Do not configure NR_MeasurementTimingConfiguration during handover when neighboring cells are at the same frequency

openair2/RRC/NR/rrc_gNB.c

@@ -3407,26 +3407,7 @@ void rrc_gNB_generate_UeContextSetupRequest(const gNB_RRC_INST *rrc,
   }
 
   nr_rrc_du_container_t *du = get_du_for_ue((gNB_RRC_INST *)rrc, ue_p->rrc_ue_id);
-  byte_array_t *meas_timing_config = NULL;
+  cu2du.meas_timing_config = get_meas_timing_config(du->mtc, ue_p->measConfig);
-  if (du->mtc && ue_p->measConfig && ue_p->measConfig->measObjectToAddModList) {
-    NR_MeasObjectToAddModList_t *mo_list = ue_p->measConfig->measObjectToAddModList;
-    NR_ARFCN_ValueNR_t ssbFrequency0;
-    for (int i = 0; i < mo_list->list.count; i++) {
-      NR_MeasObjectToAddMod_t *mo = mo_list->list.array[i];
-      if (mo->measObject.present == NR_MeasObjectToAddMod__measObject_PR_measObjectNR) {
-        NR_MeasObjectNR_t *monr = mo->measObject.choice.measObjectNR;
-        if (i == 0) {
-          ssbFrequency0 = *monr->ssbFrequency;
-        } else if (ssbFrequency0 != *monr->ssbFrequency) {
-          meas_timing_config = calloc_or_fail(1, sizeof(*meas_timing_config));
-          meas_timing_config->buf = calloc_or_fail(1, NR_RRC_BUF_SIZE);
-          meas_timing_config->len = do_NR_MeasurementTimingConfiguration(du->mtc, meas_timing_config->buf, NR_RRC_BUF_SIZE);
-          cu2du.meas_timing_config = meas_timing_config;
-          break;
-        }
-      }
-    }
-  }
 
   int nb_srb = 1;
   f1ap_srb_to_setup_t *srbs = calloc_or_fail(nb_srb, sizeof(*srbs));

openair2/RRC/NR/rrc_gNB_mobility.c

@@ -192,12 +192,7 @@ static void nr_initiate_handover(const gNB_RRC_INST *rrc,
   meas_config->buf = calloc_or_fail(1, NR_RRC_BUF_SIZE);
   meas_config->len = do_NR_MeasConfig(ue->measConfig, meas_config->buf, NR_RRC_BUF_SIZE);
 
-  byte_array_t *meas_timing_config = NULL;
+  byte_array_t *meas_timing_config = get_meas_timing_config(target_du->mtc, ue->measConfig);
-  if (target_du->mtc) {
-    meas_timing_config = calloc_or_fail(1, sizeof(*meas_timing_config));
-    meas_timing_config->buf = calloc_or_fail(1, NR_RRC_BUF_SIZE);
-    meas_timing_config->len = do_NR_MeasurementTimingConfiguration(target_du->mtc, meas_timing_config->buf, NR_RRC_BUF_SIZE);
-  }
 
   byte_array_t *hpi = malloc_or_fail(sizeof(*hpi));
   *hpi = copy_byte_array(*ho_prep_info);
@@ -618,3 +613,31 @@ void nr_HO_N2_trigger_telnet(gNB_RRC_INST *rrc, uint32_t neighbour_pci, uint32_t
 
   nr_rrc_trigger_n2_ho(rrc, UE, scell_du->nr_pci, neighbour);
 }
+
+// This function detects if there are at least two different ssbFrequency values, and if so, returns meas_timing_config;
+// otherwise, it returns NULL. When you return NULL, the measurement gaps will not be configured.
+byte_array_t *get_meas_timing_config(const NR_MeasurementTimingConfiguration_t *mtc, const NR_MeasConfig_t *measConfig)
+{
+  if (!mtc || !measConfig || !measConfig->measObjectToAddModList)
+    return NULL;
+
+  byte_array_t *meas_timing_config = NULL;
+  NR_MeasObjectToAddModList_t *mo_list = measConfig->measObjectToAddModList;
+  NR_ARFCN_ValueNR_t ssbFrequency0 = 0;
+  for (int i = 0; i < mo_list->list.count; i++) {
+    NR_MeasObjectToAddMod_t *mo = mo_list->list.array[i];
+    if (mo->measObject.present != NR_MeasObjectToAddMod__measObject_PR_measObjectNR)
+      continue;
+    NR_MeasObjectNR_t *monr = mo->measObject.choice.measObjectNR;
+    if (i == 0) {
+      ssbFrequency0 = *monr->ssbFrequency;
+    } else if (ssbFrequency0 != *monr->ssbFrequency) {
+      meas_timing_config = calloc_or_fail(1, sizeof(*meas_timing_config));
+      meas_timing_config->buf = calloc_or_fail(1, NR_RRC_BUF_SIZE);
+      meas_timing_config->len = do_NR_MeasurementTimingConfiguration(mtc, meas_timing_config->buf, NR_RRC_BUF_SIZE);
+      break;
+    }
+  }
+
+  return meas_timing_config;
+}

openair2/RRC/NR/rrc_gNB_mobility.h

@@ -108,4 +108,6 @@ void rrc_gNB_trigger_reconfiguration_for_handover(gNB_RRC_INST *rrc, gNB_RRC_UE_
 
 void nr_rrc_trigger_n2_ho_target(gNB_RRC_INST *rrc, gNB_RRC_UE_t *ue);
 
+byte_array_t *get_meas_timing_config(const NR_MeasurementTimingConfiguration_t *mtc, const NR_MeasConfig_t *measConfig);
+
 #endif /* RRC_GNB_MOBILITY_H_ */