It's the last mile that's the most difficult. That's true whether you're running a marathon or trying to figure out how to build a profitable broadband network. The most popular solution at the moment is a wireless link to make the last curb-to-home hop.
Google, which has largely backed off its ambitious Google Fiber project, is the latest to adopt the wireless last-mile strategy, rolling out something called Webpass to connect a Denver apartment complex to the internet with gigabit speeds.
Verizon, AT&T, Comcast, and others are doing the same, some more rapidly than others.
The problem with running fiber-optic cable to every single home and office in America is that it is simply too expensive, and not even possible in some remote areas. So companies like Webpass, which Google bought recently, build a network hub in or near a neighborhood or housing complex and use a wireless signal to serve nearby customers. Construction cost is minimal compared to fiber and operating costs are comparable.
Webpass and others are operating in the 3.5 Ghz spectrum recently opened up by the Federal Communications Commission. It had previously been used by naval radar systems which have moved to other frequencies.