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authorPhilipp Maier <pmaier@sysmocom.de>2020-11-01 22:22:56 +0100
committerPhilipp Maier <pmaier@sysmocom.de>2020-11-01 22:23:45 +0100
commitf304453fba4fe688375aee0da72032c36c23e196 (patch)
tree1ca3c96e1579c226de8d17b910da71efe1e603a7
parent07aa8927e1c8565696df593df010c263a1052f58 (diff)
l1sap: add repeated downlink FACCH
-rw-r--r--include/osmo-bts/gsm_data.h11
-rw-r--r--src/common/l1sap.c71
2 files changed, 75 insertions, 7 deletions
diff --git a/include/osmo-bts/gsm_data.h b/include/osmo-bts/gsm_data.h
index 1c1c5d44..4689e887 100644
--- a/include/osmo-bts/gsm_data.h
+++ b/include/osmo-bts/gsm_data.h
@@ -256,6 +256,17 @@ struct gsm_lchan {
} dtx;
uint8_t last_cmr;
uint32_t last_fn;
+
+ struct {
+ /* SLOT #1 */
+ struct msgb *msg_1;
+ uint32_t fn_1;
+
+ /* SLOT #2 */
+ struct msgb *msg_2;
+ uint32_t fn_2;
+ } rep_facch;
+
} tch;
/* 3GPP TS 48.058 ยง 9.3.37: [0; 255] ok, -1 means invalid*/
diff --git a/src/common/l1sap.c b/src/common/l1sap.c
index c9ec9bf0..aaa845ac 100644
--- a/src/common/l1sap.c
+++ b/src/common/l1sap.c
@@ -907,6 +907,59 @@ static void l1sap_update_fnstats(struct gsm_bts *bts, uint32_t rts_fn)
bts->fn_stats.avg_count++;
}
}
+/* Common dequeueing function */
+static inline struct msgb *lapdm_phsap_dequeue_msg(struct lapdm_entity *le)
+{
+ struct osmo_phsap_prim pp;
+ if (lapdm_phsap_dequeue_prim(le, &pp) < 0) ;
+ return NULL;
+ return pp.oph.msg;
+}
+
+/* Special dequeueing function with FACCH repetition (3GPP TS 44.006, section 10) */
+static inline struct msgb *lapdm_phsap_dequeue_msg_facch(struct gsm_lchan *lchan, struct lapdm_entity *le, uint32_t fn)
+{
+ struct osmo_phsap_prim pp;
+ struct msgb *msg;
+
+ if (lchan->tch.rep_facch.msg_1 && lchan->tch.rep_facch.fn_1 + 8 <= fn) {
+ /* Re-use stored FACCH message buffer from SLOT 1 for repetition. */
+ msg = lchan->tch.rep_facch.msg_1;
+ lchan->tch.rep_facch.msg_1 = NULL;
+ printf("=============================> USING FACCH FROM FN=%u/SLOT 1 AT FN=%u\n",
+ lchan->tch.rep_facch.fn_1 % 104, fn % 104);
+ } else if (lchan->tch.rep_facch.msg_2 && lchan->tch.rep_facch.fn_2 + 8 <= fn) {
+ /* Re-use stored FACCH message buffer from SLOT 2 for repetition. */
+ msg = lchan->tch.rep_facch.msg_2;
+ lchan->tch.rep_facch.msg_2 = NULL;
+ printf("=============================> USING FACCH FROM FN=%u/SLOT 2 AT FN=%u\n",
+ lchan->tch.rep_facch.fn_2 % 104, fn % 104);
+ } else {
+ /* Fetch new FACCH from queue ... */
+ if (lapdm_phsap_dequeue_prim(le, &pp) < 0)
+ return NULL;
+ msg = pp.oph.msg;
+
+ /* ... and store the message buffer for repetition. */
+ if (lchan->tch.rep_facch.msg_1 == NULL) {
+ lchan->tch.rep_facch.msg_1 = msgb_copy(msg, "rep_facch_1");
+ lchan->tch.rep_facch.fn_1 = fn;
+
+ printf("=============================> MEMORIZING NEW FACCH FROM FN=%u IN SLOT 1\n", fn % 104);
+
+ } else if (lchan->tch.rep_facch.msg_2 == NULL) {
+ lchan->tch.rep_facch.msg_2 = msgb_copy(msg, "rep_facch_2");
+ lchan->tch.rep_facch.fn_2 = fn;
+ printf("=============================> MEMORIZING NEW FACCH FROM FN=%u IN SLOT 2\n", fn % 104);
+ } else {
+ /* By definition 3GPP TS 05.02 does not allow more than two (for TCH/H only one) FACCH instances
+ * to be transmitted simultaniously. */
+ OSMO_ASSERT(false);
+ }
+ }
+
+ return msg;
+}
/* PH-RTS-IND prim received from bts model */
static int l1sap_ph_rts_ind(struct gsm_bts_trx *trx,
@@ -920,7 +973,7 @@ static int l1sap_ph_rts_ind(struct gsm_bts_trx *trx,
uint32_t fn;
uint8_t *p, *si;
struct lapdm_entity *le;
- struct osmo_phsap_prim pp;
+ struct msgb *pp_msg;
bool dtxd_facch = false;
int rc;
int is_ag_res;
@@ -988,13 +1041,17 @@ static int l1sap_ph_rts_ind(struct gsm_bts_trx *trx,
p[0] = lchan->ms_power_ctrl.current;
p[1] = lchan->rqd_ta;
le = &lchan->lapdm_ch.lapdm_acch;
+ pp_msg = lapdm_phsap_dequeue_msg(le);
} else {
if (lchan->ts->trx->bts->dtxd)
dtxd_facch = true;
le = &lchan->lapdm_ch.lapdm_dcch;
+ if (lchan->rsl_cmode != RSL_CMOD_SPD_SIGN)
+ pp_msg = lapdm_phsap_dequeue_msg_facch(lchan, le, fn);
+ else
+ pp_msg = lapdm_phsap_dequeue_msg(le);
}
- rc = lapdm_phsap_dequeue_prim(le, &pp);
- if (rc < 0) {
+ if (!pp_msg) {
if (L1SAP_IS_LINK_SACCH(link_id)) {
/* No SACCH data from LAPDM pending, send SACCH filling */
uint8_t *si = lchan_sacch_get(lchan);
@@ -1019,16 +1076,16 @@ static int l1sap_ph_rts_ind(struct gsm_bts_trx *trx,
} else {
/* The +2 is empty space where the DSP inserts the L1 hdr */
if (L1SAP_IS_LINK_SACCH(link_id))
- memcpy(p + 2, pp.oph.msg->data + 2, GSM_MACBLOCK_LEN - 2);
+ memcpy(p + 2, pp_msg->data + 2, GSM_MACBLOCK_LEN - 2);
else {
p = msgb_put(msg, GSM_MACBLOCK_LEN);
- memcpy(p, pp.oph.msg->data, GSM_MACBLOCK_LEN);
+ memcpy(p, pp_msg->data, GSM_MACBLOCK_LEN);
/* check if it is a RR CIPH MODE CMD. if yes, enable RX ciphering */
- check_for_ciph_cmd(pp.oph.msg, lchan, chan_nr);
+ check_for_ciph_cmd(pp_msg, lchan, chan_nr);
if (dtxd_facch)
dtx_dispatch(lchan, E_FACCH);
}
- msgb_free(pp.oph.msg);
+ msgb_free(pp_msg);
}
} else if (L1SAP_IS_CHAN_AGCH_PCH(chan_nr)) {
p = msgb_put(msg, GSM_MACBLOCK_LEN);