reworking response to MSG3 with DCCH/DTCH

openair1/SIMULATION/NR_PHY/dlsim.c

@@ -799,7 +799,7 @@ int main(int argc, char **argv)
   N_RB_DL = gNB->frame_parms.N_RB_DL;
   NR_UE_info_t *UE_info = RC.nrmac[0]->UE_info.list[0];
 
-  configure_UE_BWP(RC.nrmac[0], scc, &UE_info->UE_sched_ctrl, NULL, UE_info);
+  configure_UE_BWP(RC.nrmac[0], scc, &UE_info->UE_sched_ctrl, NULL, UE_info, -1, -1);
 
   // stub to configure frame_parms
   //  nr_phy_config_request_sim(gNB,N_RB_DL,N_RB_DL,mu,Nid_cell,SSB_positions);

openair2/LAYER2/NR_MAC_gNB/config.c

@@ -547,7 +547,6 @@ int rrc_mac_config_req_gNB(module_id_t Mod_idP,
       RC.nrmac[Mod_idP]->sib1_tda = sib1_tda;
       for (int n=0;n<NR_NB_RA_PROC_MAX;n++ ) {
         cc->ra[n].cfra = false;
-        cc->ra[n].msg3_dcch_dtch = false;
         cc->ra[n].rnti = 0;
         cc->ra[n].preambles.num_preambles = MAX_NUM_NR_PRACH_PREAMBLES;
         cc->ra[n].preambles.preamble_list = (uint8_t *) malloc(MAX_NUM_NR_PRACH_PREAMBLES*sizeof(uint8_t));
@@ -613,7 +612,6 @@ int rrc_mac_config_req_gNB(module_id_t Mod_idP,
         for (int i = 0; i < MAX_NUM_NR_PRACH_PREAMBLES; i++)
           ra->preambles.preamble_list[i] = i;
       }
-      ra->msg3_dcch_dtch = false;
       LOG_I(NR_MAC,"Added new RA process for UE RNTI %04x with initial CellGroup\n", rnti);
     } else { // CellGroup has been updated
       NR_UE_info_t *UE = find_nr_UE(&RC.nrmac[Mod_idP]->UE_info, rnti);

openair2/LAYER2/NR_MAC_gNB/gNB_scheduler_RA.c

@@ -571,7 +571,7 @@ void nr_initiate_ra_proc(module_id_t module_idP,
       ra_rnti = 1 + symbol + (slotP * 14) + (freq_index * 14 * 80) + (ul_carrier_id * 14 * 80 * 8);
 
     // Configure RA BWP
-    configure_UE_BWP(nr_mac, scc, NULL, ra, NULL);
+    configure_UE_BWP(nr_mac, scc, NULL, ra, NULL, -1, -1);
 
     VCD_SIGNAL_DUMPER_DUMP_FUNCTION_BY_NAME(VCD_SIGNAL_DUMPER_FUNCTIONS_INITIATE_RA_PROC, 1);
 
@@ -680,6 +680,8 @@ void nr_schedule_RA(module_id_t module_idP, frame_t frameP, sub_frame_t slotP) {
         case Msg3_retransmission:
           nr_generate_Msg3_retransmission(module_idP, CC_id, frameP, slotP, ra);
           break;
+        case Msg3_dcch_dtch:
+          nr_generate_Msg3_dcch_dtch_response(module_idP, CC_id, frameP, slotP, ra);
         case Msg4:
           nr_generate_Msg4(module_idP, CC_id, frameP, slotP, ra);
           break;
@@ -1400,8 +1402,374 @@ void nr_generate_Msg2(module_id_t module_idP, int CC_id, frame_t frameP, sub_fra
   }
 }
 
-void nr_generate_Msg4(module_id_t module_idP, int CC_id, frame_t frameP, sub_frame_t slotP, NR_RA_t *ra) {
+void prepare_dl_pdus(gNB_MAC_INST *nr_mac,
+                     NR_RA_t *ra,
+                     NR_UE_DL_BWP_t *dl_bwp,
+                     nfapi_nr_dl_tti_request_body_t *dl_req,
+                     NR_sched_pucch_t *pucch,
+                     NR_pdsch_dmrs_t dmrs_info,
+                     NR_tda_info_t tda,
+                     int aggregation_level,
+                     int CCEIndex,
+                     int tb_size, int ndi,
+                     int tpc, int delta_PRI,
+                     int current_harq_pid,
+                     int time_domain_assignment,
+                     int CC_id, int rnti, int round,
+                     int mcsIndex, int tb_scaling,
+                     int pduindex, int rbStart, int rbSize)
+{
+  // look up the PDCCH PDU for this CC, BWP, and CORESET. If it does not exist, create it. This is especially
+  // important if we have multiple RAs, and the DLSCH has to reuse them, so we need to mark them
+  NR_ControlResourceSet_t *coreset = ra->coreset;
+  const int coresetid = coreset->controlResourceSetId;
+  nfapi_nr_dl_tti_pdcch_pdu_rel15_t *pdcch_pdu_rel15 = nr_mac->pdcch_pdu_idx[CC_id][coresetid];
+  if (!pdcch_pdu_rel15) {
+    nfapi_nr_dl_tti_request_pdu_t *dl_tti_pdcch_pdu = &dl_req->dl_tti_pdu_list[dl_req->nPDUs];
+    memset(dl_tti_pdcch_pdu, 0, sizeof(nfapi_nr_dl_tti_request_pdu_t));
+    dl_tti_pdcch_pdu->PDUType = NFAPI_NR_DL_TTI_PDCCH_PDU_TYPE;
+    dl_tti_pdcch_pdu->PDUSize = (uint8_t)(2 + sizeof(nfapi_nr_dl_tti_pdcch_pdu));
+    dl_req->nPDUs += 1;
+    pdcch_pdu_rel15 = &dl_tti_pdcch_pdu->pdcch_pdu.pdcch_pdu_rel15;
+    nr_configure_pdcch(pdcch_pdu_rel15, coreset, false, &ra->sched_pdcch);
+    nr_mac->pdcch_pdu_idx[CC_id][coresetid] = pdcch_pdu_rel15;
+  }
 
