https://projects.osmocom.org/https://projects.osmocom.org/favicon.ico?16647414092018-09-19T11:48:44ZOpen Source Mobile CommunicationsOsmoBTS - Bug #3572: Incorrect TDMA frame number calculation on TCH channelshttps://projects.osmocom.org/issues/3572?journal_id=114602018-09-19T11:48:44Zfixeria
<ul><li><b>Checklist item</b> <input type='checkbox' class='checklist-checkbox' disabled> <i>Share TCH/H TDMA frame mapping helpers in libosmocore</i> added</li><li><b>Checklist item</b> <input type='checkbox' class='checklist-checkbox' disabled> <i>Implement TCH/F TDMA frame mapping helpers in libosmocore</i> added</li><li><b>Checklist item</b> <input type='checkbox' class='checklist-checkbox' disabled> <i>Fix TDMA frame number calculation for TCH/F</i> added</li><li><b>Checklist item</b> <input type='checkbox' class='checklist-checkbox' disabled> <i>Fix TDMA frame number calculation for TCH/H</i> added</li><li><b>Checklist item</b> <input type='checkbox' class='checklist-checkbox' disabled> <i>Implement basic TTCN-3 test coverage</i> added</li></ul> OsmoBTS - Bug #3572: Incorrect TDMA frame number calculation on TCH channelshttps://projects.osmocom.org/issues/3572?journal_id=137232019-03-31T22:35:39Zfixeria
<ul><li><strong>Related to</strong> <i><a class="issue tracker-1 status-3 priority-2 priority-default closed" href="/issues/3803">Bug #3803</a>: fix frame number calculation in scheduler_trx</i> added</li></ul> OsmoBTS - Bug #3572: Incorrect TDMA frame number calculation on TCH channelshttps://projects.osmocom.org/issues/3572?journal_id=143302019-05-08T18:08:37Zlaforge
<ul></ul> OsmoBTS - Bug #3572: Incorrect TDMA frame number calculation on TCH channelshttps://projects.osmocom.org/issues/3572?journal_id=143312019-05-08T18:08:47Zlaforge
<ul><li><strong>Assignee</strong> set to <i>4368</i></li></ul> OsmoBTS - Bug #3572: Incorrect TDMA frame number calculation on TCH channelshttps://projects.osmocom.org/issues/3572?journal_id=182582020-05-12T11:56:30Zlaforge
<ul><li><strong>Status</strong> changed from <i>New</i> to <i>Feedback</i></li><li><strong>Assignee</strong> changed from <i>4368</i> to <i>fixeria</i></li></ul><p><a class="user active" href="https://projects.osmocom.org/users/67">fixeria</a> what is the status of this ticket? Is it still a pending issue?</p> OsmoBTS - Bug #3572: Incorrect TDMA frame number calculation on TCH channelshttps://projects.osmocom.org/issues/3572?journal_id=182652020-05-12T12:00:39ZHoernchen
<ul></ul><p>I've stumbled upon this last week, and suspected that it was already fixed by <a class="user active" href="https://projects.osmocom.org/users/15">dexter</a> fn calculation fixes.</p> OsmoBTS - Bug #3572: Incorrect TDMA frame number calculation on TCH channelshttps://projects.osmocom.org/issues/3572?journal_id=182692020-05-12T12:04:20Ztnt
<ul></ul><p>Also ... I don't get the issue really.</p>
<p>Yeah, we assume a L2 frame number that's "arbitrarily" the 5th burst of 8 bursts where data of the L2 frame is spread over. What's the problem exactly ?<br />They will come at the right "rate" and be spread by the right amount of frame, so why does it matter if we take the first, 5th or last ? What's that number even used for ?</p> OsmoBTS - Bug #3572: Incorrect TDMA frame number calculation on TCH channelshttps://projects.osmocom.org/issues/3572?journal_id=182922020-05-12T13:17:01Zfixeria
