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laforge gerrit-no-reply at lists.osmocom.orglaforge has submitted this change. ( https://gerrit.osmocom.org/c/osmo-bts/+/20730 )
Change subject: power_control: tolerate small deviations from 'rx-target'
......................................................................
power_control: tolerate small deviations from 'rx-target'
Recently we've introduced EWMA based uplink power filtering, that
should reduce Uplink power oscillations. However, the power loop
is still quite sensitive to small deviations from the target power
level: even such an insignificant deviation like 2-5 dBm triggers
the loop to increase or decrease the MS power level. Even if the
EWMA based filtering is enabled with 80% smoothing (alpha = 0.2).
This change introduces a new configuration parameter - 'hysteresis':
uplink-power-target <-110-0> hysteresis <1-25>
that together with the 'uplink-power-target' defines a range:
[target - hysteresis .. target + hysteresis]
in which the MS power loop would not trigger any power changes.
This feature is now *enabled* by default, so given that:
- default 'uplink-power-target' is -75 dBm, and
- default 'hysteresis' is 3 dBm,
the default target Uplink power range is: -78 dBm ... -72 dBm.
Change-Id: Iacedbd4d69d3d74e2499af5622a07a8af0423da0
Related: SYS#4916
---
M include/osmo-bts/bts.h
M src/common/bts.c
M src/common/power_control.c
M src/common/vty.c
M tests/power/power_test.c
M tests/power/power_test.err
M tests/power/power_test.ok
7 files changed, 90 insertions(+), 11 deletions(-)
Approvals:
pespin: Looks good to me, but someone else must approve
laforge: Looks good to me, approved
Jenkins Builder: Verified
diff --git a/include/osmo-bts/bts.h b/include/osmo-bts/bts.h
index db8f741..a2eecc4 100644
--- a/include/osmo-bts/bts.h
+++ b/include/osmo-bts/bts.h
@@ -298,6 +298,7 @@
/* TODO: move it to bts->ul_power_ctrl struct */
int ul_power_target; /* Uplink Rx power target */
+ int ul_power_hysteresis; /* Tolerable Uplink Rx power deviation */
/* Uplink power control */
struct {
diff --git a/src/common/bts.c b/src/common/bts.c
index bb0795a..8a97b8f 100644
--- a/src/common/bts.c
+++ b/src/common/bts.c
@@ -303,6 +303,7 @@
/* configurable via VTY */
bts->paging_state = paging_init(bts, 200, 0);
bts->ul_power_target = -75; /* dBm default */
+ bts->ul_power_hysteresis = 3; /* -78 .. -72 dBm */
bts->ul_power_ctrl.pf_algo = MS_UL_PF_ALGO_EWMA;
bts->ul_power_ctrl.pf.ewma.alpha = 20; /* 80% smoothing */
bts->rtp_jitter_adaptive = false;
diff --git a/src/common/power_control.c b/src/common/power_control.c
index e2d1254..be6df48 100644
--- a/src/common/power_control.c
+++ b/src/common/power_control.c
@@ -144,12 +144,12 @@
diff = bts->ul_power_target - avg_ul_rssi_dbm;
- /* TODO: introduce 'hysteresis' defining a range of tolerable deviation */