+  nfapi_nr_dl_tti_request_pdu_t *dl_tti_pdsch_pdu = &dl_req->dl_tti_pdu_list[dl_req->nPDUs];
+  memset((void *)dl_tti_pdsch_pdu,0,sizeof(nfapi_nr_dl_tti_request_pdu_t));
+  dl_tti_pdsch_pdu->PDUType = NFAPI_NR_DL_TTI_PDSCH_PDU_TYPE;
+  dl_tti_pdsch_pdu->PDUSize = (uint8_t)(2+sizeof(nfapi_nr_dl_tti_pdsch_pdu));
+  dl_req->nPDUs+=1;
+  nfapi_nr_dl_tti_pdsch_pdu_rel15_t *pdsch_pdu_rel15 = &dl_tti_pdsch_pdu->pdsch_pdu.pdsch_pdu_rel15;
+
+  NR_COMMON_channels_t *cc = &nr_mac->common_channels[CC_id];
+  NR_ServingCellConfigCommon_t *scc = cc->ServingCellConfigCommon;
+
+  long BWPStart = 0;
+  long BWPSize = 0;
+  NR_Type0_PDCCH_CSS_config_t *type0_PDCCH_CSS_config = NULL;
+  NR_SearchSpace_t *ss = ra->ra_ss;
+  if(*ss->controlResourceSetId!=0) {
+    BWPStart = dl_bwp->BWPStart;
+    BWPSize  = dl_bwp->BWPSize;
+  } else {
+    type0_PDCCH_CSS_config = &nr_mac->type0_PDCCH_CSS_config[ra->beam_id];
+    BWPStart = type0_PDCCH_CSS_config->cset_start_rb;
+    BWPSize = type0_PDCCH_CSS_config->num_rbs;
+  }
+
+  int mcsTableIdx = dl_bwp->mcsTableIdx;
+
+  pdsch_pdu_rel15->pduBitmap = 0;
+  pdsch_pdu_rel15->rnti = rnti;
+  pdsch_pdu_rel15->pduIndex = pduindex;
+  pdsch_pdu_rel15->BWPSize  = BWPSize;
+  pdsch_pdu_rel15->BWPStart = BWPStart;
+  pdsch_pdu_rel15->SubcarrierSpacing = dl_bwp->scs;
+  pdsch_pdu_rel15->CyclicPrefix = 0;
+  pdsch_pdu_rel15->NrOfCodewords = 1;
+  int R = nr_get_code_rate_dl(mcsIndex,mcsTableIdx);
+  pdsch_pdu_rel15->targetCodeRate[0] = R;
+  int Qm = nr_get_Qm_dl(mcsIndex, mcsTableIdx);
+  pdsch_pdu_rel15->qamModOrder[0] = Qm;
+  pdsch_pdu_rel15->mcsIndex[0] = mcsIndex;
+  pdsch_pdu_rel15->mcsTable[0] = mcsTableIdx;
+  pdsch_pdu_rel15->rvIndex[0] = nr_rv_round_map[round % 4];
+  pdsch_pdu_rel15->dataScramblingId = *scc->physCellId;
+  pdsch_pdu_rel15->nrOfLayers = 1;
+  pdsch_pdu_rel15->transmissionScheme = 0;
+  pdsch_pdu_rel15->refPoint = 0;
+  pdsch_pdu_rel15->dmrsConfigType = dmrs_info.dmrsConfigType;
+  pdsch_pdu_rel15->dlDmrsScramblingId = *scc->physCellId;
+  pdsch_pdu_rel15->SCID = 0;
+  pdsch_pdu_rel15->numDmrsCdmGrpsNoData = dmrs_info.numDmrsCdmGrpsNoData;
+  pdsch_pdu_rel15->dmrsPorts = 1;
+  pdsch_pdu_rel15->resourceAlloc = 1;
+  pdsch_pdu_rel15->rbStart = rbStart;
+  pdsch_pdu_rel15->rbSize = rbSize;
+  pdsch_pdu_rel15->VRBtoPRBMapping = 0;
+  pdsch_pdu_rel15->StartSymbolIndex = tda.startSymbolIndex;
+  pdsch_pdu_rel15->NrOfSymbols = tda.nrOfSymbols;
+  pdsch_pdu_rel15->dlDmrsSymbPos = dmrs_info.dl_dmrs_symb_pos;
+
+  int x_Overhead = 0;
+  nr_get_tbs_dl(&dl_tti_pdsch_pdu->pdsch_pdu, x_Overhead, pdsch_pdu_rel15->numDmrsCdmGrpsNoData, tb_scaling);
+
+  int bw_tbslbrm = get_dlbw_tbslbrm(dl_bwp->initial_BWPSize, ra->CellGroup);
+  pdsch_pdu_rel15->maintenance_parms_v3.tbSizeLbrmBytes = nr_compute_tbslbrm(mcsTableIdx,
+                                                                             bw_tbslbrm,
+                                                                             1);
+  pdsch_pdu_rel15->maintenance_parms_v3.ldpcBaseGraph = get_BG(tb_size<<3,R);
+
+  pdsch_pdu_rel15->precodingAndBeamforming.num_prgs=1;
+  pdsch_pdu_rel15->precodingAndBeamforming.prg_size=275;
+  pdsch_pdu_rel15->precodingAndBeamforming.dig_bf_interfaces=1;
+  pdsch_pdu_rel15->precodingAndBeamforming.prgs_list[0].pm_idx = 0;
+  pdsch_pdu_rel15->precodingAndBeamforming.prgs_list[0].dig_bf_interface_list[0].beam_idx = ra->beam_id;
+
+  /* Fill PDCCH DL DCI PDU */
+  nfapi_nr_dl_dci_pdu_t *dci_pdu = &pdcch_pdu_rel15->dci_pdu[pdcch_pdu_rel15->numDlDci];
+  pdcch_pdu_rel15->numDlDci++;
+  dci_pdu->RNTI = rnti;
+  dci_pdu->ScramblingId = *scc->physCellId;
+  dci_pdu->ScramblingRNTI = 0;
+  dci_pdu->AggregationLevel = aggregation_level;
+  dci_pdu->CceIndex = CCEIndex;
+  dci_pdu->beta_PDCCH_1_0 = 0;
+  dci_pdu->powerControlOffsetSS = 1;
+
+  dci_pdu_rel15_t dci_payload;
+  dci_payload.frequency_domain_assignment.val = PRBalloc_to_locationandbandwidth0(pdsch_pdu_rel15->rbSize,
+                                                                                  pdsch_pdu_rel15->rbStart,
+                                                                                  BWPSize);
+
+  dci_payload.format_indicator = 1;
+  dci_payload.time_domain_assignment.val = time_domain_assignment;
+  dci_payload.vrb_to_prb_mapping.val = 0;
+  dci_payload.mcs = pdsch_pdu_rel15->mcsIndex[0];
+  dci_payload.tb_scaling = tb_scaling;
+  dci_payload.rv = pdsch_pdu_rel15->rvIndex[0];
+  dci_payload.harq_pid = current_harq_pid;
+  dci_payload.ndi = ndi;
+  dci_payload.dai[0].val = pucch ? (pucch->dai_c-1) & 3 : 0;
+  dci_payload.tpc = tpc; // TPC for PUCCH: table 7.2.1-1 in 38.213
+  dci_payload.pucch_resource_indicator = delta_PRI; // This is delta_PRI from 9.2.1 in 38.213
+  dci_payload.pdsch_to_harq_feedback_timing_indicator.val = pucch ? pucch->timing_indicator : 0;
+
+  LOG_D(NR_MAC,
+        "[RAPROC] DCI 1_0 payload: freq_alloc %d (%d,%d,%d), time_alloc %d, vrb to prb %d, mcs %d tb_scaling %d pucchres %d harqtiming %d\n",
+        dci_payload.frequency_domain_assignment.val,
+        pdsch_pdu_rel15->rbStart,
+        pdsch_pdu_rel15->rbSize,
+        pdsch_pdu_rel15->BWPSize,
+        dci_payload.time_domain_assignment.val,
+        dci_payload.vrb_to_prb_mapping.val,
+        dci_payload.mcs,
+        dci_payload.tb_scaling,
+        dci_payload.pucch_resource_indicator,
+        dci_payload.pdsch_to_harq_feedback_timing_indicator.val);
+
+  LOG_D(NR_MAC,
+        "[RAPROC] DCI params: rnti 0x%x, rnti_type %d, dci_format %d coreset params: FreqDomainResource %llx, start_symbol %d  n_symb %d, BWPsize %d\n",
+        pdcch_pdu_rel15->dci_pdu[0].RNTI,
+        NR_RNTI_TC,
+        NR_DL_DCI_FORMAT_1_0,
+        (unsigned long long)pdcch_pdu_rel15->FreqDomainResource,
+        pdcch_pdu_rel15->StartSymbolIndex,
+        pdcch_pdu_rel15->DurationSymbols,
+        pdsch_pdu_rel15->BWPSize);
+
+  fill_dci_pdu_rel15(scc,
+                     ra->CellGroup,
+                     dl_bwp,
+                     &ra->UL_BWP,
+                     &pdcch_pdu_rel15->dci_pdu[pdcch_pdu_rel15->numDlDci - 1],
+                     &dci_payload,
+                     NR_DL_DCI_FORMAT_1_0,
+                     NR_RNTI_TC,
+                     dl_bwp->bwp_id,
+                     ss,
+                     coreset,
+                     nr_mac->cset0_bwp_size);
+
+    LOG_D(NR_MAC,"BWPSize: %i\n", pdcch_pdu_rel15->BWPSize);
+    LOG_D(NR_MAC,"BWPStart: %i\n", pdcch_pdu_rel15->BWPStart);
+    LOG_D(NR_MAC,"SubcarrierSpacing: %i\n", pdcch_pdu_rel15->SubcarrierSpacing);
+    LOG_D(NR_MAC,"CyclicPrefix: %i\n", pdcch_pdu_rel15->CyclicPrefix);
+    LOG_D(NR_MAC,"StartSymbolIndex: %i\n", pdcch_pdu_rel15->StartSymbolIndex);
+    LOG_D(NR_MAC,"DurationSymbols: %i\n", pdcch_pdu_rel15->DurationSymbols);
+    for(int n=0;n<6;n++) LOG_D(NR_MAC,"FreqDomainResource[%i]: %x\n",n, pdcch_pdu_rel15->FreqDomainResource[n]);
+    LOG_D(NR_MAC,"CceRegMappingType: %i\n", pdcch_pdu_rel15->CceRegMappingType);
+    LOG_D(NR_MAC,"RegBundleSize: %i\n", pdcch_pdu_rel15->RegBundleSize);
+    LOG_D(NR_MAC,"InterleaverSize: %i\n", pdcch_pdu_rel15->InterleaverSize);
+    LOG_D(NR_MAC,"CoreSetType: %i\n", pdcch_pdu_rel15->CoreSetType);
+    LOG_D(NR_MAC,"ShiftIndex: %i\n", pdcch_pdu_rel15->ShiftIndex);
+    LOG_D(NR_MAC,"precoderGranularity: %i\n", pdcch_pdu_rel15->precoderGranularity);
+    LOG_D(NR_MAC,"numDlDci: %i\n", pdcch_pdu_rel15->numDlDci);
+}
+
+void nr_generate_Msg3_dcch_dtch_response(module_id_t module_idP, int CC_id, frame_t frameP, sub_frame_t slotP, NR_RA_t *ra)
+{
+  gNB_MAC_INST *nr_mac = RC.nrmac[module_idP];
+
+  // proceed only if it is a DL slot
