<p>fixeria <strong>submitted</strong> this change.</p><p><a href="https://gerrit.osmocom.org/c/osmo-bsc/+/26056">View Change</a></p><div style="white-space:pre-wrap">Approvals:
Jenkins Builder: Verified
osmith: Looks good to me, but someone else must approve
pespin: Looks good to me, approved
</div><pre style="font-family: monospace,monospace; white-space: pre-wrap;">doc/manuals: add documentation for interference reporting<br><br>Change-Id: I3c15b11bbcba0811e3a15fe64365067bf8ad0dae<br>Related: SYS#5313<br>---<br>A doc/manuals/chapters/interf_meas.adoc<br>M doc/manuals/osmobsc-usermanual.adoc<br>2 files changed, 74 insertions(+), 0 deletions(-)<br><br></pre><pre style="font-family: monospace,monospace; white-space: pre-wrap;"><span>diff --git a/doc/manuals/chapters/interf_meas.adoc b/doc/manuals/chapters/interf_meas.adoc</span><br><span>new file mode 100644</span><br><span>index 0000000..62b08c4</span><br><span>--- /dev/null</span><br><span>+++ b/doc/manuals/chapters/interf_meas.adoc</span><br><span>@@ -0,0 +1,72 @@</span><br><span style="color: hsl(120, 100%, 40%);">+== Interference reporting</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span style="color: hsl(120, 100%, 40%);">+According to 3GPP 48.058, section 6.1, the BTS shall periodically report the</span><br><span style="color: hsl(120, 100%, 40%);">+interference levels on *idle* channels using the "Radio resource indication"</span><br><span style="color: hsl(120, 100%, 40%);">+procedure. This is done by sending the `RF RESource INDication` message,</span><br><span style="color: hsl(120, 100%, 40%);">+which is specified in sections 8.6.1 and 9.3.21.</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span style="color: hsl(120, 100%, 40%);">+// TODO: BSC -> MSC reporting (3GPP TS 48.008, section 3.1.3)</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span style="color: hsl(120, 100%, 40%);">+=== Interference reporting parameters</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span style="color: hsl(120, 100%, 40%);">+The interference band is calculated by the BTS based on the `Interference level</span><br><span style="color: hsl(120, 100%, 40%);">+Boundaries` and the `Averaging period`. These parameters are sent by the BSC</span><br><span style="color: hsl(120, 100%, 40%);">+over the A-bis/OML, and can be configured via the VTY interface.</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span style="color: hsl(120, 100%, 40%);">+Below are the default values for them:</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%);">+network</span><br><span style="color: hsl(120, 100%, 40%);">+ bts 0</span><br><span style="color: hsl(120, 100%, 40%);">+ interference-meas avg-period 6 <1></span><br><span style="color: hsl(120, 100%, 40%);">+ interference-meas level-bounds -85 <2> -91 -97 -103 -109 -115 <3></span><br><span style="color: hsl(120, 100%, 40%);">+----</span><br><span style="color: hsl(120, 100%, 40%);">+<1> Averaging period (`Intave`) in SACCH multiframe periods (480ms).</span><br><span style="color: hsl(120, 100%, 40%);">+<2> Interference level boundary `0` (in dBm).</span><br><span style="color: hsl(120, 100%, 40%);">+<3> Interference level boundary `X5` (in dBm).</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span style="color: hsl(120, 100%, 40%);">+The `Intave` parameter defines the averaging and reporting period. With the</span><br><span style="color: hsl(120, 100%, 40%);">+default value of 6 SACCH multiframe periods the BTS is instructed to report</span><br><span style="color: hsl(120, 100%, 40%);">+averaged interference levels approximately every 3 seconds.</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span style="color: hsl(120, 100%, 40%);">+According to 3GPP TS 48.008, there exist five interference bands and six</span><br><span style="color: hsl(120, 100%, 40%);">+`Interference level Boundaries` (`0`, `X1`, ... `X5`). The BTS shall map the</span><br><span style="color: hsl(120, 100%, 40%);">+averaged interference levels (initially in dBm) into these 5 bands.</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%);">+-85 dBm -91 dBm -97 dBm -103 dBm -109 dBm -115 dBm</span><br><span style="color: hsl(120, 100%, 40%);">+ | <1> | <2> | <3> | <4> | <5> | <6></span><br><span style="color: hsl(120, 100%, 40%);">+ +----------+----------+----------+----------+----------+</span><br><span style="color: hsl(120, 100%, 40%);">+ | band 1 | band 2 | band 3 | band 4 | band 5 |</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%);">+<1> Interference level boundary `0` (outer).</span><br><span style="color: hsl(120, 100%, 40%);">+<2> Interference level boundary `X1`.