditchfield also recalls a recent deployment where an island off the coast of California needed help to improve the reliability of local Internet. In that case, the issue wasn't so much the distance the wireless signal had to travel, but the fact that, in order to provide backhaul capacity for the island's Internet service, the signal had to reach across water from the mainland. Unfortunately, the effects of temperature and air pressure caused the signal to bounce and bend off the water in unexpected ways, disrupting connectivity on a daily basis.

"If you're looking on a hot day down the road and you're looking at a distance and you see those heat waves where the light starts to bend a little bit, that mirage effect, that's basically what's happening with the radio frequency signals as well," explains Ditchfield.

GeoLinks and Mimosa solved the issue by dropping wireless equipment to two separate locations on the island, with a fiber run in between, and creating redundancy to counter the interference. Now when one link goes down, the local ISP fails over to the second link.

For future fixed wireless broadband expansion, there is still the issue of finding enough available spectrum to meet bandwidth demand. However, the good news is that companies that are providing fixed wireless services don't necessarily need to compete with mobile providers for some of the most coveted spectrum real estate. Mimosa Chief Product Officer Jaime Fink and others are lobbying the Federal Communications Commission (FCC) to open up more mid-band spectrum, and Fink says that while frequencies in the 3.7GHz band aren't ideal for mobile services, they are a viable option for fixed wireless connections.

The FCC issued a Notice of Inquiry to study opportunities for mid-band spectrum in July.

"Mimosa has been extremely aggressive with the FCC," says Fink, noting that the company has put together a Broadband Access Coalition that includes members such as GeoLinks, Cincinnati Bell Inc. (NYSE: CBB) and others. The coalition, as he explains it, is "really pushing the envelope of how fast can we share the 3.7GHz spectrum. It's really perfect for fixed wireless applications. It's not something that would be typically used by mobile guys out in rural areas especially so we're trying to really advance access to that band for multipoint as soon as possible."

TV white spaces, the spectrum encompassed by the guard bands around older analog television stations, offer another possible alternative. Microsoft Corp. (Nasdaq: MSFT) is pushing heavily for white spaces development as part of a $10 billion rural broadband project and Ditchfield sees the company as a potential partner for GeoLinks down the road. (See Microsoft Pushes White Spaces for Rural Broadband .)

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There's long been a question of whether fixed wireless service will eventually be a cable killer, ending cable's long dominance of the home broadband sector. Even beyond rural markets, if fixed wireless technology can cut the cost of deployments and still deliver high-speed Internet, it has the potential to radically shift market dynamics.

However, even if wireless technology becomes the preferred solution for last-mile broadband delivery in the future, it won't negate the need for wired backhaul. Fink points out that even though wireless links can span 50 miles and beyond, the more common scenario is to have a fiber connection within five miles or so of end users in order to support fixed wireless service.

The logical conclusion is that broadband going forward will be a mix of wired and wireless technologies. That's why cable ISP Charter Communications Inc. is running 5G fixed wireless trials, and why Google Fiber Inc. is considering fixed wireless solutions in conjunction with existing fiber-to-the-home deployments. (See Charter Reveals New Details on 4G/5G Trials and Google Fiber Now a Wireless ISP!.)

Fixed wireless isn't likely to kill cable, nor to let telcos off the hook for fiber. But it could still open up a lot more opportunity for broadband expansion and specifically for reaching unserved and underserved rural communities across the country.

— Mari Silbey, Senior Editor, Cable/Video, Light Reading