upper layers handling of radio link monitoring

nfapi/open-nFAPI/nfapi/public_inc/fapi_nr_ue_interface.h

@@ -49,6 +49,12 @@ typedef struct {
   uint32_t sr;
 } fapi_nr_uci_pdu_rel15_t;
 
+typedef enum {
+ RLM_no_monitoring = 0,
+ RLM_out_of_sync = 1,
+ RLM_in_sync = 2
+} rlm_t;
+
 typedef struct {
   uint32_t rsrp;
   int rsrp_dBm;
@@ -56,6 +62,7 @@ typedef struct {
   uint8_t i1;
   uint8_t i2;
   uint8_t cqi;
+  rlm_t radiolink_monitoring;
 } fapi_nr_csirs_measurements_t;
 
 typedef struct {
@@ -125,6 +132,7 @@ typedef struct {
   uint16_t cell_id;
   uint16_t ssb_start_subcarrier;
   short rsrp_dBm;
+  rlm_t radiolink_monitoring; // -1 no monitoring, 0 out_of_sync, 1 in_sync
 } fapi_nr_ssb_pdu_t;
 
 typedef struct {

openair1/PHY/NR_UE_TRANSPORT/csi_rx.c

@@ -1006,6 +1006,7 @@ void nr_ue_csi_rs_procedures(PHY_VARS_NR_UE *ue, UE_nr_rxtx_proc_t *proc, c16_t
   csirs_measurements.i1 = *i1;
   csirs_measurements.i2 = *i2;
   csirs_measurements.cqi = cqi;
+  csirs_measurements.radiolink_monitoring = RLM_no_monitoring; // TODO do be activated in case of RLM based on CSI-RS
   nr_downlink_indication_t dl_indication;
   fapi_nr_rx_indication_t rx_ind = {0};
   nr_fill_dl_indication(&dl_indication, NULL, &rx_ind, proc, ue, NULL);

openair1/SCHED_NR_UE/phy_procedures_nr_ue.c

@@ -159,15 +159,18 @@ void nr_fill_rx_indication(fapi_nr_rx_indication_t *rx_ind,
           fapiPbch_t *pbch = (fapiPbch_t *)typeSpecific;
           memcpy(ssb_pdu->pdu, pbch->decoded_output, sizeof(pbch->decoded_output));
           ssb_pdu->additional_bits = pbch->xtra_byte;
-          ssb_pdu->ssb_index = (frame_parms->ssb_index)&0x7;
+          ssb_pdu->ssb_index = (frame_parms->ssb_index) & 0x7;
           ssb_pdu->ssb_length = frame_parms->Lmax;
           ssb_pdu->cell_id = frame_parms->Nid_cell;
           ssb_pdu->ssb_start_subcarrier = frame_parms->ssb_start_subcarrier;
           ssb_pdu->rsrp_dBm = ue->measurements.ssb_rsrp_dBm[frame_parms->ssb_index];
+          ssb_pdu->radiolink_monitoring = RLM_in_sync; // TODO to be removed from here
           ssb_pdu->decoded_pdu = true;
         }
-        else
+        else {
+          ssb_pdu->radiolink_monitoring = RLM_out_of_sync; // TODO to be removed from here
           ssb_pdu->decoded_pdu = false;
+        }
       }
     break;
     case FAPI_NR_CSIRS_IND:

openair1/SIMULATION/NR_PHY/nr_dummy_functions.c

@@ -28,6 +28,10 @@ int nfapi_nr_p7_message_pack(void *pMessageBuf, void *pPackedBuf, uint32_t packe
 int nfapi_nr_p7_message_unpack(void *pMessageBuf, uint32_t messageBufLen, void *pUnpackedBuf, uint32_t unpackedBufLen, nfapi_p7_codec_config_t* config) { return 0; }
 int nfapi_p7_message_header_unpack(void *pMessageBuf, uint32_t messageBufLen, void *pUnpackedBuf, uint32_t unpackedBufLen, nfapi_p7_codec_config_t *config) { return 0; }
 
