Implementation of functions required for the BWP switching based on RRC method

openair2/LAYER2/NR_MAC_gNB/config.c

@@ -615,6 +615,8 @@ int rrc_mac_config_req_gNB(module_id_t Mod_idP,
       LOG_I(NR_MAC,"Modified UE_id %d/%x with CellGroup\n",UE_id,rnti);
       process_CellGroup(CellGroup,&UE_info->UE_sched_ctrl[UE_id]);
       NR_UE_sched_ctrl_t *sched_ctrl = &UE_info->UE_sched_ctrl[UE_id];
+      sched_ctrl->update_pdsch_ps = true;
+      sched_ctrl->update_pusch_ps = true;
       const NR_PDSCH_ServingCellConfig_t *pdsch = servingCellConfig ? servingCellConfig->pdsch_ServingCellConfig->choice.setup : NULL;
       if (sched_ctrl->available_dl_harq.len == 0) {
         // add all available DL HARQ processes for this UE in SA

openair2/LAYER2/NR_MAC_gNB/gNB_scheduler.c

@@ -346,6 +346,9 @@ void gNB_dlsch_ulsch_scheduler(module_id_t module_idP,
      LOG_I(NR_MAC,"Frame.Slot %d.%d\n%s\n",frame,slot,stats_output);
   }
 
+  // This schedules the BWP switching
+  schedule_nr_bwp_switch(module_idP, frame, slot);
+
   // This schedules MIB
   schedule_nr_mib(module_idP, frame, slot);
 

openair2/LAYER2/NR_MAC_gNB/gNB_scheduler_dlsch.c

@@ -500,14 +500,14 @@ void nr_store_dlsch_buffer(module_id_t module_id,
                                                                     0);
        stop_meas(&RC.nrmac[module_id]->rlc_status_ind);
     }
-    if(sched_ctrl->rlc_status[DL_SCH_LCID_DCCH].bytes_in_buffer > 0){
+    if(sched_ctrl->rlc_status[DL_SCH_LCID_DCCH].bytes_in_buffer > 0) {
       lcid = DL_SCH_LCID_DCCH;       
-    } 
+    } else if (sched_ctrl->rlc_status[DL_SCH_LCID_DCCH1].bytes_in_buffer > 0) {
-    else if (sched_ctrl->rlc_status[DL_SCH_LCID_DCCH1].bytes_in_buffer > 0)
-    {
       lcid = DL_SCH_LCID_DCCH1;       
-    }else{
+    } else if (sched_ctrl->bwp_switch_info.bwp_switch_state != BWP_SWITCH_RUNNING) {
-      lcid = DL_SCH_LCID_DTCH;       
+      lcid = DL_SCH_LCID_DTCH;
+    } else {
+      continue;
     }
                                                       
     sched_ctrl->num_total_bytes += sched_ctrl->rlc_status[lcid].bytes_in_buffer;
@@ -577,8 +577,10 @@ bool allocate_dl_retransmission(module_id_t module_id,
     }
     /* check whether we need to switch the TDA allocation since the last
      * (re-)transmission */
-    if (ps->time_domain_allocation != tda)
+    if (ps->time_domain_allocation != tda || sched_ctrl->update_pdsch_ps) {
       nr_set_pdsch_semi_static(scc, cg, sched_ctrl->active_bwp, bwpd, tda, f, ps);
+      sched_ctrl->update_pdsch_ps = false;
+    }
   } else {
     /* the retransmission will use a different time domain allocation, check
      * that we have enough resources */
@@ -838,8 +840,10 @@ void pf_dl(module_id_t module_id,
     NR_sched_pdsch_t *sched_pdsch = &sched_ctrl->sched_pdsch;
     NR_pdsch_semi_static_t *ps = &sched_ctrl->pdsch_semi_static;
     const long f = (sched_ctrl->active_bwp || bwpd) ? sched_ctrl->search_space->searchSpaceType->choice.ue_Specific->dci_Formats : 0;
-    if (ps->time_domain_allocation != tda)
+    if (ps->time_domain_allocation != tda || sched_ctrl->update_pdsch_ps) {
       nr_set_pdsch_semi_static(scc, UE_info->CellGroup[UE_id], sched_ctrl->active_bwp, bwpd, tda, f, ps);
+      sched_ctrl->update_pdsch_ps = false;
+    }
 
     const uint16_t slbitmap = SL_to_bitmap(ps->startSymbolIndex, ps->nrOfSymbols);
     // Freq-demain allocation
@@ -964,6 +968,70 @@ nr_pp_impl_dl nr_init_fr1_dlsch_preprocessor(module_id_t module_id, int CC_id)
   return nr_fr1_dlsch_preprocessor;
 }
 
