fix for contention resolution timer at NR UE

openair1/SIMULATION/NR_PHY/nr_dummy_functions_prach.c

@@ -315,7 +315,7 @@ void nr_Msg1_transmitted(module_id_t mod_id, uint8_t CC_id, frame_t frameP, uint
   mac->RA_attempt_number++;
 }
 
-void nr_Msg3_transmitted(module_id_t mod_id, uint8_t CC_id, frame_t frameP, uint8_t gNB_id){
+void nr_Msg3_transmitted(module_id_t mod_id, uint8_t CC_id, frame_t frameP, slot_t slotP, uint8_t gNB_id){
   AssertFatal(CC_id == 0, "Transmission on secondary CCs is not supported yet\n");
   LOG_D(MAC,"[UE %d][RAPROC] Frame %d : Msg3_tx: Starting contention resolution timer\n", mod_id, frameP);
   NR_UE_MAC_INST_t *mac = get_mac_inst(mod_id);

openair2/LAYER2/NR_MAC_UE/mac_defs.h

@@ -292,8 +292,8 @@ typedef struct {
 
   /// Random-access Contention Resolution Timer active flag
   uint8_t RA_contention_resolution_timer_active;
-  /// Random-access Contention Resolution Timer count value
-  uint8_t RA_contention_resolution_cnt;
+  int RA_contention_resolution_target_frame;
+  int RA_contention_resolution_target_slot;
   /// Transmitted UE Contention Resolution Identifier
   uint8_t cont_res_id[6];
 

openair2/LAYER2/NR_MAC_UE/mac_proto.h

@@ -360,7 +360,7 @@ void nr_get_prach_resources(module_id_t mod_id,
 
 void nr_Msg1_transmitted(module_id_t mod_id, uint8_t CC_id, frame_t frameP, uint8_t gNB_id);
 
-void nr_Msg3_transmitted(module_id_t mod_id, uint8_t CC_id, frame_t frameP, uint8_t gNB_id);
+void nr_Msg3_transmitted(module_id_t mod_id, uint8_t CC_id, frame_t frameP, slot_t slotP, uint8_t gNB_id);
 
 void nr_ue_msg2_scheduler(module_id_t mod_id, uint16_t rach_frame, uint16_t rach_slot, uint16_t *msg2_frame, uint16_t *msg2_slot);
 

openair2/LAYER2/NR_MAC_UE/nr_ra_procedures.c

@@ -457,18 +457,27 @@ void nr_Msg1_transmitted(module_id_t mod_id, uint8_t CC_id, frame_t frameP, uint
   ra->RA_attempt_number++;
 }
 
-void nr_Msg3_transmitted(module_id_t mod_id, uint8_t CC_id, frame_t frameP, uint8_t gNB_id){
+void nr_Msg3_transmitted(module_id_t mod_id, uint8_t CC_id, frame_t frameP, slot_t slotP, uint8_t gNB_id){
 
   NR_UE_MAC_INST_t *mac = get_mac_inst(mod_id);
-  NR_RACH_ConfigCommon_t *nr_rach_ConfigCommon = (mac->scc) ? 
+  RA_config_t *ra = &mac->ra;
+  NR_RACH_ConfigCommon_t *nr_rach_ConfigCommon = (mac->scc) ?
     mac->scc->uplinkConfigCommon->initialUplinkBWP->rach_ConfigCommon->choice.setup:
     mac->scc_SIB->uplinkConfigCommon->initialUplinkBWP.rach_ConfigCommon->choice.setup;
-  RA_config_t *ra = &mac->ra;
+  long mu = (mac->scc) ? 
+    mac->scc->downlinkConfigCommon->frequencyInfoDL->scs_SpecificCarrierList.list.array[0]->subcarrierSpacing :
+    mac->scc_SIB->downlinkConfigCommon.frequencyInfoDL.scs_SpecificCarrierList.list.array[0]->subcarrierSpacing;
+  int subframes_per_slot = nr_slots_per_frame[mu]/10;
+
+  // start contention resolution timer (cnt in slots)
+  int RA_contention_resolution_timer_subframes = (nr_rach_ConfigCommon->ra_ContentionResolutionTimer + 1) * 8;
+
+  ra->RA_contention_resolution_target_frame = frameP + (RA_contention_resolution_timer_subframes/10);
+  ra->RA_contention_resolution_target_slot = (slotP + (RA_contention_resolution_timer_subframes * subframes_per_slot)) % nr_slots_per_frame[mu];
 
