diff --git a/cmake_targets/CMakeLists.txt b/cmake_targets/CMakeLists.txt
index 273aad0c20..de3a08f2e0 100644
--- a/cmake_targets/CMakeLists.txt
+++ b/cmake_targets/CMakeLists.txt
@@ -1641,6 +1641,7 @@ set (MAC_NR_SRC
   ${NR_MAC_DIR}/config.c
   ${NR_MAC_DIR}/gNB_scheduler.c
   ${NR_MAC_DIR}/gNB_scheduler_bch.c
+  ${NR_MAC_DIR}/gNB_scheduler_dlsch.c
   ${NR_MAC_DIR}/gNB_scheduler_primitives.c
   ${NR_MAC_DIR}/gNB_scheduler_phytest.c
  )
@@ -1713,7 +1714,7 @@ add_dependencies(L2_UE rrc_flag s1ap_flag x2_flag)
 
 add_library( NR_L2_UE ${NR_L2_SRC_UE} ${MAC_NR_SRC_UE} )
 
-add_library( MAC_NR_COMMON ${OPENAIR2_DIR}/LAYER2/NR_MAC_gNB/nr_mac_common.c )
+add_library( MAC_NR_COMMON ${OPENAIR2_DIR}/LAYER2/NR_MAC_COMMON/nr_mac_common.c )
 
 include_directories("${OPENAIR2_DIR}/NR_UE_PHY_INTERFACE")
 include_directories("${OPENAIR2_DIR}/LAYER2/NR_MAC_UE")
diff --git a/executables/nr-gnb.c b/executables/nr-gnb.c
index b4bf5efe81..8cf64318cb 100644
--- a/executables/nr-gnb.c
+++ b/executables/nr-gnb.c
@@ -63,7 +63,7 @@
 
 
 #include "LAYER2/MAC/mac.h"
-#include "LAYER2/MAC/mac_extern.h"
+#include "LAYER2/NR_MAC_COMMON/nr_mac_extern.h"
 #include "LAYER2/MAC/mac_proto.h"
 #include "RRC/LTE/rrc_extern.h"
 #include "PHY_INTERFACE/phy_interface.h"
diff --git a/executables/nr-ru.c b/executables/nr-ru.c
index 1abcd3b7a1..a9565abd17 100644
--- a/executables/nr-ru.c
+++ b/executables/nr-ru.c
@@ -72,7 +72,7 @@
 #include "SCHED_NR/sched_nr.h"
 
 #include "LAYER2/MAC/mac.h"
-#include "LAYER2/MAC/mac_extern.h"
+#include "LAYER2/NR_MAC_COMMON/nr_mac_extern.h"
 #include "LAYER2/MAC/mac_proto.h"
 #include "RRC/LTE/rrc_extern.h"
 #include "PHY_INTERFACE/phy_interface.h"
diff --git a/openair1/SCHED_NR/nr_ru_procedures.c b/openair1/SCHED_NR/nr_ru_procedures.c
index e726bdc711..7f8dc9853b 100644
--- a/openair1/SCHED_NR/nr_ru_procedures.c
+++ b/openair1/SCHED_NR/nr_ru_procedures.c
@@ -38,7 +38,7 @@
 #include "PHY/LTE_TRANSPORT/if4_tools.h"
 #include "PHY/LTE_TRANSPORT/if5_tools.h"
 
-#include "LAYER2/MAC/mac_extern.h"
+#include "LAYER2/NR_MAC_COMMON/nr_mac_extern.h"
 #include "LAYER2/MAC/mac.h"
 #include "common/utils/LOG/log.h"
 #include "common/utils/system.h"
diff --git a/openair1/SCHED_NR_UE/defs.h b/openair1/SCHED_NR_UE/defs.h
index 8e42149add..cbcb936be3 100644
--- a/openair1/SCHED_NR_UE/defs.h
+++ b/openair1/SCHED_NR_UE/defs.h
@@ -289,7 +289,13 @@ uint16_t nr_get_Np(uint8_t N_RB_DL,uint8_t nCCE,uint8_t plus1);
 
 int8_t nr_find_ue(uint16_t rnti, PHY_VARS_eNB *phy_vars_eNB);
 