+void nr_bwp_switch(module_id_t module_id,
+                   frame_t frame,
+                   sub_frame_t slot,
+                   int UE_id,
+                   int bwp_id) {
+
+  NR_UE_info_t *UE_info = &RC.nrmac[module_id]->UE_info;
+  NR_UE_sched_ctrl_t *sched_ctrl = &UE_info->UE_sched_ctrl[UE_id];
+
+  switch(sched_ctrl->bwp_switch_info.bwp_switch_state) {
+
+    case BWP_SWITCH_TO_START:
+      LOG_W(NR_MAC,"(%d.%d) [UE_id %d] Schedule BWP switch from bwp_id %ld to %d\n",
+            frame, slot, UE_id, UE_info->UE_sched_ctrl[UE_id].active_bwp->bwp_Id, bwp_id);
+      sched_ctrl->bwp_switch_info.bwp_switch_timer = 0;
+      sched_ctrl->bwp_switch_info.bwp_switch_state = BWP_SWITCH_RUNNING;
+      nr_mac_rrc_bwp_switch_req(module_id, frame, slot, UE_info->rnti[UE_id], bwp_id);
+      break;
+
+    case BWP_SWITCH_RUNNING:
+      sched_ctrl->bwp_switch_info.bwp_switch_timer++;
+      if(sched_ctrl->bwp_switch_info.bwp_switch_timer == sched_ctrl->bwp_switch_info.bwp_switch_delay) {
+        const NR_ServingCellConfig_t *servingCellConfig = UE_info->CellGroup[UE_id] ? UE_info->CellGroup[UE_id]->spCellConfig->spCellConfigDedicated : NULL;
+        const struct NR_ServingCellConfig__downlinkBWP_ToAddModList *bwpList = servingCellConfig ? servingCellConfig->downlinkBWP_ToAddModList : NULL;
+        const int bwp_id = servingCellConfig && servingCellConfig->firstActiveDownlinkBWP_Id ?
+                           *servingCellConfig->firstActiveDownlinkBWP_Id : 0;
+        sched_ctrl->active_bwp = bwpList && bwp_id > 0 ? bwpList->list.array[bwp_id - 1] : NULL;
+        const struct NR_UplinkConfig__uplinkBWP_ToAddModList *ubwpList = servingCellConfig ? servingCellConfig->uplinkConfig->uplinkBWP_ToAddModList : NULL;
+        const int ubwp_id = servingCellConfig && servingCellConfig->uplinkConfig && servingCellConfig->uplinkConfig->firstActiveUplinkBWP_Id ?
+                            *servingCellConfig->uplinkConfig->firstActiveUplinkBWP_Id : 0;
+        sched_ctrl->active_ubwp = ubwpList && ubwp_id > 0 ? ubwpList->list.array[ubwp_id - 1] : NULL;
+        sched_ctrl->bwp_switch_info.bwp_switch_state = BWP_SWITCH_INACTIVE;
+      }
+      break;
+
+    case BWP_SWITCH_INACTIVE:
+      break;
+
+    default:
+      AssertFatal(1==0,"Invalid bwp switch state\n");
+      break;
+  }
+}
+
+void schedule_nr_bwp_switch(module_id_t module_id,
+                            frame_t frame,
+                            sub_frame_t slot) {
+
+  NR_UE_info_t *UE_info = &RC.nrmac[module_id]->UE_info;
+  const NR_list_t *UE_list = &UE_info->list;
+
+  // TODO: Implementation of a algorithm to perform:
+  //  - the BWP switch trigger: sched_ctrl->bwp_switch_info.bwp_switch_state = BWP_SWITCH_TO_START
+  //  - the BWP selection:      sched_ctrl->bwp_switch_info.next_bwp = bwp_id
+
+  for (int UE_id = UE_list->head; UE_id >= 0; UE_id = UE_list->next[UE_id]) {
+    NR_UE_sched_ctrl_t *sched_ctrl = &UE_info->UE_sched_ctrl[UE_id];
+    if(sched_ctrl->bwp_switch_info.bwp_switch_state > BWP_SWITCH_INACTIVE) {
+      nr_bwp_switch(module_id, frame, slot, UE_id, sched_ctrl->bwp_switch_info.next_bwp);
+    }
+  }
+
+}
+
 void nr_schedule_ue_spec(module_id_t module_id,
                          frame_t frame,
                          sub_frame_t slot) {

