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Sci-Tech

Closing the digital divide with solar Wi-Fi

Two colleagues develop Wi-Fi technology designed to work where sources of electricity are unreliable. Photos: Green Wi-Fi

Bruce Baikie and Marc Pomerleau are putting an earth-friendly spin on wireless networks.

Their nonprofit organization, Green Wi-Fi, is trying to bring Internet access to schools in developing countries via cheap, solar-powered Wi-Fi networks. The newly formed venture came out of a wish to which many parents can relate: showing their kids there's more to life than the daily grind of corporate politics.

"When you have children, you start really thinking about what you want to tell them that you do with your life," Pomerleau said.

Pomerleau, who until recently was a member of the marketing team for Sun's identity management products, quit his day job to focus on Green Wi-Fi, the nonprofit he started with Baikie, who kept his own day job at Sun.

The technical concept behind the Green Wi-Fi network is fairly simple. Each node in the network consists of a battery-powered router and a solar panel to charge the battery. The nodes are mounted on rooftops, and the network's Wi-Fi signals are transferred over a grid using a wireless network standard known as 802.11b/g.

The first seed money has arrived, enough to produce and test prototype nodes. It came from the One Laptop Per Child initiative (OLPC), which aims to construct a $100 laptop to be distributed to children in developing countries. OLPC showed immediate interest in the Wi-Fi initiative, Pomerleau said.

"We've heard that the strongest criticism they get when they evangelize their laptop is 'What do you do about the network?' If you have a computer but no Internet, you can play games and do spreadsheets, but accessing the world's information is really where the value is."

Green Wi-Fi

The two men decided that Wi-Fi technology would make the most sense, since it is standardized, relatively inexpensive and simple to deploy. The trick to operating a Wi-Fi system in many developing countries is to find a consistent source of electrical power. But while billions of people don't have reliable electricity, most of the developing world doesn't lack sunlight.

One of Baikie and Pomerleau's main challenges was to develop a solar-powered system that would function under variable weather conditions. A commercial solar-based system can run for as long as a week without incoming light. A monsoon season in India or a rainy season in the tropics, however, can last for a month.

Elegant degradation
The developed-world response might be to get a larger battery and a bigger solar panel to charge it, but that increases the cost. Baikie and Pomerleau set their cost ceiling at $200 dollars per node and went for a solution they call "elegant degradation."

"What we bring to the table is an intelligent charge-controller. We put the router on a diet," Pomerleau said. The controller sits between the battery and the router and regulates power to the router depending on the charge level of the battery and the amount of incoming sunlight.

Baikie, who developed the software used in the controller, explained that in implementing the Green Wi-Fi system, users are split into categories, with everyone initially able to connect. If the power level drops a bit, certain groups are cut off, leaving access only to specific school grades or teachers. When even less power is available, the system limits their bandwidth--users can send e-mails, for example, but not watch videos online. Finally, the hours of operation can be restricted to the opening hours of the school. All this is managed through a simple Web-based interface.

The first prototype was primitive and went through a tough test. In the beginning of March, Baikie stuck the solar panel on the roof of his home in San Francisco, together with the router and charge controller and sealed in a waterproof Tupperware container he filched from his kitchen. His timing helped test the limits of the device: Rain fell in the Bay Area for 28 days straight.

But the network stayed up, Pomerleau said. "At the end of the month, with the network never having gone down, we knew that we had something."

Of course, demands on a Wi-Fi network in a developing country can be considerably more severe. The equipment must cope with temperature variations, high moisture, extreme heat, dust and attacks from insects and rodents. But solving those problems wasn't all that hard, Baikie said. "The technology was there, we just needed to put it together in the right way."

The 10-watt solar panel, a Shell ST10 (PDF), was designed to withstand hail storms, which means it is not easily torn or broken.

The battery, no larger than a motorcycle battery, is sealed in a protective gel and built for heavy-duty use and many recharges. The system's Netgear WGT634U router is off-the-shelf, demands low power and accommodates variable bandwidth.

A pilot project
Before the network can deliver Internet content, though, it needs a single, primary broadband access point, which can be several kilometers away. Fortunately, the Wi-Fi nodes can be up to a kilometer apart, allowing a relatively inexpensive deployment of nodes to transfer a signal over several kilometers. In many cases, primary sources are relatively close to schools serving poor communities.

"The digital divide doesn't have to be physical distance at all," Pomerleau said. He observed that many poor schools are in urban areas, close to large, international companies that have great Internet access. "The question is, can you get to it?"

Green Wi-Fi's first full-scale pilot project is scheduled to start at the end of the summer. A Canadian aid organization has asked for Wi-Fi in three schools in Uttar Pradesh, Northern India, where one of the schools has a cable connection. The problem is the lack of reliable power in the region.

The pilot project will require more funding, but Baikie and Pomerleau say they expect help to come from Silicon Valley. "The idea of digital inclusion is very high up on the agenda of socially minded companies, especially in the valley," Pomerleau said.

On the other hand, he is also prepared for skepticism regarding the importance of bringing Internet connectivity to people who might not have enough food and water. "I think that is a very legitimate argument," he said. "But we really don't know anything about creating clean water and supply chains for food, and we do see that we're filling a gap."

Green Wi-Fi hopes to partner with other aid projects--educational groups that create Internet content and teach people how to use the Internet. Even though information is not an end in itself, Baikie noted, it opens those who access it to a world of new thoughts and possibilities.

"Access to the global marketplace can help you raise your standard of living. Indigenous craft makers can sell their products on the Internet," he said. "It creates more opportunity and chances for people to improve their lives and get clean water and food. Without money, it is quite hard to change life in very significant ways."