<p>fixeria has uploaded this change for <strong>review</strong>.</p><p><a href="https://gerrit.osmocom.org/c/osmo-bsc/+/24777">View Change</a></p><pre style="font-family: monospace,monospace; white-space: pre-wrap;">power_control: implement BCCH carrier power reduction operation<br><br>The BCCH carrier (sometimes called C0) of a BTS shall maintain<br>discontinuous Downlink transmission at full power in order to<br>stay 'visible' to the mobile stations. Because of that, early<br>versions of 3GPP TS 45.008 prohibited BS power reduction on C0.<br><br>However, in the recent 3GPP TS 45.008 there is a feature called<br>'BCCH carrier power reduction operation'. This is a special<br>mode of operation, where the variation of RF level for some<br>timeslots is relaxed for the purpose of energy saving.<br><br>In BCCH carrier power reduction operation, for timeslots on the<br>C0 carrier, except timeslots carrying BCCH/CCCH, the output power<br>may be lower than the output power used for timeslots carrying<br>BCCH/CCCH. In this case the maximum allowed difference in output<br>power actually transmitted by the BTS is 6 dB.<br><br>Introduce a VTY command to turn on and off the BCCH carrier power<br>reduction operation. On the A-bis/RSL, abuse the BS POWER CONTROL<br>message by setting the Channel Number IE to 0x80 (RSL_CHAN_BCCH).<br><br>A value greater than zero would make osmo-bts reduce the power<br>on *inactive* timeslots of the BCCH carrier. Sending zero would<br>disable the BCCH power reduction mode.<br><br>Change-Id: I047fce33d4d3e4c569dd006ba17858467a2f4783<br>Related: SYS#4919<br>---<br>M include/osmocom/bsc/bts.h<br>M src/osmo-bsc/bsc_vty.c<br>M src/osmo-bsc/bts_osmobts.c<br>M tests/osmo-bsc.vty<br>4 files changed, 77 insertions(+), 0 deletions(-)<br><br></pre><pre style="font-family: monospace,monospace; white-space: pre-wrap;">git pull ssh://gerrit.osmocom.org:29418/osmo-bsc refs/changes/77/24777/1</pre><pre style="font-family: monospace,monospace; white-space: pre-wrap;"><span>diff --git a/include/osmocom/bsc/bts.h b/include/osmocom/bsc/bts.h</span><br><span>index b6980d1..6bdf25c 100644</span><br><span>--- a/include/osmocom/bsc/bts.h</span><br><span>+++ b/include/osmocom/bsc/bts.h</span><br><span>@@ -236,6 +236,9 @@</span><br><span> int (*power_ctrl_enc_rsl_params)(struct msgb *msg, const struct gsm_power_ctrl_params *cp);</span><br><span> /* (Optional) function for sending default MS/BS Power Control paramaters */</span><br><span> int (*power_ctrl_send_def_params)(const struct gsm_bts_trx *trx);</span><br><span style="color: hsl(120, 100%, 40%);">+ /* (Optional) function for toggling BCCH carrier power reduction operation */</span><br><span style="color: hsl(120, 100%, 40%);">+ int (*power_ctrl_toggle_bcch_power_red)(const struct gsm_bts *bts,</span><br><span style="color: hsl(120, 100%, 40%);">+ const uint8_t red);</span><br><span> </span><br><span> void (*config_write_bts)(struct vty *vty, struct gsm_bts *bts);</span><br><span> void (*config_write_trx)(struct vty *vty, struct gsm_bts_trx *trx);</span><br><span>diff --git a/src/osmo-bsc/bsc_vty.c b/src/osmo-bsc/bsc_vty.c</span><br><span>index 1ec34bc..4d1d9ff 100644</span><br><span>--- a/src/osmo-bsc/bsc_vty.c</span><br><span>+++ b/src/osmo-bsc/bsc_vty.c</span><br><span>@@ -6020,6 +6020,46 @@</span><br><span> return CMD_SUCCESS;</span><br><span> }</span><br><span> </span><br><span style="color: hsl(120, 100%, 40%);">+DEFUN(bts_bcch_power_red,</span><br><span style="color: hsl(120, 100%, 40%);">+ bts_bcch_power_red_cmd,</span><br><span style="color: hsl(120, 100%, 40%);">+ "bts <0-255> bcch-power-red <0-6>",</span><br><span style="color: hsl(120, 100%, 40%);">+ "BTS Specific Commands\n" BTS_NR_STR</span><br><span style="color: hsl(120, 100%, 40%);">+ "BCCH carrier power reduction operation\n"</span><br><span style="color: hsl(120, 100%, 40%);">+ "Power reduction value (in dB, even numbers only)\n")</span><br><span style="color: hsl(120, 100%, 40%);">+{</span><br><span