hi,
while reading about SMS state machines, i found some drawings that are
not in the specs, but quite useful to understand some processes. they are:
- MM idle process (MS side)
- additions to CC (MS side)
- SMC process (MS and network side)
see http://home.eversberg.eu/gsm
they might be useful and so i think they should be placed in the wiki. i
would suggest to put them to OsmocomBB wiki in the "GSM Documentation"
section. but i don't know if it is ok to publish the CC process, because
it contains a scan of the original spec.
any suggestions?
regards,
andreas
Hello.
Current implementation of osmo_hexparse have couple of limitations (which are
undocumented btw):
* it refuses to parse odd-length numbers (e. g. 7abdf)
* it fails while parsing 0x prefix (e. g. 0xdead)
Both could be worked around by upper-layer code of course but since both cases above
are perfectly valid hexadecimal numbers I think they should be handled by
osmo_hexparse internally without complicating life of library users.
Attached patch does just that. Please review and merge if it feels OK.
--
best regards,
Max, http://fairwaves.ru
hi,
i just encountered the following problem:
the network assigns me from TS 1 to TS 3 it worked, but not when it did
another assigment from TS 3 to TS4. i just got noise instead of valid
SACCH frames.
TS Chg forth: 1 -> 3 | 1856
...
TS Chg forth: 3 -> 4 | 1875
this is the wireshark trace of both assignments. they only differ in the
assigned slot:
Frame 3225: 81 bytes on wire (648 bits), 81 bytes captured (648 bits)
Ethernet II, Src: 00:00:00_00:00:00 (00:00:00:00:00:00), Dst:
00:00:00_00:00:00 (00:00:00:00:00:00)
Internet Protocol Version 4, Src: 127.0.0.1 (127.0.0.1), Dst: 127.0.0.1
(127.0.0.1)
User Datagram Protocol, Src Port: 52261 (52261), Dst Port: gsmtap (4729)
GSM TAP Header, ARFCN: 34 (Downlink), TS: 1, Channel: SDCCH/8 (0)
Link Access Procedure, Channel Dm (LAPDm)
GSM A-I/F DTAP - Assignment Command
Protocol Discriminator: Radio Resources Management messages
DTAP Radio Resources Management Message Type: Assignment Command (0x2e)
Channel Description 2 - Description of the First Channel, after time
0000 1... = TCH/F + FACCH/F and SACCH/F
.... .011 = Timeslot: 3
000. .... = Training Sequence: 0
...1 .... = Hopping channel: Yes
Hopping channel: MAIO 0
Hopping channel: HSN 0
Power Command
0... .... = Spare: 0
.0.. .... = EPC_mode: Channel(s) not in EPC mode
..0. .... = FPC_EPC: FPC not in use/C not in use for uplink
power control
...0 0101 = POWER LEVEL: 5
Frequency List - Frequency List, after time
Element ID: 5
Length: 16
00.. 000. = Format Identifier: bit map 0 (0x00)
List of ARFCNs = 99 34
Channel Mode - Mode of the First Channel(Channel Set 1)
Element ID: 99
Channel Mode: speech full rate or half rate version 2(GSM EFR) (33)
No. Time Source Destination Protocol
Info
3243 464.672890 127.0.0.1 127.0.0.1 LAPDm
I, N(R)=1, N(S)=2(DTAP) (RR) Assignment Command
Frame 3243: 81 bytes on wire (648 bits), 81 bytes captured (648 bits)
Ethernet II, Src: 00:00:00_00:00:00 (00:00:00:00:00:00), Dst:
00:00:00_00:00:00 (00:00:00:00:00:00)
Internet Protocol Version 4, Src: 127.0.0.1 (127.0.0.1), Dst: 127.0.0.1
(127.0.0.1)
User Datagram Protocol, Src Port: 52261 (52261), Dst Port: gsmtap (4729)
GSM TAP Header, ARFCN: 99 (Downlink), TS: 3, Channel: FACCH/F (0)
Link Access Procedure, Channel Dm (LAPDm)
GSM A-I/F DTAP - Assignment Command
Protocol Discriminator: Radio Resources Management messages
DTAP Radio Resources Management Message Type: Assignment Command (0x2e)
Channel Description 2 - Description of the First Channel, after time
0000 1... = TCH/F + FACCH/F and SACCH/F
.... .100 = Timeslot: 4
000. .... = Training Sequence: 0
...1 .... = Hopping channel: Yes
Hopping channel: MAIO 0
Hopping channel: HSN 0
Power Command
0... .... = Spare: 0
.0.. .... = EPC_mode: Channel(s) not in EPC mode
..0. .... = FPC_EPC: FPC not in use/C not in use for uplink
power control
...0 0101 = POWER LEVEL: 5
Frequency List - Frequency List, after time
Element ID: 5
Length: 16
00.. 000. = Format Identifier: bit map 0 (0x00)
List of ARFCNs = 99 34
Channel Mode - Mode of the First Channel(Channel Set 1)
Element ID: 99
Channel Mode: speech full rate or half rate version 2(GSM EFR) (33)
any idea why this does not work? i used the "[WIP] Ugly hack to
compensate lost time on TS change (high TS -> low TS)" path.
regards,
andreas
Speaker: Sylvain Munaut
or how to turn a phone into a BTS
The calypso baseband and its companion chips are used on the Motorola C123
among other and are now well known for being supported by the Osmocom-BB
open source GSM baseband implementation. A couple years ago, it was hacked
a little further by using it as a raw bits capture device allowing the
interception of GSM traffic very cheaply.
This talk will present some further work on that platform, showing that
just because a device wasn't design for a given task doesn't mean it can't
do it. More specifically how you can hack this phone to act as a GSM
basestation and broadcast your own network.
http://youtu.be/xFjVcxMpA6c
Hi list,
I saw the interesting talk about turning the osmocombb-phone into a proof of concept bts using openbts. During the talk:When OpenBts
was configured(before using sipauthserve) was it the option --with-uhd (as is for umtrx )that was used?
Does anybody know when the code will be released?
[I built sylvain/testing branch as well as branch jolly/meas branch some days ago, but I couldn't find that code anywhere, so I guess it is not available anywhere yet]
regards
erich
On Thu, Jan 10, 2013 at 11:33 PM, Heiko Besemann <heiko(a)noordsee.de> wrote:
>
> Hello Alex,
You should send mail to the mailing list, instead of specific
individuals. This way, i) you may get a responder quicker, and ii)
information can reach other interested people.
>
> I read on Osmocom-BB mailing-list that you are using a GTA02 with
> cross-compiled tools. Well, I did cross-compiling of the sylvain/burst_ind
> branch for the OpenMoko, but starting osmocon I get an error that the
> higher non-standard baudrate can not be set to /dev/ttySAC0.
On the GTA02 the calypso is wired to one internal UART of the
application processor SoC. AFAIR the SoC only supports up to 115200
bps so it won't be usable with burst_ind.
Cheers,
Alex