<p>fixeria has uploaded this change for <strong>review</strong>.</p><p><a href="https://gerrit.osmocom.org/c/osmo-bts/+/24613">View Change</a></p><pre style="font-family: monospace,monospace; white-space: pre-wrap;">osmo-bts-trx: report interference levels to the upper layers<br><br>In trx_sched_ul_burst(), treat all BURST.ind and NOPE.ind mapped<br>to inactive logical channels as interference. Average the RSSI<br>values on the fly using a sliding average with constant a=0.5.<br><br>Report averaged values for each logical channel every 104 TDMA<br>frames (SACCH period) by calling gsm_lchan_interf_meas_push().<br><br>Change-Id: I4686448e42a40df56c1d27a14fd0a4d43fd144a5<br>Related: I78b6d8beffa5228a28231b75728e7aebdd3cb23c<br>Related: SYS#5313, OS#1569<br>---<br>M include/osmo-bts/scheduler.h<br>M src/common/scheduler.c<br>M src/osmo-bts-trx/scheduler_trx.c<br>3 files changed, 100 insertions(+), 10 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/13/24613/1</pre><pre style="font-family: monospace,monospace; white-space: pre-wrap;"><span>diff --git a/include/osmo-bts/scheduler.h b/include/osmo-bts/scheduler.h</span><br><span>index 86bfdf9..7b3daa3 100644</span><br><span>--- a/include/osmo-bts/scheduler.h</span><br><span>+++ b/include/osmo-bts/scheduler.h</span><br><span>@@ -132,10 +132,14 @@</span><br><span> uint8_t ul_encr_key[MAX_A5_KEY_LEN];</span><br><span> uint8_t dl_encr_key[MAX_A5_KEY_LEN];</span><br><span> </span><br><span style="color: hsl(0, 100%, 40%);">- /* Simple ring buffer (up to 8 unique measurements) */</span><br><span style="color: hsl(120, 100%, 40%);">+ /* Uplink measurements */</span><br><span> struct {</span><br><span style="color: hsl(0, 100%, 40%);">- struct l1sched_meas_set buf[8];</span><br><span style="color: hsl(120, 100%, 40%);">+ /* Active channel measurements (simple ring buffer) */</span><br><span style="color: hsl(120, 100%, 40%);">+ struct l1sched_meas_set buf[8]; /* up to 8 entries */</span><br><span> unsigned int current; /* current position */</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span style="color: hsl(120, 100%, 40%);">+ /* Interference measurements */</span><br><span style="color: hsl(120, 100%, 40%);">+ int interf_avg; /* sliding average */</span><br><span> } meas;</span><br><span> </span><br><span> /* handover */</span><br><span>diff --git a/src/common/scheduler.c b/src/common/scheduler.c</span><br><span>index 3ab94a2..f74688c 100644</span><br><span>--- a/src/common/scheduler.c</span><br><span>+++ b/src/common/scheduler.c</span><br><span>@@ -1438,6 +1438,31 @@</span><br><span> return 0;</span><br><span> }</span><br><span> </span><br><span style="color: hsl(120, 100%, 40%);">+/* Process a single noise measurement for an inactive timeslot. */</span><br><span style="color: hsl(120, 100%, 40%);">+static void trx_sched_noise_meas(struct l1sched_chan_state *l1cs,</span><br><span style="color: hsl(120, 100%, 40%);">+ const struct trx_ul_burst_ind *bi)</span><br><span style="color: hsl(120, 100%, 40%);">+{</span><br><span style="color: hsl(120, 100%, 40%);">+ int *Avg = &l1cs->meas.interf_avg;</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span style="color: hsl(120, 100%, 40%);">+ /* EWMA (Exponentially Weighted Moving Average):</span><br><span style="color: hsl(120, 100%, 40%);">+ *</span><br><span style="color: hsl(120, 100%, 40%);">+ * Avg[n] = a * Val[n] + (1 - a) * Avg[n - 1]</span><br><span style="color: hsl(120, 100%, 40%);">+ *</span><br><span style="color: hsl(120, 100%, 40%);">+ * Implemented using the '+=' operator:</span><br><span style="color: hsl(120, 100%, 40%);">+ *</span><br><span style="color: hsl(120, 100%, 40%);">+ * Avg += a * Val - a * Avg</span><br><span style="color: hsl(120, 100%, 40%);">+ * Avg += a * (Val - Avg)</span><br><span style="color: hsl(120, 100%, 40%);">+ *</span><br><span style="color: hsl(120, 100%, 40%);">+ * We use constant 'a' = 0.5, what is equal to:</span><br><span style="color: hsl(120, 100%, 40%);">+ *</span><br><span style="color: hsl(120, 100%, 40%);">+ * Avg += (Val - Avg) / 2</span><br><span style="color: hsl(120, 100%, 40%);">+ *</span><br><span style="color: hsl(120, 100%, 40%);">+ * We don't really need precisity here, so no scaling.