- if (diff == 0) {
+ /* Tolerate small deviations from 'rx-target' */
+ if (abs(diff) <= bts->ul_power_hysteresis) {
LOGPLCHAN(lchan, DLOOP, LOGL_INFO,
"Keeping MS power at control level %d (%d dBm) because diff %d dBm "
- "from 'rx-target' %d dBm is not significant\n",
- ms_power_lvl, ms_dbm, diff, bts->ul_power_target);
+ "from 'rx-target' %d dBm is not significant (hysteresis %d dBm)\n",
+ ms_power_lvl, ms_dbm, diff, bts->ul_power_target, bts->ul_power_hysteresis);
/* Keep the current power level in sync (just to be sure) */
lchan->ms_power_ctrl.current = ms_power_lvl;
bts_model_adjst_ms_pwr(lchan);
diff --git a/src/common/vty.c b/src/common/vty.c
index 16ffe72..d20b143 100644
--- a/src/common/vty.c
+++ b/src/common/vty.c
@@ -255,7 +255,10 @@
VTY_NEWLINE);
vty_out(vty, " paging lifetime %u%s", paging_get_lifetime(bts->paging_state),
VTY_NEWLINE);
- vty_out(vty, " uplink-power-target %d%s", bts->ul_power_target, VTY_NEWLINE);
+ vty_out(vty, " uplink-power-target %d", bts->ul_power_target);
+ if (bts->ul_power_hysteresis > 0)
+ vty_out(vty, " hysteresis %d", bts->ul_power_hysteresis);
+ vty_out(vty, "%s", VTY_NEWLINE);
/* MS Tx power filtering algorithm and parameters */
switch (bts->ul_power_ctrl.pf_algo) {
@@ -615,15 +618,37 @@
return CMD_SUCCESS;
}
+#define UL_POWER_TARGET_CMD \
+ "uplink-power-target <-110-0>"
+#define UL_POWER_TARGET_CMD_DESC \
+ "Set the nominal target Rx Level for uplink power control loop\n" \
+ "Target uplink Rx level in dBm\n"
+
DEFUN_ATTR(cfg_bts_ul_power_target, cfg_bts_ul_power_target_cmd,
- "uplink-power-target <-110-0>",
- "Set the nominal target Rx Level for uplink power control loop\n"
- "Target uplink Rx level in dBm\n",
+ UL_POWER_TARGET_CMD, UL_POWER_TARGET_CMD_DESC,
CMD_ATTR_IMMEDIATE)
{
struct gsm_bts *bts = vty->index;
bts->ul_power_target = atoi(argv[0]);
+ bts->ul_power_hysteresis = 0;
+
+ return CMD_SUCCESS;
+}
+
+/* FIXME: libosmovty is unable to handle 'foo <-110-0> [bar <1-25>]' */
+DEFUN_ATTR(cfg_bts_ul_power_target_hysteresis,
+ cfg_bts_ul_power_target_hysteresis_cmd,
+ UL_POWER_TARGET_CMD " hysteresis <1-25>",
+ UL_POWER_TARGET_CMD_DESC
+ "Target Rx Level hysteresis\n"
+ "Tolerable deviation in dBm\n",
+ CMD_ATTR_IMMEDIATE)
+{
+ struct gsm_bts *bts = vty->index;
+
+ bts->ul_power_target = atoi(argv[0]);
+ bts->ul_power_hysteresis = atoi(argv[1]);
return CMD_SUCCESS;
}
@@ -1849,6 +1874,7 @@
install_element(BTS_NODE, &cfg_bts_agch_queue_mgmt_default_cmd);
install_element(BTS_NODE, &cfg_bts_agch_queue_mgmt_params_cmd);
install_element(BTS_NODE, &cfg_bts_ul_power_target_cmd);
+ install_element(BTS_NODE, &cfg_bts_ul_power_target_hysteresis_cmd);
install_element(BTS_NODE, &cfg_bts_no_ul_power_filter_cmd);
install_element(BTS_NODE, &cfg_bts_ul_power_filter_ewma_cmd);
install_element(BTS_NODE, &cfg_bts_min_qual_rach_cmd);
