<p>pespin has uploaded this change for <strong>review</strong>.</p><p><a href="https://gerrit.osmocom.org/c/osmo-bts/+/25328">View Change</a></p><pre style="font-family: monospace,monospace; white-space: pre-wrap;">MS/BS Power Control Loop: Do RxLEV meas avg & delta calculations directly on RxLevels<br><br>Before this comits, averaging and delta calculation was done in RSSI,<br>but stored the averaging cached state in variables named "rxlev", which<br>was really confusing. Let's keeping averaging and delta calculations<br>based on RxLevels.<br><br>Some of the tests change results due to test passing RSSI -45, which is<br>an invalid Rxlev (only up to -47 is supported).<br><br>Change-Id: I4cff8394f22b5d47789163051364ff594b2bcd74<br>---<br>M src/common/power_control.c<br>M tests/power/ms_power_loop_test.c<br>2 files changed, 36 insertions(+), 44 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/28/25328/1</pre><pre style="font-family: monospace,monospace; white-space: pre-wrap;"><span>diff --git a/src/common/power_control.c b/src/common/power_control.c</span><br><span>index cb96177..b3066cd 100644</span><br><span>--- a/src/common/power_control.c</span><br><span>+++ b/src/common/power_control.c</span><br><span>@@ -113,22 +113,18 @@</span><br><span> * to be applied to the current Tx power level to approach the target level. */</span><br><span> static int calc_delta_rxlev(const struct gsm_power_ctrl_params *params,</span><br><span> struct lchan_power_ctrl_state *state,</span><br><span style="color: hsl(0, 100%, 40%);">- const int rxlev_dbm_avg)</span><br><span style="color: hsl(120, 100%, 40%);">+ const uint8_t rxlev)</span><br><span> {</span><br><span style="color: hsl(0, 100%, 40%);">- uint8_t rxlev_avg;</span><br><span> int delta;</span><br><span> </span><br><span style="color: hsl(0, 100%, 40%);">- /* FIXME: avoid this conversion, accept RxLev as-is */</span><br><span style="color: hsl(0, 100%, 40%);">- rxlev_avg = dbm2rxlev(rxlev_dbm_avg);</span><br><span style="color: hsl(0, 100%, 40%);">-</span><br><span> /* Check if RxLev is within the threshold window */</span><br><span style="color: hsl(0, 100%, 40%);">- if (rxlev_avg >= params->rxlev_meas.lower_thresh &&</span><br><span style="color: hsl(0, 100%, 40%);">- rxlev_avg <= params->rxlev_meas.upper_thresh)</span><br><span style="color: hsl(120, 100%, 40%);">+ if (rxlev >= params->rxlev_meas.lower_thresh &&</span><br><span style="color: hsl(120, 100%, 40%);">+ rxlev <= params->rxlev_meas.upper_thresh)</span><br><span> return 0;</span><br><span> </span><br><span> /* How many dBs measured power should be increased (+) or decreased (-)</span><br><span> * to reach expected power. */</span><br><span style="color: hsl(0, 100%, 40%);">- delta = CALC_TARGET(params->rxlev_meas) - rxlev_avg;</span><br><span style="color: hsl(120, 100%, 40%);">+ delta = CALC_TARGET(params->rxlev_meas) - rxlev;</span><br><span> </span><br><span> /* Don't ever change more than PWR_{LOWER,RAISE}_MAX_DBM during one loop</span><br><span> * iteration, i.e. reduce the speed at which the MS transmit power can</span><br><span>@@ -183,7 +179,7 @@</span><br><span> enum gsm_band band = bts->band;</span><br><span> int8_t new_power_lvl; /* TS 05.05 power