rrc inactivity timer created, S1 ue context release request sent on timeout,...

rrc inactivity timer created, S1 ue context release request sent on timeout, timer set at RRC connection complete reception

openair2/RRC/LTE/L2_interface.c

@@ -279,6 +279,9 @@ mac_rrc_data_ind(
 }
 
 //------------------------------------------------------------------------------
+/*
+* Get RRC status (Connected, Idle...) of UE from RNTI
+*/
 int
 mac_eNB_get_rrc_status(
   const module_id_t Mod_idP,
@@ -287,9 +290,7 @@ mac_eNB_get_rrc_status(
 //------------------------------------------------------------------------------
 {
   struct rrc_eNB_ue_context_s* ue_context_p = NULL;
-  ue_context_p = rrc_eNB_get_ue_context(
-                   RC.rrc[Mod_idP],
-                   rntiP);
+  ue_context_p = rrc_eNB_get_ue_context(RC.rrc[Mod_idP], rntiP);
 
   if (ue_context_p != NULL) {
     return(ue_context_p->ue_context.Status);

openair2/RRC/LTE/rrc_defs.h

@@ -552,7 +552,7 @@ typedef struct eNB_RRC_UE_s {
   CipheringAlgorithm_r12_t                          ciphering_algorithm;
   e_SecurityAlgorithmConfig__integrityProtAlgorithm integrity_algorithm;
 
-  uint8_t                            Status;
+  uint8_t                            Status; // RRC status, type enum UE_STATE_t
   rnti_t                             rnti;
   uint64_t                           random_ue_identity;
 
@@ -599,6 +599,9 @@ typedef struct eNB_RRC_UE_s {
   uint32_t                           ue_release_timer_thres_rrc;
   uint32_t                           ue_reestablishment_timer;
   uint32_t                           ue_reestablishment_timer_thres;
+  /* RRC inactivity timer: on timeout, should release RRC connection for inactivity on all E-RABs */
+  uint32_t                           ue_rrc_inactivity_timer;
+  uint32_t                           ue_rrc_inactivity_timer_thres;     
   uint8_t                            e_rab_release_command_flag;
   int8_t                             reestablishment_xid;
 } eNB_RRC_UE_t;

openair2/RRC/LTE/rrc_eNB.c

@@ -862,13 +862,13 @@ rrc_eNB_free_UE(
       rnti);
 
     if (EPC_MODE_ENABLED) {
-      if((ue_context_pP->ue_context.ul_failure_timer >= 20000) && (mac_eNB_get_rrc_status(enb_mod_idP,rnti) >= RRC_CONNECTED)) {
-        LOG_I(RRC, "[eNB %d] S1AP_UE_CONTEXT_RELEASE_REQ sent for RNTI %x\n", 
+      if((ue_context_pP->ue_context.ul_failure_timer >= 20000) && (mac_eNB_get_rrc_status(enb_mod_idP, rnti) >= RRC_CONNECTED)) {
+        LOG_I(RRC, "[eNB %d] S1AP_UE_CONTEXT_RELEASE_REQ sent for RNTI %x, cause 21, radio connection with ue lost\n", 
           enb_mod_idP, 
           rnti);
         
         rrc_eNB_send_S1AP_UE_CONTEXT_RELEASE_REQ(enb_mod_idP, ue_context_pP, S1AP_CAUSE_RADIO_NETWORK, 21); 
-        // send cause 21: connection with ue lost
+        // send cause 21: radio connection with ue lost
         /* From 3GPP 36300v10 p129 : 19.2.2.2.2 S1 UE Context Release Request (eNB triggered)
          * If the E-UTRAN internal reason is a radio link failure detected in the eNB, the eNB shall wait a sufficient time before
          *  triggering the S1 UE Context Release Request procedure in order to allow the UE to perform the NAS recovery
@@ -877,7 +877,18 @@ rrc_eNB_free_UE(
          
         return;
       }
-      // TODO : add here cause ul inactivity
+      
+      if((ue_context_pP->ue_context.ue_rrc_inactivity_timer >= ue_context_pP->ue_context.ue_rrc_inactivity_timer_thres) &&
+        (mac_eNB_get_rrc_status(enb_mod_idP, rnti) >= RRC_CONNECTED)) {
+        LOG_I(RRC, "[eNB %d] S1AP_UE_CONTEXT_RELEASE_REQ sent for RNTI %x, cause 20, user inactivity\n", 
+          enb_mod_idP, 
+          rnti);
+        
+        rrc_eNB_send_S1AP_UE_CONTEXT_RELEASE_REQ(enb_mod_idP, ue_context_pP, S1AP_CAUSE_RADIO_NETWORK, 20); 
+        // send cause 20: user inactivity
+
+        return;
+      }
     }
 
     // add UE info to freeList
@@ -1012,11 +1023,14 @@ void release_UE_in_freeList(module_id_t mod_id)
 }
 
 //-----------------------------------------------------------------------------
+/*
+* Process the rrc connection setup complete message from UE (SRB1 Active)
+*/
 void
 rrc_eNB_process_RRCConnectionSetupComplete(
-  const protocol_ctxt_t* const ctxt_pP,
-  rrc_eNB_ue_context_t*         ue_context_pP,
-  RRCConnectionSetupComplete_r8_IEs_t * rrcConnectionSetupComplete
+  const protocol_ctxt_t *const ctxt_pP,
+  rrc_eNB_ue_context_t *ue_context_pP,
+  RRCConnectionSetupComplete_r8_IEs_t *rrcConnectionSetupComplete
 )
 //-----------------------------------------------------------------------------
 {
@@ -1024,22 +1038,19 @@ rrc_eNB_process_RRCConnectionSetupComplete(
         PROTOCOL_RRC_CTXT_UE_FMT" [RAPROC] Logical Channel UL-DCCH, " "processing RRCConnectionSetupComplete from UE (SRB1 Active)\n",
         PROTOCOL_RRC_CTXT_UE_ARGS(ctxt_pP));
 