diff --git a/tests/power/power_test.c b/tests/power/power_test.c
index bf474ac..c5c4db3 100644
--- a/tests/power/power_test.c
+++ b/tests/power/power_test.c
@@ -1,5 +1,6 @@
/*
* (C) 2013,2014 by Holger Hans Peter Freyther
+ * Contributions by sysmocom - s.m.f.c. GmbH <info at sysmocom.de>
*
* All Rights Reserved
*
@@ -205,6 +206,32 @@
CHECK_UL_RSSI_AVG100(-92.0);
}
+static void test_power_hysteresis(void)
+{
+ struct gsm_lchan *lchan;
+
+ init_test(__func__);
+ lchan = &g_trx->ts[0].lchan[0];
+
+ /* Tolerate power deviations in range -80 .. -70 */
+ g_bts->ul_power_hysteresis = 5;
+
+ lchan->ms_power_ctrl.current = ms_pwr_ctl_lvl(GSM_BAND_1800, 0);
+ OSMO_ASSERT(lchan->ms_power_ctrl.current == 15);
+ lchan->ms_power_ctrl.max = ms_pwr_ctl_lvl(GSM_BAND_1800, 26);
+ OSMO_ASSERT(lchan->ms_power_ctrl.max == 2);
+
+ apply_power_test(lchan, g_bts->ul_power_target, 0, 15);
+ apply_power_test(lchan, g_bts->ul_power_target + 3, 0, 15);
+ apply_power_test(lchan, g_bts->ul_power_target - 3, 0, 15);
+
+ apply_power_test(lchan, g_bts->ul_power_target, 0, 15);
+ apply_power_test(lchan, g_bts->ul_power_target + 5, 0, 15);
+ apply_power_test(lchan, g_bts->ul_power_target - 5, 0, 15);
+
+ apply_power_test(lchan, g_bts->ul_power_target - 10, 1, 13);
+}
+
int main(int argc, char **argv)
{
printf("Testing power loop...\n");
@@ -220,6 +247,7 @@
test_power_loop();
test_pf_algo_ewma();
+ test_power_hysteresis();
printf("Power loop test OK\n");
diff --git a/tests/power/power_test.err b/tests/power/power_test.err
index 1aac5e5..988b3ba 100644
--- a/tests/power/power_test.err
+++ b/tests/power/power_test.err
@@ -4,7 +4,7 @@
(bts=0,trx=0,ts=0,ss=0) Raising MS power from control level 11 (8 dBm) to 9, 12 dBm (rx-ms-pwr-lvl 11, max-ms-pwr-lvl 2, rx-current -90 dBm, rx-target -75 dBm)
(bts=0,trx=0,ts=0,ss=0) Raising MS power from control level 9 (12 dBm) to 7, 16 dBm (rx-ms-pwr-lvl 9, max-ms-pwr-lvl 2, rx-current -90 dBm, rx-target -75 dBm)
(bts=0,trx=0,ts=0,ss=0) Raising MS power from control level 7 (16 dBm) to 5, 20 dBm (rx-ms-pwr-lvl 7, max-ms-pwr-lvl 2, rx-current -90 dBm, rx-target -75 dBm)
-(bts=0,trx=0,ts=0,ss=0) Keeping MS power at control level 5 (20 dBm) because diff 0 dBm from 'rx-target' -75 dBm is not significant
+(bts=0,trx=0,ts=0,ss=0) Keeping MS power at control level 5 (20 dBm) because diff 0 dBm from 'rx-target' -75 dBm is not significant (hysteresis 0 dBm)
(bts=0,trx=0,ts=0,ss=0) Raising MS power from control level 5 (20 dBm) to 3, 24 dBm (rx-ms-pwr-lvl 5, max-ms-pwr-lvl 2, rx-current -90 dBm, rx-target -75 dBm)
(bts=0,trx=0,ts=0,ss=0) Raising MS power from control level 3 (24 dBm) to 2, 26 dBm (rx-ms-pwr-lvl 3, max-ms-pwr-lvl 2, rx-current -90 dBm, rx-target -75 dBm)
(bts=0,trx=0,ts=0,ss=0) Keeping MS power at control level 2, 26 dBm (rx-ms-pwr-lvl 2, max-ms-pwr-lvl 2, rx-current -90 dBm, rx-target -75 dBm)
