The broadcast spectrum that allowed people in isolated rural areas to watch television long before cable and satellite services could also provide underserved parts of the U.S. with access to broadband Internet service, according to Microsoft.

Yesterday, the company announced a plan to bring broadband connectivity to millions of rural residents through unused spectrum, so-called "white space," in the 600 MHz UHF television bands. Microsoft, which has already used such technology to connect people to the Internet in other parts of the world, said it's the most promising strategy for low-density communities where other broadband systems would be too expensive.

Nearly 34 million people in the U.S. lack access to advanced telecommunications capabilities, meaning broadband download speeds of 25 Mbps, according to the Federal Communication Commission's 2016 Broadband Progress Report. Of these, an estimated 23.4 million live in rural areas.

Goal: 'Eliminate Rural Gap' in 5 Years

"In urban America, we've thankfully become accustomed to ongoing capital investments to expand broadband capacity in areas that already have broadband coverage," Microsoft president and chief legal officer Brad Smith wrote in a blog post yesterday. "But the time has come to extend this coverage to the rural areas that lack it entirely."

Through its Rural Airband Initiative, Microsoft will partner with telecommunications companies to bring broadband Internet connectivity to 2 million people in remote parts of the U.S. by 2022, Smith said. Over the coming year, the effort will aim to have "at least 12 projects up and running in 12 states," he said. In the long term, Microsoft's goal is to help "eliminate the rural broadband gap within the next five years by July 4, 2022," he said.

Microsoft will also work to provide training to residents in those areas to help people develop the skills they need to "improve education, health care and agriculture, as well as transform their businesses," Smith added. Finally, the company plans to promote further broadband investment by others through a new program that will provide royalty-free access to "at least 39 patents and sample source code related to technology we've developed to better enable broadband connectivity through TV white spaces spectrum in rural areas," he said.

U.S. Speeds in 10th Place Globally

When it comes to the broadband connection speeds available to most residents, the U.S. lags behind many other countries. The U.S. is currently in 10th place with an average connection speed of 18.7 Mbps, compared to the 28.6 Mbps average of connectivity leader South Korea, according to the Q1 2017 State of the Internet report from content delivery network provider Akamai Technologies.

The FCC paved the way for using TV white space spectrum for broadband services with rule changes it adopted in 2010. The technology for using that portion of the spectrum has now advanced to "a critical threshold" where the market can, with the right strategies, accelerate its use, Smith said. Microsoft has already used such technology to deploy 20 TV white space projects that serve 185,000 users in 17 countries, he noted.

Smith said the best way to bring broadband connectivity to those who lack it will involve a combination of technologies, with TV white space for areas with population densities of two to 200 people per square mile, satellite services for areas with fewer than two people per square mile, and fixed wireless or limited fiber for communities with more than 200 people per square mile.

"By relying on this mixture of technologies, the total capital and initial operating cost to eliminate the rural broadband gap falls into a range of $8 to $12 billion," Smith said. "This is roughly 80 percent less than the cost of using fiber cables alone, and it's over 50 percent cheaper than the cost of current fixed wireless technology like 4G."