<p>pespin has uploaded this change for <strong>review</strong>.</p><p><a href="https://gerrit.osmocom.org/c/osmo-bts/+/16142">View Change</a></p><pre style="font-family: monospace,monospace; white-space: pre-wrap;">power_control.c: Limit speed of announced MS Power Level value changes<br><br>It's not a good idea to request big changes in MS Power based on<br>sporadic bad signal received, let's instead change announced MS power<br>levels more smoothly to avoid possible big signal strength fluctations,<br>similar to what is already done in osmo-bts-trx specific loop (loops.c).<br><br>Related: OS#1851<br>Change-Id: Iecc4ec7e21471ec853ad2d5659af4052aba5444c<br>---<br>M src/common/power_control.c<br>M tests/power/power_test.c<br>2 files changed, 20 insertions(+), 5 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/42/16142/1</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 d08ed5e..d2a6c1d 100644</span><br><span>--- a/src/common/power_control.c</span><br><span>+++ b/src/common/power_control.c</span><br><span>@@ -30,6 +30,11 @@</span><br><span> #include <osmo-bts/measurement.h></span><br><span> #include <osmo-bts/bts_model.h></span><br><span> #include <osmo-bts/l1sap.h></span><br><span style="color: hsl(120, 100%, 40%);">+#include <osmo-bts/power_control.h></span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span style="color: hsl(120, 100%, 40%);">+/* how many dB do we raise/lower as maximum (1 ms power level = 2 dB) */</span><br><span style="color: hsl(120, 100%, 40%);">+#define MS_RAISE_MAX_DB 4</span><br><span style="color: hsl(120, 100%, 40%);">+#define MS_LOWER_MAX_DB 8</span><br><span> </span><br><span> /*! compute the new MS POWER LEVEL communicated to the MS and store it in lchan.</span><br><span> * \param lchan logical channel for which to compute (and in which to store) new power value.</span><br><span>@@ -51,10 +56,6 @@</span><br><span> if (lchan->ms_power_ctrl.fixed)</span><br><span> return 0;</span><br><span> </span><br><span style="color: hsl(0, 100%, 40%);">- /* How many dBs measured power should be increased (+) or decreased (-)</span><br><span style="color: hsl(0, 100%, 40%);">- to reach expected power. */</span><br><span style="color: hsl(0, 100%, 40%);">- diff = bts->ul_power_target - rxLevel;</span><br><span style="color: hsl(0, 100%, 40%);">-</span><br><span> current_dbm = ms_pwr_dbm(band, ms_power);</span><br><span> if (current_dbm < 0) {</span><br><span> LOGPLCHAN(lchan, DLOOP, LOGL_NOTICE,</span><br><span>@@ -70,6 +71,18 @@</span><br><span> return 0;</span><br><span> }</span><br><span> </span><br><span style="color: hsl(120, 100%, 40%);">+ /* How many dBs measured power should be increased (+) or decreased (-)</span><br><span style="color: hsl(120, 100%, 40%);">+ to reach expected power. */</span><br><span style="color: hsl(120, 100%, 40%);">+ diff = bts->ul_power_target - rxLevel;</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span style="color: hsl(120, 100%, 40%);">+ /* don't ever change more than MS_{LOWER,RAISE}_MAX_DBM during one loop</span><br><span style="color: hsl(120, 100%, 40%);">+ iteration, i.e. reduce the speed at which the MS transmit power can</span><br><span style="color: hsl(120, 100%, 40%);">+ change. A higher value means a lower level (and vice versa) */</span><br><span style="color: hsl(120, 100%, 40%);">+ if (diff > MS_RAISE_MAX_DB)</span><br><span style="color: hsl(120, 100%, 40%);">+ diff = MS_RAISE_MAX_DB;</span><br><span style="color: hsl(120, 100%, 40%);">+ else if (diff < -MS_LOWER_MAX_DB)</span><br><span style="color: hsl(120, 100%, 40%);">+ diff = -MS_LOWER_MAX_DB;</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span> new_dbm = current_dbm + diff;</span><br><span> </span><br><span> /* Make sure new_dbm is never negative. ms_pwr_ctl_lvl() can later on</span><br><span>diff --git a/tests/power/power_test.c b/tests/power/power_test.c</span><br><span>index 30fbb64..0e08f0b 100644</span><br><span>--- a/tests/power/power_test.c</span><br><span>+++ b/tests/power/power_test.c</span><br><span>@@ -64,8 +64,10 @@</span><br><span> </span><br><span> /*</span><br><span> * Now 15 dB too little and we should power it up. Could be a</span><br><span style="color: hsl(0, 100%, 40%);">- * power level of 7 or 8 for 15 dBm</span><br><span style="color: hsl(120, 100%, 40%);">+ * power level of 7 or 8 for 15 dBm. However, since we limit peace at</span><br><span style="color: hsl(120, 100%, 40%);">+ * which we change values, expect several steps of MS_RAISE_MAX_DB/2 levels:</span><br><span> */</span><br><span style="color: hsl(120, 100%, 40%);">+ apply_power_test(lchan, -90, 1, 11);</span><br><span> apply_power_test(lchan, -90, 1, 7);</span><br><span> </span><br><span> /* It should be clamped to level 0 and 30 dBm */</span><br><span></span><br></pre><p>To view, visit <a href="https://gerrit.osmocom.org/c/osmo-bts/+/16142">change 16142</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: Iecc4ec7e21471ec853ad2d5659af4052aba5444c </div>
<div style="display:none"> Gerrit-Change-Number: 16142 </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>