improvements in retxBSR_Timer implementation

openair2/LAYER2/NR_MAC_UE/config_ue.c

@@ -1590,6 +1590,50 @@ static uint32_t get_sr_DelayTimer(long logicalChannelSR_DelayTimer)
   return timer;
 }
 
+static uint32_t nr_get_sf_retxBSRTimer(long retxBSR_Timer)
+{
+  uint32_t timer = 0;
+  switch (retxBSR_Timer) {
+    case NR_BSR_Config__retxBSR_Timer_sf10:
+      timer = 10;
+      break;
+    case NR_BSR_Config__retxBSR_Timer_sf20:
+      timer = 20;
+      break;
+    case NR_BSR_Config__retxBSR_Timer_sf40:
+      timer = 40;
+      break;
+    case NR_BSR_Config__retxBSR_Timer_sf80:
+      timer = 80;
+      break;
+    case NR_BSR_Config__retxBSR_Timer_sf160:
+      timer = 160;
+      break;
+    case NR_BSR_Config__retxBSR_Timer_sf320:
+      timer = 320;
+      break;
+    case NR_BSR_Config__retxBSR_Timer_sf640:
+      timer = 640;
+      break;
+    case NR_BSR_Config__retxBSR_Timer_sf1280:
+      timer = 1280;
+      break;
+    case NR_BSR_Config__retxBSR_Timer_sf2560:
+      timer = 2560;
+      break;
+    case NR_BSR_Config__retxBSR_Timer_sf5120:
+      timer = 5120;
+      break;
+    case NR_BSR_Config__retxBSR_Timer_sf10240:
+      timer = 10240;
+      break;
+    default:
+      AssertFatal(false, "Invalid retxBSR_Timer %ld\n", retxBSR_Timer);
+  }
+  return timer;
+}
+
+
 static void configure_maccellgroup(NR_UE_MAC_INST_t *mac, const NR_MAC_CellGroupConfig_t *mcg)
 {
   NR_UE_SCHEDULING_INFO *si = &mac->scheduling_info;
@@ -1625,10 +1669,11 @@ static void configure_maccellgroup(NR_UE_MAC_INST_t *mac, const NR_MAC_CellGroup
   if (mcg->bsr_Config) {
     int subframes_per_slot = nr_slots_per_frame[mac->current_UL_BWP->scs] / 10;
     si->periodicBSR_Timer = mcg->bsr_Config->periodicBSR_Timer;
-    si->retxBSR_Timer = mcg->bsr_Config->retxBSR_Timer;
+    uint32_t retx_sf = nr_get_sf_retxBSRTimer(mcg->bsr_Config->retxBSR_Timer);
+    nr_timer_setup(&si->retxBSR_Timer, retx_sf * subframes_per_slot, 1); // 1 slot update rate
     if (mcg->bsr_Config->logicalChannelSR_DelayTimer) {
-      uint32_t target_sf = get_sr_DelayTimer(*mcg->bsr_Config->logicalChannelSR_DelayTimer);
-      nr_timer_setup(&si->sr_DelayTimer, target_sf * subframes_per_slot, 1); // 1 slot update rate
+      uint32_t dt_sf = get_sr_DelayTimer(*mcg->bsr_Config->logicalChannelSR_DelayTimer);
+      nr_timer_setup(&si->sr_DelayTimer, dt_sf * subframes_per_slot, 1); // 1 slot update rate
     }
   }
   if (mcg->tag_Config) {

openair2/LAYER2/NR_MAC_UE/mac_defs.h

@@ -214,10 +214,8 @@ typedef struct {
   uint16_t SR_COUNTER;
   // logicalChannelSR-DelayTimer
   NR_timer_t sr_DelayTimer;
-  /// retxBSR-Timer, default value is sf2560
-  uint16_t retxBSR_Timer;
-  /// retxBSR_SF, number of subframe before triggering a regular BSR
-  uint16_t retxBSR_SF;
+  /// retxBSR-Timer
+  NR_timer_t retxBSR_Timer;
   /// periodicBSR-Timer, default to infinity
   uint16_t periodicBSR_Timer;
   /// periodicBSR_SF, number of subframe before triggering a periodic BSR

openair2/LAYER2/NR_MAC_UE/mac_proto.h

@@ -146,13 +146,6 @@ uint8_t nr_locate_BsrIndexByBufferSize(const uint32_t *table, int size,
 */
 int nr_get_sf_periodicBSRTimer(uint8_t bucketSize);
 
-/*! \fn  int nr_get_sf_retxBSRTimer(uint8_t retxBSR_Timer)
-   \brief get the number of subframe form the bucket size duration configured by the higher layer
-\param[in]  retxBSR_Timer timer for regular BSR
-\return the time in sf
-*/
-int nr_get_sf_retxBSRTimer(uint8_t retxBSR_Timer);
-
 int8_t nr_ue_process_dci(NR_UE_MAC_INST_t *mac,
                          int cc_id,
                          frame_t frame,

openair2/LAYER2/NR_MAC_UE/main_ue_nr.c

@@ -94,7 +94,12 @@ void nr_ue_init_mac(NR_UE_MAC_INST_t *mac)
 void nr_ue_mac_default_configs(NR_UE_MAC_INST_t *mac)
 {
   // default values as defined in 38.331 sec 9.2.2
-  mac->scheduling_info.retxBSR_Timer = NR_BSR_Config__retxBSR_Timer_sf80;
+
+  // sf80 default for retxBSR_Timer
+  int mu = mac->current_UL_BWP ? mac->current_UL_BWP->scs : get_softmodem_params()->numerology;
+  int subframes_per_slot = nr_slots_per_frame[mu] / 10;
+  nr_timer_setup(&mac->scheduling_info.retxBSR_Timer, 80 * subframes_per_slot, 1); // 1 slot update rate
+
   mac->scheduling_info.periodicBSR_Timer = NR_BSR_Config__periodicBSR_Timer_sf10;
   mac->scheduling_info.periodicPHR_Timer = NR_PHR_Config__phr_PeriodicTimer_sf10;
   mac->scheduling_info.prohibitPHR_Timer = NR_PHR_Config__phr_ProhibitTimer_sf10;
@@ -170,6 +175,7 @@ void reset_mac_inst(NR_UE_MAC_INST_t *nr_mac)
   }
   nr_timer_stop(&nr_mac->ra.contention_resolution_timer);
   nr_timer_stop(&nr_mac->scheduling_info.sr_DelayTimer);
+  nr_timer_stop(&nr_mac->scheduling_info.retxBSR_Timer);
 
   // consider all timeAlignmentTimers as expired and perform the corresponding actions in clause 5.2
   // TODO
@@ -197,7 +203,6 @@ void reset_mac_inst(NR_UE_MAC_INST_t *nr_mac)
 
   // cancel any triggered Buffer Status Reporting procedure
   nr_mac->scheduling_info.periodicBSR_SF = NR_MAC_UE_BSR_TIMER_NOT_RUNNING;
-  nr_mac->scheduling_info.retxBSR_SF = NR_MAC_UE_BSR_TIMER_NOT_RUNNING;
   nr_mac->BSR_reporting_active = NR_BSR_TRIGGER_NONE;
 
   // cancel any triggered Power Headroom Reporting procedure

openair2/LAYER2/NR_MAC_UE/nr_ue_scheduler.c

@@ -115,10 +115,40 @@ NR_LC_SCHEDULING_INFO *get_scheduling_info_from_lcid(NR_UE_MAC_INST_t *mac, NR_L
   return &mac->scheduling_info.lc_sched_info[idx];
 }
 
