Hi all!
Thanks everyone for the great pointers. I think there's lots of stuff to
digest and research.
> but FIC may not appreciate the discussion on
> their mailing list either.
Well, as Neo's don't come with a SIM lock, there's hardly a point here.
Besides that, I can see nothing wrong with trying to implement the
officialy published SIM Access Profile. And I think we need to know now
what to look for.
The question one could debate is to that extend this is a GSM technology
mailing list or not, especially if we'd go further down the road of:
> Henryk Plötz wrote:
> IIRC you'd need dual radios for [... using two SIMs at a time]
> anyways.
I understand that GSM is based on time slots. So theoretically, I should
be able to make the same radio talk to network A in one timeslot and
network B in another. But that might be too simplicistic for whatever
reasons. Also there is still the use case that I had two SIMs (just with
different numbers and maybe different accounts == phone bills) but still
on the same phyiscal GSM network. At least that should be doable with
one radio, shouldn't it?
Well, I think this is getting OT for this list, isn't it?
Regards,
Torsten
Steve schrieb:
Joe Pfeiffer wrote:
(just a couple of additional comments to what Steve says)
Steve writes:
The GSM Modem as a black box:
From my understanding of the NEO 1973, the GSM modem is roughly
analogous to a computer modem from the past. (Not the cheap "winmodems"
that are so abundant these days.) It is connected via a serial
connection to the portion that runs open software and communicates over
the GSM network. TI has provided a set of "AT" commands to preform a
limited subset of the functionality that the modem is capable of. If
you want to use more advanced or unintended functionality, you'll have
to figure out how to do that on your own.
The AT commands are actually part of the GSM standard (I don't know if
TI has agumented, nor if they've implemented all of them). My
understanding is that getting any additional functionality out of it
starts with prying the cover off the chip and goes downhill from
there :)
I'd agree with the statement about the AT commands, but I do think its
probably possible to get unintended functionality out of the GSM modem
without resorting to decapping the chip. After all that is exactly what
the unlockers are doing.
The unlockers are probably a major reason why TI is so paranoid about
the workings of their chipset since that is where the SIM and provider
locks are usually implemented. I wish I could give you more information
about the techniques they use, but I don't know what they are. It would
be interesting to find out, but FIC may not appreciate the discussion on
their mailing list either.
-Steve
