cellbarredNTN indicates notbarred in SIB1 if NTN access is available

38.331 release 18  section 5.2.2.4.2 indicates that to access NTN, cellbarredNTN in SIB1 should be set to notbarred.

openair2/RRC/NR/nr_rrc_config.c

@@ -2303,6 +2303,19 @@ static long get_NR_UE_TimersAndConstants_t319(const nr_mac_timers_t *timer_confi
   }
 }
 
+static bool is_ntn_band(int band)
+{
+  // TS 3GPP 38.101-5 V1807 Section 5.2.2
+  if (band >= 254 && band <= 256) // FR1 NTN
+    return true;
+
+  // TS 3GPP 38.101-5 V1807 Section 5.2.3
+  if (band >= 510 && band <= 512) // FR2 NTN
+    return true;
+
+  return false;
+}
+
 NR_BCCH_DL_SCH_Message_t *get_SIB1_NR(const NR_ServingCellConfigCommon_t *scc,
                                       const f1ap_plmn_t *plmn,
                                       uint64_t cellID,
@@ -2401,12 +2414,26 @@ NR_BCCH_DL_SCH_Message_t *get_SIB1_NR(const NR_ServingCellConfigCommon_t *scc,
 
   asn1cSeqAdd(&sib1->si_SchedulingInfo->schedulingInfoList.list,schedulingInfo);*/
 
-  // sib19 scheduling info
-  // ensure ntn-config is initialized 
-  if (scc->ext2 && scc->ext2->ntn_Config_r17) {
+  const NR_FreqBandIndicatorNR_t band = *scc->downlinkConfigCommon->frequencyInfoDL->frequencyBandList.list.array[0];
+  if (is_ntn_band(band)) {
     sib1->nonCriticalExtension = CALLOC(1, sizeof(struct NR_SIB1_v1610_IEs));
     sib1->nonCriticalExtension->nonCriticalExtension = CALLOC(1, sizeof(struct NR_SIB1_v1630_IEs));
     sib1->nonCriticalExtension->nonCriticalExtension->nonCriticalExtension = CALLOC(1, sizeof(struct NR_SIB1_v1700_IEs));
+    // If cell provides NTN access, set cellBarredNTN to notBarred.
+    struct NR_SIB1_v1700_IEs *sib1_v1700 = sib1->nonCriticalExtension->nonCriticalExtension->nonCriticalExtension;
+    sib1_v1700->cellBarredNTN_r17 = CALLOC(1, sizeof(long));
+    *sib1_v1700->cellBarredNTN_r17 = NR_SIB1_v1700_IEs__cellBarredNTN_r17_notBarred;
+  }
+
+  // sib19 scheduling info
+  // ensure ntn-config is initialized
+  if (scc->ext2 && scc->ext2->ntn_Config_r17) {
+    if (sib1->nonCriticalExtension == NULL)
+      sib1->nonCriticalExtension = CALLOC(1, sizeof(struct NR_SIB1_v1610_IEs));
+    if (sib1->nonCriticalExtension->nonCriticalExtension == NULL)
+      sib1->nonCriticalExtension->nonCriticalExtension = CALLOC(1, sizeof(struct NR_SIB1_v1630_IEs));
+    if (sib1->nonCriticalExtension->nonCriticalExtension->nonCriticalExtension == NULL)
+      sib1->nonCriticalExtension->nonCriticalExtension->nonCriticalExtension = CALLOC(1, sizeof(struct NR_SIB1_v1700_IEs));
 
     struct NR_SI_SchedulingInfo_v1700 *sib_v17_scheduling_info = CALLOC(1, sizeof(struct NR_SI_SchedulingInfo_v1700));
 
@@ -2438,7 +2465,6 @@ NR_BCCH_DL_SCH_Message_t *get_SIB1_NR(const NR_ServingCellConfigCommon_t *scc,
         frequencyInfoDL->frequencyBandList.list.array[i];
   }
 
-  const NR_FreqBandIndicatorNR_t band = *scc->downlinkConfigCommon->frequencyInfoDL->frequencyBandList.list.array[0];
   frequency_range_t frequency_range = band > 256 ? FR2 : FR1;
   sib1->servingCellConfigCommon->downlinkConfigCommon.frequencyInfoDL.offsetToPointA = get_ssb_offset_to_pointA(*scc->downlinkConfigCommon->frequencyInfoDL->absoluteFrequencySSB,
                                scc->downlinkConfigCommon->frequencyInfoDL->absoluteFrequencyPointA,

openair2/RRC/NR_UE/rrc_UE.c

@@ -308,6 +308,20 @@ static void nr_rrc_configure_default_SI(NR_UE_RRC_SI_INFO *SI_info,
   }
 }
 
+static void verify_NTN_access(const NR_UE_RRC_SI_INFO *SI_info, const NR_SIB1_v1700_IEs_t *sib1_v1700)
+{
+  // SIB1 indicates if NTN access is present in the cell
+  bool ntn_access = false;
+  if (sib1_v1700 && sib1_v1700->cellBarredNTN_r17
+      && *sib1_v1700->cellBarredNTN_r17 == NR_SIB1_v1700_IEs__cellBarredNTN_r17_notBarred)
+    ntn_access = true;
+
+  uint32_t sib19_mask = 1 << NR_SIB_TypeInfo_v1700__sibType_r17__type1_r17_sibType19;
+  int sib19_present = SI_info->SInfo_r17.default_otherSI_map_r17 & sib19_mask;
+
+  AssertFatal(!ntn_access || sib19_present, "NTN cell, but SIB19 not configured.\n");
+}
+
 static void nr_rrc_process_sib1(NR_UE_RRC_INST_t *rrc, NR_UE_RRC_SI_INFO *SI_info, NR_SIB1_t *sib1)
 {
   if(g_log->log_component[NR_RRC].level >= OAILOG_DEBUG)
@@ -321,15 +335,19 @@ static void nr_rrc_process_sib1(NR_UE_RRC_INST_t *rrc, NR_UE_RRC_SI_INFO *SI_inf
     nr_rrc_ue_prepare_RRCSetupRequest(rrc);
   }
 
+  NR_SIB1_v1700_IEs_t *sib1_v1700 = NULL;
   NR_SI_SchedulingInfo_v1700_t *si_SchedInfo_v1700 = NULL;
   if (sib1->nonCriticalExtension
       && sib1->nonCriticalExtension->nonCriticalExtension
       && sib1->nonCriticalExtension->nonCriticalExtension->nonCriticalExtension) {
-    si_SchedInfo_v1700 = sib1->nonCriticalExtension->nonCriticalExtension->nonCriticalExtension->si_SchedulingInfo_v1700;
+    sib1_v1700 = sib1->nonCriticalExtension->nonCriticalExtension->nonCriticalExtension;
+    si_SchedInfo_v1700 = sib1_v1700->si_SchedulingInfo_v1700;
   }
 
   // configure default SI
   nr_rrc_configure_default_SI(SI_info, sib1->si_SchedulingInfo, si_SchedInfo_v1700);
+  verify_NTN_access(SI_info, sib1_v1700);
+
   // configure timers and constant
   nr_rrc_set_sib1_timers_and_constants(&rrc->timers_and_constants, sib1);
   // RRC storage of SIB1 timers and constants (eg needed in re-establishment)