Mobile Phone Virus Warning !

[mattb 0]

SIM cards in US cell phones ? ? ?

Few and far between

[billvon 3,076]

>Uhh...you can already be quite easily tracked via your cell phone.
>Even if you aren't talking on it.

You can track a phone to a given cell via registration attempts, and you can track AMPS phones individually with a doppler scanner, but right now there's no way to accurately track a CDMA digital phone down to a few meters (the most popular type) or to track large numbers of AMPS phones down to a few meters. This is why the E911 requirement has proven so hard to implement, and why GPS is now being used for that purpose.

[freeflir29 0]

Quote

but right now there's no way to accurately track a CDMA digital phone down to a few meters

So CDMA does not transmit a signal? DF?

[billvon 3,076]

>So CDMA does not transmit a signal? DF?

During idle a CDMA phone transmits a signal only during re-registration i.e. leaving or entering a new cell. In addition, all CDMA phones in an area use the same frequency; they are separated only in codespace. There are no DF's currently available that can distinguish several transmitters all on the same frequency separated only by codespace.

[freeflir29 0]

Quote

There are no DF's currently available that can distinguish several transmitters all on the same frequency separated only by codespace

Ahhh...interesting. Doesn't the CDMA network know the difference between each phone though?

[billvon 3,076]

>Ahhh...interesting. Doesn't the CDMA network know the difference
>between each phone though?

Yes, through its PN (pseudorandom noise) number. It is a very, very long sequence (repeats every 3 months or something) that the receiver must both know and synchronize to to be able to receive the signal. In normal operation, the phone listens to the pilot and then sync channels of the base station, and through these channels the base station tells the phone to start its PN at a certain point. The phone does, and the cellsite then compares its PN to a list of 'known-good' list of phones, and if the received signal matches one of those, the base station begins demodulating that particular PN code.

So problem 1 is that you'd have to 'take over' the phone and pretend to be a cell site, so the phone would provide you a PN you could sync to. Problem 2 is you'd have to know what possible PN's the phone could have (theoretically possible if you hack the provider's computer.) Problem 3 is that you're now receiving the signal, but a regular DF will still do you no good, since there's no one RF signal to lock onto. A mechanically scanned antenna would be your best bet, since you could use the signal strength received as you move the antenna around as a rough guide to which direction it's in.

Of course, if you could do all that, you probably already work for Qualcomm.

[Spy38W 0]

**fizzle fizzle, pop....**

--
Hook high, flare on time

[n2skdvn 0]

uh.... what bill said

if my calculations are correct SLINKY + ESCULATOR = EVERLASTING FUN
my site