-  ue_context_pP->ue_context.Srb1.Active=1;  
+  ue_context_pP->ue_context.Srb1.Active = 1;
+  ue_context_pP->ue_context.Status = RRC_CONNECTED;
+  ue_context_pP->ue_context.ue_rrc_inactivity_timer = 1; // set rrc inactivity when UE goes into RRC_CONNECTED
+
   T(T_ENB_RRC_CONNECTION_SETUP_COMPLETE, T_INT(ctxt_pP->module_id), T_INT(ctxt_pP->frame),
     T_INT(ctxt_pP->subframe), T_INT(ctxt_pP->rnti));
 
   if (EPC_MODE_ENABLED == 1) {
     // Forward message to S1AP layer
-    rrc_eNB_send_S1AP_NAS_FIRST_REQ(
-      ctxt_pP,
-      ue_context_pP,
-      rrcConnectionSetupComplete);
+    rrc_eNB_send_S1AP_NAS_FIRST_REQ(ctxt_pP, ue_context_pP, rrcConnectionSetupComplete);
   } else {
     // RRC loop back (no S1AP), send SecurityModeCommand to UE
-    rrc_eNB_generate_SecurityModeCommand(
-      ctxt_pP,
-      ue_context_pP);
-    // rrc_eNB_generate_UECapabilityEnquiry(enb_mod_idP,frameP,ue_mod_idP);
+    rrc_eNB_generate_SecurityModeCommand(ctxt_pP, ue_context_pP);
   }
 }
 
@@ -5364,6 +5375,11 @@ rrc_eNB_generate_RRCConnectionReconfiguration_handover(
 */
 
 //-----------------------------------------------------------------------------
+/*
+* TODO: * add function description
+*       * add ue_rrc_inactivity_timer set
+*       * format the function correctly
+*/
 void
 rrc_eNB_process_RRCConnectionReconfigurationComplete(
   const protocol_ctxt_t* const ctxt_pP,
@@ -6868,7 +6884,6 @@ if (ue_context_p->ue_context.nb_of_modify_e_rabs > 0) {
             ctxt_pP,
             ue_context_p,
             &ul_dcch_msg->message.choice.c1.choice.rrcConnectionSetupComplete.criticalExtensions.choice.c1.choice.rrcConnectionSetupComplete_r8);
-          ue_context_p->ue_context.Status = RRC_CONNECTED;
           LOG_I(RRC, PROTOCOL_RRC_CTXT_UE_FMT" UE State = RRC_CONNECTED \n",
                 PROTOCOL_RRC_CTXT_UE_ARGS(ctxt_pP));
 	  
@@ -7901,6 +7916,18 @@ rrc_rx_tx(
       } // end if (rrc_release_info.num_UEs > 0)
       pthread_mutex_unlock(&rrc_release_freelist);
 
+      if (ue_context_p->ue_context.ue_rrc_inactivity_timer > 0) {
+        ue_context_p->ue_context.ue_rrc_inactivity_timer++;
+
+        if (ue_context_p->ue_context.ue_rrc_inactivity_timer >= ue_context_p->ue_context.ue_rrc_inactivity_timer_thres) {
+          LOG_I(RRC, "Removing UE %x instance because of rrc_inactivity_timer timeout\n", 
+            ue_context_p->ue_context.rnti);
+          
+          ue_to_be_removed = ue_context_p;
+          break; // break RB_FOREACH
+        }
+      }
+
       if (ue_context_p->ue_context.ue_reestablishment_timer > 0) {
         ue_context_p->ue_context.ue_reestablishment_timer++;
 
@@ -7935,7 +7962,8 @@ rrc_rx_tx(
     } // end RB_FOREACH
 
     if (ue_to_be_removed) {
-      if (ue_to_be_removed->ue_context.ul_failure_timer >= 20000) {
+      if ((ue_to_be_removed->ue_context.ul_failure_timer >= 20000) || 
+        (ue_to_be_removed->ue_context.ue_rrc_inactivity_timer >= ue_to_be_removed->ue_context.ue_rrc_inactivity_timer_thres)) {
         ue_to_be_removed->ue_context.ue_release_timer_s1 = 1;
         ue_to_be_removed->ue_context.ue_release_timer_thres_s1 = 100;
         ue_to_be_removed->ue_context.ue_release_timer = 0;
@@ -7947,6 +7975,10 @@ rrc_rx_tx(
       if (ue_to_be_removed->ue_context.ul_failure_timer >= 20000) {
         ue_to_be_removed->ue_context.ul_failure_timer = 0;
       }
+
+      if (ue_to_be_removed->ue_context.ue_rrc_inactivity_timer >= ue_to_be_removed->ue_context.ue_rrc_inactivity_timer_thres) {
+        ue_to_be_removed->ue_context.ue_rrc_inactivity_timer = 0; //reset timer after S1 command UE context release request is sent
+      }
     }
 
 #ifdef RRC_LOCALIZATION