</span><br><span style="color: hsl(120, 100%, 40%);">+<3> Interference level boundary `X2`.</span><br><span style="color: hsl(120, 100%, 40%);">+<4> Interference level boundary `X3`.</span><br><span style="color: hsl(120, 100%, 40%);">+<5> Interference level boundary `X4`.</span><br><span style="color: hsl(120, 100%, 40%);">+<6> Interference level boundary `X5` (outer).</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span style="color: hsl(120, 100%, 40%);">+Unfortunately, it's not clearly defined by 3GPP how the BTS is supposed to map</span><br><span style="color: hsl(120, 100%, 40%);">+dBm values outside of the outer boundaries (`0` and `X5`) to band values. The</span><br><span style="color: hsl(120, 100%, 40%);">+ip.access nanoBTS, for example, would map values -75 dBm and -120 dBm to bands</span><br><span style="color: hsl(120, 100%, 40%);">+1 and 5, respectively. osmo-bts replicates this behavior.</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span style="color: hsl(120, 100%, 40%);">+=== PDCH and dynamic timeslot handling</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span style="color: hsl(120, 100%, 40%);">+The BTS may optionally report interference levels for PDCH timeslots. This</span><br><span style="color: hsl(120, 100%, 40%);">+may be useful for the BSC to determine whether dynamic PDCH timeslots might</span><br><span style="color: hsl(120, 100%, 40%);">+be better used for new circuit switched connections, or whether alternative</span><br><span style="color: hsl(120, 100%, 40%);">+PDCH resources should be allocated for interference reasons.</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span style="color: hsl(120, 100%, 40%);">+NOTE: Currently osmo-bsc makes no use of PDCH interference reports, neither</span><br><span style="color: hsl(120, 100%, 40%);">+they get forwarded to the BSC co-located PCU over the PCUIF.</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span style="color: hsl(120, 100%, 40%);">+For dynamic timeslots (`TCH/F_TCH/H_SDCCH/8_PDCH` and `TCH/F_PDCH`), the</span><br><span style="color: hsl(120, 100%, 40%);">+following expectations apply:</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span style="color: hsl(120, 100%, 40%);">+* when in TCH/F mode: no interference reports, because the only sub-channel is active;</span><br><span style="color: hsl(120, 100%, 40%);">+* when in TCH/H mode: interference reports for *inactive* sub-channels only;</span><br><span style="color: hsl(120, 100%, 40%);">+* when in SDCCH mode: interference reports for *inactive* sub-channels only;</span><br><span style="color: hsl(120, 100%, 40%);">+* when in PDCH mode: optional interference reports;</span><br><span style="color: hsl(120, 100%, 40%);">+** measurements can be performed during IDLE TDMA frames.</span><br><span>diff --git a/doc/manuals/osmobsc-usermanual.adoc b/doc/manuals/osmobsc-usermanual.adoc</span><br><span>index 120fe2c..0afa015 100644</span><br><span>--- a/doc/manuals/osmobsc-usermanual.adoc</span><br><span>+++ b/doc/manuals/osmobsc-usermanual.adoc</span><br><span>@@ -26,6 +26,8 @@</span><br><span> </span><br><span> include::{srcdir}/chapters/power_control.adoc[]</span><br><span> </span><br><span style="color: hsl(120, 100%, 40%);">+include::{srcdir}/chapters/interf_meas.adoc[]</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span> include::{srcdir}/chapters/handover.adoc[]</span><br><span> </span><br><span> include::{srcdir}/chapters/smscb.adoc[]</span><br><span></span><br></pre><p>To view, visit <a href="https://gerrit.osmocom.org/c/osmo-bsc/+/26056">change 26056</a>. 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<div style="display:none"> Gerrit-Project: osmo-bsc </div>
<div style="display:none"> Gerrit-Branch: master </div>
<div style="display:none"> Gerrit-Change-Id: I3c15b11bbcba0811e3a15fe64365067bf8ad0dae </div>
<div style="display:none"> Gerrit-Change-Number: 26056 </div>
<div style="display:none"> Gerrit-PatchSet: 3 </div>
<div style="display:none"> Gerrit-Owner: fixeria <vyanitskiy@sysmocom.de> </div>
<div style="display:none"> Gerrit-Reviewer: Jenkins Builder </div>
<div style="display:none"> Gerrit-Reviewer: fixeria <vyanitskiy@sysmocom.de> </div>
<div style="display:none"> Gerrit-Reviewer: laforge <laforge@osmocom.org> </div>
<div style="display:none"> Gerrit-Reviewer: neels <nhofmeyr@sysmocom.de> </div>
<div style="display:none"> Gerrit-Reviewer: osmith <osmith@sysmocom.de> </div>
<div style="display:none"> Gerrit-Reviewer: pespin <pespin@sysmocom.de> </div>
<div style="display:none"> Gerrit-MessageType: merged </div>