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."