@@ -13,7 +13,7 @@
(bts=0,trx=0,ts=0,ss=0) Raising MS power from control level 0 (30 dBm) to 30, 34 dBm (rx-ms-pwr-lvl 0, max-ms-pwr-lvl 29, rx-current -90 dBm, rx-target -75 dBm)
(bts=0,trx=0,ts=0,ss=0) Raising MS power from control level 30 (34 dBm) to 29, 36 dBm (rx-ms-pwr-lvl 30, max-ms-pwr-lvl 29, rx-current -90 dBm, rx-target -75 dBm)
(bts=0,trx=0,ts=0,ss=0) Keeping MS power at control level 29, 36 dBm (rx-ms-pwr-lvl 29, max-ms-pwr-lvl 29, rx-current -90 dBm, rx-target -75 dBm)
-(bts=0,trx=0,ts=0,ss=0) Keeping MS power at control level 29 (36 dBm) because diff 0 dBm from 'rx-target' -75 dBm is not significant
+(bts=0,trx=0,ts=0,ss=0) Keeping MS power at control level 29 (36 dBm) because diff 0 dBm from 'rx-target' -75 dBm is not significant (hysteresis 0 dBm)
(bts=0,trx=0,ts=0,ss=0) Lowering MS power from control level 29 (36 dBm) to 1, 28 dBm (rx-ms-pwr-lvl 29, max-ms-pwr-lvl 29, rx-current -45 dBm, rx-target -75 dBm)
(bts=0,trx=0,ts=0,ss=0) Lowering MS power from control level 1 (28 dBm) to 5, 20 dBm (rx-ms-pwr-lvl 1, max-ms-pwr-lvl 29, rx-current -45 dBm, rx-target -75 dBm)
(bts=0,trx=0,ts=0,ss=0) Lowering MS power from control level 5 (20 dBm) to 9, 12 dBm (rx-ms-pwr-lvl 5, max-ms-pwr-lvl 29, rx-current -45 dBm, rx-target -75 dBm)
@@ -21,10 +21,17 @@
(bts=0,trx=0,ts=0,ss=0) Raising MS power from control level 10 (10 dBm) to 9, 12 dBm (rx-ms-pwr-lvl 10, max-ms-pwr-lvl 29, rx-current -77 dBm, rx-target -75 dBm)
(bts=0,trx=0,ts=0,ss=0) Lowering MS power from control level 9 (12 dBm) to 14, 2 dBm (rx-ms-pwr-lvl 9, max-ms-pwr-lvl 14, rx-current -73 dBm, rx-target -75 dBm)
(bts=0,trx=0,ts=0,ss=0) Lowering MS power from control level 14 (2 dBm) to 15, 0 dBm (rx-ms-pwr-lvl 14, max-ms-pwr-lvl 0, rx-current -40 dBm, rx-target -75 dBm)
-(bts=0,trx=0,ts=0,ss=0) Keeping MS power at control level 15 (0 dBm) because diff 0 dBm from 'rx-target' -75 dBm is not significant
+(bts=0,trx=0,ts=0,ss=0) Keeping MS power at control level 15 (0 dBm) because diff 0 dBm from 'rx-target' -75 dBm is not significant (hysteresis 0 dBm)
(bts=0,trx=0,ts=0,ss=0) Raising MS power from control level 15 (0 dBm) to 13, 3 dBm (rx-ms-pwr-lvl 15, max-ms-pwr-lvl 2, rx-current -78 dBm, rx-target -75 dBm)
(bts=0,trx=0,ts=0,ss=0) Raising MS power from control level 13 (4 dBm) to 11, 8 dBm (rx-ms-pwr-lvl 13, max-ms-pwr-lvl 2, rx-current -80 dBm, rx-target -75 dBm)
(bts=0,trx=0,ts=0,ss=0) Raising MS power from control level 11 (8 dBm) to 9, 11 dBm (rx-ms-pwr-lvl 11, max-ms-pwr-lvl 2, rx-current -78 dBm, rx-target -75 dBm)
(bts=0,trx=0,ts=0,ss=0) Keeping MS power at control level 15, 0 dBm (rx-ms-pwr-lvl 15, max-ms-pwr-lvl 2, rx-current -50 dBm, rx-target -75 dBm)
(bts=0,trx=0,ts=0,ss=0) Keeping MS power at control level 15, 0 dBm (rx-ms-pwr-lvl 15, max-ms-pwr-lvl 2, rx-current -50 dBm, rx-target -75 dBm)
