Hello Harald, thanks for you quick answer, I'll take a look on that.
Have a nice day, Antony
On Fri, Apr 6, 2018 at 10:59 AM, Harald Welte laforge@gnumonks.org wrote:
Hi Antony,
On Fri, Apr 06, 2018 at 10:36:06AM +0200, Antony Lemmens wrote:
I have read articles about the superframe mechanism but I do not figure
out
how to advertise the CBCH functionality on the BCCH,
The Osmocom stack should take care of this "automatically" if the osmo-bts-trx low-level code gets the required support.
As you may have seen, CBCH operation is already supported with several other BTS back-ends inside osmo-bts. Unfortunately, for osmo-bts-trx nobody has been contributing the related code so far.
nor how to adapt the scheduler to enable the CB channel.
This boils down to the tables in osmo-bts/src/scheduler_mframe.c where you can e.g. find "static const struct trx_sched_frame frame_bcch[51]" which defines the 51-multiframe for the non-combined BCCH and "static const struct trx_sched_frame frame_bcch_sdcch4[102]" for the combined BCCH, as well as "static const struct trx_sched_frame frame_sdcch8"
AFAIR, the BCCH can be on a combined BCCH or on a SDCCH/8. You would have to create copies of "frame_bcch_sdcch4" and "frame_sdcch8" and edit those copies to confirm with the way how the respective multiframe is specified when CBCH is enabled. As far as I remember from memory, it's always the second sub-channel that's replaced with CBCH instead of SDCCH. See the related specs, I think mostly 3GPP TS 45.002
Is it someone also interrested in this and/or working on the Bug 1617?
I'm interested but seriously have no time to work on this. At sysmocm we could work on it as a development project under contract, but we also have quite a backlog so it might be best if somebody else works on this.
Or is it someone that can me give a track to start the implementation?
My notes above should help with implementing it.
--
- Harald Welte laforge@gnumonks.org
http://laforge.gnumonks.org/
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