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. 鈥淭hey are in an island of non-connectivity,鈥� says Amro Al-Akkad, an engineer with the in St Augustin, Germany.
Then his colleague, Leonardo Ramirez, noticed the mischievous messages his neighbours broadcast by changing the name of their home Wi-Fi networks, such as 鈥渘o smoking on the balcony鈥� and 鈥渢urn the noise down鈥�. He realised that you could use an app to insert a short SOS message into the name field of a phone鈥檚 Wi-Fi hotspot, too, which broadcasts a radio signal without requiring internet access. Rescuers can read the message with their own Wi-Fi app.
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The team consulted emergency workers from the Haiti and Fukushima disasters and developed a 鈥渧ictim app鈥� and a 鈥渟eeker app鈥�. 鈥淭hey wanted it simple, unencrypted and smart,鈥� says Al-Akkad.That meant avoiding known problems like low-power, low-range Bluetooth radio links, which often fail to connect 鈥� or 鈥減air鈥� 鈥� with each other amid the clutter of metallic debris in broken buildings. So they stuck to the much more robust and receivable Wi-Fi radio.
Victim app
With the victim app a trapped person can write a 27-character message such as 鈥渂roken leg stuck in bank鈥� or 鈥渘eed help fire on 4th floor鈥� and a seeker app up to 100 metres away can pick it up. The app found two 鈥渢rapped鈥� people in a large-scale, simulated terrorist attack at a seaside chemical plant in Stavanger, Norway 鈥� an exercise organised by the Norway-based research organisation .
The team will present the apps at a in Toronto, Canada, in April 鈥� and they also hope to demonstrate them to rescue professionals at a in Pennsylvania in May.
They want the victim app to be incorporated in Android or iOS operating systems, but they are also investigating a way to distribute the app virally at a disaster scene. 鈥淲e need this as no one expects to be in a disaster and won鈥檛 download the app,鈥� says Al-Akkad.
The fact that the system works on standard hardware impresses Per Ola Kristensson, an interactive systems engineer at the University of St Andrews in the UK: 鈥淚t鈥檚 interesting how they have appropriated widely deployed smartphone hardware in a new and unexpected way. That鈥檚 the beauty of software. It鈥檚 much easier than trying to push newly invented hardware into people鈥檚 hands.鈥�
