<p>dexter has uploaded this change for <strong>review</strong>.</p><p><a href="https://gerrit.osmocom.org/c/osmo-bts/+/21014">View Change</a></p><pre style="font-family: monospace,monospace; white-space: pre-wrap;">l1sap: add repeated downlink FACCH<br><br>3GPP TS 44.006, section 10 describes a method how the downlink<br>FACCH transmission can be repeated to increase transmission<br>reliability.<br><br>Change-Id: I72f0cf7eaaef9f80fc35e752c90ae0e2d24d0c75<br>Related: OS#4796 SYS#5114<br>---<br>M include/osmo-bts/bts.h<br>M include/osmo-bts/gsm_data.h<br>M src/common/l1sap.c<br>M src/common/vty.c<br>4 files changed, 95 insertions(+), 7 deletions(-)<br><br></pre><pre style="font-family: monospace,monospace; white-space: pre-wrap;">git pull ssh://gerrit.osmocom.org:29418/osmo-bts refs/changes/14/21014/1</pre><pre style="font-family: monospace,monospace; white-space: pre-wrap;"><span>diff --git a/include/osmo-bts/bts.h b/include/osmo-bts/bts.h</span><br><span>index ce7d9d4..fdcc67b 100644</span><br><span>--- a/include/osmo-bts/bts.h</span><br><span>+++ b/include/osmo-bts/bts.h</span><br><span>@@ -338,6 +338,9 @@</span><br><span> struct osmo_fsm_inst *shutdown_fi; /* FSM instance to manage shutdown procedure during process exit */</span><br><span> struct osmo_tdef *T_defs; /* Timer defines */</span><br><span> </span><br><span style="color: hsl(120, 100%, 40%);">+ /* 3GPP TS 44.006, section 10, Repeated Downlink FACCH */</span><br><span style="color: hsl(120, 100%, 40%);">+ bool facch_repetition_enabled;</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span> void *model_priv; /* Allocated by bts_model, contains model specific data pointer */</span><br><span> };</span><br><span> </span><br><span>diff --git a/include/osmo-bts/gsm_data.h b/include/osmo-bts/gsm_data.h</span><br><span>index 1c1c5d4..4689e88 100644</span><br><span>--- a/include/osmo-bts/gsm_data.h</span><br><span>+++ b/include/osmo-bts/gsm_data.h</span><br><span>@@ -256,6 +256,17 @@</span><br><span> } dtx;</span><br><span> uint8_t last_cmr;</span><br><span> uint32_t last_fn;</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span style="color: hsl(120, 100%, 40%);">+ struct {</span><br><span style="color: hsl(120, 100%, 40%);">+ /* SLOT #1 */</span><br><span style="color: hsl(120, 100%, 40%);">+ struct msgb *msg_1;</span><br><span style="color: hsl(120, 100%, 40%);">+ uint32_t fn_1;</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span style="color: hsl(120, 100%, 40%);">+ /* SLOT #2 */</span><br><span style="color: hsl(120, 100%, 40%);">+ struct msgb *msg_2;</span><br><span style="color: hsl(120, 100%, 40%);">+ uint32_t fn_2;</span><br><span style="color: hsl(120, 100%, 40%);">+ } rep_facch;</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span> } tch;</span><br><span> </span><br><span> /* 3GPP TS 48.058 ยง 9.3.37: [0; 255] ok, -1 means invalid*/</span><br><span>diff --git a/src/common/l1sap.c b/src/common/l1sap.c</span><br><span>index c9ec9bf..20b1f55 100644</span><br><span>--- a/src/common/l1sap.c</span><br><span>+++ b/src/common/l1sap.c</span><br><span>@@ -907,6 +907,51 @@</span><br><span> bts->fn_stats.avg_count++;</span><br><span> }</span><br><span> }</span><br><span style="color: hsl(120, 100%, 40%);">+/* Common dequeueing function */</span><br><span style="color: hsl(120, 100%, 40%);">+static inline struct msgb *lapdm_phsap_dequeue_msg(struct lapdm_entity *le)</span><br><span style="color: hsl(120, 100%, 40%);">+{</span><br><span style="color: hsl(120, 100%, 40%);">+ struct osmo_phsap_prim pp;</span><br><span style="color: hsl(120, 100%, 40%);">+ if (lapdm_phsap_dequeue_prim(le, &pp) < 0)</span><br><span style="color: hsl(120, 100%, 40%);">+ return NULL;</span><br><span style="color: hsl(120, 100%, 40%);">+ return pp.oph.msg;</span><br><span style="color: hsl(120, 100%, 40%);">+}</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span style="color: hsl(120, 100%, 40%);">+/* Special dequeueing function with FACCH repetition (3GPP TS 44.006, section 10) */</span><br><span style="color: hsl(120, 100%, 40%);">+static inline struct msgb *lapdm_phsap_dequeue_msg_facch(struct gsm_lchan *lchan, struct lapdm_entity *le, uint32_t fn)</span><br><span style="color: hsl(120, 100%, 40%);">+{</span><br><span style="color: hsl(120, 100%, 40%);">+ struct osmo_phsap_prim pp;</span><br><span style="color: hsl(120, 100%, 40%);">+ struct msgb *msg;</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span style="color: hsl(120, 100%, 40%);">+ if (lchan->tch.rep_facch.msg_1 && lchan->tch.rep_facch.fn_1 + 8 <= fn) {</span><br><span style="color: hsl(120, 100%, 40%);">+ /* Re-use stored FACCH message buffer from SLOT 1 for repetition. */</span><br><span style="color: hsl(120, 100%, 40%);">+ msg = lchan->tch.rep_facch.msg_1;</span><br><span style="color: hsl(120, 100%, 40%);">+ lchan->tch.rep_facch.msg_1 = NULL;</span><br><span style="color: hsl(120, 100%, 40%);">+ } else if (lchan->tch.rep_facch.msg_2 && lchan->tch.rep_facch.fn_2 + 8 <= fn) {</span><br><span style="color: hsl(120, 100%, 40%);">+ /* Re-use stored FACCH message buffer from SLOT 2 for repetition. */</span><br><span style="color: hsl(120, 100%, 40%);">+ msg = lchan->tch.rep_facch.msg_2;</span><br><span style="color: hsl(120, 100%, 40%);">+ lchan->tch.rep_facch.msg_2 = NULL;</span><br><span style="color: hsl(120, 100%, 40%);">+ } else {</span><br><span style="color: hsl(120, 100%, 40%);">+ /* Fetch new FACCH from queue ... */</span><br><span style="color: hsl(120, 100%, 40%);">+ if (lapdm_phsap_dequeue_prim(le, &pp) < 0)</span><br><span style="color: hsl(120, 100%, 40%);">+ return NULL;</span><br><span style="color: hsl(120, 100%, 40%);">+ msg = pp.oph.msg;</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span style="color: hsl(120, 100%, 40%);">+ /* ... and store the message buffer for repetition. */</span><br><span style="color: hsl(120, 100%, 40%);">+ if (lchan->tch.rep_facch.msg_1 == NULL) {</span><br><span style="color: hsl(120, 100%, 40%);">+ lchan->tch.rep_facch.msg_1 = msgb_copy(msg, "rep_facch_1");</span><br><span style="color: hsl(120, 100%, 40%);">+ lchan->tch.rep_facch.fn_1 = fn;</span><br><span style="color: hsl(120, 100%, 40%);">+ } else if (lchan->tch.rep_facch.msg_2 == NULL) {</span><br><span style="color: hsl(120, 100%, 40%);">+ lchan->tch.rep_facch.msg_2 = msgb_copy(msg, "rep_facch_2");</span><br><span style="color: hsl(120, 100%, 40%);">+ lchan->tch.rep_facch.fn_2 = fn;</span><br><span style="color: hsl(120, 100%, 40%);">+ } else {</span><br><span style="color: hsl(120, 100%, 40%);">+ /* By definition 3GPP TS 05.02 does not allow more than two (for TCH/H only one) FACCH instances</span><br><span style="color: hsl(120, 100%, 40%);">+ * to be transmitted simultaniously. */</span><br><span style="color: hsl(120, 100%, 40%);">+ OSMO_ASSERT(false);</span><br><span style="color: hsl(120, 100%, 40%);">+ }</span><br><span style="color: hsl(120, 100%, 40%);">+ }</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span style="color: hsl(120, 100%, 40%);">+ return msg;</span><br><span style="color: hsl(120, 100%, 