style="color: hsl(120, 100%, 40%);">+ int bts_nr = atoi(argv[0]);</span><br><span style="color: hsl(120, 100%, 40%);">+ int red = atoi(argv[1]);</span><br><span style="color: hsl(120, 100%, 40%);">+ struct gsm_bts *bts;</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span style="color: hsl(120, 100%, 40%);">+ if (red % 2 != 0) {</span><br><span style="color: hsl(120, 100%, 40%);">+ vty_out(vty, "%% Incorrect BCCH power reduction value, "</span><br><span style="color: hsl(120, 100%, 40%);">+ "an even number is expected%s", VTY_NEWLINE);</span><br><span style="color: hsl(120, 100%, 40%);">+ return CMD_WARNING;</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%);">+ bts = gsm_bts_num(gsmnet_from_vty(vty), bts_nr);</span><br><span style="color: hsl(120, 100%, 40%);">+ if (!bts) {</span><br><span style="color: hsl(120, 100%, 40%);">+ vty_out(vty, "%% No such BTS (%d)%s", bts_nr, VTY_NEWLINE);</span><br><span style="color: hsl(120, 100%, 40%);">+ return CMD_WARNING;</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%);">+ if (bts->model->power_ctrl_toggle_bcch_power_red == NULL ||</span><br><span style="color: hsl(120, 100%, 40%);">+ !osmo_bts_has_feature(&bts->features, BTS_FEAT_BCCH_POWER_RED)) {</span><br><span style="color: hsl(120, 100%, 40%);">+ vty_out(vty, "%% BCCH carrier power reduction operation "</span><br><span style="color: hsl(120, 100%, 40%);">+ "for BTS%d is not supported%s", bts_nr, VTY_NEWLINE);</span><br><span style="color: hsl(120, 100%, 40%);">+ return CMD_WARNING;</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%);">+ if (bts->model->power_ctrl_toggle_bcch_power_red(bts, red) != 0) {</span><br><span style="color: hsl(120, 100%, 40%);">+ vty_out(vty, "%% Failed to %sable BCCH carrier power reduction "</span><br><span style="color: hsl(120, 100%, 40%);">+ "operation mode for BTS (%d)%s", red ? "en" : "dis",</span><br><span style="color: hsl(120, 100%, 40%);">+ bts_nr, VTY_NEWLINE);</span><br><span style="color: hsl(120, 100%, 40%);">+ return CMD_WARNING;</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 CMD_SUCCESS;</span><br><span style="color: hsl(120, 100%, 40%);">+}</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span> /* this command is now hidden, as it's a low-level debug hack, and people should</span><br><span> * instead use osmo-cbc these days */</span><br><span> DEFUN_HIDDEN(smscb_cmd, smscb_cmd_cmd,</span><br><span>@@ -8171,6 +8211,7 @@</span><br><span> install_element(ENABLE_NODE, &restart_bts_cmd);</span><br><span> install_element(ENABLE_NODE, &bts_resend_sysinfo_cmd);</span><br><span> install_element(ENABLE_NODE, &bts_resend_power_ctrl_params_cmd);</span><br><span style="color: hsl(120, 100%, 40%);">+ install_element(ENABLE_NODE, &bts_bcch_power_red_cmd);</span><br><span> install_element(ENABLE_NODE, &pdch_act_cmd);</span><br><span> install_element(ENABLE_NODE, &lchan_act_cmd);</span><br><span> install_element(ENABLE_NODE, &lchan_act_all_cmd);</span><br><span>diff --git a/src/osmo-bsc/bts_osmobts.c b/src/osmo-bsc/bts_osmobts.c</span><br><span>index 1814ada..a61f49b 100644</span><br><span>--- a/src/osmo-bsc/bts_osmobts.c</span><br><span>+++ b/src/osmo-bsc/bts_osmobts.c</span><br><span>@@ -1,6 +1,7 @@</span><br><span> /* Osmocom OsmoBTS specific code */</span><br><span> </span><br><span> /* (C) 2010-2012 by Harald Welte <laforge@gnumonks.org></span><br><span style="color: hsl(120, 100%, 40%);">+ * (C) 2021 by sysmocom - s.m.f.c. GmbH <info@sysmocom.de></span><br><span> *</span><br><span> * All Rights Reserved</span><br><span> *</span><br><span>@@ -43,6 +44,33 @@</span><br><span> </span><br><span> static struct gsm_bts_model model_osmobts;</span><br><span> </span><br><span style="color: hsl(120, 100%, 40%);">+static int power_ctrl_toggle_bcch_power_red(const struct gsm_bts *bts,</span><br><span style="color: hsl(120, 100%, 40%);">+ const uint8_t red)</span><br><span style="color: hsl(120, 100%, 40%);">+{</span><br><span style="color: hsl(120, 100%, 40%);">+ struct