-void nr_process_timing_advance(module_id_t Mod_id,uint8_t CC_id,int16_t timing_advance);
+/*! \brief Compute the timing adjustment at UE side from the old TA offset and the new received TA command
+  @param Mod_id Local UE index on which to act
+  @param CC_id Component Carrier Index
+  @param timing_advance TA command
+  @param mu numerology index (0,1,2..)
+*/
+void nr_process_timing_advance(module_id_t Mod_id,uint8_t CC_id,uint8_t timing_advance, uint8_t mu);
 void nr_process_timing_advance_rar(PHY_VARS_NR_UE *phy_vars_ue,UE_nr_rxtx_proc_t *proc,uint16_t timing_advance);
 
 unsigned int get_tx_amp(int power_dBm, int power_max_dBm, int N_RB_UL, int nb_rb);
diff --git a/openair1/SCHED_NR_UE/phy_procedures_nr_ue.c b/openair1/SCHED_NR_UE/phy_procedures_nr_ue.c
index 60378d81fc..2ad57beba9 100644
--- a/openair1/SCHED_NR_UE/phy_procedures_nr_ue.c
+++ b/openair1/SCHED_NR_UE/phy_procedures_nr_ue.c
@@ -21,11 +21,11 @@
 
 /*! \file phy_procedures_nr_ue.c
  * \brief Implementation of UE procedures from 36.213 LTE specifications
- * \author R. Knopp, F. Kaltenberger, N. Nikaein, A. Mico Pereperez
+ * \author R. Knopp, F. Kaltenberger, N. Nikaein, A. Mico Pereperez, G. Casati
  * \date 2018
  * \version 0.1
  * \company Eurecom
- * \email: knopp@eurecom.fr,florian.kaltenberger@eurecom.fr, navid.nikaein@eurecom.fr
+ * \email: knopp@eurecom.fr,florian.kaltenberger@eurecom.fr, navid.nikaein@eurecom.fr, guido.casati@iis.fraunhofer.de
  * \note
  * \warning
  */
@@ -421,22 +421,6 @@ void nr_process_timing_advance_rar(PHY_VARS_NR_UE *ue,UE_nr_rxtx_proc_t *proc,ui
   LOG_I(PHY,"[UE %d] AbsoluteSubFrame %d.%d, received (rar) timing_advance %d\n",ue->Mod_id,proc->frame_rx, proc->nr_tti_rx, ue->timing_advance);
 #endif
 
-}
-
-void nr_process_timing_advance(uint8_t Mod_id,uint8_t CC_id,int16_t timing_advance)
-{
-
-  //  uint32_t frame = PHY_vars_UE_g[Mod_id]->frame;
-
-  // timing advance has Q1.5 format
-  timing_advance = timing_advance - 31;
-
-  PHY_vars_UE_g[Mod_id][CC_id]->timing_advance = PHY_vars_UE_g[Mod_id][CC_id]->timing_advance+timing_advance*4; //this is for 25RB only!!!
-
-
-  LOG_D(PHY,"[UE %d] Got timing advance %d from MAC, new value %d\n",Mod_id, timing_advance, PHY_vars_UE_g[Mod_id][CC_id]->timing_advance);
-
-
 }
 
 uint8_t nr_is_SR_TXOp(PHY_VARS_NR_UE *ue,UE_nr_rxtx_proc_t *proc,uint8_t eNB_id)
@@ -1560,6 +1544,19 @@ VCD_SIGNAL_DUMPER_DUMP_FUNCTION_BY_NAME(VCD_SIGNAL_DUMPER_FUNCTIONS_PHY_PROCEDUR
 
 #endif
 
+
+void nr_process_timing_advance(module_id_t Mod_id, uint8_t CC_id, uint8_t timing_advance, uint8_t mu){
+
+  // 3GPP TS 38.213 p4.2
+
+  int factor_mu = 1 << mu;
+
+  PHY_vars_UE_g[Mod_id][CC_id]->timing_advance += (timing_advance - 31) * 1024 / factor_mu ;
+
+
+  LOG_D(PHY,"[UE %d] Got timing advance %d from MAC, new value is %d\n",Mod_id, timing_advance, PHY_vars_UE_g[Mod_id][CC_id]->timing_advance);
+}
+
 void ue_ulsch_uespec_procedures(PHY_VARS_NR_UE *ue,
 								UE_nr_rxtx_proc_t *proc,
 								uint8_t eNB_id,
@@ -3361,7 +3358,7 @@ void nr_ue_pdsch_procedures(PHY_VARS_NR_UE *ue, UE_nr_rxtx_proc_t *proc, int eNB
     uint16_t s0 =  dlsch0->harq_processes[harq_pid]->start_symbol;
     uint16_t s1 =  dlsch0->harq_processes[harq_pid]->nb_symbols;
 
