Re: [Discuss-gnuradio] Picking up RF cellular signals

[Sylvain Munaut]

> So it works, but only if the phone is currently transmitting to the network
> (phone call, internet, etc..)
>
> I'm trying to find a solution for this,
> There has to be a way of knowing that some kind of RF transmitter/receiver
> is near me...

Well ... no, not realistically.

An idle phone doesn't TX. It only powers up periodically to check the
paging channel. (For GSM it would be roughly 16ms every couple of
seconds).
During the RX the only thing you could detect is the LO leaking ...
that would be 50+ dB weaker than the phone itself (and I'm being
generous). Good luck detecting that ...


> If anyone can shed some light on this subject, what can i do or if i need to
> go in another way, i'll be very grateful!
> right now i'm stuck.

For disaster sites the most realistic option is a portable basestation
where the victim phone would automatically register to. Then once the
phone is on that BTS instead of the real network, establish an active
channel (doesn't need to be audio) so you can track it.

Cheers,

    Sylvain