openair2/LAYER2/NR_MAC_gNB/gNB_scheduler_primitives.c

@@ -2076,6 +2076,11 @@ int add_new_nr_ue(module_id_t mod_idP, rnti_t rntiP, NR_CellGroupConfig_t *CellG
                                                   scc,
                                                   genericParameters,
                                                   NULL);
+    sched_ctrl->bwp_switch_info.current_bwp = bwp_id;
+    sched_ctrl->bwp_switch_info.next_bwp = -1;
+    sched_ctrl->bwp_switch_info.bwp_switch_timer = 0;
+    sched_ctrl->bwp_switch_info.bwp_switch_state = BWP_SWITCH_INACTIVE;
+    sched_ctrl->bwp_switch_info.bwp_switch_delay = 40;
     const struct NR_UplinkConfig__uplinkBWP_ToAddModList *ubwpList = servingCellConfig ? servingCellConfig->uplinkConfig->uplinkBWP_ToAddModList : NULL;
     if (ubwpList) AssertFatal(ubwpList->list.count <= NR_MAX_NUM_BWP,
 			      "uplinkBWP_ToAddModList has %d BWP!\n",

openair2/LAYER2/NR_MAC_gNB/gNB_scheduler_ulsch.c

@@ -983,8 +983,11 @@ bool allocate_ul_retransmission(module_id_t module_id,
 
     if (ps->time_domain_allocation != tda
         || ps->dci_format != dci_format
-        || ps->num_dmrs_cdm_grps_no_data != num_dmrs_cdm_grps_no_data)
+        || ps->num_dmrs_cdm_grps_no_data != num_dmrs_cdm_grps_no_data
+        || sched_ctrl->update_pusch_ps) {
       nr_set_pusch_semi_static(scc, sched_ctrl->active_ubwp, ubwpd, dci_format, tda, num_dmrs_cdm_grps_no_data, ps);
+      sched_ctrl->update_pusch_ps = false;
+    }
     LOG_D(NR_MAC, "%s(): retransmission keeping TDA %d and TBS %d\n", __func__, tda, retInfo->tb_size);
   } else {
     /* the retransmission will use a different time domain allocation, check
@@ -1163,6 +1166,10 @@ void pf_ul(module_id_t module_id,
     if (B == 0 && !do_sched)
       continue;
 
+    if(sched_ctrl->bwp_switch_info.bwp_switch_state == BWP_SWITCH_RUNNING) {
+      continue;
+    }
+
     /* Schedule UE on SR or UL inactivity and no data (otherwise, will be scheduled
      * based on data to transmit) */
     if (B == 0 && do_sched) {
@@ -1220,8 +1227,11 @@ void pf_ul(module_id_t module_id,
       const int tda = sched_ctrl->active_ubwp ? nrmac->preferred_ul_tda[sched_ctrl->active_ubwp->bwp_Id][slot] : 0;
       if (ps->time_domain_allocation != tda
           || ps->dci_format != dci_format
-          || ps->num_dmrs_cdm_grps_no_data != num_dmrs_cdm_grps_no_data)
+          || ps->num_dmrs_cdm_grps_no_data != num_dmrs_cdm_grps_no_data
+          || sched_ctrl->update_pusch_ps) {
         nr_set_pusch_semi_static(scc, sched_ctrl->active_ubwp, ubwpd, dci_format, tda, num_dmrs_cdm_grps_no_data, ps);
+        sched_ctrl->update_pusch_ps = false;
+      }
       NR_sched_pusch_t *sched_pusch = &sched_ctrl->sched_pusch;
       sched_pusch->mcs = 9;
       update_ul_ue_R_Qm(sched_pusch, ps);
@@ -1337,8 +1347,11 @@ void pf_ul(module_id_t module_id,
     const int tda = sched_ctrl->active_ubwp ? nrmac->preferred_ul_tda[sched_ctrl->active_ubwp->bwp_Id][slot] : 0;
     if (ps->time_domain_allocation != tda
         || ps->dci_format != dci_format
-        || ps->num_dmrs_cdm_grps_no_data != num_dmrs_cdm_grps_no_data)
+        || ps->num_dmrs_cdm_grps_no_data != num_dmrs_cdm_grps_no_data
+        || sched_ctrl->update_pusch_ps) {
       nr_set_pusch_semi_static(scc, sched_ctrl->active_ubwp, ubwpd, dci_format, tda, num_dmrs_cdm_grps_no_data, ps);
+      sched_ctrl->update_pusch_ps = false;
+    }
     update_ul_ue_R_Qm(sched_pusch, ps);
 