40%);">+}</span><br><span> </span><br><span> /* PH-RTS-IND prim received from bts model */</span><br><span> static int l1sap_ph_rts_ind(struct gsm_bts_trx *trx,</span><br><span>@@ -920,7 +965,7 @@</span><br><span> uint32_t fn;</span><br><span> uint8_t *p, *si;</span><br><span> struct lapdm_entity *le;</span><br><span style="color: hsl(0, 100%, 40%);">- struct osmo_phsap_prim pp;</span><br><span style="color: hsl(120, 100%, 40%);">+ struct msgb *pp_msg;</span><br><span> bool dtxd_facch = false;</span><br><span> int rc;</span><br><span> int is_ag_res;</span><br><span>@@ -988,13 +1033,17 @@</span><br><span> p[0] = lchan->ms_power_ctrl.current;</span><br><span> p[1] = lchan->rqd_ta;</span><br><span> le = &lchan->lapdm_ch.lapdm_acch;</span><br><span style="color: hsl(120, 100%, 40%);">+ pp_msg = lapdm_phsap_dequeue_msg(le);</span><br><span> } else {</span><br><span> if (lchan->ts->trx->bts->dtxd)</span><br><span> dtxd_facch = true;</span><br><span> le = &lchan->lapdm_ch.lapdm_dcch;</span><br><span style="color: hsl(120, 100%, 40%);">+ if (lchan->ts->trx->bts->facch_repetition_enabled && lchan->rsl_cmode != RSL_CMOD_SPD_SIGN)</span><br><span style="color: hsl(120, 100%, 40%);">+ pp_msg = lapdm_phsap_dequeue_msg_facch(lchan, le, fn);</span><br><span style="color: hsl(120, 100%, 40%);">+ else</span><br><span style="color: hsl(120, 100%, 40%);">+ pp_msg = lapdm_phsap_dequeue_msg(le);</span><br><span> }</span><br><span style="color: hsl(0, 100%, 40%);">- rc = lapdm_phsap_dequeue_prim(le, &pp);</span><br><span style="color: hsl(0, 100%, 40%);">- if (rc < 0) {</span><br><span style="color: hsl(120, 100%, 40%);">+ if (!pp_msg) {</span><br><span> if (L1SAP_IS_LINK_SACCH(link_id)) {</span><br><span> /* No SACCH data from LAPDM pending, send SACCH filling */</span><br><span> uint8_t *si = lchan_sacch_get(lchan);</span><br><span>@@ -1019,16 +1068,16 @@</span><br><span> } else {</span><br><span> /* The +2 is empty space where the DSP inserts the L1 hdr */</span><br><span> if (L1SAP_IS_LINK_SACCH(link_id))</span><br><span style="color: hsl(0, 100%, 40%);">- memcpy(p + 2, pp.oph.msg->data + 2, GSM_MACBLOCK_LEN - 2);</span><br><span style="color: hsl(120, 100%, 40%);">+ memcpy(p + 2, pp_msg->data + 2, GSM_MACBLOCK_LEN - 2);</span><br><span> else {</span><br><span> p = msgb_put(msg, GSM_MACBLOCK_LEN);</span><br><span style="color: hsl(0, 100%, 40%);">- memcpy(p, pp.oph.msg->data, GSM_MACBLOCK_LEN);</span><br><span style="color: hsl(120, 100%, 40%);">+ memcpy(p, pp_msg->data, GSM_MACBLOCK_LEN);</span><br><span> /* check if it is a RR CIPH MODE CMD. if yes, enable RX ciphering */</span><br><span style="color: hsl(0, 100%, 40%);">- check_for_ciph_cmd(pp.oph.msg, lchan, chan_nr);</span><br><span style="color: hsl(120, 100%, 40%);">+ check_for_ciph_cmd(pp_msg, lchan, chan_nr);</span><br><span> if (dtxd_facch)</span><br><span> dtx_dispatch(lchan, E_FACCH);</span><br><span> }</span><br><span style="color: hsl(0, 100%, 40%);">- msgb_free(pp.oph.msg);</span><br><span style="color: hsl(120, 100%, 40%);">+ msgb_free(pp_msg);</span><br><span> }</span><br><span> } else if (L1SAP_IS_CHAN_AGCH_PCH(chan_nr)) {</span><br><span> p = msgb_put(msg, GSM_MACBLOCK_LEN);</span><br><span>diff --git a/src/common/vty.c b/src/common/vty.c</span><br><span>index d20b143..53f75e9 100644</span><br><span>--- a/src/common/vty.c</span><br><span>+++ b/src/common/vty.c</span><br><span>@@ -305,6 +305,8 @@</span><br><span> vty_out(vty, " smscb queue-max-length %d%s", bts->smscb_queue_max_len, VTY_NEWLINE);</span><br><span> vty_out(vty, " smscb