abis_rsl_dchan_hdr *dh;</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%);">+ msg = rsl_msgb_alloc();</span><br><span style="color: hsl(120, 100%, 40%);">+ if (msg == NULL)</span><br><span style="color: hsl(120, 100%, 40%);">+ return -ENOMEM;</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span style="color: hsl(120, 100%, 40%);">+ LOGP(DRSL, LOGL_NOTICE, "%sabling BCCH carrier power reduction "</span><br><span style="color: hsl(120, 100%, 40%);">+ "operation mode for BTS%u (maximum %u dB)\n",</span><br><span style="color: hsl(120, 100%, 40%);">+ red ? "En" : "Dis", red, bts->nr);</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span style="color: hsl(120, 100%, 40%);">+ dh = (struct abis_rsl_dchan_hdr *) msgb_put(msg, sizeof(*dh));</span><br><span style="color: hsl(120, 100%, 40%);">+ dh->c.msg_discr = ABIS_RSL_MDISC_COM_CHAN;</span><br><span style="color: hsl(120, 100%, 40%);">+ dh->c.msg_type = RSL_MT_BS_POWER_CONTROL;</span><br><span style="color: hsl(120, 100%, 40%);">+ dh->ie_chan = RSL_IE_CHAN_NR;</span><br><span style="color: hsl(120, 100%, 40%);">+ dh->chan_nr = RSL_CHAN_BCCH;</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span style="color: hsl(120, 100%, 40%);">+ msgb_tv_put(msg, RSL_IE_BS_POWER, red / 2);</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span style="color: hsl(120, 100%, 40%);">+ msg->dst = bts->c0->rsl_link_primary;</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span style="color: hsl(120, 100%, 40%);">+ return abis_rsl_sendmsg(msg);</span><br><span style="color: hsl(120, 100%, 40%);">+}</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span> int bts_model_osmobts_init(void)</span><br><span> {</span><br><span> model_osmobts = bts_model_nanobts;</span><br><span>@@ -52,6 +80,10 @@</span><br><span> /* Unlike nanoBTS, osmo-bts does support SI2bis and SI2ter fine */</span><br><span> model_osmobts.force_combined_si = false;</span><br><span> </span><br><span style="color: hsl(120, 100%, 40%);">+ /* Power control API */</span><br><span style="color: hsl(120, 100%, 40%);">+ model_osmobts.power_ctrl_toggle_bcch_power_red = \</span><br><span style="color: hsl(120, 100%, 40%);">+ &power_ctrl_toggle_bcch_power_red;</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span> model_osmobts.features.data = &model_osmobts._features_data[0];</span><br><span> model_osmobts.features.data_len =</span><br><span> sizeof(model_osmobts._features_data);</span><br><span>diff --git a/tests/osmo-bsc.vty b/tests/osmo-bsc.vty</span><br><span>index 48f3f0b..573e949 100644</span><br><span>--- a/tests/osmo-bsc.vty</span><br><span>+++ b/tests/osmo-bsc.vty</span><br><span>@@ -46,6 +46,7 @@</span><br><span> OsmoBSC# bts 0 ?</span><br><span> resend-system-information Re-generate + re-send BCCH SYSTEM INFORMATION</span><br><span> resend-power-control-defaults Re-generate + re-send default MS/BS Power control parameters</span><br><span style="color: hsl(120, 100%, 40%);">+ bcch-power-red BCCH carrier power reduction operation</span><br><span> trx TRX for manual command</span><br><span> oml Manipulate the OML managed objects</span><br><span> om2000 Manipulate the OM2000 managed objects</span><br><span></span><br></pre><p>To view, visit <a href="https://gerrit.osmocom.org/c/osmo-bsc/+/24777">change 24777</a>. To unsubscribe, or for help writing mail filters, visit <a href="https://gerrit.osmocom.org/settings">settings</a>.</p><div itemscope itemtype="http://schema.org/EmailMessage"><div itemscope itemprop="action" itemtype="http://schema.org/ViewAction"><link itemprop="url" href="https://gerrit.osmocom.org/c/osmo-bsc/+/24777"/><meta itemprop="name" content="View Change"/></div></div>
<div style="display:none"> Gerrit-Project: osmo-bsc </div>
<div style="display:none"> Gerrit-Branch: master </div>
<div style="display:none"> Gerrit-Change-Id: I047fce33d4d3e4c569dd006ba17858467a2f4783 </div>
<div style="display:none"> Gerrit-Change-Number: 24777 </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>