Hi,
I've hacked something together to quickly test non-combined CCCH.
However, I've hit a problem when trying to receive anything on another
timeslot than 0.
The TX side seems to work fine as the BTS can see my location update
request and answers with a reject, but on the MS side, I never see the
reject and wireshark only shows invalid incohrent data on the RX.
The frames for SDCCH/8 show really nothing valid (looks like random
bytes), things like
09 80 7f 47 49 06 1d 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
09 00 47 d5 2d 06 1e 00 00 69 7c a0 91 3d 22 ff ab fe 6c 4f 56 4f 36
...
while the frames for the associated SAACH show at least something gsm-like :
03 03 01 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b
but that's not quite a SI5/6 ...
To RX/TX on TS=1, I just delayed the RX/TX window by 625 bits (4 *
156.25) when I'm in dedicated channel mode by chaning the 'start' in
l1s_tx_win_ctrl / l1s_rx_win_ctrl
Is there something else that should be done ?
Cheers,
Sylvain
Hi!
Recently we've had the idea of using OsmocomBB with a simple firmware
that synchronizes to an existing GSM networks FCCH and use the resulting
13MHz clock to drive the USRP for airprobe or OpenBTS.
Ideally, we would even use the Calypso-internal PLL (for ARM or DSP) to
multiply it up to the required 52 MHz. However, neither the Openmoko
nor the Compal/Motorola phones expose any of the 3 clock output pads :(
So the only choice is to use something along the lines of the
http://focus.ti.com/docs/prod/folders/print/cdcvf25084.html
as a quad clock multiplier and attach it to the CLK13OUT signal of the
phone.
The chip is available for 9 USD in single quantities at digikey, and
possibly cheaper at other sources. Combined with a sub-20EUR phone it
might be a very cheap but still accurate frequency source for OpenBTS -
at least as long as there are any commercial gsm networks available.
Regards,
Harald
--
- Harald Welte <laforge(a)gnumonks.org> http://laforge.gnumonks.org/
============================================================================
"Privacy in residential applications is a desirable marketing option."
(ETSI EN 300 175-7 Ch. A6)
Hi!
I've been offered a 'developer room' at FrOSCon 2010 (http://www.froscon.de/)
which will be at FH Bonn-Rhein-Sieg (http://www.fh-brs.de/) in Sankt Augustin
from August 21/22 this year.
Before sending a response, I would like to inquire whom of you would actually
have any intention of visiting this conference and spending time in the
developer room to work on OpenBSC or OsmocomBB ?
I think the idea is great to meet some of you guys [again], not only at the
annual CCC congress in winter. But there is little point for me to go there if
there is no interest from the wider project community.
Please provide your feedback ASAP.
--
- Harald Welte <laforge(a)gnumonks.org> http://laforge.gnumonks.org/
============================================================================
"Privacy in residential applications is a desirable marketing option."
(ETSI EN 300 175-7 Ch. A6)
Hi,
I converted the X font 5x8 for use in BB and added an goto_xy
routine in case anyone wants to put something entertaining on
the LCD (besides Hello World).
Compared to the old 8x8 font..
- doesn't miss the topmost line of pixels :-)
- needs 475 bytes instead of 4k (only includes characters
ASCII 32 .. 126)
- allows for 19x8 characters on the screen
hello_world.bin prints out all glyphs for testing.
Applies to current "master" (as of 9.4.2010/15:30 MESZ).
Chris
Hi all!
In case you're interested, there seems to be a public project on
code.google.com that contains the build environment and baseband
firmware sdk from mediatek:
svn checkout http://mobile-phone-mtk-project.googlecode.com/svn mtk-project
Please note that I don't know about the legality of this. However, it
is distributed on a public server/service without any kind of
authentication...
Regards,
Harald
--
- Harald Welte <laforge(a)gnumonks.org> http://laforge.gnumonks.org/
============================================================================
"Privacy in residential applications is a desirable marketing option."
(ETSI EN 300 175-7 Ch. A6)
hi,
i like to change some tracked files without committing them. when i do
"git commit -a", every change is comitted.
sometimes i like to play with layer1 code or even change Makefile.inc,
but i don't want to reset my changes before committing.
any idea how to create a list of omitted files?
andreas
Hi!
I think we corrently have the following TODO list.
GSM Layer 1:
* implement transmit power control for transmit
* implement SDCCH/8 on TS1-7 (Sylvain)
* implement frequency hopping
* proper split between synchronous and asynchronous part of L1 (Harald)
* TCH/F support (Dieter, after L3 RR/MM/CC is working)
* A5/1 and A5/2 encryption support
GSM Layer 2:
* implement a real layer2 that deserves the name (full LAPDm implementation)
* properly encapsulate / abstract the L1 "MPH" primitives so L3 doesnt
call L1 directly anymore
GSM Layer 3:
* test most of the code that Andreas has written (depends on L1 / L2)
Misc:
* SIM card driver + ISO7816 FS API
* Battery charger driver
* UI framework
* minimal journalling flash file system
* decide which RTOS kernel we want to use (Harald)
* fully support a working firmware build for the openmoko gta01/gta02 GSM modem
using calypso romloader
For people who don't feel like they can take any of this work, there is some
other work, regarding the mid-term port to our next target platform:
* implement host utility for the medaitek MT622x romloader serial protocol
* try to get a minimal hello world codebase to run on the MT622x
* write hardware drivers for UART, PMU, I2C, SPI, ... of the MT622x
Regards,
Harald.
--
- Harald Welte <laforge(a)gnumonks.org> http://laforge.gnumonks.org/
============================================================================
"Privacy in residential applications is a desirable marketing option."
(ETSI EN 300 175-7 Ch. A6)
Hello Harald,
On Wed, 28 Apr 2010 20:26:07 +0200, "Harald Welte" <laforge(a)gnumonks.org> wrote:
>
> GSM Layer 1:
> * implement transmit power control for transmit
> * implement SDCCH/8 on TS1-7 (Sylvain)
> * implement frequency hopping
> * proper split between synchronous and asynchronous part of L1 (Harald)
> * TCH/F support (Dieter, after L3 RR/MM/CC is working)
> * A5/1 and A5/2 encryption support
I can take care of
* implement frequency hopping
* A5/1 and A5/2 encryption support
in addition to
* TCH/F support
because this would fit together (just different setting on the GSM
testset to do frequency hopping or encryption with a TCH).
Best regards,
Dieter
--
Dieter Spaar, Germany spaar(a)mirider.augusta.de
> This is a known problem, but despite working from morning through
night I
> really don't have any time to fix the various layer1 issues at the
moment,
> sorry. In fact, there are some fundamental changes/cleanups required,
and
> I've already literally spent days in coming up with an architecture
that seems
> to make sense to me :/
> I know it must be frustrating for you, but it seems our schedules
didn't match
> very well.
hi harald,
i am currently testing the process of cell selection. when i limit the
number of cells down to 1, i can test some parts of the process.
don't worry about frustrating me. i can wait until these issues are
solved. until then, there is so much more for me todo:
- system information parsing test
- testing location update procedure
- working on incomplete radio ressource process
- maybe start working on some layer 4 application (lcr interface)
regards,
andreas
hi,
while debugging my layer3 code and testing bcch_scan, i got the following problem:
the fist 'tuning' message L1CTL_NEW_CCCH_REQ to layer 1 works, system informations are received. subsequently tuning to another channel does not give any rx data. any idea?
andreas
Mit freundlichen Grüßen,
.-.
/'v'\
(/ \)
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Network Operations / 2nd Level Data - KC Internet
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