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_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) {
-      // switching to initial BWP
-      DL_BWP->bwp_id = 0;
-      UL_BWP->bwp_id = 0;
-      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;
-      }
+    if(dl_bwp_switch >= 0 && ul_bwp_switch >= 0) {
+      AssertFatal(dl_bwp_switch == ul_bwp_switch, "Different UL and DL BWP not supported\n");
+      DL_BWP->bwp_id = dl_bwp_switch;
+      UL_BWP->bwp_id = ul_bwp_switch;
     }
     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) {
@@ -775,9 +774,14 @@ 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->msg3_dcch_dtch?ra->crnti:ra->rnti), ra->state);
+                    ra->rnti, ra->state);
+              ra->state = Msg4;
+            }
           }
           else {
             nr_mac_remove_ra_rnti(gnb_mod_idP, ra->rnti);

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,
-  WAIT_Msg4_ACK = 5
+  Msg3_dcch_dtch = 4,
+  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;