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dexter gerrit-no-reply at lists.osmocom.orgdexter has uploaded this change for review. ( https://gerrit.osmocom.org/c/osmo-bts/+/21014 )
Change subject: l1sap: add repeated downlink FACCH
......................................................................
l1sap: add repeated downlink FACCH
3GPP TS 44.006, section 10 describes a method how the downlink
FACCH transmission can be repeated to increase transmission
reliability.
Change-Id: I72f0cf7eaaef9f80fc35e752c90ae0e2d24d0c75
Related: OS#4796 SYS#5114
---
M include/osmo-bts/bts.h
M include/osmo-bts/gsm_data.h
M src/common/l1sap.c
M src/common/vty.c
4 files changed, 95 insertions(+), 7 deletions(-)
git pull ssh://gerrit.osmocom.org:29418/osmo-bts refs/changes/14/21014/1
diff --git a/include/osmo-bts/bts.h b/include/osmo-bts/bts.h
index ce7d9d4..fdcc67b 100644
--- a/include/osmo-bts/bts.h
+++ b/include/osmo-bts/bts.h
@@ -338,6 +338,9 @@
struct osmo_fsm_inst *shutdown_fi; /* FSM instance to manage shutdown procedure during process exit */
struct osmo_tdef *T_defs; /* Timer defines */
+ /* 3GPP TS 44.006, section 10, Repeated Downlink FACCH */
+ bool facch_repetition_enabled;
+
void *model_priv; /* Allocated by bts_model, contains model specific data pointer */
};
diff --git a/include/osmo-bts/gsm_data.h b/include/osmo-bts/gsm_data.h
index 1c1c5d4..4689e88 100644
--- a/include/osmo-bts/gsm_data.h
+++ b/include/osmo-bts/gsm_data.h
@@ -256,6 +256,17 @@
} 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 § 9.3.37: [0; 255] ok, -1 means invalid*/
diff --git a/src/common/l1sap.c b/src/common/l1sap.c
index c9ec9bf..20b1f55 100644
--- a/src/common/l1sap.c
+++ b/src/common/l1sap.c
@@ -907,6 +907,51 @@
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;
+ } 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;
+ } 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;
+ } 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;
+ } 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 +965,7 @@
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 +1033,17 @@
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->ts->trx->bts->facch_repetition_enabled && 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 +1068,16 @@
} 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);
diff --git a/src/common/vty.c b/src/common/vty.c
index d20b143..53f75e9 100644
--- a/src/common/vty.c
+++ b/src/common/vty.c
@@ -305,6 +305,8 @@
vty_out(vty, " smscb queue-max-length %d%s", bts->smscb_queue_max_len, VTY_NEWLINE);
vty_out(vty, " smscb queue-target-length %d%s", bts->smscb_queue_tgt_len, VTY_NEWLINE);
vty_out(vty, " smscb queue-hysteresis %d%s", bts->smscb_queue_hyst, VTY_NEWLINE);
+ if (bts->facch_repetition_enabled)
+ vty_out(vty, " facch-repetition%s", VTY_NEWLINE);
bts_model_config_write_bts(vty, bts);
@@ -789,6 +791,27 @@
return CMD_SUCCESS;
}
+DEFUN_ATTR(cfg_bts_facch_repetition, cfg_bts_facch_repetition_cmd,
+ "facch-repetition",
+ "enable downlink FACCH repetition\n",
+ CMD_ATTR_IMMEDIATE)
+{
+ struct gsm_bts *bts = vty->index;
+
+ bts->facch_repetition_enabled = true;
+ return CMD_SUCCESS;
+}
+
+DEFUN_ATTR(cfg_bts_no_facch_repetition, cfg_bts_no_facch_repetition_cmd,
+ "no facch-repetition",
+ "disable downlink FACCH repetition\n",
+ CMD_ATTR_IMMEDIATE)
+{
+ struct gsm_bts *bts = vty->index;
+
+ bts->facch_repetition_enabled = false;
+ return CMD_SUCCESS;
+}
#define DB_MDB_STR \
"Unit is dB (decibels)\n" \
@@ -1886,6 +1909,8 @@
install_element(BTS_NODE, &cfg_bts_smscb_max_qlen_cmd);
install_element(BTS_NODE, &cfg_bts_smscb_tgt_qlen_cmd);
install_element(BTS_NODE, &cfg_bts_smscb_qhyst_cmd);
+ install_element(BTS_NODE, &cfg_bts_facch_repetition_cmd);
+ install_element(BTS_NODE, &cfg_bts_no_facch_repetition_cmd);
install_element(BTS_NODE, &cfg_trx_gsmtap_sapi_all_cmd);
install_element(BTS_NODE, &cfg_trx_gsmtap_sapi_cmd);
--
To view, visit https://gerrit.osmocom.org/c/osmo-bts/+/21014
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Gerrit-Project: osmo-bts
Gerrit-Branch: master
Gerrit-Change-Id: I72f0cf7eaaef9f80fc35e752c90ae0e2d24d0c75
Gerrit-Change-Number: 21014
Gerrit-PatchSet: 1
Gerrit-Owner: dexter <pmaier at sysmocom.de>
Gerrit-MessageType: newchange
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