queue-target-length %d%s", bts->smscb_queue_tgt_len, VTY_NEWLINE);</span><br><span> vty_out(vty, " smscb queue-hysteresis %d%s", bts->smscb_queue_hyst, VTY_NEWLINE);</span><br><span style="color: hsl(120, 100%, 40%);">+ if (bts->facch_repetition_enabled)</span><br><span style="color: hsl(120, 100%, 40%);">+ vty_out(vty, " facch-repetition%s", VTY_NEWLINE);</span><br><span> </span><br><span> bts_model_config_write_bts(vty, bts);</span><br><span> </span><br><span>@@ -789,6 +791,27 @@</span><br><span> return CMD_SUCCESS;</span><br><span> }</span><br><span> </span><br><span style="color: hsl(120, 100%, 40%);">+DEFUN_ATTR(cfg_bts_facch_repetition, cfg_bts_facch_repetition_cmd,</span><br><span style="color: hsl(120, 100%, 40%);">+ "facch-repetition",</span><br><span style="color: hsl(120, 100%, 40%);">+ "enable downlink FACCH repetition\n",</span><br><span style="color: hsl(120, 100%, 40%);">+ CMD_ATTR_IMMEDIATE)</span><br><span style="color: hsl(120, 100%, 40%);">+{</span><br><span style="color: hsl(120, 100%, 40%);">+ struct gsm_bts *bts = vty->index;</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span style="color: hsl(120, 100%, 40%);">+ bts->facch_repetition_enabled = true;</span><br><span style="color: hsl(120, 100%, 40%);">+ return CMD_SUCCESS;</span><br><span style="color: hsl(120, 100%, 40%);">+}</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span style="color: hsl(120, 100%, 40%);">+DEFUN_ATTR(cfg_bts_no_facch_repetition, cfg_bts_no_facch_repetition_cmd,</span><br><span style="color: hsl(120, 100%, 40%);">+ "no facch-repetition",</span><br><span style="color: hsl(120, 100%, 40%);">+ "disable downlink FACCH repetition\n",</span><br><span style="color: hsl(120, 100%, 40%);">+ CMD_ATTR_IMMEDIATE)</span><br><span style="color: hsl(120, 100%, 40%);">+{</span><br><span style="color: hsl(120, 100%, 40%);">+ struct gsm_bts *bts = vty->index;</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span style="color: hsl(120, 100%, 40%);">+ bts->facch_repetition_enabled = false;</span><br><span style="color: hsl(120, 100%, 40%);">+ return CMD_SUCCESS;</span><br><span style="color: hsl(120, 100%, 40%);">+}</span><br><span> </span><br><span> #define DB_MDB_STR \</span><br><span> "Unit is dB (decibels)\n" \</span><br><span>@@ -1886,6 +1909,8 @@</span><br><span> install_element(BTS_NODE, &cfg_bts_smscb_max_qlen_cmd);</span><br><span> install_element(BTS_NODE, &cfg_bts_smscb_tgt_qlen_cmd);</span><br><span> install_element(BTS_NODE, &cfg_bts_smscb_qhyst_cmd);</span><br><span style="color: hsl(120, 100%, 40%);">+ install_element(BTS_NODE, &cfg_bts_facch_repetition_cmd);</span><br><span style="color: hsl(120, 100%, 40%);">+ install_element(BTS_NODE, &cfg_bts_no_facch_repetition_cmd);</span><br><span> </span><br><span> install_element(BTS_NODE, &cfg_trx_gsmtap_sapi_all_cmd);</span><br><span> install_element(BTS_NODE, &cfg_trx_gsmtap_sapi_cmd);</span><br><span></span><br></pre><p>To view, visit <a href="https://gerrit.osmocom.org/c/osmo-bts/+/21014">change 21014</a>. 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<div style="display:none"> Gerrit-Project: osmo-bts </div>
<div style="display:none"> Gerrit-Branch: master </div>
<div style="display:none"> Gerrit-Change-Id: I72f0cf7eaaef9f80fc35e752c90ae0e2d24d0c75 </div>
<div style="display:none"> Gerrit-Change-Number: 21014 </div>
<div style="display:none"> Gerrit-PatchSet: 1 </div>
<div style="display:none"> Gerrit-Owner: dexter <pmaier@sysmocom.de> </div>
<div style="display:none"> Gerrit-MessageType: newchange </div>