Recommendations for a data-only GSM/UMTS device in USB stick ff

Michael Sokolov msokolov at ivan.Harhan.ORG
Tue Nov 15 02:24:09 CET 2011

Hello Om community,

Given that the GTA04 contains an off-the-shelf UMTS module and, if my
understanding is correct, truly off-the-shelf GSM/GPRS/UMTS modems in
the consumer USB stick form factor have been used during the
BeagleBoard prototyping phase for the GTA04, I've figured that someone
here might have some experience with / knowledge of these USB sticks,
hence me asking here...

I'm looking for a GSM/GPRS/EDGE/UMTS "cell modem" device in the
"USB stick" form factor which I would plug into my x86 laptop, running
Linux, currently Ubuntu, hoping to switch to Slackware or Linux From
Scratch some day.  My requirements / wish list items are:

* USB stick form factor, encased as it would be for a normal consumer,
  internal antenna and all.

* No battery, drawing power from the laptop when in use, no possibility
  of any internal components being powered up when the stick is not
  inserted into a laptop's USB port.

* I want to buy this thing from someone who just sells equipment, not
  service.  I need this thing to take SIM cards, and I know I can get
  a SIM card from my local GSM/UMTS service provider without getting
  their equipment.

* I need something that is sufficiently well documented in terms of
  its external interface (AT commands?) so that I can drive it from,
  say, minicom.

* I need this device to be capable of placing old-fashioned data calls,
  not just Internet access.  By old-fashioned data calls I mean the
  arrangement where one dials a number from the mobile device with
  ATD<number> (no semicolon at the end, making it a data rather than
  voice call), and the number being dialed is a POTS land line with a
  plain old analog modem answering the call.  I want to be able to
  connect to my personal data center from remote locations bypassing
  the Internet.

* I need this device to support GSM/GPRS/EDGE fallback, not just UMTS.
  I would like to have UMTS capability, but only in addition to plain
  GSM/GPRS, not instead of.  I would also very much like to be able
  to switch between GSM and UMTS manually with AT commands, e.g., to
  force GSM/GPRS mode even when UMTS is available.

* I need this thing to support the 1900 MHz band when operating in the
  GSM/GPRS/EDGE fallback mode, so I can use it with T-Mobile USA.

So, would anyone here be able to recommend such a USB stick device for
me?  Maybe even with pointers to where I can buy one?

My original plan was to use my GTA02 for this purpose, but I'm not
currently able to do anything with that device because of the
community's discriminatory handling of the Calypso FW semi-source
code.  Let me clarify: while of course the ideal situation would be
for everyone in the world to have free access to the GSM fw source
code, I can grudgingly accept using consumer off-the-shelf hardware
for which *no one* in the supposed-open-source community has any
firmware source.  But I philosophically object to using a device for
which Paul Fertser has a copy of the AT interpreter source code while
I'm denied a copy of the same.

Not being able to use the GTA02, I'm still using my old Motorola V66
phone: it's a *very* dumb phone (well below what one would call a
feature phone) and it's full of misfeatures which I don't like (a UI
design that suits me very poorly, bad pre-USB connector for the charger
and data port interfaces, no ability to connect the data port and
external power at the same time, etc), but what makes it morally
acceptable is that I'm not aware of any supposed-open-source
developer(s) hoarding a copy of its firmware source, selectively
denying it to new entrants into the field.

With the Mot V66 poorly suited as a device for making data calls from
a Linux/x86 laptop and the GTA02 unusable altogether for moral /
philosophical reasons, I'm now looking into the possibility of getting
a separate data-only device in the USB stick form factor and keeping
it separate from my voice phone, as in a separate SIM card from my
service provider.  (I already have several lines on my account for my
large pseudofamily, no difficulty with adding one more.)

I'm not aware of any cellular data USB sticks with hackable GSM/UMTS/
whatever firmware, but I can grudgingly live with that because it
isn't the same as having a clique of supposed open source developers
exclusively hoarding the FW source.  From what I understand, the GTA04
developers were able to get docs for the external interface (AT
commands or whatever) to their UMTS modem without having to sign their
lives away in NDAs, right?

Oh, and before anyone accuses me of being a hypocrite and hoarding or
not-sharing the TSM30 FW source which I have finally located, let me
reiterate I *do* freely and readily share this source with everyone in
the world, just not via the Internet.  Not via the Internet because my
current FTP server doesn't have enough disk space and my external
Internet connection is too slow.  Instead I am offering a CD-R copy by
snail mail to anyone in the world who wants one.  Just give me a snail
mail address (PO Box / anonymous / whatever, I don't care) and I'll
send a CD-R copy out the same week, maybe even the same day.  Anyone
who would like to see it made freely available via the Internet is
welcome to get the CD-R copy from me, then host it on his/her own
server: everyone in the world but me uses newer HW for which half a
GiB is nothing, and I'm sure that most people in the world have
faster Internet connections than my 384 kbps symmetric.

And I do have hardware docs for both Calypso and Glamo on my public
FTP site: they are small enough, unlike the *gigantic* TSM30 FW source
and the associated development environment.  (The latter is for
Windows unfortunately, and is required to compile the darned thing,
until someone does the massive work to port it to compile with gcc &
binutils toolchain.)


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