+void nr_mac_rrc_sync_ind(const module_id_t module_id,
+                         const frame_t frame,
+                         const bool in_sync) {}
+
 void rrc_data_ind(const protocol_ctxt_t *const ctxt_pP,
                   const rb_id_t                Srb_id,
                   const sdu_size_t             sdu_sizeP,

openair2/COMMON/mac_messages_def.h

@@ -30,6 +30,7 @@
 // Messages between RRC and MAC layers
 MESSAGE_DEF(RRC_MAC_IN_SYNC_IND,        MESSAGE_PRIORITY_MED_PLUS, RrcMacInSyncInd,             rrc_mac_in_sync_ind)
 MESSAGE_DEF(RRC_MAC_OUT_OF_SYNC_IND,    MESSAGE_PRIORITY_MED_PLUS, RrcMacOutOfSyncInd,          rrc_mac_out_of_sync_ind)
+MESSAGE_DEF(NR_RRC_MAC_SYNC_IND,        MESSAGE_PRIORITY_MED_PLUS, NRRrcMacSyncInd,             nr_rrc_mac_sync_ind)
 
 MESSAGE_DEF(RRC_MAC_BCCH_DATA_REQ,      MESSAGE_PRIORITY_MED_PLUS, RrcMacBcchDataReq,           rrc_mac_bcch_data_req)
 MESSAGE_DEF(RRC_MAC_BCCH_DATA_IND,      MESSAGE_PRIORITY_MED_PLUS, RrcMacBcchDataInd,           rrc_mac_bcch_data_ind)

openair2/COMMON/mac_messages_types.h

@@ -36,13 +36,14 @@
 // Defines to access message fields.
 #define RRC_MAC_IN_SYNC_IND(mSGpTR)             (mSGpTR)->ittiMsg.rrc_mac_in_sync_ind
 #define RRC_MAC_OUT_OF_SYNC_IND(mSGpTR)         (mSGpTR)->ittiMsg.rrc_mac_out_of_sync_ind
+#define NR_RRC_MAC_SYNC_IND(mSGpTR)             (mSGpTR)->ittiMsg.nr_rrc_mac_sync_ind
 
 #define RRC_MAC_BCCH_DATA_REQ(mSGpTR)           (mSGpTR)->ittiMsg.rrc_mac_bcch_data_req
 #define RRC_MAC_BCCH_DATA_IND(mSGpTR)           (mSGpTR)->ittiMsg.rrc_mac_bcch_data_ind
 #define NR_RRC_MAC_BCCH_DATA_IND(mSGpTR)        (mSGpTR)->ittiMsg.nr_rrc_mac_bcch_data_ind
 
-#define RRC_MAC_BCCH_MBMS_DATA_REQ(mSGpTR)           (mSGpTR)->ittiMsg.rrc_mac_bcch_mbms_data_req
-#define RRC_MAC_BCCH_MBMS_DATA_IND(mSGpTR)           (mSGpTR)->ittiMsg.rrc_mac_bcch_mbms_data_ind
+#define RRC_MAC_BCCH_MBMS_DATA_REQ(mSGpTR)      (mSGpTR)->ittiMsg.rrc_mac_bcch_mbms_data_req
+#define RRC_MAC_BCCH_MBMS_DATA_IND(mSGpTR)      (mSGpTR)->ittiMsg.rrc_mac_bcch_mbms_data_ind
 
 #define RRC_MAC_CCCH_DATA_REQ(mSGpTR)           (mSGpTR)->ittiMsg.rrc_mac_ccch_data_req
 #define RRC_MAC_CCCH_DATA_CNF(mSGpTR)           (mSGpTR)->ittiMsg.rrc_mac_ccch_data_cnf
@@ -72,6 +73,11 @@ typedef struct RrcMacInSyncInd_s {
 
 typedef RrcMacInSyncInd RrcMacOutOfSyncInd;
 