level */</span><br><span> int8_t ms_dbm, new_dbm, current_dbm, bsc_max_dbm;</span><br><span style="color: hsl(0, 100%, 40%);">- int8_t ul_rssi_dbm_avg;</span><br><span style="color: hsl(120, 100%, 40%);">+ uint8_t rxlev_avg;</span><br><span> int16_t ul_lqual_cb_avg;</span><br><span> const struct gsm_power_ctrl_meas_params *ci_meas;</span><br><span> </span><br><span>@@ -221,14 +217,14 @@</span><br><span> /* If computed C/I is out of acceptable thresholds: */</span><br><span> ci_meas = lchan_get_ci_thresholds(lchan);</span><br><span> ul_lqual_cb_avg = do_avg_algo(ci_meas, &state->ci_meas_proc, ul_lqual_cb);</span><br><span style="color: hsl(0, 100%, 40%);">- ul_rssi_dbm_avg = do_avg_algo(¶ms->rxlev_meas, &state->rxlev_meas_proc, ul_rssi_dbm);</span><br><span style="color: hsl(120, 100%, 40%);">+ rxlev_avg = do_avg_algo(¶ms->rxlev_meas, &state->rxlev_meas_proc, dbm2rxlev(ul_rssi_dbm));</span><br><span> if (ul_lqual_cb_avg < ci_meas->lower_thresh * 10) {</span><br><span> new_dbm = ms_dbm + params->inc_step_size_db;</span><br><span> } else if (ul_lqual_cb_avg > ci_meas->upper_thresh * 10) {</span><br><span> new_dbm = ms_dbm - params->red_step_size_db;</span><br><span> } else {</span><br><span> /* Calculate the new Tx power value (in dBm) */</span><br><span style="color: hsl(0, 100%, 40%);">- new_dbm = ms_dbm + calc_delta_rxlev(params, state, ul_rssi_dbm_avg);</span><br><span style="color: hsl(120, 100%, 40%);">+ new_dbm = ms_dbm + calc_delta_rxlev(params, state, rxlev_avg);</span><br><span> }</span><br><span> </span><br><span> /* Make sure new_dbm is never negative. ms_pwr_ctl_lvl() can later on</span><br><span>@@ -252,7 +248,7 @@</span><br><span> LOGPLCHAN(lchan, DLOOP, LOGL_INFO, "Keeping MS power at control level %d (%d dBm): "</span><br><span> "ms-pwr-lvl[curr %" PRIu8 ", max %" PRIu8 "], RSSI[curr %d, avg %d, thresh %d..%d] dBm,"</span><br><span> " C/I[curr %d, avg %d, thresh %d..%d] dB\n",</span><br><span style="color: hsl(0, 100%, 40%);">- new_power_lvl, new_dbm, ms_power_lvl, state->max, ul_rssi_dbm, ul_rssi_dbm_avg,</span><br><span style="color: hsl(120, 100%, 40%);">+ new_power_lvl, new_dbm, ms_power_lvl, state->max, ul_rssi_dbm, rxlev2dbm(rxlev_avg),</span><br><span> rxlev2dbm(params->rxlev_meas.lower_thresh), rxlev2dbm(params->rxlev_meas.upper_thresh),</span><br><span> ul_lqual_cb/10, ul_lqual_cb_avg/10, ci_meas->lower_thresh, ci_meas->upper_thresh);</span><br><span> return 0;</span><br><span>@@ -264,7 +260,7 @@</span><br><span> " C/I[curr %d, avg %d, thresh %d..%d] dB\n",</span><br><span> (new_dbm > current_dbm) ? "Raising" : "Lowering",</span><br><span> state->current, current_dbm, new_power_lvl, new_dbm, ms_power_lvl,</span><br><span style="color: hsl(0, 100%, 40%);">- state->max, ul_rssi_dbm, ul_rssi_dbm_avg,</span><br><span style="color: hsl(120, 100%, 40%);">+ state->max, ul_rssi_dbm, rxlev2dbm(rxlev_avg),</span><br><span> rxlev2dbm(params->rxlev_meas.lower_thresh), rxlev2dbm(params->rxlev_meas.upper_thresh),</span><br><span> ul_lqual_cb/10, ul_lqual_cb_avg/10, ci_meas->lower_thresh, ci_meas->upper_thresh);</span><br><span> </span><br><span>@@ -286,8 +282,7 @@</span><br><span> const struct gsm_power_ctrl_params *params = state->dpc_params;</span><br><span> uint8_t