+  if (!is_xlsch_in_slot(nr_mac->dlsch_slot_bitmap[slotP / 64], slotP))
+    return;
+
+  // UE is known by the network, C-RNTI to be used instead of TC-RNTI
+  int rnti = ra->crnti;
+
+  NR_UE_info_t *UE = find_nr_UE(&nr_mac->UE_info, rnti);
+  if (!UE) {
+    LOG_E(NR_MAC, "Received Msg3 with C-RNTI but rnti %04x not in the table\n", rnti);
+    return;
+  }
+
+  NR_COMMON_channels_t *cc = &nr_mac->common_channels[CC_id];
+  NR_ServingCellConfigCommon_t *scc = cc->ServingCellConfigCommon;
+  NR_SearchSpace_t *ss = ra->ra_ss;
+
+  NR_ControlResourceSet_t *coreset = ra->coreset;
+  AssertFatal(coreset!=NULL,"Coreset cannot be null for RA-Msg4\n");
+
+  // Only need to schedule DCI with and empty DL
+  NR_UE_DL_BWP_t *dl_bwp = &ra->DL_BWP;
+  long BWPStart = 0;
+  long BWPSize = 0;
+  NR_Type0_PDCCH_CSS_config_t *type0_PDCCH_CSS_config = NULL;
+  if(*ss->controlResourceSetId!=0) {
+    BWPStart = dl_bwp->BWPStart;
+    BWPSize  = dl_bwp->BWPSize;
+  } else {
+    type0_PDCCH_CSS_config = &nr_mac->type0_PDCCH_CSS_config[ra->beam_id];
+    BWPStart = type0_PDCCH_CSS_config->cset_start_rb;
+    BWPSize = type0_PDCCH_CSS_config->num_rbs;
+  }
+
+  // get CCEindex, needed also for PUCCH and then later for PDCCH
+  uint8_t aggregation_level;
+  int CCEIndex = get_cce_index(nr_mac,
+                               CC_id, slotP, 0,
+                               &aggregation_level,
+                               ss,
+                               coreset,
+                               &ra->sched_pdcch,
+                               true);
+
+  if (CCEIndex < 0) {
+    LOG_E(NR_MAC, "%s(): cannot find free CCE for RA RNTI 0x%04x!\n", __func__, rnti);
+    return;
+  }
+
+  // Checking if the DCI allocation is feasible in current subframe
+  nfapi_nr_dl_tti_request_body_t *dl_req = &nr_mac->DL_req[CC_id].dl_tti_request_body;
+  if (dl_req->nPDUs > NFAPI_NR_MAX_DL_TTI_PDUS - 2) {
+    LOG_I(NR_MAC, "[RAPROC] Subframe %d: FAPI DL structure is full, skip scheduling UE %d\n", slotP, rnti);
+    return;
+  }
+
+  uint8_t time_domain_assignment = get_dl_tda(nr_mac, scc, slotP);
+  int mux_pattern = type0_PDCCH_CSS_config ? type0_PDCCH_CSS_config->type0_pdcch_ss_mux_pattern : 1;
+  NR_tda_info_t tda = get_dl_tda_info(dl_bwp, ss->searchSpaceType->present, time_domain_assignment,
+                                      scc->dmrs_TypeA_Position, mux_pattern, NR_RNTI_C, coreset->controlResourceSetId, false);
+
+  NR_pdsch_dmrs_t dmrs_info = get_dl_dmrs_params(scc,
+                                                 dl_bwp,
+                                                 &tda,
+                                                 1);
+
+  int subheader_len = sizeof(NR_MAC_SUBHEADER_SHORT);
+  int pdu_length = subheader_len + 7; // 7 is contetion resolution length
+
+  int mcsTableIdx = dl_bwp->mcsTableIdx;
+  int mcsIndex = 0;
+  int rbStart = 0;
+  int rbSize = 0;
+  int tb_scaling = 0;
+  uint32_t tb_size = 0;
+
+  // increase PRBs until we get to BWPSize or TBS is bigger than MAC PDU size
+  do {
+    if(rbSize < BWPSize)
+      rbSize++;
+    else
+      mcsIndex++;
+    LOG_D(NR_MAC,"Calling nr_compute_tbs with N_PRB_DMRS %d, N_DMRS_SLOT %d\n",dmrs_info.N_PRB_DMRS,dmrs_info.N_DMRS_SLOT);
+    tb_size = nr_compute_tbs(nr_get_Qm_dl(mcsIndex, mcsTableIdx),
+                             nr_get_code_rate_dl(mcsIndex, mcsTableIdx),
+                             rbSize, tda.nrOfSymbols, dmrs_info.N_PRB_DMRS * dmrs_info.N_DMRS_SLOT, 0, tb_scaling,1) >> 3;
+  } while (tb_size < pdu_length && mcsIndex<=28);
+
+  AssertFatal(tb_size >= pdu_length,"Cannot allocate response to MSG3 with DCCH\n");
+
+  int i = 0;
+  uint16_t *vrb_map = cc[CC_id].vrb_map;
+  while ((i < rbSize) && (rbStart + rbSize <= BWPSize)) {
+    if (vrb_map[BWPStart + rbStart + i]&SL_to_bitmap(tda.startSymbolIndex, tda.nrOfSymbols)) {
+      rbStart += i+1;
+      i = 0;
+    } else {
+      i++;
+    }
+  }
+
+  if (rbStart > (BWPSize - rbSize)) {
+    LOG_E(NR_MAC, "%s(): cannot find free vrb_map for RNTI %04x!\n", __func__, rnti);
+    return;
+  }
+
+  // Remove UE associated to TC-RNTI
+  mac_remove_nr_ue(nr_mac, ra->rnti);
+
+
+  // If the UE used MSG3 to transfer a DCCH or DTCH message, then contention resolution is successful if the UE receives a PDCCH transmission which has its CRC bits scrambled by the C-RNTI
+  // Just send padding LCID
+  uint8_t buf[tb_size];
+  NR_MAC_SUBHEADER_FIXED *padding = (NR_MAC_SUBHEADER_FIXED *) &buf[0];
+  padding->R = 0;
+  padding->LCID = DL_SCH_LCID_PADDING;
+  for(int k = 1; k < tb_size; k++)
+    buf[k] = 0;
+
+  T(T_GNB_MAC_DL_PDU_WITH_DATA, T_INT(module_idP), T_INT(CC_id), T_INT(ra->rnti),
+    T_INT(frameP), T_INT(slotP), T_INT(0), T_BUFFER(buf, tb_size));
+
+  // SCF222: PDU index incremented for each PDSCH PDU sent in TX control message. This is used to associate control
+  // information to data and is reset every slot.
+  const int pduindex = nr_mac->pdu_index[CC_id]++;
+
+  prepare_dl_pdus(nr_mac, ra, dl_bwp, dl_req, NULL, dmrs_info, tda, aggregation_level, CCEIndex, tb_size, 0, 0, 0,
+                  0, time_domain_assignment, CC_id, rnti, 0, mcsIndex, tb_scaling, pduindex, rbStart, rbSize);
+
+  // DL TX request
+  nfapi_nr_pdu_t *tx_req = &nr_mac->TX_req[CC_id].pdu_list[nr_mac->TX_req[CC_id].Number_of_PDUs];
+  memcpy(tx_req->TLVs[0].value.direct, buf, sizeof(uint8_t) * tb_size);
+  tx_req->PDU_length =  tb_size;
+  tx_req->PDU_index = pduindex;
+  tx_req->num_TLV = 1;
+  tx_req->TLVs[0].length =  tb_size + 2;
+  nr_mac->TX_req[CC_id].SFN = frameP;
+  nr_mac->TX_req[CC_id].Number_of_PDUs++;
+  nr_mac->TX_req[CC_id].Slot = slotP;
+
+  // Mark the corresponding symbols and RBs as used
+  fill_pdcch_vrb_map(nr_mac,
+                     CC_id,
+                     &ra->sched_pdcch,
+                     CCEIndex,
+                     aggregation_level);
+  for (int rb = 0; rb < rbSize; rb++)
+    vrb_map[BWPStart + rb + rbStart] |= SL_to_bitmap(tda.startSymbolIndex, tda.nrOfSymbols);
+
+
+  // If the UE used MSG3 to transfer a DCCH or DTCH message, then contention resolution is successful upon transmission of PDCCH
+  LOG_A(NR_MAC, "(ue rnti 0x%04x) CBRA procedure succeeded!\n", ra->rnti);
+  nr_clear_ra_proc(module_idP, CC_id, frameP, ra);
+  UE->Msg4_ACKed = true;
+  UE->ra_timer = 0;
+
+  if(!UE->CellGroup) {
+    // In the  specific scenario where UE correctly received MSG4 (assuming it decoded RRCsetup with CellGroup) and gNB didn't correctly received an ACK, 
+    // the UE would already have CG but the UE-dedicated gNB structure wouldn't (because RA didn't complete on gNB side).
+    uper_decode(NULL,
+                &asn_DEF_NR_CellGroupConfig,   //might be added prefix later
+                (void **)&UE->CellGroup,
+                (uint8_t *)UE->cg_buf,
+                (UE->enc_rval.encoded+7)/8, 0, 0);
+  }
+
+  NR_UE_sched_ctrl_t *sched_ctrl = &UE->UE_sched_ctrl;
+  process_CellGroup(UE->CellGroup, sched_ctrl);
+  // switching to initial BWP
+  configure_UE_BWP(nr_mac, scc, sched_ctrl, NULL, UE, 0, 0);
+
+  // Reset uplink failure flags/counters/timers at MAC so gNB will resume again scheduling resources for this UE
+  sched_ctrl->pusch_consecutive_dtx_cnt = 0;
+  sched_ctrl->ul_failure = 0;
+}
+
+void nr_generate_Msg4(module_id_t module_idP, int CC_id, frame_t frameP, sub_frame_t slotP, NR_RA_t *ra)
+{
   gNB_MAC_INST *nr_mac = RC.nrmac[module_idP];
   NR_COMMON_channels_t *cc = &nr_mac->common_channels[CC_id];
   NR_UE_DL_BWP_t *dl_bwp = &ra->DL_BWP;
@@ -1418,12 +1786,6 @@ void nr_generate_Msg4(module_id_t module_idP, int CC_id, frame_t frameP, sub_fra
 
