TELECOMMUNICATIONS | Wherever you go, there you are. But where is that? Two startups have come up with potentially more reliable ways of finding out. If adopted, both techniques could hasten the arrival of the U.S. government-mandated E911 system, under which all mobile-phone users must, by Dec. 31, 2005, have technology available to them that can transmit their locations to emergency-service providers. Some cell phones are already equipped with Global Positioning System receivers, which reckon location from radio signals beamed from satellites, but they don't work well in buildings or urban canyons. Modifying cell phone towers to send special positioning signals is another proposal―but it would be costly.
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