Solar power, white spaces bring 16Mbps broadband to towns without electricity
Jon Brodkin via Ars Technica –
White space networks haven’t exactly revolutionized Internet access in the US, but that doesn’t mean the technology can’t have a major impact in countries that lack consistent access to the Internet. The latest project showing the power of white spaces is unfolding in Kenya, where a solar-powered network is bringing the Internet to people who aren’t even connected to an electric grid.
Microsoft deployed the network last month in conjunction with Kenyan government officials. It is serving a health care clinic in Burguret, a primary and secondary school in Male (that’s pronounced “mah-lay”), a secondary school in Gakawa, and a library in Laikipia. The network will be expanded to 20 locations in the coming months.
“Down in the valley, nobody has electricity,” Paul Garnett, director of technology policy at Microsoft, told Ars. Garnett has been shuttling back and forth between the US and Kenya to get the white spaces network up and running, and he gave me an update on the project in a recent phone interview.
Some of these areas did have mobile Internet access, but “it’s so expensive that nobody ever uses it,” Garnett said. Electricity isn’t completely unavailable, but it is sparse. In one case, a school has electricity going to the principal’s office but nowhere else, he said.
That’s where solar power comes in. 4.5 kilowatt hours (kWh) of energy per day are derived from 7-square-meter panels.
“During the day the solar panel is providing enough to run the network and provide some charging capability, and then in evenings there is this battery backup that can continue to provide broadband access, plus you have excess capacity for overnight charging,” Garnett said. “Think of the school scenario where you’ve got a computer lab that the kids can use during of the day, and drain down the batteries in the tablets during the day. And then in the evening you have a charging station where all the tablets are plugged in and can recharge overnight.”
White space networks take advantage of spectrum in unused TV channels, typically in the 600MHz range. These lower-than-Wi-Fi frequencies allow signals to pass through walls and are ideal for long-range wireless networks.
Although white spaces are pitched as a solution for rural US areas without broadband, adoption has been slow. Garnett blamed this partly on “regulatory uncertainty” in the US related to the amount of spectrum available to white space networks. Although a planned incentive auction designed to repurpose spectrum used by TV broadcasters could increase the amount of airwaves available to white space devices, it is also possible that the auction will result in fewer airwaves devoted to white spaces.
This uncertainty makes it hard to commit lots of money toward white spaces networks, although it may work out well in the end. “The good news is the FCC [Federal Communications Commission] does appear committed to finding more white spaces spectrum,” Garnett said.
Spectrum shortage? Not here
In contrast to the US, the Kenyan airwaves are free and clear.
“We’ve never seen a cleaner profile,” Garnett said. “There are just several hundred megahertz of unused spectrum that could be put to use for this kind of connectivity. Capacity really isn’t an issue. Range is great. This is a real opportunity from our perspective.”
Most end-user devices (laptops, tablets, phones) aren’t made to connect to access points operating in white space frequencies, but there are ways of working around that. The Kenya white spaces network starts with a solar-powered base station near the town of Nanyuki, which connects back to fiber access from an Internet Service Provider called Indigo. This base station sends signals to the schools, health care clinic, and library, which have “two-headed” devices that act as both white space receivers and Wi-Fi hotspots. These devices (manufactured by Adaptrum) take the white space signal and distribute wireless Internet access via the 2.4GHz and 5GHz Wi-Fi airwaves that typical consumer devices can connect to.
Microsoft says it can achieve a range of at least 10 kilometers around a base station using a single TV channel, with 16Mbps throughput to end users. Ultimately, Microsoft will need two base stations to power 20 locations because they are divided into two geographical areas hundreds of kilometers apart. Latency is about the same as any typical broadband deployment, Garnett said.
“We’re able to do a variety of applications that are latency sensitive,” he said. “You can do video Skype calling or other types of applications that require a network that doesn’t have a whole lot of latency. There’s no reason why you can’t do a full range of applications on a white spaces network.”
What does Microsoft get out of all this? The company does lots of charitable work, of course. But also, like Google, Microsoft stands to benefit from increasing use of the Web. Besides Hotmail and Bing, the moneymaker Microsoft Office is increasingly becoming Web-based. The Kenyans using Microsoft’s white spaces network are also becoming familiar with Microsoft’s Surface hardware, as you can see in this picture:
“We basically want more of the world’s consumers to be connected, everyone to be connected over inexpensive forms of access,” Garnett said.
The Kenya project is similar to one in South Africa just announced by Google, which is broadcasting from three base stations to ten schools.
Microsoft has previously set up white spaces networks on its own campus in Redmond, WA, as well as in Singapore and England. In the US, Microsoft is on track to be one of ten providers of white spaces databases. Despite the regulatory uncertainty Garnett mentioned, he does expect white spaces deployments to expand in the US as more databases come online and the technology improves.
But in terms of the impact on people’s lives, the Kenya project will be tough to beat.
“You’re talking about delivering broadband access to communities without any electricity whatsoever, without paved roads; all these things we take as normal don’t exist in these communities,” Garnett said. “It’s exciting to be in schools where kids have never used the Internet before. Within 90 seconds they’re surfing the ‘Net, they’re using a touchscreen, and they’re off and running. It’s an amazing thing.”