     uint16_t mac_sdu_length = 0;
 
-    // If UE is known by the network, C-RNTI to be used instead of TC-RNTI
-    rnti_t tc_rnti = ra->rnti;
-    if (ra->msg3_dcch_dtch) {
-      ra->rnti = ra->crnti;
-    }
-
     NR_UE_info_t *UE = find_nr_UE(&nr_mac->UE_info, ra->rnti);
     if (!UE) {
       LOG_E(NR_MAC, "want to generate Msg4, but rnti %04x not in the table\n", ra->rnti);
@@ -1435,7 +1797,7 @@ void nr_generate_Msg4(module_id_t module_idP, int CC_id, frame_t frameP, sub_fra
     int current_harq_pid = sched_ctrl->retrans_dl_harq.head;
 
     logical_chan_id_t lcid = DL_SCH_LCID_CCCH;
-    if (ra->msg3_dcch_dtch == false && current_harq_pid < 0) {
+    if (current_harq_pid < 0) {
       // Check for data on SRB0 (RRCSetup)
       mac_rlc_status_resp_t srb_status = mac_rlc_status_ind(module_idP, ra->rnti, module_idP, frameP, slotP, ENB_FLAG_YES, MBMS_FLAG_NO, lcid, 0, 0);
 
@@ -1543,7 +1905,7 @@ void nr_generate_Msg4(module_id_t module_idP, int CC_id, frame_t frameP, sub_fra
       return;
     }
 
-    const int delta_PRI=0;
+    const int delta_PRI = 0;
     int r_pucch = nr_get_pucch_resource(coreset, ra->UL_BWP.pucch_Config, CCEIndex);
 
     LOG_D(NR_MAC,"[RAPROC] Msg4 r_pucch %d (CCEIndex %d, delta_PRI %d)\n", r_pucch, CCEIndex, delta_PRI);
@@ -1569,11 +1931,6 @@ void nr_generate_Msg4(module_id_t module_idP, int CC_id, frame_t frameP, sub_fra
     harq->is_waiting = true;
     ra->harq_pid = current_harq_pid;
 
