Phone’s Wi-Fi hotspot acts as SOS beacon in disasters

An app that turns a smartphone into a wireless SOS beacon could one day help rescuers track down people who have been trapped in collapsed buildings after natural disasters or bombings. Because such events often knock out phone and internet networks, trapped people cannot make calls, send texts or email for help. "They are in an island of non-connectivity," says Amro Al-Akkad, an engineer with the Fraunhofer Institute for Applied Information Technology in St Augustin, Germany.