7 Jul
2014
7 Jul
'14
10 p.m.
On Mon, Jul 07, 2014 at 01:39:06PM +0200, Norbert Englberger wrote:
Hello everybody,
Hi,
1. The students told me, that OpenBSC doesn't behave like all the BTS from
commercial Providers they analysed:
The say that on commercial nets at the beginning of a phone call there will
be send an "Immediate assignment" sending the MS always to a SDCCH on TS 1
or TS2 where the encryption will be startet. After establishing the
encryption another "Immediate assignment" will occour and send the MS to a
Traffic Channel (which also contains the FACCH / SACCH) for the actual
Communication.
OpenBSC also sends the "Immediate assignment" on TS0 but sends the MS
directly to Timeslot with a Traffic Channel where all the signalling, like
encryption, will be done in the SACCH.
Is there any way to configure OsmoBSC to behave like the commercial BTS the
students described?
it is not a question of BTS but the BSC. The role of the BSC is to manage
the channels. Inside src/libbsc/gsm_04_08_utils.c you will see a table
that determines how the BSC/NITB will respond to "channel request" inside
the RACH request by the phone.
E.g. if you change get_ctype_by_chreq to always return LCHAN_SDCCH you
should be close to the behavior you have described.