I thought not of building a phone itself but we could use some of the
parts which have been used in the nokia 3210.
Same approach as airprobe with usrp just another specialised radio
peripheral with a fast and huge fpga and a logic to downmix just the GSM
bands. We have fixed frequency bands , the downmixing should be
implemented the same way as the nokia 3210 does it, maybe we can reuse
the technology / copy the layout until the point where we got the
IF-signal.
All further tasks can be done via the FPGA, just as it was planned with
the USRP2, or via software.
What do you think?

On Mon, 2010-01-04 at 15:50 +0330, p q wrote:
> you can not just build a phone . it needs a dozen of legal steps to
> take , huge investment and very huge production line . i dont even go
> far to explain how complicated and expensive this is . to use a phone
> as a GSM receiver you need to hack into the baseband processor to be
> able to control the L1 IC . its usually a DSP implementing the layer-1
> Radio interface . you can not own such chip . there are a few
> producers offering it only to huge vendors , NDA , Legal subjects .
> etc . your only chance is to hack into baseband . 
> that'd be a very difficult job i must confess but not impossible . if
> somebody can hack into a baseband processor and control the L1 DSP
> that's only the start of this work because you need to put a phone
> into a scanner , learn about active channels , then tune the other
> phones to follow that channel . still , this is not going to be cheap
> and most certainly not going to be easy . if you do that and put the
> hacked firmware on the internet if the phone is old you have low
> chances to be able to buy it , if its new the vendor will make a
> little change and present the newly built ones get hacked . after
> all , this is a billion dollars business and people who design and
> build phones know what they are doing
> 
>         
>         
>         ---------- Forwarded message ----------
>         From: Evgeniy Shelepov <[email protected]>
>         Date: Mon, Jan 4, 2010 at 3:43 PM
>         Subject: Re: [A51] Truth about this work
>         
>         To: a51 <[email protected]>
>         
>         
>         Hello,
>         
>         
>         Yes, it looks a good idea to make a phone. BTW, why isn't it
>         possible
>         to make a sniffer from a cell phone, it has all the components
>         that
>         are needed. Probably it is possible to write a firmware and to
>         simulate some tricky simcard to make it do what we need.
>         
>         2010/1/4 Clemens Gruber <[email protected]>:
>         
>         > see this listing of the nokia 3210 hardware:
>         > https://www.pqgruber.com/other/Portable.pdf
>         > Maybe we can use similar parts and build our own peripheral
>         perfectly
>         > fitting our needs.. it should be much cheaper than 2 usrp2s
>         with
>         > daughterboards etc.
>         > if there are enough interested people, it will be possible.
>         >
>         > on the other hand, the idea of combining a usrp1 with a new
>         fpga-card
>         > (spartan, virtex, ...) sounds very good because the fpga
>         seems to be the
>         > bottleneck.
>         > does anybody know if it's possible to create a fast
>         > data-transfer-connection between these 2 devices?
>         >
>         > On Mon, 2010-01-04 at 14:16 +0330, p q wrote:
>         
>         
>         >> thanks for the last two questions
>         >> this was also the important facts that nobody mentioned
>         them . to do
>         >> a successful attack to A5/1 enabled GSM you need to capture
>         signal on
>         >> a wide-band style meaning you need to capture all the bands
>         that may
>         >> have carrier on them . this is highly depended on the
>         network
>         >> configuration specially the design on BTS .
>         >>
>         >>
>         >> real world BTSs are offering services on different bands
>         and calls are
>         >> always get handover between the bands due to radio resource
>         >> management . for a sucsessful GSM interception you at least
>         need to
>         >> capture Downlink . considering the current opensource and
>         cheap
>         >> hardware you can simple forget to capture both uplink and
>         downlink ,
>         >> that's just not possible .
>         >>
>         >>
>         >> to capture Downlink of a BTS that offers GSM1800 you need
>         to capture
>         >> at least 75 MB of the spectrum space . this is far more
>         than USRP and
>         >> also beyond USRP2
>         >> yes its possible to do this on GSM900 but you have to first
>         find a BTS
>         >> that only offers downlink on GSM900 and this is not going
>         to be easy
>         >>
>         >>
>         >> the idea of being able to build the RF part of a GSM
>         interceptor that
>         >> works on real world BTSs across the world using cheap stuff
>         like USRP
>         >> is just delusional . never gonna happen . this is another
>         truth about
>         >> this work . giving ourselves promises that's just not
>         technically
>         >> possible is not going to go far
>         >>
>         >>
>         >> what is possible to do ? it is possible to build a
>         GSM900-only capture
>         >> system using at least two USRP2 and still it depends on the
>         number of
>         >> TRXs that's installed on the BTS . if we want to go out
>         there and
>         >> really capture data from a real BTS we need to consider
>         these things
>         >> before getting ahead of ourselves . a two-unit USRP2 system
>         might be
>         >> able to fully capture the downlink of a real BTS operating
>         in GSM900
>         >> only in a not so crowded area
>         >>
>         >>
>         >> i saw people are fantasizing this work to put it on some
>         hacker CD
>         >> like Wifi and WEP stuff . i'm going to go out and say it :
>         people ,
>         >> this is far more complicated and more expensive than that .
>         this is
>         >> all just because of the expensive and close nature of
>         cellular network
>         >> business and RF problems , not just because of the
>         cryptography like i
>         >> said before A5/1 is just a part of the problem . even if we
>         can prove
>         >> we can crack A5/1 which is not happened yet next step is
>         the real pain
>         >> in the ass
>         >>
>         >>
>         >> regards
>         >>
>         >>
>         >>
>         >>
>         >> On Mon, Jan 4, 2010 at 1:58 PM, Gregory Maxwell
>         <[email protected]>
>         >> wrote:
>         >>         [Please don't send HTML mail to mailing lists]
>         >>         On Mon, Jan 4, 2010 at 4:31 AM, p q
>         <[email protected]>
>         >>         wrote:
>         >>         >
>         >>         > USRP even in a two-unit configuration is no good
>         since it
>         >>         can not handle GSM1800
>         >>
>         >>
>         >>         I was under the impression that provider
>         allocations are still
>         >>         no more
>         >>         than 10mhz wide in the 1800mhz band, are they not?
>         >>
>         >>
>         
>         >> ______________________________________________
>         
> 
> 
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