<ul><li><b>Checklist item</b> <input type='checkbox' class='checklist-checkbox' checked disabled> <i>Share TCH/H TDMA frame mapping helpers in libosmocore</i> set to Done</li><li><b>Checklist item</b> <input type='checkbox' class='checklist-checkbox' checked disabled> <i>Implement TCH/F TDMA frame mapping helpers in libosmocore</i> set to Done</li><li><b>Checklist item</b> <input type='checkbox' class='checklist-checkbox' checked disabled> <i>Fix TDMA frame number calculation for TCH/F</i> set to Done</li><li><b>Checklist item</b> <input type='checkbox' class='checklist-checkbox' checked disabled> <i>Fix TDMA frame number calculation for TCH/H</i> set to Done</li><li><strong>% Done</strong> changed from <i>0</i> to <i>80</i></li></ul><p>tnt wrote:</p>
<blockquote>
<p>Also ... I don't get the issue really.</p>
<p>Yeah, we assume a L2 frame number that's "arbitrarily" the 5th burst of 8 bursts where data of the L2 frame is spread over. What's the problem exactly ?<br />They will come at the right "rate" and be spread by the right amount of frame, so why does it matter if we take the first, 5th or last ? What's that number even used for ?</p>
</blockquote>
<p>The problem is that some lchan handlers report frame number of the first burst, some report frame number of the last burst... This inconsistency is what I really dislike, but to be honest, I don't know whether it's really that critical. Probably yes for the measurement processing, or maybe for DTX mode of operation (which we don't yet support to my best knowledge).</p>
<p>laforge wrote:</p>
<blockquote>
<p><a class="user active" href="https://projects.osmocom.org/users/67">fixeria</a> what is the status of this ticket? Is it still a pending issue?</p>
</blockquote>
<p>I quickly checked the source code of the recent master, and it looks good to me. Just submitted a cosmetic change:</p>
<p><a class="external" href="https://gerrit.osmocom.org/c/osmo-bts/+/18218">https://gerrit.osmocom.org/c/osmo-bts/+/18218</a> osmo-bts-trx/scheduler: remove a left-over from UL TCH handlers</p>
<p>The libosmocore's frame (re)mapping API has some unit tests, but I have not seen anything covering osmo-bts-trx itself. Let me know if I should implement a TTCN-3 test case.</p> OsmoBTS - Bug #3572: Incorrect TDMA frame number calculation on TCH channelshttps://projects.osmocom.org/issues/3572?journal_id=183002020-05-12T14:43:15Zlaforge
<ul></ul><p>On Tue, May 12, 2020 at 01:17:03PM +0000, fixeria [REDMINE] wrote:</p>
<blockquote>
<p>The problem is that some lchan handlers report frame number of the first burst, some report frame number of the last burst... This inconsistency is what I really dislike, but to be honest, I don't know whether it's really that critical. Probably yes for the measurement processing, or maybe for DTX mode of operation (which we don't yet support to my best knowledge).</p>
</blockquote>
<p>We should have one unified understanding of which frame nubmer we use<br />for reporting the burst, as this is indeed important for parts of the<br />common code such as measurement processing and uplink DTX - both or<br />which are important and supported; DTX historically not for<br />osmo-bts-trx, but I think actually also by now, <a class="user active" href="https://projects.osmocom.org/users/15">dexter</a> has done a lot<br />of work on this in terms of correctly marking the related frames etc.</p>
<blockquote>
<p>The libosmocore's frame (re)mapping API has some unit tests, but I have not seen anything covering osmo-bts-trx itself. Let me know if I should implement a TTCN-3 test case.</p>
</blockquote>
<p>I think it's fine as-is, thanks.</p> OsmoBTS - Bug #3572: Incorrect TDMA frame number calculation on TCH channelshttps://projects.osmocom.org/issues/3572?journal_id=183012020-05-12T14:55:57Zfixeria
<ul><li><strong>Status</strong> changed from <i>Feedback</i> to <i>Closed</i></li></ul><blockquote>
<p>I think it's fine as-is, thanks.</p>
</blockquote>
<p>Then I am closing this ticket, since there is nothing left to do.</p>