rxqual_full, rxqual_sub;</span><br><span> uint8_t rxlev_full, rxlev_sub;</span><br><span style="color: hsl(0, 100%, 40%);">- uint8_t rxqual, rxqual_avg, rxlev;</span><br><span style="color: hsl(0, 100%, 40%);">- int8_t dl_rssi_dbm, dl_rssi_dbm_avg;</span><br><span style="color: hsl(120, 100%, 40%);">+ uint8_t rxqual, rxqual_avg, rxlev, rxlev_avg;</span><br><span> int new_att;</span><br><span> </span><br><span> /* Check if dynamic BS Power Control is enabled */</span><br><span>@@ -341,8 +336,7 @@</span><br><span> rxlev = rxlev_full;</span><br><span> }</span><br><span> </span><br><span style="color: hsl(0, 100%, 40%);">- dl_rssi_dbm = rxlev2dbm(rxlev);</span><br><span style="color: hsl(0, 100%, 40%);">- dl_rssi_dbm_avg = do_avg_algo(¶ms->rxlev_meas, &state->rxlev_meas_proc, dl_rssi_dbm);</span><br><span style="color: hsl(120, 100%, 40%);">+ rxlev_avg = do_avg_algo(¶ms->rxlev_meas, &state->rxlev_meas_proc, rxlev);</span><br><span> rxqual_avg = do_avg_algo(¶ms->rxqual_meas, &state->rxqual_meas_proc, rxqual);</span><br><span> /* If RxQual > L_RXQUAL_XX_P, try to increase Tx power */</span><br><span> if (rxqual_avg > params->rxqual_meas.lower_thresh) {</span><br><span>@@ -365,7 +359,7 @@</span><br><span> * RxLev + Delta = TxPwr - PathLoss - TxAtt + Delta</span><br><span> * RxLev + Delta = TxPwr - PathLoss - (TxAtt - Delta)</span><br><span> */</span><br><span style="color: hsl(0, 100%, 40%);">- new_att = state->current - calc_delta_rxlev(params, state, dl_rssi_dbm_avg);</span><br><span style="color: hsl(120, 100%, 40%);">+ new_att = state->current - calc_delta_rxlev(params, state, rxlev_avg);</span><br><span> }</span><br><span> </span><br><span> /* Make sure new TxAtt is never negative: */</span><br><span>@@ -380,7 +374,7 @@</span><br><span> LOGPLCHAN(lchan, DLOOP, LOGL_INFO, "Keeping DL attenuation at %u dB: "</span><br><span> "max %u dB, RSSI[curr %d, avg %d, thresh %d..%d] dBm, "</span><br><span> "RxQual[curr %d, avg %d, thresh %d..%d]\n",</span><br><span style="color: hsl(0, 100%, 40%);">- state->current, state->max, dl_rssi_dbm, dl_rssi_dbm_avg,</span><br><span style="color: hsl(120, 100%, 40%);">+ state->current, state->max, rxlev2dbm(rxlev), rxlev2dbm(rxlev_avg),</span><br><span> rxlev2dbm(params->rxlev_meas.lower_thresh), rxlev2dbm(params->rxlev_meas.upper_thresh),</span><br><span> rxqual, rxqual_avg, params->rxqual_meas.lower_thresh, params->rxqual_meas.upper_thresh);</span><br><span> return 0;</span><br><span>@@ -390,7 +384,7 @@</span><br><span> "max %u dB, RSSI[curr %d, avg %d, thresh %d..%d] dBm, "</span><br><span> "RxQual[curr %d, avg %d, thresh %d..%d]\n",</span><br><span> (new_att > state->current) ? "Raising" : "Lowering",</span><br><span style="color: hsl(0, 100%, 40%);">- state->current, new_att, state->max, dl_rssi_dbm, dl_rssi_dbm_avg,</span><br><span style="color: hsl(120, 100%, 40%);">+ state->current, new_att, state->max, rxlev2dbm(rxlev), rxlev2dbm(rxlev_avg),</span><br><span> rxlev2dbm(params->rxlev_meas.lower_thresh), rxlev2dbm(params->rxlev_meas.upper_thresh),</span><br><span> rxqual, rxqual_avg, params->rxqual_meas.lower_thresh, params->rxqual_meas.upper_thresh);</span><br><span> state->current = new_att;</span><br><span>diff --git