-  LOG_D(MAC,"In %s: [UE %d] Frame %d, CB-RA: starting contention resolution timer\n", __FUNCTION__, mod_id, frameP);
+  LOG_D(MAC,"In %s: [UE %d] CB-RA: starting contention resolution timer set in frame.slot %d.%d and expiring in %d.%d\n",
+       __FUNCTION__, mod_id, frameP, slotP, ra->RA_contention_resolution_target_frame, ra->RA_contention_resolution_target_slot);
 
-  // start contention resolution timer
-  ra->RA_contention_resolution_cnt = (nr_rach_ConfigCommon->ra_ContentionResolutionTimer + 1) * 8;
   ra->RA_contention_resolution_timer_active = 1;
   ra->ra_state = WAIT_CONTENTION_RESOLUTION;
 
@@ -736,20 +745,15 @@ void nr_ue_contention_resolution(module_id_t module_id, int cc_id, frame_t frame
   RA_config_t *ra = &mac->ra;
 
   if (ra->RA_contention_resolution_timer_active == 1) {
-
-      ra->RA_contention_resolution_cnt--;
-
-      LOG_D(MAC, "In %s: [%d.%d] RA contention resolution timer %d\n", __FUNCTION__, frame, slot, ra->RA_contention_resolution_cnt);
-
-      if (ra->RA_contention_resolution_cnt == 0) {
-        ra->t_crnti = 0;
-        ra->RA_active = 0;
-        ra->RA_contention_resolution_timer_active = 0;
-        // Signal PHY to quit RA procedure
-        LOG_E(MAC, "[UE %d] CB-RA: Contention resolution timer has expired, RA procedure has failed...\n", module_id);
-        nr_ra_failed(module_id, cc_id, prach_resources, frame, slot);
-      }
-    
+    if (frame >= ra->RA_contention_resolution_target_frame &&
+      slot >= ra->RA_contention_resolution_target_frame) {
+      ra->t_crnti = 0;
+      ra->RA_active = 0;
+      ra->RA_contention_resolution_timer_active = 0;
+      // Signal PHY to quit RA procedure
+      LOG_E(MAC, "[UE %d] CB-RA: Contention resolution timer has expired, RA procedure has failed...\n", module_id);
+      nr_ra_failed(module_id, cc_id, prach_resources, frame, slot);
+    }
   }
 }
 
@@ -773,7 +777,6 @@ void nr_ra_succeeded(module_id_t mod_id, frame_t frame, int slot){
 
     LOG_I(MAC, "[UE %d][%d.%d][RAPROC] RA procedure succeeded. CB-RA: Contention Resolution is successful.\n", mod_id, frame, slot);
 
-    ra->RA_contention_resolution_cnt = -1;
     ra->RA_contention_resolution_timer_active = 0;
     mac->crnti = ra->t_crnti;
     ra->t_crnti = 0;

openair2/LAYER2/NR_MAC_UE/nr_ue_scheduler.c

@@ -1091,7 +1091,7 @@ NR_UE_L2_STATE_t nr_ue_scheduler(nr_downlink_indication_t *dl_info, nr_uplink_in
 
           if (ra->ra_state == WAIT_RAR && !ra->cfra){
             LOG_I(NR_MAC,"[RAPROC] RA-Msg3 transmitted\n");
-            nr_Msg3_transmitted(ul_info->module_id, ul_info->cc_id, ul_info->frame_tx, ul_info->gNB_index);
+            nr_Msg3_transmitted(ul_info->module_id, ul_info->cc_id, ul_info->frame_tx, ul_info->slot_tx, ul_info->gNB_index);
           }
 
         }