From fae529b384c2ff1b56cad38ebc1db16fa4ce6b89 Mon Sep 17 00:00:00 2001 From: Thomas Schlichter Date: Tue, 23 Jul 2024 10:42:10 +0200 Subject: [PATCH] add documentation for `disable_harq` flag in NTN section of doc/RUNMODEM.md --- doc/RUNMODEM.md | 14 ++++++++++++++ 1 file changed, 14 insertions(+) diff --git a/doc/RUNMODEM.md b/doc/RUNMODEM.md index 9ee9083e6d..b1b5090ae7 100644 --- a/doc/RUNMODEM.md +++ b/doc/RUNMODEM.md @@ -182,6 +182,20 @@ Besides this, some timers, e.g. `sr_ProhibitTimer_v1700`, `t300`, `t301` and `t3 ... ``` +To improve the achievable UL and DL throughput in conditions with large RTT, there is a feature defined in REL17 to disable HARQ feedback. +This allows to reuse HARQ processes immediately, but it breaks compatibility with UEs not supporting this REL17 feature. +To enable this feature, the `disable_harq` flag has to be added to the gNB conf file in the section `gNBs.[0]` +``` +... + sib1_tda = 5; + min_rxtxtime = 6; + disable_harq = 1; // <-- + + servingCellConfigCommon = ( + { +... +``` + So with these modifications to the file `targets/PROJECTS/GENERIC-NR-5GC/CONF/gnb.sa.band66.fr1.25PRB.usrpx300.conf` an example gNB command for FDD, 5 MHz BW, 15 kHz SCS, GEO satellite 5G NR NTN is this: ``` cd cmake_targets