With the technology, a person trapped in a building could hold up a cell phone to a ceiling light, and rescuers would be able to pinpoint his or her exact location. Similarly, cars could exchange information through headlights and taillights, and car computer systems could tell drivers if there were major stalls ahead.

Conceivably, entire movies could be shuttled from one TV to another in a few seconds through signals bouncing between the two screens.

Formed two years ago, the group is holding its first public demonstrations of the concept at CEATEC, a sprawling tech show taking place here this week.

“Although there are no concrete plans right now for making it into a standard, some companies are very serious,” said Shinichiro Haruyama, a professor of information and computer science at Keio University.

The consortium is essentially trying to capitalize on the growing proliferation of LEDs and their improving capabilities, said Masao Nakagawa, the professor at Keio who first came up with the idea seven years ago.

LEDs function in a manner similar to the light source inside optical fiber. They emit light at a specific bandwidth: To harness the light, engineers create modulators that cut it up into data that can subsequently be interpreted as 1s or 0s by a computer.

Unlike fiber, LEDs, which emit bright light and consume little power, are expected to be everywhere soon. “In the next five to 10 years, most light bulbs will be replaced by LEDs, then fluorescent bulbs will follow,” Nakagawa said.

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