improvements in handling RRC Release

openair2/RRC/NR_UE/rrc_UE.c

@@ -1623,15 +1623,14 @@ static int nr_rrc_ue_decode_dcch(NR_UE_RRC_INST_t *rrc,
         } break;
 
         case NR_DL_DCCH_MessageType__c1_PR_rrcResume:
-          LOG_I(NR_RRC, "Received rrcResume on DL-DCCH-Message\n");
+          LOG_E(NR_RRC, "Received rrcResume on DL-DCCH-Message -> Not handled\n");
           break;
         case NR_DL_DCCH_MessageType__c1_PR_rrcRelease:
           LOG_I(NR_RRC, "[UE %ld] Received RRC Release (gNB %d)\n", rrc->ue_id, gNB_indexP);
-          // TODO properly implement procedures in 5.3.8.3 of 38.331
-          NR_Release_Cause_t cause = OTHER;
-          if (rrc->detach_after_release)
-            rrc->nrRrcState = RRC_STATE_DETACH_NR;
-          nr_rrc_going_to_IDLE(rrc, cause, dl_dcch_msg->message.choice.c1->choice.rrcRelease);
+          // delay the actions 60 ms from the moment the RRCRelease message was received
+          UPDATE_IE(rrc->RRCRelease, dl_dcch_msg->message.choice.c1->choice.rrcRelease, NR_RRCRelease_t);
+          nr_timer_setup(&rrc->release_timer, 60, 10); // 10ms step
+          nr_timer_start(&rrc->release_timer);
           break;
 
         case NR_DL_DCCH_MessageType__c1_PR_ueCapabilityEnquiry:
@@ -2136,6 +2135,46 @@ static void process_lte_nsa_msg(NR_UE_RRC_INST_t *rrc, nsa_msg_t *msg, int msg_l
   }
 }
 
+void handle_RRCRelease(NR_UE_RRC_INST_t *rrc)
+{
+  NR_UE_Timers_Constants_t *tac = &rrc->timers_and_constants;
+  // stop timer T380, if running
+  nr_timer_stop(&tac->T380);
+  // stop timer T320, if running
+  nr_timer_stop(&tac->T320);
+  if (rrc->detach_after_release)
+    rrc->nrRrcState = RRC_STATE_DETACH_NR;
+  const struct NR_RRCRelease_IEs *rrcReleaseIEs = rrc->RRCRelease ? rrc->RRCRelease->criticalExtensions.choice.rrcRelease : NULL;
+  if (!rrc->as_security_activated) {
+    // ignore any field included in RRCRelease message except waitTime
+    // perform the actions upon going to RRC_IDLE as specified in 5.3.11 with the release cause 'other'
+    // upon which the procedure ends
+    NR_Release_Cause_t cause = OTHER;
+    nr_rrc_going_to_IDLE(rrc, cause, rrc->RRCRelease);
+    asn1cFreeStruc(asn_DEF_NR_RRCRelease, rrc->RRCRelease);
+    return;
+  }
+  bool suspend = false;
+  if (rrcReleaseIEs) {
+    if (rrcReleaseIEs->redirectedCarrierInfo)
+      LOG_E(NR_RRC, "redirectedCarrierInfo in RRCRelease not handled\n");
+    if (rrcReleaseIEs->cellReselectionPriorities)
+      LOG_E(NR_RRC, "cellReselectionPriorities in RRCRelease not handled\n");
+    if (rrcReleaseIEs->deprioritisationReq)
+      LOG_E(NR_RRC, "deprioritisationReq in RRCRelease not handled\n");
+    if (rrcReleaseIEs->suspendConfig) {
+      suspend = true;
+      // procedures to go in INACTIVE state
+      AssertFatal(false, "Inactive State not supported\n");
+    }
+  }
+  if (!suspend) {
+    NR_Release_Cause_t cause = OTHER;
+    nr_rrc_going_to_IDLE(rrc, cause, rrc->RRCRelease);
+  }
+  asn1cFreeStruc(asn_DEF_NR_RRCRelease, rrc->RRCRelease);
+}
+
 void nr_rrc_going_to_IDLE(NR_UE_RRC_INST_t *rrc,
                           NR_Release_Cause_t release_cause,
                           NR_RRCRelease_t *RRCRelease)

openair2/RRC/NR_UE/rrc_defs.h

@@ -159,6 +159,7 @@ typedef struct NR_UE_Timers_Constants_s {
   NR_timer_t T320;
   NR_timer_t T321;
   NR_timer_t T325;
+  NR_timer_t T380;
   NR_timer_t T390;
   // counters
   uint32_t N310_cnt;
@@ -217,10 +218,10 @@ typedef struct NR_UE_RRC_INST_s {
   long keyToUse;
   bool as_security_activated;
   bool detach_after_release;
-
-  long               selected_plmn_identity;
-  Rrc_State_NR_t     nrRrcState;
-  as_nas_info_t      initialNasMsg;
+  NR_timer_t release_timer;
+  NR_RRCRelease_t *RRCRelease;
+  long selected_plmn_identity;
+  Rrc_State_NR_t nrRrcState;
 
   //Sidelink params
   NR_SL_PreconfigurationNR_r16_t *sl_preconfig;

openair2/RRC/NR_UE/rrc_proto.h

@@ -86,7 +86,7 @@ void nr_mac_rrc_sync_ind(const module_id_t module_id,
 void nr_rrc_going_to_IDLE(NR_UE_RRC_INST_t *rrc,
                           NR_Release_Cause_t release_cause,
                           NR_RRCRelease_t *RRCRelease);
-
+void handle_RRCRelease(NR_UE_RRC_INST_t *rrc);
 void nr_mac_rrc_ra_ind(const module_id_t mod_id, int frame, bool success);
 void nr_mac_rrc_msg3_ind(const module_id_t mod_id, const int rnti, int gnb_id);
 void set_rlf_sib1_timers_and_constants(NR_UE_Timers_Constants_t *tac, NR_SIB1_t *sib1);

openair2/RRC/NR_UE/rrc_timers_and_constants.c

@@ -119,6 +119,10 @@ void nr_rrc_handle_timers(NR_UE_RRC_INST_t *rrc)
 {
   NR_UE_Timers_Constants_t *timers = &rrc->timers_and_constants;
 
+  bool release_timer_expired = nr_timer_tick(&rrc->release_timer);
+  if (release_timer_expired)
+    handle_RRCRelease(rrc);
+
   bool t300_expired = nr_timer_tick(&timers->T300);
   if(t300_expired) {
     LOG_W(NR_RRC, "Timer T300 expired! No timely response to RRCSetupRequest\n");