OAI UE: add shared RSRP Table 10.1.6.1-1 mapping helper and adopt it RRC UE

- Add to common/utils/nr/nr_common remove from NR_MAC_UE/nr_ue_procedures.c
- Adopt in asn1_msg.c for MeasurementReport: this solves the following assert:

Assertion (enc_rval.encoded > 0) failed!
In do_nrMeasurementReport_SA() /oai-ran/openair2/RRC/NR/MESSAGES/asn1_msg.c:898
ASN1 message encoding failed (MeasResultServMOList, 18446744073709551615)!

Motivation: unify RSRP-to-index mapping across layers and fix NR RRC MeasurementReport
encoding failures due to out-of-range values by reusing the validated mapping.

Note NR_RSRP-Range.c constraint:
	{ APC_CONSTRAINED,	 7,  7,  0,  127 }	/* (0..127) */

common/utils/nr/nr_common.c

@@ -152,6 +152,17 @@ void reverse_bits_u8(uint8_t const* in, size_t sz, uint8_t* out)
 #endif
 }
 
+/** @brief 3GPP TS 38.133 Table 10.1.6.1-1 mapping from dBm to RSRP index */
+uint8_t get_rsrp_index(int rsrp_dBm)
+{
+  int index = rsrp_dBm + 157;
+  if (rsrp_dBm > -44)
+    index = 113;
+  if (rsrp_dBm < -140)
+    index = 16;
+  return (uint8_t)index;
+}
+
 // Reverse bits implementation based on http://graphics.stanford.edu/~seander/bithacks.html
 uint64_t reverse_bits(uint64_t in, int n_bits)
 {

common/utils/nr/nr_common.h

@@ -186,6 +186,9 @@ typedef struct meas_s {
   val_init_t csi_rsrp_dBm;
 } meas_t;
 
+/** @brief Returns NR RSRP index per 3GPP TS 38.133 Table 10.1.6.1-1 */
+uint8_t get_rsrp_index(int rsrp_dBm);
+
 /**
  * @brief To start a timer
  * @param timer Timer to be started

openair2/LAYER2/NR_MAC_UE/nr_ue_procedures.c

@@ -2916,17 +2916,6 @@ static int compare_ssb_rsrp(const void *a, const void *b)
   return mb->ssb_rsrp_dBm - ma->ssb_rsrp_dBm;
 }
 
-// returns index from RSRP
-// according to Table 10.1.6.1-1 in 38.133
-static uint8_t get_rsrp_index(int rsrp)
-{
-  int index = rsrp + 157;
-  if (rsrp > -44)
-    index = 113;
-  if (rsrp < -140)
-    index = 16;
-  return index;
-}
 
 static csi_payload_t get_ssb_rsrp_payload(NR_UE_MAC_INST_t *mac,
                                           struct NR_CSI_ReportConfig *csi_reportconfig,

openair2/RRC/NR/MESSAGES/asn1_msg.c

@@ -855,7 +855,7 @@ int do_nrMeasurementReport_SA(NR_MeasurementReport_t *measurementReport,
                               long trigger_quantity,
                               long rs_type,
                               uint16_t Nid_cell,
-                              int rsrp_dBm,
+                              int rsrp_index,
                               uint8_t *buffer,
                               size_t buffer_size)
 {
@@ -884,9 +884,9 @@ int do_nrMeasurementReport_SA(NR_MeasurementReport_t *measurementReport,
   struct NR_MeasQuantityResults *active_mq_res = CALLOC(1, sizeof(struct NR_MeasQuantityResults));
 
   if (trigger_quantity == NR_MeasTriggerQuantityOffset_PR_rsrp) {
-    active_mq_res->rsrp = CALLOC(1, sizeof(NR_RSRP_Range_t));
-
-    *active_mq_res->rsrp = rsrp_dBm + 157;
+    asn1cCalloc(active_mq_res->rsrp, rsrp);
+    // Assign precomputed RSRP index
+    *rsrp = rsrp_index;
     if (rs_type == NR_NR_RS_Type_ssb)
       measResultServingCell->measResult.cellResults.resultsSSB_Cell = active_mq_res;
     else

openair2/RRC/NR/MESSAGES/asn1_msg.h

@@ -130,7 +130,7 @@ int do_nrMeasurementReport_SA(NR_MeasurementReport_t *measurementReport,
                               long trigger_quantity,
                               long rs_type,
                               uint16_t Nid_cell,
-                              int rsrp_dBm,
+                              int rsrp_index,
                               uint8_t *buffer,
                               size_t buffer_size);
 

openair2/RRC/NR_UE/rrc_UE.c

@@ -3242,12 +3242,13 @@ void rrc_ue_generate_measurementReport(rrcPerNB_t *rrc, instance_t ue_id)
   NR_MeasurementReport_t measurementReport = {0};
   l3_measurements_t *l3m = &rrc->l3_measurements;
   int rsrp_dBm = l3m->rs_type == NR_NR_RS_Type_ssb ? l3m->serving_cell.ss_rsrp_dBm.val : l3m->serving_cell.csi_rsrp_dBm.val;
+  int rsrp_index = get_rsrp_index(rsrp_dBm);
   uint8_t size = do_nrMeasurementReport_SA(&measurementReport,
                                            l3m->trigger_to_measid,
                                            l3m->trigger_quantity,
                                            l3m->rs_type,
                                            l3m->serving_cell.Nid_cell,
-                                           rsrp_dBm,
+                                           rsrp_index,
                                            buffer,
                                            sizeof(buffer));