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A 50-Watt Cellular Network

Solar-powered base stations can link up remote rural areas.
February 10, 2010

An Indian telecom company is deploying simple cell phone base stations that need as little as 50 watts of solar-provided power. It will soon announce plans to sell the equipment in Africa, expanding cell phone access to new ranks of rural villagers who live far from electricity supplies.

Cellular power: A low-power cell phone base station made by VNL on a rural rooftop in India.

Over the past year, VNL, based in Haryana, India, has reengineered the traditional technology of the dominant cellular standard, called GSM, in order to create base stations that only require between 50 and 150 watts of power, supplied by a solar-charged battery. The components can be assembled and booted up by two people and mounted on a rooftop in six hours.

One such station–dubbed a “village station”–can handle hundreds of users. Groups of such village stations feed signals to a required larger VNL base station within five kilometers. In turn that larger station, which is also solar-powered, relays signals to the main network. The village station can turn a profit even if customers spend on average only $2 a month on the service, instead of the $6 required to make traditional systems cost-effective, the company says.

“We’ve scaled down the cost, the energy, and the equipment so that almost anybody can deploy it,” says Rajiv Mehrotra, VNL’s CEO. “It lends itself to many business models that can serve the bottom of the pyramid,” a reference to the roughly 1.5 billion rural people who do not have access to electricity grids around the world.

To date, some 50 VNL base stations have been installed in the Indian state of Rajasthan, introducing thousands of people to cell phone service for the first time. An African rollout is imminent, the company says, without elaborating. The initial batch of 50 stations support voice and data transmission–but not initially text-messaging, a decision mainly based on the fact that many new users may not be able to read or write.

Besides enabling basic communication, cell phones can provide enormous financial opportunities for rural people, especially if those people adopt services that provide banking and lending via cell phone. More than half of India’s 1.1 billion people lack any access to basic financial services, and instead pay usurious rates to local loan sharks. Furthermore, while microlending can lift people from poverty, only about 150 million people worldwide use such services. Expanded cell networks, together with banking programs geared to the rural poor, could change all of that.

The base station rollouts are “incredibly empowering for the world’s remote and low-income masses,” says Valerie Rozycki, head of strategic initiatives at mChek, a mobile-payment platform based in Bangalore that is unconnected with VNL.

Expanding cell networks in many rural areas comes down to the availability of sufficient electricity to power base stations. Existing off-the-grid base stations in India require expensive diesel generators. “The cost is substantial enough to make many rural markets unprofitable and therefore unwired,” says Ethan Zuckerman, cofounder of Global Voices, an aggregator and promoter of blogging worldwide. “Solutions that reduce the cost of building a base station are helpful, and those that reduce the costs of powering a base station are crucial.”

Russell Southwood, CEO of Balancing Act, a London-based telecom and Internet consultancy focused on Africa, says low-energy, self-sufficient solutions will be key to expanding cellular access further in the developing world. “Energy costs are particularly high, as [base-station] sites often have two generators and some have three months’ supply of fuel,” he says. “Anything that cuts fuel costs is bound to be attractive to operators, and it’s also a more sustainable, green approach to communications.”

But while VNL has optimized its unit for rural areas, it is not the only company making low-cost, low-power base stations. “We are seeing a trend toward commoditization” in the cellular industry, says Ray Raychaudhuri, director of WinLab, a wireless research laboratory at Rutgers University. “Where it was traditionally vertically integrated, you are seeing that break down into something that looks more like a Wi-Fi architecture, where you can buy a box and install it.”

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