+static void trigger_regular_bsr(NR_UE_MAC_INST_t *mac, bool sr_DelayTimerApplied)
+{
+  // call SR procedure to generate pending SR and BSR for next PUCCH/PUSCH TxOp.  This should implement the procedures
+  // outlined in Sections 5.4.4 an 5.4.5 of 38.321
+  mac->scheduling_info.SR_pending = 1;
+  // Regular BSR trigger
+  mac->BSR_reporting_active |= NR_BSR_TRIGGER_REGULAR;
+  // if the BSR is triggered for a logical channel for which logicalChannelSR-DelayTimerApplied with value true
+  // start or restart the logicalChannelSR-DelayTimer
+  // else stop the logicalChannelSR-DelayTimer
+  if (sr_DelayTimerApplied)
+    nr_timer_start(&mac->scheduling_info.sr_DelayTimer);
+  else
+    nr_timer_stop(&mac->scheduling_info.sr_DelayTimer);
+}
+
 void update_mac_timers(NR_UE_MAC_INST_t *mac)
 {
   nr_timer_tick(&mac->ra.contention_resolution_timer);
   nr_timer_tick(&mac->scheduling_info.sr_DelayTimer);
+  bool retxBSR_expired = nr_timer_tick(&mac->scheduling_info.retxBSR_Timer);
+  if (retxBSR_expired) {
+    LOG_D(NR_MAC, "retxBSR timer expired\n");
+    for (int i = 0; i < mac->lc_ordered_list.count; i++) {
+      nr_lcordered_info_t *lc_info = mac->lc_ordered_list.array[i];
+      NR_LogicalChannelIdentity_t lcid = lc_info->lcid;
+      // if at least one of the logical channels which belong to an LCG contains UL data
+      NR_LC_SCHEDULING_INFO *lc_sched_info = get_scheduling_info_from_lcid(mac, lcid);
+      if (lc_sched_info->LCGID < NR_MAX_NUM_LCGID && lc_sched_info->LCID_buffer_remain > 0) {
+        LOG_D(NR_MAC, "Triggering regular BSR after retxBSR timer expired\n");
+        trigger_regular_bsr(mac, lc_info->sr_DelayTimerApplied);
+      }
+    }
+  }
   for (int i = 0; i < NR_MAX_NUM_LCID; i++)
     AssertFatal(!nr_timer_tick(&mac->scheduling_info.lc_sched_info[i].Bj_timer),
                 "Bj timer for LCID %d expired! That should never happen\n",
@@ -574,7 +604,7 @@ int nr_config_pusch_pdu(NR_UE_MAC_INST_t *mac,
     //Optional Data only included if indicated in pduBitmap
     pusch_config_pdu->pusch_data.rv_index = 0;  // 8.3 in 38.213
     pusch_config_pdu->pusch_data.harq_process_id = 0;
-    pusch_config_pdu->pusch_data.new_data_indicator = 1; // new data
+    pusch_config_pdu->pusch_data.new_data_indicator = true; // new data
     pusch_config_pdu->pusch_data.num_cb = 0;
     pusch_config_pdu->tbslbrm = 0;
 
@@ -825,6 +855,10 @@ int nr_config_pusch_pdu(NR_UE_MAC_INST_t *mac,
 
   pusch_config_pdu->ldpcBaseGraph = get_BG(pusch_config_pdu->pusch_data.tb_size << 3, pusch_config_pdu->target_code_rate);
 
+  //The MAC entity shall restart retxBSR-Timer upon reception of a grant for transmission of new data on any UL-SCH
+  if (pusch_config_pdu->pusch_data.new_data_indicator && dci && dci->ulsch_indicator)
+    nr_timer_start(&mac->scheduling_info.retxBSR_Timer);
+
   if (pusch_config_pdu->pusch_data.tb_size == 0) {
     LOG_E(MAC, "Invalid TBS = 0. Probably caused by missed detection of DCI\n");
     return -1;
@@ -1180,12 +1214,6 @@ void nr_ue_ul_scheduler(NR_UE_MAC_INST_t *mac, nr_uplink_indication_t *ul_info)
 
   // Call BSR procedure as described in Section 5.4.5 in 38.321
 
-  // First check ReTxBSR Timer because it is always configured
-  // Decrement ReTxBSR Timer if it is running and not null
-  if ((mac->scheduling_info.retxBSR_SF != NR_MAC_UE_BSR_TIMER_NOT_RUNNING) && (mac->scheduling_info.retxBSR_SF != 0)) {
-    mac->scheduling_info.retxBSR_SF--;
-  }
-
   // Decrement Periodic Timer if it is running and not null
   if ((mac->scheduling_info.periodicBSR_SF != NR_MAC_UE_BSR_TIMER_NOT_RUNNING) && (mac->scheduling_info.periodicBSR_SF != 0)) {
     mac->scheduling_info.periodicBSR_SF--;
@@ -1250,11 +1278,7 @@ void nr_update_bsr(NR_UE_MAC_INST_t *mac, frame_t frameP, slot_t slotP, uint8_t
 
