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Hello Jenkins Builder,

I'd like you to reexamine a change. Please visit

https://gerrit.osmocom.org/c/osmo-bts/+/32714

to look at the new patch set (#2).

Change subject: TCH DL, FR & EFR: reshape SIDs per 06.31/06.81 section 5.1.2 ......................................................................

TCH DL, FR & EFR: reshape SIDs per 06.31/06.81 section 5.1.2

Section 5.1.2 of GSM 06.31 & 06.81 specifies the expected shape of radio downlink for FR & EFR in the presence of SIDs: one SID frame after each talkspurt (after speech frames), and one SID frame in every SACCH-aligned position every 480 ms, or if the actual SACCH- aligned position is taken up by FACCH, then just one SID frame as soon as possible after that FACCH - and no transmitted SID frames in other positions.

This prescribed shape of call leg B DL won't happen on its own if the RTP stream comes from call leg A UL in a TrFO scenario - whichever SID frames are present will be in wrong positions for leg B DL, and even in the case of transcoded calls the responsibility for DL SID shaping cannot be placed on the RTP stream source because that source won't know where SACCH alignment will lie. Therefore, the necessary DL SID reshaping has to be done in the RTP stream receiver in OsmoBTS.

Related: OS#5996 Change-Id: I924ab21952dcf8bb03ba7ccef790474bf66fc9e5 --- M include/osmo-bts/lchan.h M src/common/l1sap.c 2 files changed, 142 insertions(+), 0 deletions(-)

git pull ssh://gerrit.osmocom.org:29418/osmo-bts refs/changes/14/32714/2