The Internet may feel like it is everywhere, but large pockets of sky, swaths of land and most of the oceans are still beyond a signal's reach.
Three decades after the first cellphone went on sale — the $4,000 Motorola DynaTAC 8000X "brick" — half the world remains unconnected. For some it costs too much, but up to a fifth of the world's population — some 1.4 billion people — live where "the basic network infrastructure has yet to be built," according to a Facebook white paper last month.
Even these figures, says Kurtis Heimerl, whose Berkeley-based startup Endaga has helped build one of the world's smallest telecom networks in an eastern Indonesian village, ignore the many people who have a cellphone but have to travel hours to make a call or send a message. "Everyone in our community has a phone and a SIM card," he said. "But they're not covered."