-    // Remove UE associated to TC-RNTI
-    if(harq->round==0 && ra->msg3_dcch_dtch) {
-      mac_remove_nr_ue(nr_mac, tc_rnti);
-    }
-
     NR_sched_pucch_t *pucch = &sched_ctrl->sched_pucch[alloc];
     harq->feedback_slot = pucch->ul_slot;
     harq->feedback_frame = pucch->frame;
@@ -1582,187 +1939,45 @@ void nr_generate_Msg4(module_id_t module_idP, int CC_id, frame_t frameP, sub_fra
     uint8_t *buf = (uint8_t *) harq->transportBlock;
     // Bytes to be transmitted
     if (harq->round == 0) {
-      if (ra->msg3_dcch_dtch) {
+      // UE Contention Resolution Identity MAC CE
-        // If the UE used MSG3 to transfer a DCCH or DTCH message, then contention resolution is successful if the UE receives a PDCCH transmission which has its CRC bits scrambled by the C-RNTI
+      uint16_t mac_pdu_length = nr_write_ce_dlsch_pdu(module_idP, nr_mac->sched_ctrlCommon, buf, 255, ra->cont_res_id);
-        // Just send padding LCID
+      LOG_D(NR_MAC,"Encoded contention resolution mac_pdu_length %d\n",mac_pdu_length);
-        ra->mac_pdu_length = 0;
+      uint8_t buffer[CCCH_SDU_SIZE];
+      uint8_t mac_subheader_len = sizeof(NR_MAC_SUBHEADER_SHORT);
+      // Get RLC data on the SRB (RRCSetup, RRCReestablishment)
+      mac_sdu_length = mac_rlc_data_req(module_idP,
+                                        ra->rnti,
+                                        module_idP,
+                                        frameP,
+                                        ENB_FLAG_YES,
+                                        MBMS_FLAG_NO,
+                                        lcid,
+                                        CCCH_SDU_SIZE,
+                                        (char *)buffer,
+                                        0,
+                                        0);
+
+      if (mac_sdu_length < 256) {
+        ((NR_MAC_SUBHEADER_SHORT *)&buf[mac_pdu_length])->R = 0;
+        ((NR_MAC_SUBHEADER_SHORT *)&buf[mac_pdu_length])->F = 0;
+        ((NR_MAC_SUBHEADER_SHORT *)&buf[mac_pdu_length])->LCID = lcid;
+        ((NR_MAC_SUBHEADER_SHORT *)&buf[mac_pdu_length])->L = mac_sdu_length;
+        ra->mac_pdu_length = mac_pdu_length + mac_sdu_length + sizeof(NR_MAC_SUBHEADER_SHORT);
       } else {
-        // UE Contention Resolution Identity MAC CE
+        mac_subheader_len = sizeof(NR_MAC_SUBHEADER_LONG);
-        uint16_t mac_pdu_length = nr_write_ce_dlsch_pdu(module_idP, nr_mac->sched_ctrlCommon, buf, 255, ra->cont_res_id);
+        ((NR_MAC_SUBHEADER_LONG *)&buf[mac_pdu_length])->R = 0;
-        LOG_D(NR_MAC,"Encoded contention resolution mac_pdu_length %d\n",mac_pdu_length);
+        ((NR_MAC_SUBHEADER_LONG *)&buf[mac_pdu_length])->F = 1;
-        uint8_t buffer[CCCH_SDU_SIZE];
+        ((NR_MAC_SUBHEADER_LONG *)&buf[mac_pdu_length])->LCID = lcid;
-        uint8_t mac_subheader_len = sizeof(NR_MAC_SUBHEADER_SHORT);
+        ((NR_MAC_SUBHEADER_LONG *)&buf[mac_pdu_length])->L = htons(mac_sdu_length);
-        // Get RLC data on the SRB (RRCSetup, RRCReestablishment)
+        ra->mac_pdu_length = mac_pdu_length + mac_sdu_length + sizeof(NR_MAC_SUBHEADER_LONG);
-        mac_sdu_length = mac_rlc_data_req(module_idP,
-                                          ra->rnti,
-                                          module_idP,
-                                          frameP,
-                                          ENB_FLAG_YES,
-                                          MBMS_FLAG_NO,
-                                          lcid,
-                                          CCCH_SDU_SIZE,
-                                          (char *)buffer,
-                                          0,
-                                          0);
-
-        if (mac_sdu_length < 256) {
-          ((NR_MAC_SUBHEADER_SHORT *)&buf[mac_pdu_length])->R = 0;
-          ((NR_MAC_SUBHEADER_SHORT *)&buf[mac_pdu_length])->F = 0;
-          ((NR_MAC_SUBHEADER_SHORT *)&buf[mac_pdu_length])->LCID = lcid;
-          ((NR_MAC_SUBHEADER_SHORT *)&buf[mac_pdu_length])->L = mac_sdu_length;
-          ra->mac_pdu_length = mac_pdu_length + mac_sdu_length + sizeof(NR_MAC_SUBHEADER_SHORT);
-        } else {
-          mac_subheader_len = sizeof(NR_MAC_SUBHEADER_LONG);
-          ((NR_MAC_SUBHEADER_LONG *)&buf[mac_pdu_length])->R = 0;
-          ((NR_MAC_SUBHEADER_LONG *)&buf[mac_pdu_length])->F = 1;
-          ((NR_MAC_SUBHEADER_LONG *)&buf[mac_pdu_length])->LCID = lcid;
-          ((NR_MAC_SUBHEADER_LONG *)&buf[mac_pdu_length])->L = htons(mac_sdu_length);
-          ra->mac_pdu_length = mac_pdu_length + mac_sdu_length + sizeof(NR_MAC_SUBHEADER_LONG);
-        }
-        LOG_I(NR_MAC,"Encoded RRCSetup Piggyback (%d + %d bytes), mac_pdu_length %d\n", mac_sdu_length, mac_subheader_len, ra->mac_pdu_length);
-        memcpy(&buf[mac_pdu_length + mac_subheader_len], buffer, mac_sdu_length);
       }
+      LOG_I(NR_MAC,"Encoded RRCSetup Piggyback (%d + %d bytes), mac_pdu_length %d\n", mac_sdu_length, mac_subheader_len, ra->mac_pdu_length);
+      memcpy(&buf[mac_pdu_length + mac_subheader_len], buffer, mac_sdu_length);
     }
 
