https://projects.osmocom.org/https://projects.osmocom.org/favicon.ico?16647414092018-09-17T20:24:45ZOpen Source Mobile CommunicationsOsmocomBB - Feature #3558: trxcon/scheduler: implement CBCH supporthttps://projects.osmocom.org/issues/3558?journal_id=114042018-09-17T20:24:45Zfixeria
<ul><li><strong>Related to</strong> <i><a class="issue tracker-1 status-3 priority-3 priority-high3 closed" href="/issues/1617">Bug #1617</a>: osmo-bts-trx doesn't support CBCH</i> added</li></ul> OsmocomBB - Feature #3558: trxcon/scheduler: implement CBCH supporthttps://projects.osmocom.org/issues/3558?journal_id=116872018-09-29T11:47:24Zfixeria
<ul></ul><p>Initial attempt to extend L1CTL with CBCH was already done in 2013, please see:</p>
<p><a class="external" href="http://lists.osmocom.org/pipermail/baseband-devel/2013-January/003833.html">http://lists.osmocom.org/pipermail/baseband-devel/2013-January/003833.html</a></p>
<p>I think (ab)using L1CTL_DM_EST_REQ message is a bad idea. The L23 applications<br />should be able to receive CBCH messages without switching to a dedicated mode,<br />i.e. while being in IDLE mode.</p> OsmocomBB - Feature #3558: trxcon/scheduler: implement CBCH supporthttps://projects.osmocom.org/issues/3558?journal_id=118312018-10-01T19:51:28Zfixeria
<ul><li><strong>Status</strong> changed from <i>New</i> to <i>In Progress</i></li><li><strong>% Done</strong> changed from <i>0</i> to <i>80</i></li></ul><p>I just implemented CBCH support for both Capypso and trxcon PHYs, please see:</p>
<p><a class="external" href="https://gerrit.osmocom.org/11178/">https://gerrit.osmocom.org/11178/</a> trxcon/sched_lchan_desc.c: fix wrong chan_nr for PDCH<br /><a class="external" href="https://gerrit.osmocom.org/11179/">https://gerrit.osmocom.org/11179/</a> trxcon/l1ctl.c: properly handle indicated CCCH mode<br /><a class="external" href="https://gerrit.osmocom.org/11180/">https://gerrit.osmocom.org/11180/</a> firmware/layer1: inform about unhandled scheduler tasks<br /><a class="external" href="https://gerrit.osmocom.org/11181/">https://gerrit.osmocom.org/11181/</a> firmware/layer1: add scheduler tasks for CBCH<br /><a class="external" href="https://gerrit.osmocom.org/11182/">https://gerrit.osmocom.org/11182/</a> trxcon/scheduler: add CCCH/SDCCH mframe layouts with CBCH<br /><a class="external" href="https://gerrit.osmocom.org/11183/">https://gerrit.osmocom.org/11183/</a> l1ctl_proto.h: extend ccch_mode enum with CBCH</p>
<p>Please note that the L23 applications are unable to handle CBCH messages properly,<br />because we are using Osmocom specific cbits to "identify" them. But for TTCN-3<br />there should be no difference ;)</p>
<p>In short, sending L1CTL_FBSB_REQ or L1CTL_CCCH_MODE_REQ with CCCH_MODE_COMBINED_CBCH<br />would enable CBCH decoding tasks for both PHYs in idle mode (i.e. there is no need to<br />switch PHY to dedicated mode). This is actual for SDCCH/4+CBCH only!</p>
<p>In order to test CBCH on SDCCH/8, one would need to send regular L1CTL_DM_EST_REQ.<br />The problem is that decoded CBCH messages would arrive with cbits != 0xc8, because<br />the L1 code still needs to be modified in order to distinguish CBCH on SDCCH/8.</p> OsmocomBB - Feature #3558: trxcon/scheduler: implement CBCH supporthttps://projects.osmocom.org/issues/3558?journal_id=118332018-10-01T21:57:49Zfixeria
<ul><li><strong>Status</strong> changed from <i>In Progress</i> to <i>Feedback</i></li><li><strong>% Done</strong> changed from <i>80</i> to <i>90</i></li></ul><p>Ok, I've finally decided to split CBCH into two separate logical channels. This is required<br />because we need to distinguish between CBCH on SDCCH/4 (C0/TS0) and CBCH on SDCCH/8 (CX/TS0).</p>
<p>Also, activating CBCH on SDCCH/4 by default makes much more sense than on SDCCH/8, because<br />in the second case it can be a hopping channel (unlike SDCCH/4), so we would get garbage...</p>
<blockquote>
<p>The problem is that decoded CBCH messages would arrive with cbits != 0xc8, because<br />the L1 code still needs to be modified in order to distinguish CBCH on SDCCH/8.</p>
</blockquote>
<p>This should have been fixed in the latest patch set.</p> OsmocomBB - Feature #3558: trxcon/scheduler: implement CBCH supporthttps://projects.osmocom.org/issues/3558?journal_id=119342018-10-03T09:10:05Zfixeria
<ul><li><strong>Status</strong> changed from <i>Feedback</i> to <i>Resolved</i></li><li><strong>% Done</strong> changed from <i>90</i> to <i>100</i></li></ul><p>Merged. Please re-open if something wouldn't work.</p> OsmocomBB - Feature #3558: trxcon/scheduler: implement CBCH supporthttps://projects.osmocom.org/issues/3558?journal_id=149242019-06-21T11:56:35Zptrkrysik
<ul><li><strong>Target version</strong> deleted (<del><i>Improvement of the higher layers of OsmocomBB</i></del>)</li></ul>