     /* Calculate the current scheduling bytes and the necessary RBs */

openair2/LAYER2/NR_MAC_gNB/mac_proto.h

@@ -64,6 +64,10 @@ void clear_nr_nfapi_information(gNB_MAC_INST * gNB,
 void gNB_dlsch_ulsch_scheduler(module_id_t module_idP,
 			       frame_t frame_rxP, sub_frame_t slot_rxP);
 
+void schedule_nr_bwp_switch(module_id_t module_id,
+                            frame_t frame,
+                            sub_frame_t slot);
+
 /* \brief main DL scheduler function. Calls a preprocessor to decide on
  * resource allocation, then "post-processes" resource allocation (nFAPI
  * messages, statistics, HARQ handling, CEs, ... */

openair2/LAYER2/NR_MAC_gNB/nr_mac_gNB.h

@@ -551,6 +551,20 @@ typedef struct NR_UE_ul_harq {
   NR_sched_pusch_t sched_pusch;
 } NR_UE_ul_harq_t;
 
+typedef enum {
+  BWP_SWITCH_INACTIVE = 0,
+  BWP_SWITCH_TO_START,
+  BWP_SWITCH_RUNNING
+} NR_BWP_switch_states_t;
+
+typedef struct NR_BWP_switch_info {
+  NR_BWP_Id_t current_bwp;
+  NR_BWP_Id_t next_bwp;
+  int bwp_switch_timer;
+  uint8_t bwp_switch_delay;
+  NR_BWP_switch_states_t bwp_switch_state;
+} NR_BWP_switch_info_t;
+
 /*! \brief scheduling control information set through an API */
 #define MAX_CSI_REPORTS 48
 typedef struct {
@@ -558,6 +572,10 @@ typedef struct {
   NR_BWP_Downlink_t *active_bwp;
   /// the currently active BWP in UL
   NR_BWP_Uplink_t *active_ubwp;
+
+  /// the state of bwp switch procedure
+  NR_BWP_switch_info_t bwp_switch_info;
+
   /// CCE index and aggregation, should be coherent with cce_list
   NR_SearchSpace_t *search_space;
   NR_ControlResourceSet_t *coreset;
@@ -624,7 +642,8 @@ typedef struct {
   int ul_failure;
   struct CSI_Report CSI_report[MAX_CSI_REPORTS];
   bool SR;
-
+  bool update_pdsch_ps;
+  bool update_pusch_ps;
   /// information about every HARQ process
   NR_UE_harq_t harq_processes[NR_MAX_NB_HARQ_PROCESSES];
   /// HARQ processes that are free

openair2/RRC/NR/L2_nr_interface.c

@@ -304,6 +304,19 @@ uint16_t mac_rrc_nr_data_req(const module_id_t Mod_idP,
 
 }
 
+int8_t nr_mac_rrc_bwp_switch_req(const module_id_t     module_idP,
+                                 const frame_t         frameP,
+                                 const sub_frame_t     sub_frameP,
+                                 const rnti_t          rntiP,
+                                 const int             bwp_id) {
+
+  struct rrc_gNB_ue_context_s *ue_context_p = rrc_gNB_get_ue_context(RC.nrrrc[module_idP], rntiP);
+
+  protocol_ctxt_t ctxt;
+  PROTOCOL_CTXT_SET_BY_MODULE_ID(&ctxt, module_idP, GNB_FLAG_YES, rntiP, frameP, sub_frameP, 0);
+  nr_rrc_reconfiguration_req(ue_context_p, &ctxt, bwp_id);
+}
+
 int8_t nr_mac_rrc_data_ind(const module_id_t     module_idP,
                            const int             CC_id,
                            const frame_t         frameP,

openair2/RRC/NR/MESSAGES/asn1_msg.c

@@ -2493,7 +2493,9 @@ int16_t do_RRCReconfiguration(
             enc_rval.failed_type->name, enc_rval.encoded);
         return -1;
       }
-      xer_fprint(stdout, &asn_DEF_NR_CellGroupConfig, (const void*)cellGroupConfig);
+      if ( LOG_DEBUGFLAG(DEBUG_ASN1) ) {
+        xer_fprint(stdout, &asn_DEF_NR_CellGroupConfig, (const void *) cellGroupConfig);
+      }
       ie->nonCriticalExtension->masterCellGroup = calloc(1,sizeof(OCTET_STRING_t));
 
       ie->nonCriticalExtension->masterCellGroup->buf = masterCellGroup_buf;
@@ -2502,9 +2504,9 @@ int16_t do_RRCReconfiguration(
 
     dl_dcch_msg.message.choice.c1->choice.rrcReconfiguration->criticalExtensions.choice.rrcReconfiguration = ie;
 