-    // look up the PDCCH PDU for this CC, BWP, and CORESET. If it does not exist, create it. This is especially
-    // important if we have multiple RAs, and the DLSCH has to reuse them, so we need to mark them
-    const int coresetid = coreset->controlResourceSetId;
-    nfapi_nr_dl_tti_pdcch_pdu_rel15_t *pdcch_pdu_rel15 = nr_mac->pdcch_pdu_idx[CC_id][coresetid];
-    if (!pdcch_pdu_rel15) {
-      nfapi_nr_dl_tti_request_pdu_t *dl_tti_pdcch_pdu = &dl_req->dl_tti_pdu_list[dl_req->nPDUs];
-      memset(dl_tti_pdcch_pdu, 0, sizeof(nfapi_nr_dl_tti_request_pdu_t));
-      dl_tti_pdcch_pdu->PDUType = NFAPI_NR_DL_TTI_PDCCH_PDU_TYPE;
-      dl_tti_pdcch_pdu->PDUSize = (uint8_t)(2 + sizeof(nfapi_nr_dl_tti_pdcch_pdu));
-      dl_req->nPDUs += 1;
-      pdcch_pdu_rel15 = &dl_tti_pdcch_pdu->pdcch_pdu.pdcch_pdu_rel15;
-      nr_configure_pdcch(pdcch_pdu_rel15, coreset, false, &ra->sched_pdcch);
-      nr_mac->pdcch_pdu_idx[CC_id][coresetid] = pdcch_pdu_rel15;
-    }
-
-    nfapi_nr_dl_tti_request_pdu_t *dl_tti_pdsch_pdu = &dl_req->dl_tti_pdu_list[dl_req->nPDUs];
-    memset((void *)dl_tti_pdsch_pdu,0,sizeof(nfapi_nr_dl_tti_request_pdu_t));
-    dl_tti_pdsch_pdu->PDUType = NFAPI_NR_DL_TTI_PDSCH_PDU_TYPE;
-    dl_tti_pdsch_pdu->PDUSize = (uint8_t)(2+sizeof(nfapi_nr_dl_tti_pdsch_pdu));
-    dl_req->nPDUs+=1;
-    nfapi_nr_dl_tti_pdsch_pdu_rel15_t *pdsch_pdu_rel15 = &dl_tti_pdsch_pdu->pdsch_pdu.pdsch_pdu_rel15;
-
-    LOG_A(NR_MAC, "[gNB %d] [RAPROC] CC_id %d Frame %d, slotP %d: Generating RA-Msg4 DCI, state %d\n", module_idP, CC_id, frameP, slotP, ra->state);
-
-    // SCF222: PDU index incremented for each PDSCH PDU sent in TX control message. This is used to associate control
-    // information to data and is reset every slot.
     const int pduindex = nr_mac->pdu_index[CC_id]++;
-
+    prepare_dl_pdus(nr_mac, ra, dl_bwp, dl_req, pucch, dmrs_info, msg4_tda, aggregation_level, CCEIndex, tb_size, harq->ndi, sched_ctrl->tpc1, delta_PRI,
-    pdsch_pdu_rel15->pduBitmap = 0;
+                    current_harq_pid, time_domain_assignment, CC_id, ra->rnti, harq->round, mcsIndex, tb_scaling, pduindex, rbStart, rbSize);
-    pdsch_pdu_rel15->rnti = ra->rnti;
-    pdsch_pdu_rel15->pduIndex = pduindex;
-    pdsch_pdu_rel15->BWPSize  = BWPSize;
-    pdsch_pdu_rel15->BWPStart = BWPStart;
-    pdsch_pdu_rel15->SubcarrierSpacing = dl_bwp->scs;
-    pdsch_pdu_rel15->CyclicPrefix = 0;
-    pdsch_pdu_rel15->NrOfCodewords = 1;
-    int R = nr_get_code_rate_dl(mcsIndex,mcsTableIdx);
-    pdsch_pdu_rel15->targetCodeRate[0] = R;
-    int Qm = nr_get_Qm_dl(mcsIndex, mcsTableIdx);
-    pdsch_pdu_rel15->qamModOrder[0] = Qm;
-    pdsch_pdu_rel15->mcsIndex[0] = mcsIndex;
-    pdsch_pdu_rel15->mcsTable[0] = mcsTableIdx;
-    pdsch_pdu_rel15->rvIndex[0] = nr_rv_round_map[harq->round%4];
-    pdsch_pdu_rel15->dataScramblingId = *scc->physCellId;
-    pdsch_pdu_rel15->nrOfLayers = 1;
-    pdsch_pdu_rel15->transmissionScheme = 0;
-    pdsch_pdu_rel15->refPoint = 0;
-    pdsch_pdu_rel15->dmrsConfigType = dmrs_info.dmrsConfigType;
-    pdsch_pdu_rel15->dlDmrsScramblingId = *scc->physCellId;
-    pdsch_pdu_rel15->SCID = 0;
-    pdsch_pdu_rel15->numDmrsCdmGrpsNoData = dmrs_info.numDmrsCdmGrpsNoData;
-    pdsch_pdu_rel15->dmrsPorts = 1;
-    pdsch_pdu_rel15->resourceAlloc = 1;
-    pdsch_pdu_rel15->rbStart = rbStart;
-    pdsch_pdu_rel15->rbSize = rbSize;
-    pdsch_pdu_rel15->VRBtoPRBMapping = 0;
-    pdsch_pdu_rel15->StartSymbolIndex = msg4_tda.startSymbolIndex;
-    pdsch_pdu_rel15->NrOfSymbols = msg4_tda.nrOfSymbols;
-    pdsch_pdu_rel15->dlDmrsSymbPos = dmrs_info.dl_dmrs_symb_pos;
-
-    int x_Overhead = 0;
-    nr_get_tbs_dl(&dl_tti_pdsch_pdu->pdsch_pdu, x_Overhead, pdsch_pdu_rel15->numDmrsCdmGrpsNoData, tb_scaling);
-
-    int bw_tbslbrm = get_dlbw_tbslbrm(dl_bwp->initial_BWPSize, ra->CellGroup);
-    pdsch_pdu_rel15->maintenance_parms_v3.tbSizeLbrmBytes = nr_compute_tbslbrm(mcsTableIdx,
-                                                                               bw_tbslbrm,
-                                                                               1);
-    pdsch_pdu_rel15->maintenance_parms_v3.ldpcBaseGraph = get_BG(harq->tb_size<<3,R);
-
-    pdsch_pdu_rel15->precodingAndBeamforming.num_prgs=1;
-    pdsch_pdu_rel15->precodingAndBeamforming.prg_size=275;
-    pdsch_pdu_rel15->precodingAndBeamforming.dig_bf_interfaces=1;
-    pdsch_pdu_rel15->precodingAndBeamforming.prgs_list[0].pm_idx = 0;
-    pdsch_pdu_rel15->precodingAndBeamforming.prgs_list[0].dig_bf_interface_list[0].beam_idx = ra->beam_id;
-
-    /* Fill PDCCH DL DCI PDU */
-    nfapi_nr_dl_dci_pdu_t *dci_pdu = &pdcch_pdu_rel15->dci_pdu[pdcch_pdu_rel15->numDlDci];
-    pdcch_pdu_rel15->numDlDci++;
-    dci_pdu->RNTI = ra->rnti;
-    dci_pdu->ScramblingId = *scc->physCellId;
-    dci_pdu->ScramblingRNTI = 0;
-    dci_pdu->AggregationLevel = aggregation_level;
-    dci_pdu->CceIndex = CCEIndex;
-    dci_pdu->beta_PDCCH_1_0 = 0;
-    dci_pdu->powerControlOffsetSS = 1;
-
-    dci_pdu_rel15_t dci_payload;
-    dci_payload.frequency_domain_assignment.val = PRBalloc_to_locationandbandwidth0(pdsch_pdu_rel15->rbSize,
-                                                                                    pdsch_pdu_rel15->rbStart,
-                                                                                    BWPSize);
-
-    dci_payload.format_indicator = 1;
-    dci_payload.time_domain_assignment.val = time_domain_assignment;
-    dci_payload.vrb_to_prb_mapping.val = 0;
-    dci_payload.mcs = pdsch_pdu_rel15->mcsIndex[0];
-    dci_payload.tb_scaling = tb_scaling;
-    dci_payload.rv = pdsch_pdu_rel15->rvIndex[0];
-    dci_payload.harq_pid = current_harq_pid;
-    dci_payload.ndi = harq->ndi;
-    dci_payload.dai[0].val = (pucch->dai_c-1)&3;
-    dci_payload.tpc = sched_ctrl->tpc1; // TPC for PUCCH: table 7.2.1-1 in 38.213
-    dci_payload.pucch_resource_indicator = delta_PRI; // This is delta_PRI from 9.2.1 in 38.213
-    dci_payload.pdsch_to_harq_feedback_timing_indicator.val = pucch->timing_indicator;
-
-    LOG_D(NR_MAC,
-          "[RAPROC] DCI 1_0 payload: freq_alloc %d (%d,%d,%d), time_alloc %d, vrb to prb %d, mcs %d tb_scaling %d pucchres %d harqtiming %d\n",
-          dci_payload.frequency_domain_assignment.val,
-          pdsch_pdu_rel15->rbStart,
-          pdsch_pdu_rel15->rbSize,
-          pdsch_pdu_rel15->BWPSize,
-          dci_payload.time_domain_assignment.val,
-          dci_payload.vrb_to_prb_mapping.val,
-          dci_payload.mcs,
-          dci_payload.tb_scaling,
-          dci_payload.pucch_resource_indicator,
-          dci_payload.pdsch_to_harq_feedback_timing_indicator.val);
-
-    LOG_D(NR_MAC,
-          "[RAPROC] DCI params: rnti 0x%x, rnti_type %d, dci_format %d coreset params: FreqDomainResource %llx, start_symbol %d  n_symb %d, BWPsize %d\n",
-          pdcch_pdu_rel15->dci_pdu[0].RNTI,
-          NR_RNTI_TC,
-          NR_DL_DCI_FORMAT_1_0,
-          (unsigned long long)pdcch_pdu_rel15->FreqDomainResource,
-          pdcch_pdu_rel15->StartSymbolIndex,
-          pdcch_pdu_rel15->DurationSymbols,
-          pdsch_pdu_rel15->BWPSize);
-
-    fill_dci_pdu_rel15(scc,
-                       ra->CellGroup,
-                       dl_bwp,
-                       &ra->UL_BWP,
-                       &pdcch_pdu_rel15->dci_pdu[pdcch_pdu_rel15->numDlDci - 1],
-                       &dci_payload,
-                       NR_DL_DCI_FORMAT_1_0,
-                       NR_RNTI_TC,
-                       dl_bwp->bwp_id,
-                       ss,
-                       coreset,
-                       nr_mac->cset0_bwp_size);
 