         if (!bsr_regular_triggered) {
           bsr_regular_triggered = true;
-          // call SR procedure to generate pending SR and BSR for next PUCCH/PUSCH TxOp.  This should implement the procedures
-          // outlined in Sections 5.4.4 an 5.4.5 of 38.321
-          mac->scheduling_info.SR_pending = 1;
-          // Regular BSR trigger
-          mac->BSR_reporting_active |= NR_BSR_TRIGGER_REGULAR;
+          trigger_regular_bsr(mac, lc_info->sr_DelayTimerApplied);
           LOG_D(NR_MAC,
                 "[UE %d] MAC BSR Triggered LCID %d LCGID %d data become available at frame %d slot %d\n",
                 mac->ue_id,
@@ -1262,13 +1286,6 @@ void nr_update_bsr(NR_UE_MAC_INST_t *mac, frame_t frameP, slot_t slotP, uint8_t
                 lcgid,
                 frameP,
                 slotP);
-          // if the BSR is triggered for a logical channel for which logicalChannelSR-DelayTimerApplied with value true
-          // start or restart the logicalChannelSR-DelayTimer
-          // else stop the logicalChannelSR-DelayTimer
-          if (lc_info->sr_DelayTimerApplied)
-            nr_timer_start(&mac->scheduling_info.sr_DelayTimer);
-          else
-            nr_timer_stop(&mac->scheduling_info.sr_DelayTimer);
         }
       }
     }
@@ -1379,58 +1396,6 @@ int nr_get_sf_periodicBSRTimer(uint8_t sf_offset) {
   }
 }
 
-int nr_get_sf_retxBSRTimer(uint8_t sf_offset) {
-  switch (sf_offset) {
-    case NR_BSR_Config__retxBSR_Timer_sf10:
-      return 10;
-      break;
-
-    case NR_BSR_Config__retxBSR_Timer_sf20:
-      return 20;
-      break;
-
-    case NR_BSR_Config__retxBSR_Timer_sf40:
-      return 40;
-      break;
-
-    case NR_BSR_Config__retxBSR_Timer_sf80:
-      return 80;
-      break;
-
-    case NR_BSR_Config__retxBSR_Timer_sf160:
-      return 160;
-      break;
-
-    case NR_BSR_Config__retxBSR_Timer_sf320:
-      return 320;
-      break;
-
-    case NR_BSR_Config__retxBSR_Timer_sf640:
-      return 640;
-      break;
-
-    case NR_BSR_Config__retxBSR_Timer_sf1280:
-      return 1280;
-      break;
-
-    case NR_BSR_Config__retxBSR_Timer_sf2560:
-      return 2560;
-      break;
-
-    case NR_BSR_Config__retxBSR_Timer_sf5120:
-      return 5120;
-      break;
-
-    case NR_BSR_Config__retxBSR_Timer_sf10240:
-      return 10240;
-      break;
-
-    default:
-      return -1;
-      break;
-  }
-}
-
 // PUSCH scheduler:
 // - Calculate the slot in which ULSCH should be scheduled. This is current slot + K2,
 // - where K2 is the offset between the slot in which UL DCI is received and the slot
@@ -2563,11 +2528,6 @@ static int nr_ue_get_sdu_mac_ce_pre(NR_UE_MAC_INST_t *mac,
     lcg_id++;
   }
 
-  //Restart ReTxBSR Timer at new grant indication (38.321)
-  if (mac->scheduling_info.retxBSR_SF != NR_MAC_UE_BSR_TIMER_NOT_RUNNING) {
-    mac->scheduling_info.retxBSR_SF = nr_get_sf_retxBSRTimer(mac->scheduling_info.retxBSR_Timer);
-  }
-
   // periodicBSR-Timer expires, trigger BSR
   if ((mac->scheduling_info.periodicBSR_Timer != NR_BSR_Config__periodicBSR_Timer_infinity)
       && (mac->scheduling_info.periodicBSR_SF == 0)) {
@@ -2780,9 +2740,7 @@ static void nr_ue_get_sdu_mac_ce_post(NR_UE_MAC_INST_t *mac,
           mac_ce_p->bsr_header_len,
           buflen);
     // Reset ReTx BSR Timer
-    mac->scheduling_info.retxBSR_SF = nr_get_sf_retxBSRTimer(mac->scheduling_info.retxBSR_Timer);
-    LOG_D(NR_MAC, "[UE %d] MAC ReTx BSR Timer Reset =%d\n", mac->ue_id, mac->scheduling_info.retxBSR_SF);
-
+    nr_timer_start(&mac->scheduling_info.retxBSR_Timer);
     // Reset Periodic Timer except when BSR is truncated
     if ((mac_ce_p->bsr_t == NULL) && (mac->scheduling_info.periodicBSR_Timer != NR_BSR_Config__periodicBSR_Timer_infinity)) {
       mac->scheduling_info.periodicBSR_SF = nr_get_sf_periodicBSRTimer(mac->scheduling_info.periodicBSR_Timer);