+typedef struct NRRrcMacSyncInd_s {
+  uint32_t frame;
+  bool in_sync;
+} NRRrcMacSyncInd;
+
 typedef struct RrcMacBcchDataReq_s {
   uint32_t  frame;
   uint32_t  sdu_size;

openair2/LAYER2/NR_MAC_UE/mac_defs.h

@@ -367,12 +367,9 @@ typedef struct {
 } PUCCH_sched_t;
 
 typedef struct {
-
   uint32_t ssb_index;
   /// SSB RSRP in dBm
   short ssb_rsrp_dBm;
-  int consecutive_bch_failures;
-
 } NR_SSB_meas_t;
 
 typedef struct NR_UL_TIME_ALIGNMENT {

openair2/LAYER2/NR_MAC_UE/nr_ue_procedures.c

@@ -269,8 +269,6 @@ int8_t nr_ue_decode_mib(module_id_t module_id,
     
   AssertFatal(mac->mib != NULL, "nr_ue_decode_mib() mac->mib == NULL\n");
 
-  mac->ssb_measurements.consecutive_bch_failures = 0; // resetting decoding failures
-
   uint16_t frame = (mac->mib->systemFrameNumber.buf[0] >> mac->mib->systemFrameNumber.bits_unused);
   uint16_t frame_number_4lsb = 0;
 

openair2/NR_UE_PHY_INTERFACE/NR_IF_Module.c

@@ -1052,14 +1052,6 @@ int handle_bcch_bch(module_id_t module_id, int cc_id,
 
 }
 
-void handle_bch_failure(NR_UE_MAC_INST_t *mac)
-{
-  mac->ssb_measurements.consecutive_bch_failures++;
-  //TODO handle this properly by scheduling re-synchronization
-  AssertFatal(mac->ssb_measurements.consecutive_bch_failures < 100,
-              "Radio link failure caused by 100 consecutive PBCH detection failures.\n");
-}
-
 //  L2 Abstraction Layer
 int handle_bcch_dlsch(module_id_t module_id, int cc_id, unsigned int gNB_index, uint8_t ack_nack, uint8_t *pduP, uint32_t pdu_len){
   return nr_ue_decode_BCCH_DL_SCH(module_id, cc_id, gNB_index, ack_nack, pduP, pdu_len);
@@ -1098,7 +1090,17 @@ int8_t handle_dlsch(nr_downlink_indication_t *dl_info, int pdu_id)
   return 0;
 }
 
-int8_t handle_csirs_measurements(module_id_t module_id, frame_t frame, int slot, fapi_nr_csirs_measurements_t *csirs_measurements) {
+void handle_rlm(rlm_t rlm_result, int frame, module_id_t module_id)
+{
+  if (rlm_result == RLM_no_monitoring)
+    return;
+  bool is_sync = rlm_result == RLM_in_sync ? true : false;
+  nr_mac_rrc_sync_ind(module_id, frame, is_sync);
+}
+
+int8_t handle_csirs_measurements(module_id_t module_id, frame_t frame, int slot, fapi_nr_csirs_measurements_t *csirs_measurements)
+{
+  handle_rlm(csirs_measurements->radiolink_monitoring, frame, module_id);
   return nr_ue_process_csirs_measurements(module_id, frame, slot, csirs_measurements);
 }
 
@@ -1197,6 +1199,9 @@ int nr_ue_dl_indication(nr_downlink_indication_t *dl_info)
 
         switch(rx_indication_body.pdu_type){
           case FAPI_NR_RX_PDU_TYPE_SSB:
+            handle_rlm(rx_indication_body.ssb_pdu.radiolink_monitoring,
+                       dl_info->frame,
+                       dl_info->module_id);
             if(rx_indication_body.ssb_pdu.decoded_pdu) {
               handle_ssb_meas(mac,
                               rx_indication_body.ssb_pdu.ssb_index,
@@ -1209,8 +1214,6 @@ int nr_ue_dl_indication(nr_downlink_indication_t *dl_info)
                                            rx_indication_body.ssb_pdu.ssb_start_subcarrier,
                                            rx_indication_body.ssb_pdu.cell_id)) << FAPI_NR_RX_PDU_TYPE_SSB;
             }
-            else
-              handle_bch_failure(mac);
             break;
           case FAPI_NR_RX_PDU_TYPE_SIB:
             ret_mask |= (handle_bcch_dlsch(dl_info->module_id,

openair2/RRC/NR_UE/L2_interface_ue.c

@@ -39,6 +39,16 @@
 
 typedef uint32_t channel_t;
 
