OpenBTS workshop in June (Pfarrkirchen/Germany)
If you've always been interested in Open Source / Free Software GSM
using OpenBTS, you might be
interested in the upcoming three-day
OpenBTS workshop in Pfarrkirchen/Germany.
The workshop is held by OpenBTS project leader David Burgess, and will
cover subjects ranging from OpenBTS installation, configuration and
deployment down to actually extending OpenBTS with some custom code.
p.s.: Please don't misunderstand, the workshop really is about OpenBTS
not OpenBSC - though there might be OpenBSC folks hanging around ;)
Holidays in Taiwan
Just in case you are wondering why there are no updates here: I'm
currently on holidays in Taiwan and thus not working much on my various
projects, i.e. no major updates on this blog until some early/mid April.
OsmocomBB now performing location updating procedure against GSM cell
I haven't had much time for blogging recently, too much exciting work
going on at OsmocomBB:
- we now have simplistic support for Uplink (transmit) on SDCCH/4
- we have a minimal Layer2 (LAPDm) implementation
- we can send LOCATION UPDATING REQUEST to the network, and receive
the respective response
- there's wireshark integration, i.e. all packets on the L1-L2 interface
can be sent into wireshark for protocol analysis
There are still many limitations, but this is a major milestone in the project:
We have working bi-directional communication from the phone to the network!
The limitations include:
- The cell has to use a combined CCCH (SDCCH/4 on timeslot 0)
- The cell has to use no encryption/authentication
- The layer2 is not finished, especially re-transmissions will not work yet
- There's no power control loop yet
- There's no timing advance correction
However, most of those are more or less simple we know what needs to be
done, its just a matter of getting it done
kind of tasks. There are no big
unknowns involved, and particularly no further reverse-engineering of the hardware
Also, the existence of a stable bi-directional communications channel between
the network and the phone means that anyone interested in working on the higher
layers can now actually do so. Completing and testing layer2 as well as
RR/MM/CC on layer3 is a major task in itself, and it definitely requires
the lower layers to be there.
The other good part is that development of layer2 and layer3 can happen
entirely on the host PC, where debugging is much easier and there's no need for
cross-compilation and we can use all the usual debugging options (gdb,
I'm now almost heading off for holidays (starting March 10), so don't expect
any major progress from me anytime soon. I hope other interested developers
will be able to take it from here and fill in some missing gaps until I'll get
Looking for documentation on sunplus SPMA100B
In the Motorola/Compal C155 phone
supported by OsmocomBB, we have found a ringtone
melody chip called SPMA100B from sunplus.
As strange as it might seem, this is the only part used in the phone for which we have
not been able to find any kind of programming information. So if you know anything
about how to program this part from software (register map, programming manual, ...)
please let me know!
And no, we don't need electrical/mechanical data sheets, thanks :)