a/tests/power/ms_power_loop_test.c b/tests/power/ms_power_loop_test.c</span><br><span>index f0c0250..e53cc43 100644</span><br><span>--- a/tests/power/ms_power_loop_test.c</span><br><span>+++ b/tests/power/ms_power_loop_test.c</span><br><span>@@ -185,32 +185,30 @@</span><br><span> lchan->ms_power_ctrl.max = ms_pwr_ctl_lvl(GSM_BAND_1800, 26);</span><br><span> OSMO_ASSERT(lchan->ms_power_ctrl.max == 2);</span><br><span> </span><br><span style="color: hsl(0, 100%, 40%);">-#define CHECK_UL_RSSI_AVG100(exp) \</span><br><span style="color: hsl(0, 100%, 40%);">- printf("\tAvg[t] is %2.2f dBm (expected %2.2f dBm)\n", \</span><br><span style="color: hsl(120, 100%, 40%);">+#define CHECK_RXLEV_AVG100(exp) \</span><br><span style="color: hsl(120, 100%, 40%);">+ printf("\tAvg[t] is RxLev %2.2f (expected %2.2f)\n", \</span><br><span> ((float) *avg100) / 100, exp);</span><br><span> </span><br><span> /* UL RSSI remains constant => no UL power change */</span><br><span> apply_power_test(lchan, -75, good_lqual, 0, 15);</span><br><span style="color: hsl(0, 100%, 40%);">- CHECK_UL_RSSI_AVG100(-75.00);</span><br><span style="color: hsl(120, 100%, 40%);">+ CHECK_RXLEV_AVG100((float)dbm2rxlev(-75)); /* RXLEV 35 */</span><br><span> </span><br><span style="color: hsl(0, 100%, 40%);">- /* Avg[t] = (0.2 * -90) + (0.8 * -75) = -78.0 dBm */</span><br><span style="color: hsl(0, 100%, 40%);">- apply_power_test(lchan, -90, good_lqual, 1, 13);</span><br><span style="color: hsl(0, 100%, 40%);">- CHECK_UL_RSSI_AVG100(-78.00);</span><br><span style="color: hsl(120, 100%, 40%);">+ /* Avg[t] = (0.2 * 20) + (0.8 * 35) = RXLEV 32, (-78 dBm) */</span><br><span style="color: hsl(120, 100%, 40%);">+ apply_power_test(lchan, -90, good_lqual, 1, 13); /* -90 dBm = RXLEV 20 */</span><br><span style="color: hsl(120, 100%, 40%);">+ CHECK_RXLEV_AVG100(32.00);</span><br><span> </span><br><span style="color: hsl(0, 100%, 40%);">- /* Avg[t] = (0.2 * -90) + (0.8 * -78) = -80.4 dBm */</span><br><span style="color: hsl(0, 100%, 40%);">- apply_power_test(lchan, -90, good_lqual, 1, 11);</span><br><span style="color: hsl(0, 100%, 40%);">- CHECK_UL_RSSI_AVG100(-80.40);</span><br><span style="color: hsl(120, 100%, 40%);">+ /* Avg[t] = (0.2 * 20) + (0.8 * 32) = RXLEV 29.6 (-80.4 dBm) */</span><br><span style="color: hsl(120, 100%, 40%);">+ apply_power_test(lchan, -90, good_lqual, 1, 11); /* -90 dBm = RXLEV 20 */</span><br><span style="color: hsl(120, 100%, 40%);">+ CHECK_RXLEV_AVG100(29.60);</span><br><span> </span><br><span style="color: hsl(0, 100%, 40%);">- /* Avg[t] = (0.2 * -70) + (0.8 * -80.4) = -78.32 dBm,</span><br><span style="color: hsl(120, 100%, 40%);">+ /* Avg[t] = (0.2 * 40) + (0.8 * 29.60) = RXLEV 31.68 (-78.32 dBm),</span><br><span> * but due to up-/down-scaling artefacts we get the following:</span><br><span> * Avg100[t] = Avg100[t - 1] + A * (Pwr - Avg[t] / 100)</span><br><span style="color: hsl(0, 100%, 40%);">- * Avg100[t] = -8040 + 20 * (-70 - (-8040 / 100))</span><br><span style="color: hsl(0, 100%, 40%);">- * Avg100[t] = -8040 + 20 * (-70 - (-8040 / 100))</span><br><span style="color: hsl(0, 100%, 40%);">- * Avg100[t] = -8040 + 20 * (-70 + 80)</span><br><span style="color: hsl(0, 100%, 40%);">- * Avg100[t] = -8040 + 200 = -7840</span><br><span style="color: hsl(0, 100%, 40%);">- * Avg[t] = -7840 / 100 = -78.4 */</span><br><span style="color: hsl(0, 100%, 40%);">- apply_power_test(lchan, -70, good_lqual, 1, 9);</span><br><span style="color: hsl(0, 100%, 40%);">- CHECK_UL_RSSI_AVG100(-78.40);</span><br><span style="color: hsl(120, 100%, 40%);">+ * Avg100[t] = 2960 + 20 * (40 - (2960 / 100))</span><br><span style="color: hsl(120, 100%, 40%);">+ * Avg100[t] = 2960 + 20 * (40 - 29)</span><br><span style="color: hsl(120, 100%, 40%);">+ * Avg100[t] = 3180 / 100 = 31.80 */</span><br><span style="color: hsl(120, 100%, 40%);">+ apply_power_test(lchan, -70, good_lqual, 1, 9); /* RXLEV 40 */</span><br><span style="color: hsl(120, 100%, 40%);">+ CHECK_RXLEV_AVG100(31.80);</span><br><span> </span><br><span> mp->ewma.alpha = 70; /* 30% smoothing */</span><br><span> lchan->ms_power_ctrl.current = 15;</span><br><span>@@ -218,17 +216,17 @@</span><br><span> (struct gsm_power_ctrl_meas_proc_state) { 0 };</span><br><span> </span><br><span> /* This is the first sample, the filter outputs it as-is */</span><br><span style="color: hsl(0, 100%, 40%);">- apply_power_test(lchan, -50, good_lqual, 0, 15);</span><br><span style="color: hsl(0, 100%, 40%);">- CHECK_UL_RSSI_AVG100(-50.00);</span><br><span style="color: hsl(120, 100%, 40%);">+ apply_power_test(lchan, -50, good_lqual, 0, 15); /* RXLEV 60 */</span><br><span style="color: hsl(120, 100%, 40%);">+ CHECK_RXLEV_AVG100((float)dbm2rxlev(-50));</span><br><span> </span><br><span style="color: hsl(0, 100%, 40%);">- /* Avg[t] = (0.7 * -50) + (0.3 * -50) = -50.0 dBm */</span><br><span style="color: hsl(120, 100%, 40%);">+ /* Avg[t] = (0.7 * 60) + (0.3 * 60) = RXLEV 60 (-50.0 dBm) */</span><br><span> apply_power_test(lchan, -50, good_lqual, 0, 15);</span><br><span style="color: hsl(0, 100%, 40%);">- CHECK_UL_RSSI_AVG100(-50.0);</span><br><span style="color: hsl(120, 100%, 40%);">+ CHECK_RXLEV_AVG100((float)dbm2rxlev(-50));</span><br><span> </span><br><span> /* Simulate SACCH block loss (-110 dBm):</span><br><span style="color: hsl(0, 100%, 40%);">- * Avg[t] = (0.7 * -110) + (0.3 * -50) = -92.0 dBm */</span><br><span style="color: hsl(0, 100%, 40%);">- apply_power_test(lchan, -110, good_lqual, 1, 13);</span><br><span style="color: hsl(0, 100%, 40%);">- CHECK_UL_RSSI_AVG100(-92.0);</span><br><span style="color: hsl(120, 100%, 40%);">+ * Avg[t] = (0.7 * 0) + (0.3 * 60) = RXLEV 18.0 (-92.0 dBm) */</span><br><span style="color: hsl(120, 100%, 40%);">+ apply_power_test(lchan, -110, good_lqual, 1, 13); /* RXLEV 0 */</span><br><span style="color: hsl(120, 100%, 40%);">+ CHECK_RXLEV_AVG100(18.0);</span><br><span> }</span><br><span> </span><br><span> static void test_power_hysteresis(void)</span><br><span></span><br></pre><p>To view, visit <a href="https://gerrit.osmocom.org/c/osmo-bts/+/25328">change 25328</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: I4cff8394f22b5d47789163051364ff594b2bcd74 </div>
<div style="display:none"> Gerrit-Change-Number: 25328 </div>
<div style="display:none"> Gerrit-PatchSet: 1 </div>
<div style="display:none"> Gerrit-Owner: pespin <pespin@sysmocom.de> </div>
<div style="display:none"> Gerrit-MessageType: newchange </div>