Can a computer be enhanced by some (maybe USB) stuff to be detect the presence/use of cell-phones?

I'd need a cheaper alternative to dedicated devices to cell-phone detection. Analyzing type of use (SMS, whether it is transmitting), and location would be a plus.

Otherwise, what is the cheapest way of implementing a cell-phone finder device?


closed as off-topic by tcrosley, placeholder, Leon Heller, Daniel Grillo, Matt Young May 14 '14 at 17:03

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  • \$\begingroup\$ If you are talking about processing cell phone signals digitally, I don't think that's feasible because the cell bands are in the Ghz range, AFAIK. Also the power levels are low enough that it definitely needs some analog front-end equipment. \$\endgroup\$ – sgauria May 14 '14 at 14:57
  • 1
    \$\begingroup\$ Yes, I mean enhanced by some piece of hardware able to emit and receive Ghz range waves (but process them in the computer, not with a cell-phone module). I know that won't be as easy as buying a wire with 3.5mm jack and plugging it into the line in of my sound card and hear to radio. \$\endgroup\$ – Quora Feans May 14 '14 at 14:59

The general technique would be "software defined radio": http://www.rtl-sdr.com/tag/gsm/ especially http://www.rtl-sdr.com/rtl-sdr-tutorial-analyzing-gsm-with-airprobe-and-wireshark/

This relies on using a particular model of digital TV tuner USB stick which can be tuned across a very wide band to detect signals in the 900MHz band used by GSM. (Note: some systems in some countries are not GSM).

It doesn't give you location other than "nearby": micro-location is extremely hard.

  • \$\begingroup\$ I'd take a look on it. I suppose the location could be deduced analyzing the strength of the signal from different spots. \$\endgroup\$ – Quora Feans May 14 '14 at 15:55

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