(bts=0,trx=0,ts=0,ss=0) Raising MS power from control level 15 (0 dBm) to 13, 4 dBm (rx-ms-pwr-lvl 15, max-ms-pwr-lvl 2, rx-current -92 dBm, rx-target -75 dBm)
+(bts=0,trx=0,ts=0,ss=0) Keeping MS power at control level 15 (0 dBm) because diff 0 dBm from 'rx-target' -75 dBm is not significant (hysteresis 5 dBm)
+(bts=0,trx=0,ts=0,ss=0) Keeping MS power at control level 15 (0 dBm) because diff -3 dBm from 'rx-target' -75 dBm is not significant (hysteresis 5 dBm)
+(bts=0,trx=0,ts=0,ss=0) Keeping MS power at control level 15 (0 dBm) because diff 3 dBm from 'rx-target' -75 dBm is not significant (hysteresis 5 dBm)
+(bts=0,trx=0,ts=0,ss=0) Keeping MS power at control level 15 (0 dBm) because diff 0 dBm from 'rx-target' -75 dBm is not significant (hysteresis 5 dBm)
+(bts=0,trx=0,ts=0,ss=0) Keeping MS power at control level 15 (0 dBm) because diff -5 dBm from 'rx-target' -75 dBm is not significant (hysteresis 5 dBm)
+(bts=0,trx=0,ts=0,ss=0) Keeping MS power at control level 15 (0 dBm) because diff 5 dBm from 'rx-target' -75 dBm is not significant (hysteresis 5 dBm)
+(bts=0,trx=0,ts=0,ss=0) Raising MS power from control level 15 (0 dBm) to 13, 4 dBm (rx-ms-pwr-lvl 15, max-ms-pwr-lvl 2, rx-current -85 dBm, rx-target -75 dBm)
diff --git a/tests/power/power_test.ok b/tests/power/power_test.ok
index 25551d8..d463d87 100644
--- a/tests/power/power_test.ok
+++ b/tests/power/power_test.ok
@@ -72,4 +72,20 @@
lchan_ms_pwr_ctrl(RxLvl=-110 dBm) returns 1 (expected 1)
MS current power 15 -> 13 (expected 13)
Avg[t] is -92.00 dBm (expected -92.00 dBm)
+
+Starting test case 'test_power_hysteresis'
+lchan_ms_pwr_ctrl(RxLvl=-75 dBm) returns 0 (expected 0)
+ MS current power 15 -> 15 (expected 15)
+lchan_ms_pwr_ctrl(RxLvl=-72 dBm) returns 0 (expected 0)
+ MS current power 15 -> 15 (expected 15)
+lchan_ms_pwr_ctrl(RxLvl=-78 dBm) returns 0 (expected 0)
+ MS current power 15 -> 15 (expected 15)
+lchan_ms_pwr_ctrl(RxLvl=-75 dBm) returns 0 (expected 0)
+ MS current power 15 -> 15 (expected 15)
+lchan_ms_pwr_ctrl(RxLvl=-70 dBm) returns 0 (expected 0)
+ MS current power 15 -> 15 (expected 15)
+lchan_ms_pwr_ctrl(RxLvl=-80 dBm) returns 0 (expected 0)
+ MS current power 15 -> 15 (expected 15)
+lchan_ms_pwr_ctrl(RxLvl=-85 dBm) returns 1 (expected 1)
+ MS current power 15 -> 13 (expected 13)
Power loop test OK
--
To view, visit https://gerrit.osmocom.org/c/osmo-bts/+/20730
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Gerrit-Project: osmo-bts
Gerrit-Branch: master
Gerrit-Change-Id: Iacedbd4d69d3d74e2499af5622a07a8af0423da0
Gerrit-Change-Number: 20730
Gerrit-PatchSet: 4
Gerrit-Owner: fixeria <vyanitskiy at sysmocom.de>
Gerrit-Reviewer: Jenkins Builder
Gerrit-Reviewer: laforge <laforge at osmocom.org>
Gerrit-Reviewer: pespin <pespin at sysmocom.de>
Gerrit-MessageType: merged
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