-    //if ( LOG_DEBUGFLAG(DEBUG_ASN1) ) {
+    if ( LOG_DEBUGFLAG(DEBUG_ASN1) ) {
-        xer_fprint(stdout, &asn_DEF_NR_DL_DCCH_Message, (void *)&dl_dcch_msg);
+      xer_fprint(stdout, &asn_DEF_NR_DL_DCCH_Message, (void *)&dl_dcch_msg);
-    //}
+    }
 
     enc_rval = uper_encode_to_buffer(&asn_DEF_NR_DL_DCCH_Message,
                                     NULL,

openair2/RRC/NR/nr_rrc_proto.h

@@ -178,6 +178,12 @@ int
 nr_rrc_mac_remove_ue(module_id_t mod_idP,
                   rnti_t rntiP);
 
+int8_t nr_mac_rrc_bwp_switch_req(const module_id_t     module_idP,
+                                 const frame_t         frameP,
+                                 const sub_frame_t     sub_frameP,
+                                 const rnti_t          rntiP,
+                                 const int             bwp_id);
+
 int8_t nr_mac_rrc_data_ind(
     const module_id_t     module_idP,
     const int             CC_id,
@@ -191,6 +197,10 @@ int8_t nr_mac_rrc_data_ind(
     const boolean_t   brOption
 );
 
+int nr_rrc_reconfiguration_req(rrc_gNB_ue_context_t         *const ue_context_pP,
+                               protocol_ctxt_t              *const ctxt_pP,
+                               const int                    bwp_id);
+
 int nr_rrc_gNB_decode_ccch(protocol_ctxt_t    *const ctxt_pP,
                            const uint8_t      *buffer,
                            int                buffer_length,

openair2/RRC/NR/rrc_gNB.c

@@ -1775,6 +1775,44 @@ rrc_gNB_process_RRCConnectionReestablishmentComplete(
 }
 //-----------------------------------------------------------------------------
 
+int nr_rrc_reconfiguration_req(rrc_gNB_ue_context_t         *const ue_context_pP,
+                               protocol_ctxt_t              *const ctxt_pP,
+                               const int                    bwp_id) {
+
+  uint8_t buffer[RRC_BUF_SIZE];
+  memset(buffer, 0, sizeof(buffer));
+  uint8_t xid = rrc_gNB_get_next_transaction_identifier(ctxt_pP->module_id);
+
+  NR_CellGroupConfig_t *masterCellGroup = ue_context_pP->ue_context.masterCellGroup;
+  *masterCellGroup->spCellConfig->spCellConfigDedicated->firstActiveDownlinkBWP_Id = bwp_id;
+  *masterCellGroup->spCellConfig->spCellConfigDedicated->defaultDownlinkBWP_Id = bwp_id;
+  *masterCellGroup->spCellConfig->spCellConfigDedicated->uplinkConfig->firstActiveUplinkBWP_Id = bwp_id;
+
+  uint16_t  size = do_RRCReconfiguration(ctxt_pP,
+                                         buffer,
+                                         sizeof(buffer),
+                                         xid,
+                                         NULL,
+                                         NULL,
+                                         NULL,
+                                         NULL,
+                                         NULL,
+                                         NULL,
+                                         NULL,
+                                         NULL,
+                                         masterCellGroup);
+
+  nr_rrc_data_req(ctxt_pP,
+                  DCCH,
+                  rrc_gNB_mui++,
+                  SDU_CONFIRM_NO,
+                  size,
+                  buffer,
+                  PDCP_TRANSMISSION_MODE_CONTROL);
+
+  return 0;
+}
+
 /*------------------------------------------------------------------------------*/
 int nr_rrc_gNB_decode_ccch(protocol_ctxt_t    *const ctxt_pP,
                            const uint8_t      *buffer,