fixeria has uploaded this change for review. ( https://gerrit.osmocom.org/c/osmo-bts/+/27721 ) Change subject: scheduler: rts_tchh_fn(): use a lookup table for FACCH/H ...................................................................... scheduler: rts_tchh_fn(): use a lookup table for FACCH/H Unlike TCH/F, TCH/H imposes some additional requirements on the FACCH transmission, so that a signalling block can be transmitted only at specific TDMA frame numbers defined in 3GPP TS 45.002, table 1. This is why in rts_tchh_fn() we need to check the given TDMA frame number and tell rts_tch_common() whether FACCH/H is permitted or not. The check is based on a magic formula, which I find a bit hard to read and understand. Let's better use a lookup table. Change-Id: I3dba243e5a1b7c8008ef0178ea18ed885256c50d Related: SYS#5916, OS#5518 --- M src/common/scheduler.c 1 file changed, 11 insertions(+), 2 deletions(-) git pull ssh://gerrit.osmocom.org:29418/osmo-bts refs/changes/21/27721/1 diff --git a/src/common/scheduler.c b/src/common/scheduler.c index 99ab597..96189ef 100644 --- a/src/common/scheduler.c +++ b/src/common/scheduler.c @@ -996,12 +996,21 @@ return rts_tch_common(l1ts, br, true); } +/* FACCH/H channel mapping for Downlink (see 3GPP TS 45.002, table 1). + * This mapping is valid for both FACCH/H(0) and FACCH/H(1). */ +static const uint8_t sched_tchh_dl_facch_map[26] = { + [4] = 1, /* FACCH/H(0): B0(4,6,8,10,13,15) */ + [5] = 1, /* FACCH/H(1): B0(5,7,9,11,14,16) */ + [13] = 1, /* FACCH/H(0): B1(13,15,17,19,21,23) */ + [14] = 1, /* FACCH/H(1): B1(14,16,18,20,22,24) */ + [21] = 1, /* FACCH/H(0): B2(21,23,0,2,4,6) */ + [22] = 1, /* FACCH/H(1): B2(22,24,1,3,5,7) */ +}; /* RTS for half rate traffic frame */ static int rts_tchh_fn(const struct l1sched_ts *l1ts, const struct trx_dl_burst_req *br) { - /* the FN 4/5, 13/14, 21/22 defines that FACCH may be included. */ - return rts_tch_common(l1ts, br, ((br->fn % 26) >> 2) & 1); + return rts_tch_common(l1ts, br, sched_tchh_dl_facch_map[br->fn % 26]); } /* set multiframe scheduler to given pchan */ -- To view, visit https://gerrit.osmocom.org/c/osmo-bts/+/27721 To unsubscribe, or for help writing mail filters, visit https://gerrit.osmocom.org/settings Gerrit-Project: osmo-bts Gerrit-Branch: master Gerrit-Change-Id: I3dba243e5a1b7c8008ef0178ea18ed885256c50d Gerrit-Change-Number: 27721 Gerrit-PatchSet: 1 Gerrit-Owner: fixeria <vyanitskiy(a)sysmocom.de> Gerrit-MessageType: newchange