maki/openairinterface5g
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

UE NTN: changed handling of SIB19 periodic reception

Browse Source
This commit is contained in:
Raghavendra Dinavahi
2025-12-16 15:50:56 +01:00
parent 6900edbf92
commit 1cca7f090e
1 changed files with 9 additions and 12 deletions
Download Patch File Download Diff File Expand all files Collapse all files
openair2/RRC/NR_UE/rrc_UE.c
+9 -12
View File
@@ -248,22 +248,19 @@ static int eval_epoch_time(NR_UE_RRC_SI_INFO *SI_info, NR_NTN_Config_r17_t *ntnc
static int get_ntn_timervalues(NR_UE_RRC_SI_INFO *SI_info, NR_NTN_Config_r17_t *ntncfg, int diff_frames, int *val430_ms)
{
int val430 = get_ulsyncvalidityduration_timer_value(ntncfg);
int sib19_periodicity_ms = (SI_info->sib19_periodicity + 1) * 10;
int sib19_periodicity_ms = SI_info->sib19_periodicity * 10;
*val430_ms = val430 * 1000 + diff_frames * 10; // in ms
if (*val430_ms <= sib19_periodicity_ms)
LOG_E(NR_RRC, "Too small T430 value. Might result in frequent ULSYNC failure\n");
// Depending on ulsyncvalidity duration, SIB19 timer expires 15secs/2secs before T430
// LArger values might be used for GEO and epoch time interval can be around 10 secs
// Lower values will be used for NGSO (LEO/MEO), epoch time interval can be between 2-3 secs.
// TODO remove the hardoded values and define a better strategy to determine the time of expiry
// with real GEO/LEO/MEO SATs.
int expire_before_ms = ((val430 >= 120) ? 10000 : 2000);
// SIB19 periodicity even for LEO could be configured to be more than epoch time interval (2 secs)
if (expire_before_ms < 2 * sib19_periodicity_ms)
expire_before_ms = 2 * sib19_periodicity_ms;
int diff = *val430_ms - expire_before_ms;
int sib19_timer_ms = (diff > 0) ? diff : ((*val430_ms - sib19_periodicity_ms) > 0) ? (*val430_ms - sib19_periodicity_ms) : 0;
// by default SIB19 reception is started from the middle of the ulsyncvalidity duration.(i.e val430 in ms / 2)
int sib19_timer_ms = val430 * 500 + diff_frames * 10;
// if this is less than the SIB19 periodicity, use that instead.
// set the timer to expire 1 frame (10 ms) before periodicity, to not miss the SIB19
if (sib19_timer_ms <= sib19_periodicity_ms)
sib19_timer_ms = sib19_periodicity_ms - 10;
LOG_I(NR_RRC, "val430:%d s, T430:%d ms, sib19_timer:%d ms\n", val430, *val430_ms, sib19_timer_ms);
return sib19_timer_ms;
}