Less Radiation

No, we’re not suggesting getting your mobile phone wet.

New Scientist magazine reported yesterday – researchers have put up several Bluetooth monitoring points around Bath town centre. As around 50% of people that own mobiles walk around with Bluetooth enabled, the researchers were able to track peoples movements and social interactions around the town centre. (For ‘Social Interaction’ read – blokes beaming porn to each other in the pub.)

Vassilis Kostakos from the University of Bath sited four Bluetooth transmitters in the city centre. If you live in Bath and were wondering why your battery has been going flatter quicker, now you know why.

Vassilis’s tracking stations have been beaming out Bluetooth Inquiry Requests to every phone with Bluetooth enabled, and each time a visible Bluetooth phone receives an Inquiry Request it transmits a packet back to the device querying it. This packet contains the phones unique Bluetooth OUI, which is burned into each cellphones firmware.

The OUI is in the form 00:11:22:33:55:FF and the first 3 pairs identify the manufacturer of the device. Also, they would be able to collect your phone name, which is the identifier you can edit yourself – a lot of people change this to their real name, or nickname.

Of course it’s also possible to track someone using the regular GSM phone signal, by using several masts to triangulate the signal – but this is only good to a few hundred metres in the most ideal conditions – and unlike Bluetooth tracking, it’s not easy for an amateur to setup.

Vassilis’s experiment proves that using a combination of GSM & Bluetooth, you could track an individual at close range. If you were privy to the phone companies inside information you could look up the IMEI number in their database to find the home address of any individual… hypothetically of course!

Bluetooth is normally a short range technology, 10 metres for most phones and 100m for Bluetooth on a PC. However, our own experiments with modified USB Bluetooth dongles & external antennas show that you can pickup the signals from Bluetooth devices comfortably at 700 metres with a directional dish antenna.