+void nr_mac_rrc_sync_ind(const module_id_t module_id,
+                         const frame_t frame,
+                         const bool in_sync)
+{
+  MessageDef *message_p = itti_alloc_new_message(TASK_MAC_UE, 0, NR_RRC_MAC_SYNC_IND);
+  NR_RRC_MAC_SYNC_IND (message_p).frame = frame;
+  NR_RRC_MAC_SYNC_IND (message_p).in_sync = in_sync;
+  itti_send_msg_to_task(TASK_RRC_NRUE, GNB_MODULE_ID_TO_INSTANCE(module_id), message_p);
+}
+
 int8_t nr_mac_rrc_data_ind_ue(const module_id_t module_id,
                               const int CC_id,
                               const uint8_t gNB_index,

openair2/RRC/NR_UE/rrc_UE.c

@@ -2264,24 +2264,6 @@ nr_rrc_ue_establish_srb2(
    return 0;
  }
 
-
-void nr_rrc_handle_timers(unsigned int mod_id)
-{
-  NR_UE_Timers_Constants_t *timers = &NR_UE_rrc_inst[mod_id].timers_and_constants;
-  // T304
-  if (timers->T304_active == true) {
-    timers->T304_cnt += 10;
-    if(timers->T304_cnt >= timers->T304_k) {
-      // TODO
-      // For T304 of MCG, in case of the handover from NR or intra-NR
-      // handover, initiate the RRC re-establishment procedure;
-      // In case of handover to NR, perform the actions defined in the
-      // specifications applicable for the source RAT.
-    }
-  }
-}
-
-
 void *rrc_nrue_task(void *args_p)
 {
    MessageDef *msg_p;
@@ -2308,10 +2290,22 @@ void *rrc_nrue_task(void *args_p)
          LOG_D(NR_RRC, "[UE %d] Received %s\n", ue_mod_id, ITTI_MSG_NAME (msg_p));
          break;
 
+       case NR_RRC_MAC_SYNC_IND:
+         LOG_D(NR_RRC, "[UE %d] Received %s: frame %d\n",
+               ue_mod_id,
+               ITTI_MSG_NAME (msg_p),
+               NR_RRC_MAC_SYNC_IND (msg_p).frame);
+         nr_sync_msg_t sync_msg = NR_RRC_MAC_SYNC_IND (msg_p).in_sync ?
+                                  IN_SYNC : OUT_OF_SYNC;
+         NR_UE_Timers_Constants_t *tac = &NR_UE_rrc_inst[ue_mod_id].timers_and_constants;
+         handle_rlf_sync(tac, sync_msg);
+         break;
+
        case NRRRC_SLOT_PROCESS:
          LOG_D(NR_RRC, "[UE %d] Receided %s: frame %d slot %d\n",
                ue_mod_id, ITTI_MSG_NAME (msg_p), NRRRC_SLOT_PROCESS (msg_p).frame, NRRRC_SLOT_PROCESS (msg_p).slot);
-         nr_rrc_handle_timers(ue_mod_id);
+         NR_UE_Timers_Constants_t *timers = &NR_UE_rrc_inst[ue_mod_id].timers_and_constants;
+         nr_rrc_handle_timers(timers);
          break;
 
        case NR_RRC_MAC_BCCH_DATA_IND:

openair2/RRC/NR_UE/rrc_defs.h

@@ -182,6 +182,11 @@ typedef struct NR_UE_Timers_Constants_s {
   uint32_t T319_k;
 } NR_UE_Timers_Constants_t;
 
+typedef enum {
+  OUT_OF_SYNC = 0,
+  IN_SYNC = 1
+} nr_sync_msg_t;
+
 typedef struct NR_UE_RRC_INST_s {
 
     NR_MeasConfig_t        *meas_config;

openair2/RRC/NR_UE/rrc_proto.h

@@ -113,6 +113,10 @@ int8_t nr_mac_rrc_data_ind_ue(const module_id_t module_id,
                               const uint8_t* pduP,
                               const sdu_size_t pdu_len);
 
+void nr_mac_rrc_sync_ind(const module_id_t module_id,
+                         const frame_t frame,
+                         const bool in_sync);
+
 /**\brief
    \param module_id  module id
    \param CC_id      component carrier id
@@ -133,8 +137,7 @@ int8_t nr_rrc_RA_succeeded(const module_id_t mod_id, const uint8_t gNB_index);
    \param void *args_p Pointer on arguments to start the task. */
 void *rrc_nrue_task(void *args_p);
 
