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Feature #1563

Downlink DTX support

Added by laforge almost 2 years ago. Updated over 1 year ago.

Status:
Closed
Priority:
Urgent
Assignee:
Category:
-
Target version:
-
Start date:
05/09/2016
Due date:
06/10/2016
% Done:

100%

Spec Reference:

Description

This is not as important as uplink DTX, but helps with reducing interference toward surrounding cells on same/adjacent ARFCN


Related issues

Related to OsmoBTS - Feature #1562: Uplink DTX support Closed 02/23/2016 06/10/2016
Related to OpenBSC - Feature #1701: DTXd support from BSC side Closed 05/04/2016 06/10/2016
Related to OsmoBTS - Bug #1750: DTXu/DTXd support for osmo-bts-trx Stalled 06/13/2016

History

#1 Updated by laforge almost 2 years ago

  • Tracker changed from Bug to Feature

#5 Updated by laforge over 1 year ago

#6 Updated by laforge over 1 year ago

  • Priority changed from Low to Normal

In Downlink DTX, the BTS is muting some bursts/blocks during times with no voice activity in the downlink side towards the phone. This basically means that there are RTP SID frames (possibly at larger-than-20ms-intervals), which should trigger the muting of some bursts from the BTS.

So basically
  • if we are on a secondary TRX (not TRX0 which carries the BCCH), and
  • if DTXd is active, and
  • we get a PH-RTS.ind from the PHY for the TCH (not SACCH!), but we do not have a valid codec frame with actual voice data (but rather no codec frame or a SID frame), then we chose to mute the transceiver for this burst, rather than sending a normal/dummy burst.

In terms of measurement reporting, the phone will perform the downlink rxqual and rxlev calculations for both FULL (all frames) and SUB (only sacch frames) and report this to the BTS, who will forward it in the RSL MEAS REP to the BSC. The BTS does not need to perform any processing here, as far as I know.

#7 Updated by laforge over 1 year ago

  • Due date set to 05/10/2016

#8 Updated by laforge over 1 year ago

#9 Updated by laforge over 1 year ago

  • Due date changed from 05/10/2016 to 06/10/2016
  • Start date changed from 02/23/2016 to 05/09/2016

#10 Updated by laforge over 1 year ago

  • Priority changed from Normal to High

#11 Updated by laforge over 1 year ago

  • Priority changed from High to Urgent

#12 Updated by laforge over 1 year ago

test update, please ignore

#13 Updated by laforge over 1 year ago

  • Assignee set to msuraev

#14 Updated by msuraev over 1 year ago

  • Status changed from New to In Progress

#15 Updated by msuraev over 1 year ago

  • % Done changed from 0 to 90

The patches are pushed to gerrit/users/max/dtx-test branch and are ready for review/testing. Note support is implemented for sysmoBTS and LC15 BTS models.

#16 Updated by msuraev over 1 year ago

Note: testing require fix for libosmo-abis which is under review in gerrit: 217.

#17 Updated by msuraev over 1 year ago

  • Related to Bug #1750: DTXu/DTXd support for osmo-bts-trx added

#18 Updated by msuraev over 1 year ago

  • Status changed from In Progress to Resolved
  • Assignee changed from msuraev to laforge
  • % Done changed from 90 to 100

Support has been merged to master.

#19 Updated by laforge over 1 year ago

  • Status changed from Resolved to Closed

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