posted on March 22, 2010 11:15
A system developed by a French company could revolutionize the search for people lost in mountains, even those buried under an avalanche. The device, a portable IMSI (International Mobile Subscriber Identity) catcher, developed by French company Diginext, is currently in use by the military.
An IMSI catcher acts as a base station. Mobile phones within its range will attach to the catcher. For intelligence use it can force connected mobile phones to not use call encryption. By relaying the signal to a real base station it allows call data to be intercepted in a classic a man in the middle attack.
The Diginext device, called the Pic 2G consists of a box about the size of a portable computer and a directional antenna which enables a mobile phone to be localized. The device is being tested in conjunction with the PGHM (Mountain Rescue Services) in the Alps. The first thing they wanted to confirm was that the Pic 2G doesn’t interfere with other equipment such as avalanche beacons and Reccos.
Assuming the mobile phone is switched on the Pic 2G can detect the signal within a 2km range. It would be ideal for helicopter based searches. As well as giving the location (direction and distance) of the phone, the operator can call the user. The system can be used where there is no mobile phone coverage which is frequently the case in the mountains. The Pic 2G can differentiate between the various mobile phones within range. However the device currently requires a skilled operator. It will have to be simplified for S&R use.
Given the widespread use of mobile phones the device could be a real advance in search and rescue, especially for people who are caught out by bad weather who can be given advice on how to seek shelter or give basic treatment for injuries. It will change the information frequently given by guides to turn mobile phones off in the backcountry.