</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%);">+ *Avg += (bi->rssi - *Avg) / 2;</span><br><span style="color: hsl(120, 100%, 40%);">+}</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span> /* Process an Uplink burst indication */</span><br><span> int trx_sched_ul_burst(struct l1sched_ts *l1ts, struct trx_ul_burst_ind *bi)</span><br><span> {</span><br><span>@@ -1463,15 +1488,13 @@</span><br><span> l1cs = &l1ts->chan_state[bi->chan];</span><br><span> func = trx_chan_desc[bi->chan].ul_fn;</span><br><span> </span><br><span style="color: hsl(0, 100%, 40%);">- /* TODO: handle noise measurements */</span><br><span style="color: hsl(0, 100%, 40%);">- if (bi->chan == TRXC_IDLE && bi->flags & TRX_BI_F_NOPE_IND) {</span><br><span style="color: hsl(0, 100%, 40%);">- LOGL1SB(DL1P, LOGL_DEBUG, l1ts, bi, "Rx noise measurement (%d)\n", bi->rssi);</span><br><span style="color: hsl(0, 100%, 40%);">- return -ENOTSUP;</span><br><span style="color: hsl(0, 100%, 40%);">- }</span><br><span style="color: hsl(0, 100%, 40%);">-</span><br><span> /* check if channel is active */</span><br><span style="color: hsl(0, 100%, 40%);">- if (!TRX_CHAN_IS_ACTIVE(l1cs, bi->chan))</span><br><span style="color: hsl(0, 100%, 40%);">- return -EINVAL;</span><br><span style="color: hsl(120, 100%, 40%);">+ if (!TRX_CHAN_IS_ACTIVE(l1cs, bi->chan)) {</span><br><span style="color: hsl(120, 100%, 40%);">+ /* handle noise measurements */</span><br><span style="color: hsl(120, 100%, 40%);">+ if (bi->chan >= TRXC_TCHF)</span><br><span style="color: hsl(120, 100%, 40%);">+ trx_sched_noise_meas(l1cs, bi);</span><br><span style="color: hsl(120, 100%, 40%);">+ return 0;</span><br><span style="color: hsl(120, 100%, 40%);">+ }</span><br><span> </span><br><span> /* omit bursts which have no handler, like IDLE bursts */</span><br><span> if (!func)</span><br><span>diff --git a/src/osmo-bts-trx/scheduler_trx.c b/src/osmo-bts-trx/scheduler_trx.c</span><br><span>index 1a4f03f..0a2052c 100644</span><br><span>--- a/src/osmo-bts-trx/scheduler_trx.c</span><br><span>+++ b/src/osmo-bts-trx/scheduler_trx.c</span><br><span>@@ -60,6 +60,65 @@</span><br><span> return 0;</span><br><span> }</span><br><span> </span><br><span style="color: hsl(120, 100%, 40%);">+static void ts_report_interf_meas(const struct gsm_bts_trx_ts *ts)</span><br><span style="color: hsl(120, 100%, 40%);">+{</span><br><span style="color: hsl(120, 100%, 40%);">+ const struct l1sched_ts *l1ts = ts->priv;</span><br><span style="color: hsl(120, 100%, 40%);">+ unsigned int ln;</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span style="color: hsl(120, 100%, 40%);">+ for (ln = 0; ln < ARRAY_SIZE(ts->lchan); ln++) {</span><br><span style="color: hsl(120, 100%, 40%);">+ const struct gsm_lchan *lchan = &ts->lchan[ln];</span><br><span style="color: hsl(120, 100%, 40%);">+ enum trx_chan_type dcch, acch;</span><br><span style="color: hsl(120, 100%, 40%);">+ int interf_avg;</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span style="color: hsl(120, 100%, 40%);">+ /* We're not interested in active channels */</span><br><span style="color: hsl(120, 100%, 40%);">+ if (lchan->state == LCHAN_S_ACTIVE)</span><br><span style="color: hsl(120, 100%, 40%);">+ continue;</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span style="color: hsl(120, 100%, 40%);">+ switch (lchan->type) {</span><br><span style="color: hsl(120, 100%, 40%);">+ case GSM_LCHAN_SDCCH:</span><br><span style="color: hsl(120, 100%, 40%);">+ if (ts->pchan == GSM_PCHAN_CCCH_SDCCH4 ||</span><br><span style="color: hsl(120, 100%, 40%);">+ ts->pchan == GSM_PCHAN_CCCH_SDCCH4_CBCH) {</span><br><span