-/**\brief RRC timers update at UE. */
-void *nr_rrc_timers_update();
+void nr_rrc_handle_timers(NR_UE_Timers_Constants_t *timers);
 
 /**\brief RRC NSA UE task.
    \param void *args_p Pointer on arguments to start the task. */
@@ -162,6 +165,8 @@ void reset_rlf_timers_and_constants(NR_UE_Timers_Constants_t *tac);
 void set_default_timers_and_constants(NR_UE_Timers_Constants_t *tac);
 void nr_rrc_set_sib1_timers_and_constants(NR_UE_Timers_Constants_t *tac, NR_SIB1_t *sib1);
 void nr_rrc_set_T304(NR_UE_Timers_Constants_t *tac, NR_ReconfigurationWithSync_t *reconfigurationWithSync);
+void handle_rlf_sync(NR_UE_Timers_Constants_t *tac,
+                     nr_sync_msg_t sync_msg);
 void nr_rrc_handle_SetupRelease_RLF_TimersAndConstants(NR_UE_RRC_INST_t *rrc,
                                                        struct NR_SetupRelease_RLF_TimersAndConstants *rlf_TimersAndConstants);
 

openair2/RRC/NR_UE/rrc_timers_and_constants.c

@@ -21,6 +21,29 @@
 
 #include "openair2/RRC/NR_UE/rrc_proto.h"
 
+void nr_rrc_handle_timers(NR_UE_Timers_Constants_t *timers)
+{
+  // T304
+  if (timers->T304_active == true) {
+    timers->T304_cnt += 10;
+    if(timers->T304_cnt >= timers->T304_k) {
+      // TODO
+      // For T304 of MCG, in case of the handover from NR or intra-NR
+      // handover, initiate the RRC re-establishment procedure;
+      // In case of handover to NR, perform the actions defined in the
+      // specifications applicable for the source RAT.
+    }
+  }
+  if (timers->T310_active == true) {
+    timers->T310_cnt += 10;
+    if(timers->T310_cnt >= timers->T310_k) {
+      // TODO
+      // handle detection of radio link failure
+      // as described in 5.3.10.3 of 38.331
+      AssertFatal(false, "Radio link failure! Not handled yet!\n");
+    }
+  }
+}
 
 void nr_rrc_set_T304(NR_UE_Timers_Constants_t *tac, NR_ReconfigurationWithSync_t *reconfigurationWithSync)
 {
@@ -402,6 +425,43 @@ void nr_rrc_handle_SetupRelease_RLF_TimersAndConstants(NR_UE_RRC_INST_t *rrc,
   }
 }
 
+void handle_rlf_sync(NR_UE_Timers_Constants_t *tac,
+                     nr_sync_msg_t sync_msg)
+{
+  if (sync_msg == IN_SYNC) {
+    tac->N310_cnt = 0;
+    if (tac->T310_active) {
+      tac->N311_cnt++;
+      // Upon receiving N311 consecutive "in-sync" indications
+      if (tac->N311_cnt >= tac->N311_k) {
+        // stop timer T310
+        tac->T310_active = false;
+        tac->T310_cnt = 0;
+        tac->N311_cnt = 0;
+      }
+    }
+  }
+  else {
+    // OUT_OF_SYNC
+    tac->N311_cnt = 0;
+    if(tac->T300_active ||
+       tac->T301_active ||
+       tac->T304_active ||
+       tac->T310_active ||
+       tac->T311_active ||
+       tac->T319_active)
+      return;
+    tac->N310_cnt++;
+    // upon receiving N310 consecutive "out-of-sync" indications
+    if (tac->N310_cnt >= tac->N310_k) {
+      // start timer T310
+        tac->T310_active = true;
+        tac->T310_cnt = 0;
+        tac->N310_cnt = 0;
+    }
+  }
+}
+
 void set_default_timers_and_constants(NR_UE_Timers_Constants_t *tac)
 {
   // 38.331 9.2.3 Default values timers and constants