     // Add padding header and zero rest out if there is space left
     if (ra->mac_pdu_length < harq->tb_size) {
@@ -1794,58 +2009,12 @@ void nr_generate_Msg4(module_id_t module_idP, int CC_id, frame_t frameP, sub_fra
                        &ra->sched_pdcch,
                        CCEIndex,
                        aggregation_level);
-    for (int rb = 0; rb < pdsch_pdu_rel15->rbSize; rb++) {
+    for (int rb = 0; rb < rbSize; rb++) {
-      vrb_map[BWPStart + rb + pdsch_pdu_rel15->rbStart] |= SL_to_bitmap(msg4_tda.startSymbolIndex, msg4_tda.nrOfSymbols);
+      vrb_map[BWPStart + rb + rbStart] |= SL_to_bitmap(msg4_tda.startSymbolIndex, msg4_tda.nrOfSymbols);
     }
 
-    LOG_D(NR_MAC,"BWPSize: %i\n", pdcch_pdu_rel15->BWPSize);
+    ra->state = WAIT_Msg4_ACK;
-    LOG_D(NR_MAC,"BWPStart: %i\n", pdcch_pdu_rel15->BWPStart);
+    LOG_D(NR_MAC,"[gNB %d][RAPROC] Frame %d, Subframe %d: RA state %d\n", module_idP, frameP, slotP, ra->state);
-    LOG_D(NR_MAC,"SubcarrierSpacing: %i\n", pdcch_pdu_rel15->SubcarrierSpacing);
-    LOG_D(NR_MAC,"CyclicPrefix: %i\n", pdcch_pdu_rel15->CyclicPrefix);
-    LOG_D(NR_MAC,"StartSymbolIndex: %i\n", pdcch_pdu_rel15->StartSymbolIndex);
-    LOG_D(NR_MAC,"DurationSymbols: %i\n", pdcch_pdu_rel15->DurationSymbols);
-    for(int n=0;n<6;n++) LOG_D(NR_MAC,"FreqDomainResource[%i]: %x\n",n, pdcch_pdu_rel15->FreqDomainResource[n]);
-    LOG_D(NR_MAC,"CceRegMappingType: %i\n", pdcch_pdu_rel15->CceRegMappingType);
-    LOG_D(NR_MAC,"RegBundleSize: %i\n", pdcch_pdu_rel15->RegBundleSize);
-    LOG_D(NR_MAC,"InterleaverSize: %i\n", pdcch_pdu_rel15->InterleaverSize);
-    LOG_D(NR_MAC,"CoreSetType: %i\n", pdcch_pdu_rel15->CoreSetType);
-    LOG_D(NR_MAC,"ShiftIndex: %i\n", pdcch_pdu_rel15->ShiftIndex);
-    LOG_D(NR_MAC,"precoderGranularity: %i\n", pdcch_pdu_rel15->precoderGranularity);
-    LOG_D(NR_MAC,"numDlDci: %i\n", pdcch_pdu_rel15->numDlDci);
-
-    if(ra->msg3_dcch_dtch) {
-      // If the UE used MSG3 to transfer a DCCH or DTCH message, then contention resolution is successful upon transmission of PDCCH
-      LOG_A(NR_MAC, "(ue rnti 0x%04x) CBRA procedure succeeded!\n", ra->rnti);
-      nr_clear_ra_proc(module_idP, CC_id, frameP, ra);
-      UE->Msg3_dcch_dtch = true;
-      UE->Msg4_ACKed = true;
-      UE->ra_timer = 0;
-
-      remove_front_nr_list(&sched_ctrl->feedback_dl_harq);
-      harq->feedback_slot = -1;
-      harq->is_waiting = false;
-      add_tail_nr_list(&sched_ctrl->available_dl_harq, current_harq_pid);
-      harq->round = 0;
-      harq->ndi ^= 1;
-
-      if(!UE->CellGroup)
-        // In the  specific scenario where UE correctly received MSG4 (assuming it decoded RRCsetup with CellGroup) and gNB didn't correctly received an ACK, 
-        // the UE would already have CG but the UE-dedicated gNB structure wouldn't (because RA didn't complete on gNB side).
-        uper_decode(NULL,
-                    &asn_DEF_NR_CellGroupConfig,   //might be added prefix later
-                    (void **)&UE->CellGroup,
-                    (uint8_t *)UE->cg_buf,
-                    (UE->enc_rval.encoded+7)/8, 0, 0);
-      process_CellGroup(UE->CellGroup, sched_ctrl);
-      configure_UE_BWP(nr_mac, scc, sched_ctrl, NULL, UE);
-
-      // Reset uplink failure flags/counters/timers at MAC so gNB will resume again scheduling resources for this UE
-      UE->UE_sched_ctrl.pusch_consecutive_dtx_cnt = 0;
-      UE->UE_sched_ctrl.ul_failure = 0;
-    } else {
-      ra->state = WAIT_Msg4_ACK;
-      LOG_D(NR_MAC,"[gNB %d][RAPROC] Frame %d, Subframe %d: RA state %d\n", module_idP, frameP, slotP, ra->state);
-    }
   }
 }
 
@@ -1897,7 +2066,6 @@ void nr_clear_ra_proc(module_id_t module_idP, int CC_id, frame_t frameP, NR_RA_t
   ra->timing_offset = 0;
   ra->RRC_timer = 20;
   ra->msg3_round = 0;
-  ra->msg3_dcch_dtch = false;
   ra->crnti = 0;
   if(ra->cfra == false) {
     ra->rnti = 0;

openair2/LAYER2/NR_MAC_gNB/gNB_scheduler_primitives.c

@@ -2021,8 +2021,10 @@ void configure_UE_BWP(gNB_MAC_INST *nr_mac,
                       NR_ServingCellConfigCommon_t *scc,
                       NR_UE_sched_ctrl_t *sched_ctrl,
                       NR_RA_t *ra,
-                      NR_UE_info_t *UE) {
+                      NR_UE_info_t *UE,
-
+                      int dl_bwp_switch,
+                      int ul_bwp_switch)
+{
   AssertFatal((ra != NULL && UE == NULL) || (ra == NULL && UE != NULL), "RA and UE structures are mutually exlusive in BWP configuration\n");
 
   NR_CellGroupConfig_t *CellGroup;
@@ -2067,23 +2069,10 @@ void configure_UE_BWP(gNB_MAC_INST *nr_mac,
 
     target_ss = NR_SearchSpace__searchSpaceType_PR_ue_Specific;
 