style="color: hsl(120, 100%, 40%);">+ dcch = TRXC_SDCCH4_0 + ln;</span><br><span style="color: hsl(120, 100%, 40%);">+ acch = TRXC_SACCH4_0 + ln;</span><br><span style="color: hsl(120, 100%, 40%);">+ } else { /* SDCCH/8 otherwise */</span><br><span style="color: hsl(120, 100%, 40%);">+ dcch = TRXC_SDCCH8_0 + ln;</span><br><span style="color: hsl(120, 100%, 40%);">+ acch = TRXC_SACCH8_0 + ln;</span><br><span style="color: hsl(120, 100%, 40%);">+ }</span><br><span style="color: hsl(120, 100%, 40%);">+ break;</span><br><span style="color: hsl(120, 100%, 40%);">+ case GSM_LCHAN_TCH_F:</span><br><span style="color: hsl(120, 100%, 40%);">+ dcch = TRXC_TCHF;</span><br><span style="color: hsl(120, 100%, 40%);">+ acch = TRXC_SACCHTF;</span><br><span style="color: hsl(120, 100%, 40%);">+ break;</span><br><span style="color: hsl(120, 100%, 40%);">+ case GSM_LCHAN_TCH_H:</span><br><span style="color: hsl(120, 100%, 40%);">+ dcch = TRXC_TCHH_0 + ln;</span><br><span style="color: hsl(120, 100%, 40%);">+ acch = TRXC_SACCHTH_0 + ln;</span><br><span style="color: hsl(120, 100%, 40%);">+ break;</span><br><span style="color: hsl(120, 100%, 40%);">+ default:</span><br><span style="color: hsl(120, 100%, 40%);">+ /* Skip other lchan types */</span><br><span style="color: hsl(120, 100%, 40%);">+ continue;</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%);">+ OSMO_ASSERT(dcch < ARRAY_SIZE(l1ts->chan_state));</span><br><span style="color: hsl(120, 100%, 40%);">+ OSMO_ASSERT(acch < ARRAY_SIZE(l1ts->chan_state));</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span style="color: hsl(120, 100%, 40%);">+ interf_avg = (l1ts->chan_state[dcch].meas.interf_avg +</span><br><span style="color: hsl(120, 100%, 40%);">+ l1ts->chan_state[acch].meas.interf_avg) / 2;</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span style="color: hsl(120, 100%, 40%);">+ gsm_lchan_interf_meas_push((struct gsm_lchan *) lchan, interf_avg);</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%);">+static void bts_report_interf_meas(const struct gsm_bts *bts)</span><br><span style="color: hsl(120, 100%, 40%);">+{</span><br><span style="color: hsl(120, 100%, 40%);">+ const struct gsm_bts_trx *trx;</span><br><span style="color: hsl(120, 100%, 40%);">+ unsigned int tn;</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span style="color: hsl(120, 100%, 40%);">+ llist_for_each_entry(trx, &bts->trx_list, list) {</span><br><span style="color: hsl(120, 100%, 40%);">+ for (tn = 0; tn < ARRAY_SIZE(trx->ts); tn++)</span><br><span style="color: hsl(120, 100%, 40%);">+ ts_report_interf_meas(&trx->ts[tn]);</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> /* Find a route (PHY instance) for a given Downlink burst request */</span><br><span> static struct phy_instance *dlfh_route_br(const struct trx_dl_burst_req *br,</span><br><span> struct gsm_bts_trx_ts *ts)</span><br><span>@@ -189,6 +248,10 @@</span><br><span> struct gsm_bts_trx *trx;</span><br><span> unsigned int tn;</span><br><span> </span><br><span style="color: hsl(120, 100%, 40%);">+ /* Report interference measurements */</span><br><span style="color: hsl(120, 100%, 40%);">+ if (fn % 104 == 0) /* SACCH period */</span><br><span style="color: hsl(120, 100%, 40%);">+ bts_report_interf_meas(bts);</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span> /* send time indication */</span><br><span> l1if_mph_time_ind(bts, fn);</span><br><span> </span><br><span></span><br></pre><p>To view, visit <a href="https://gerrit.osmocom.org/c/osmo-bts/+/24613">change 24613</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: I4686448e42a40df56c1d27a14fd0a4d43fd144a5 </div>
<div style="display:none"> Gerrit-Change-Number: 24613 </div>
<div style="display:none"> Gerrit-PatchSet: 1 </div>
<div style="display:none"> Gerrit-Owner: fixeria <vyanitskiy@sysmocom.de> </div>
<div style="display:none"> Gerrit-MessageType: newchange </div>