Attention is currently required from: laforge, fixeria.
Hello Jenkins Builder, fixeria,
I'd like you to reexamine a change. Please visit
https://gerrit.osmocom.org/c/libosmocore/+/33063
to look at the new patch set (#2).
Change subject: coding: gsm0503_tch_{fr,hr}_encode(): add ability to emit BFI ......................................................................
coding: gsm0503_tch_{fr,hr}_encode(): add ability to emit BFI
Every BTS needs to have some graceful handling for the scenario where it is time to send out a speech frame on TCH DL, but there is no frame to be sent. One possible solution is to transmit dummy FACCH, but this option is unattractive for TCH/HS where FACCH displaces two speech frames rather than one. A more elegant solution is to emit a speech frame with inverted CRC3, causing the MS receiver to declare a BFI condition to its Rx DTX handler. Setting all u(k) bits to 0 is one way to produce such an inverted-CRC speech frame (normal TCH FR/HR CRC3 for an all-zeros frame would be 111), and this method is in fact what sysmoBTS PHY is observed to do. Add the same ability to gsm0503_tch_{fr,hr}_encode() functions, indicated by payload length of 0.
Change-Id: Iade3310e16b906efb6892d28f474a0d15204e861 --- M src/coding/gsm0503_coding.c 1 file changed, 43 insertions(+), 1 deletion(-)
git pull ssh://gerrit.osmocom.org:29418/libosmocore refs/changes/63/33063/2