How can wireless help close the U.S. digital divide?

There are quite a lot of places in the United States where there is no wired or wireless internet connection. The Federal Communications Commission (FCC) is currently in the first phase of creating more accurate maps to identify these unserved areas.

Microsoft’s data finds that of about 330 million people in the U.S., 157 million people do not use the internet at broadbands speeds. And BroadbandNow finds that at least 45 million people (about 14% of the U.S. population) do not have broadband access at all.

Even if there are macro wireless towers in a rural area, those towers provide service to smartphones. But they don’t help people connect their other devices such as laptops and smart TVs.

T-Mobile, Verizon tackle FWA

A couple of the big carriers – T-Mobile and Verizon – have recently announced that they’re piggy-backing on their existing LTE spectrum and macro towers to deliver LTE-based fixed wireless access.

T-Mobile said in October that it is expanding its LTE fixed wireless access pilot to more than 20 million households in parts of 450 cities and towns. T-Mobile’s President of Technology Neville Ray has said, “As we look ahead at driving competition, one of our major focuses is on fixed broadband. Today this is one of the most uncompetitive industries in America. Across the U.S., and in rural areas in particular, people lack options, and millions of folks are suffering from high prices and no choice. We’re going to change that.”

T-Mobile isn’t just broadening its coverage to rural areas out of the goodness of its heart. The company made specific commitments to the FCC and the Department of Justice as part of the approval process for its purchase of Sprint. For example, T-Mobile has pledged to cover 85% of rural America with 5G on low-band spectrum in three years and 90% in six years.

Verizon is also using FWA as a way to increase market share and supply broadband to rural areas. In September Verizon announced that it had expanded its fixed wireless access rollout on LTE to cover rural parts of 189 markets in 48 states.

But Wave7 Research principal Jeff Moore said in a recent FWA report that he’s “not sensing any energy for Verizon’s LTE Home Internet; with no advertising or store displays, reps seem baffled when asked about it.”

Ed Gubbins, principal analyst with GlobalData, said these FWA deployments by the big carriers use the same base station radios that are used to provide LTE mobile service. But instead of connecting to a phone, they connect to customer premise equipment (CPE), and that CPE is usually also connected to the home’s Wi-Fi router.

“Over time, LTE technology has advanced with features like carrier aggregation that combines different channels of spectrum so you have a fatter pipe,” said Gubbins. “When you combine that increased speed with the fact that the price of LTE technology has come down over the years, you get the kind of cost per bit that allows you to make a business case for serving these residential broadband use cases in a more reasonable way.”

But Gubbins said there are some issues with LTE FWA related to capacity. “If you’re going to use an LTE base station for both mobile and FWA residential broadband, then you have to think about capacity of that base station and how it’s being divided. If a lot of capacity goes to FWA users, how does that impact mobile users and vice versa?”

Operators could add more capacity to the site. But additional baseband and radio equipment could stress the space limits on towers, especially if operators are also adding 5G and massive MIMO gear.

“I think some of those decisions can be difficult, and the needs can vary from site to site,” said Gubbins. “They’ve done it a lot in China for the digital divide.”

LTE backhaul in rural areas

Gubbins focuses on telecom vendors working in the mobile access infrastructure ecosystem. He said Huawei is doing a lot of LTE-based FWA in China. Huawei is working with Chinese operators to use integrated access and backhaul (IAB) in some rural areas where it’s too difficult to access fiber or use microwave links for backhaul.

RELATED: Huawei taps integrated access backhaul to deliver rural LTE

In the United States, Airspan Networks provides some products that do IAB for LTE networks, although it calls its backhaul technology “small cell relay” or “iRelay.”

The downside to IAB is that it uses some of the valuable spectrum that would otherwise be available to deliver mobile services or home broadband via FWA. It probably wouldn’t make sense to use IAB excessively because it would eat up too much spectrum, especially if end users are trying to do things like stream Netflix.

“Some of that depends on each operator’s spectrum holdings and how they want to use their spectrum,” said Gubbins.

However, another thing to consider is that some of these FWA deployments that piggyback off LTE are in extremely unpopulated areas where much of the available mobile capacity is hardly used.

Smaller operators and FWA

While big U.S. carriers are finally showing some interest in serving rural areas with FWA, up until recently it has been wireless internet service providers (WISPs) that have been the primary movers when it comes to using wireless technologies to bring broadband to rural America.

RELATED: Why small wireless carriers care about all the CBRS hullabaloo

Many of these WISPs are founded by scrappy entrepreneurs who simply got so frustrated about the lack of internet in their area that they set up their own companies to provide it via FWA. This involves finding some vertical infrastructure, such as a water tower, to set up point-to-point or point-to-multipoint antennas to serve a several-mile area. Another critical piece of the puzzle is to access spectrum. CBRS spectrum in the 3.5 GHz band is often a good choice. And of course, there’s a need for backhaul. The WISPs can sometimes reach fiber via a telephone pole for their backhaul. But often they have to access fiber via a couple of microwave hops.

In addition to its 4G/5G products, Airspan is also helping to close the digital divide with its Mimosa FWA portfolio.

Jaime Fink, VP of technology for fixed wireless at Airspan, said that Mimosa is focused on helping WISPs, DSL providers and cable operators to provide FWA. “Mimosa is extremely strong on high-performance backhaul,” said Fink. “We offer both backhaul point-to-point and edge multipoint FWA subscriber service as alternatives to mobile tech. We do this in a mix of unlicensed 5 GHz, the new 6 GHz band, and certain dedicated point-to-point licensed microwave and lower millimeter wave bands like 11 GHz and 24 GHz.”

Fink said Mimosa’s backhaul technology uses “our own proprietary MAC/PHY techniques and spectrum reuse techniques” that Mimosa overlays onto lower-cost commercial silicon. “We’re just providing low-cost, IP-based capacity pipes, or subscriber connectivity (not providing direct service to a mobile phone), so it’s a very similar radio concept to mobile physical layers and microwave, but at a radically lower cost basis.” 
The company is especially enthused about new funding that will come from the Rural Digital Opportunity Fund (RDOF) to bring wireless technology to unserved areas.

RELATED: Charter scores big in Phase I of the FCC's RDOF auction for rural broadband builds

The biggest winner of the first phase of the RDOF auction, which concluded in December, was LTD Broadband, which bid $1.3 billion, pledging to provide FWA service to 528,000 locations across 15 states.