-    if(UE && UE->Msg3_dcch_dtch) {
+    if(dl_bwp_switch >= 0 && ul_bwp_switch >= 0) {
-      // switching to initial BWP
+      AssertFatal(dl_bwp_switch == ul_bwp_switch, "Different UL and DL BWP not supported\n");
-      DL_BWP->bwp_id = 0;
+      DL_BWP->bwp_id = dl_bwp_switch;
-      UL_BWP->bwp_id = 0;
+      UL_BWP->bwp_id = ul_bwp_switch;
-      UE->Msg3_dcch_dtch = false;
-
-      // Schedule BWP switching to the first active BWP (previous active BWP before RA with Msg3 carrying DCCH or DTCH message)
-      if (servingCellConfig->firstActiveDownlinkBWP_Id) {
-        sched_ctrl->next_dl_bwp_id = *servingCellConfig->firstActiveDownlinkBWP_Id;
-      } else {
-        sched_ctrl->next_dl_bwp_id = 0;
-      }
-      if (servingCellConfig->uplinkConfig->firstActiveUplinkBWP_Id) {
-        sched_ctrl->next_ul_bwp_id = *servingCellConfig->uplinkConfig->firstActiveUplinkBWP_Id;
-      } else {
-        sched_ctrl->next_ul_bwp_id = 0;
-      }
     }
     else {
       // (re)configuring BWP
@@ -2335,7 +2324,7 @@ NR_UE_info_t *add_new_nr_ue(gNB_MAC_INST *nr_mac, rnti_t rntiP, NR_CellGroupConf
   memset(dl_bwp, 0, sizeof(*dl_bwp));
   NR_UE_UL_BWP_t *ul_bwp = &UE->current_UL_BWP;
   memset(ul_bwp, 0, sizeof(*ul_bwp));
-  configure_UE_BWP(nr_mac, scc, sched_ctrl, NULL, UE);
+  configure_UE_BWP(nr_mac, scc, sched_ctrl, NULL, UE, -1, -1);
 
   /* set illegal time domain allocation to force recomputation of all fields */
   sched_ctrl->sched_pdsch.time_domain_allocation = -1;
@@ -2811,7 +2800,7 @@ void nr_mac_update_timers(module_id_t module_id,
         process_CellGroup(cg,&UE->UE_sched_ctrl);
         NR_UE_sched_ctrl_t *sched_ctrl = &UE->UE_sched_ctrl;
 
-        configure_UE_BWP(RC.nrmac[module_id], scc, sched_ctrl, NULL, UE);
+        configure_UE_BWP(RC.nrmac[module_id], scc, sched_ctrl, NULL, UE, -1, -1);
 
         if (get_softmodem_params()->sa) {
           // add all available DL HARQ processes for this UE in SA

openair2/LAYER2/NR_MAC_gNB/gNB_scheduler_ulsch.c

@@ -227,7 +227,7 @@ int nr_process_mac_pdu(instance_t module_idP,
           NR_RA_t *ra = &RC.nrmac[module_idP]->common_channels[CC_id].ra[i];
           if (ra->state >= WAIT_Msg3 && ra->rnti == UE->rnti) {
             ra->crnti = ((pduP[1]&0xFF)<<8)|(pduP[2]&0xFF);
-            ra->msg3_dcch_dtch = true;
+            ra->state = Msg3_dcch_dtch;
             LOG_I(NR_MAC, "Received UL_SCH_LCID_C_RNTI with C-RNTI 0x%04x\n", ra->crnti);
             break;
           }
@@ -755,9 +755,8 @@ void nr_rx_sdu(const module_id_t gnb_mod_idP,
           // harq_pid set a non valid value because it is not used in this call
           // the function is only called to decode the contention resolution sub-header
           if (nr_process_mac_pdu(gnb_mod_idP, UE, CC_idP, frameP, slotP, sduP, sdu_lenP, -1) == 0) {
-            ra->state = Msg4;
             
-            if (ra->msg3_dcch_dtch) {
+            if (ra->state == Msg3_dcch_dtch) {
               // Check if the UE identified by C-RNTI still exists at the gNB
               NR_UE_info_t * UE_C = find_nr_UE(&gNB_mac->UE_info, ra->crnti);
               if (!UE_C) {
@@ -775,13 +774,18 @@ void nr_rx_sdu(const module_id_t gnb_mod_idP,
                 reset_dl_harq_list(&UE_C->UE_sched_ctrl);
                 reset_ul_harq_list(&UE_C->UE_sched_ctrl);
               }
+              LOG_I(NR_MAC, "Activating scheduling response to MSG3 with DCCH/DTCCH and RNTI 0x%04x (state %d)\n",
+                    ra->crnti, ra->state);
+            }
+            else {
+              LOG_I(NR_MAC, "Activating scheduling RA-Msg4 for TC_RNTI 0x%04x (state %d)\n",
+                    ra->rnti, ra->state);
+              ra->state = Msg4;
             }
-            LOG_I(NR_MAC, "Activating scheduling RA-Msg4 for TC_RNTI 0x%04x (state %d)\n",
-                  (ra->msg3_dcch_dtch?ra->crnti:ra->rnti), ra->state);
           }
           else {
-             nr_mac_remove_ra_rnti(gnb_mod_idP, ra->rnti);
+            nr_mac_remove_ra_rnti(gnb_mod_idP, ra->rnti);
-             nr_clear_ra_proc(gnb_mod_idP, CC_idP, frameP, ra);
+            nr_clear_ra_proc(gnb_mod_idP, CC_idP, frameP, ra);
           }
         }
         return;

openair2/LAYER2/NR_MAC_gNB/mac_proto.h

@@ -343,7 +343,9 @@ void configure_UE_BWP(gNB_MAC_INST *nr_mac,
                       NR_ServingCellConfigCommon_t *scc,
                       NR_UE_sched_ctrl_t *sched_ctrl,
                       NR_RA_t *ra,
-                      NR_UE_info_t *UE);
+                      NR_UE_info_t *UE,
+                      int dl_bwp_switch,
+                      int ul_bwp_switch);
 
 NR_UE_info_t* add_new_nr_ue(gNB_MAC_INST *nr_mac, rnti_t rntiP, NR_CellGroupConfig_t *CellGroup);
 
@@ -371,6 +373,8 @@ void nr_generate_Msg4(module_id_t module_idP, int CC_id, frame_t frameP, sub_fra
 
 void nr_check_Msg4_Ack(module_id_t module_id, int CC_id, frame_t frame, sub_frame_t slot, NR_RA_t *ra);
 
+void nr_generate_Msg3_dcch_dtch_response(module_id_t module_idP, int CC_id, frame_t frameP, sub_frame_t slotP, NR_RA_t *ra);
+
 int binomial(int n, int k);
 
 bool is_xlsch_in_slot(uint64_t bitmap, sub_frame_t slot);

openair2/LAYER2/NR_MAC_gNB/nr_mac_gNB.h

@@ -94,8 +94,9 @@ typedef enum {
   Msg2 = 1,
   WAIT_Msg3 = 2,
   Msg3_retransmission = 3,
-  Msg4 = 4,
+  Msg3_dcch_dtch = 4,
-  WAIT_Msg4_ACK = 5
+  Msg4 = 5,
+  WAIT_Msg4_ACK = 6
 } RA_gNB_state_t;
 
 typedef struct NR_preamble_ue {
@@ -163,8 +164,6 @@ typedef struct {
   uint8_t msg3_cqireq;
   /// Round of Msg3 HARQ
   uint8_t msg3_round;
-  /// Flag to indicate if Msg3 carries a DCCH or DTCH message
-  bool msg3_dcch_dtch;
   int msg3_startsymb;
   int msg3_nrsymb;
   /// TBS used for Msg4
@@ -659,7 +658,6 @@ typedef struct {
   asn_enc_rval_t enc_rval;
   // UE selected beam index
   uint8_t UE_beam_index;
-  bool Msg3_dcch_dtch;
   bool Msg4_ACKed;
   uint32_t ra_timer;
   float ul_thr_ue;