-    LOG_D(PHY,"[UE %d] PDSCH type %d active in nr_tti_rx %d, harq_pid %d, rb_start %d, nb_rb %d, symbol_start %d, nb_symbols %d\n",ue->Mod_id,pdsch,nr_tti_rx,harq_pid,pdsch_start_rb,pdsch_nb_rb,s0,s1);
+    LOG_I(PHY,"[UE %d] PDSCH type %d active in nr_tti_rx %d, harq_pid %d, rb_start %d, nb_rb %d, symbol_start %d, nb_symbols %d\n",ue->Mod_id,pdsch,nr_tti_rx,harq_pid,pdsch_start_rb,pdsch_nb_rb,s0,s1);
 
     for (m = s0; m < (s1 + s0); m++) {
 
@@ -3528,7 +3525,7 @@ void nr_ue_dlsch_procedures(PHY_VARS_NR_UE *ue,
   int frame_rx = proc->frame_rx;
   int nr_tti_rx = proc->nr_tti_rx;
   int ret=0, ret1=0;
-  //int CC_id = ue->CC_id;
+  uint8_t CC_id = ue->CC_id;
   NR_UE_PDSCH *pdsch_vars;
   uint8_t is_cw0_active = 0;
   uint8_t is_cw1_active = 0;
@@ -3800,11 +3797,89 @@ void nr_ue_dlsch_procedures(PHY_VARS_NR_UE *ue,
       if (ue->if_inst && ue->if_inst->dl_indication)
       ue->if_inst->dl_indication(&dl_indication);
       }
-    }
 
+      // TODO CRC check for CW0
 
+      // Check CRC for CW 0
+      /*if (ret == (1+dlsch0->max_turbo_iterations)) {
+        *dlsch_errors=*dlsch_errors+1;
+        if(dlsch0->rnti != 0xffff){
+          LOG_D(PHY,"[UE  %d][PDSCH %x/%d] AbsSubframe %d.%d : DLSCH CW0 in error (rv %d,round %d, mcs %d,TBS %d)\n",
+          ue->Mod_id,dlsch0->rnti,
+          harq_pid,frame_rx,subframe_rx,
+          dlsch0->harq_processes[harq_pid]->rvidx,
+          dlsch0->harq_processes[harq_pid]->round,
+          dlsch0->harq_processes[harq_pid]->mcs,
+          dlsch0->harq_processes[harq_pid]->TBS);
+        }
+      } else {
+        if(dlsch0->rnti != 0xffff){
+          LOG_D(PHY,"[UE  %d][PDSCH %x/%d] AbsSubframe %d.%d : Received DLSCH CW0 (rv %d,round %d, mcs %d,TBS %d)\n",
+          ue->Mod_id,dlsch0->rnti,
+          harq_pid,frame_rx,subframe_rx,
+          dlsch0->harq_processes[harq_pid]->rvidx,
+          dlsch0->harq_processes[harq_pid]->round,
+          dlsch0->harq_processes[harq_pid]->mcs,
+          dlsch0->harq_processes[harq_pid]->TBS);
+        }
+        if ( LOG_DEBUGFLAG(DEBUG_UE_PHYPROC)){
+          int j;
+          LOG_D(PHY,"dlsch harq_pid %d (rx): \n",dlsch0->current_harq_pid);
 
+          for (j=0; j<dlsch0->harq_processes[dlsch0->current_harq_pid]->TBS>>3; j++)
+            LOG_T(PHY,"%x.",dlsch0->harq_processes[dlsch0->current_harq_pid]->b[j]);
+          LOG_T(PHY,"\n");
+      }*/
 
+      if (ue->mac_enabled == 1) {
+        switch (pdsch) {
+          case PDSCH:
+          printf("PDSCH procedures\n");
+          nr_ue_send_sdu(ue->Mod_id,
+                      CC_id,
+                      frame_rx,
+                      nr_tti_rx,
+                      dlsch0->harq_processes[harq_pid]->b,
+                      dlsch0->harq_processes[harq_pid]->TBS>>3,
+                      eNB_id);
+          break;
+          case SI_PDSCH:
+          /*ue_decode_si(ue->Mod_id,
+                      CC_id,
+                      frame_rx,
+                      eNB_id,
+                      ue->dlsch_SI[eNB_id]->harq_processes[0]->b,
+                      ue->dlsch_SI[eNB_id]->harq_processes[0]->TBS>>3);*/
+          break;
+          case P_PDSCH:
+          /*ue_decode_p(ue->Mod_id,
+                      CC_id,
+                      frame_rx,
+                      eNB_id,
+                      ue->dlsch_SI[eNB_id]->harq_processes[0]->b,
+                      ue->dlsch_SI[eNB_id]->harq_processes[0]->TBS>>3);*/
+          break;
+          case RA_PDSCH:
+          /*process_rar(ue,proc,eNB_id,mode,abstraction_flag);*/
+          break;
+          case PDSCH1:
+          /*LOG_E(PHY,"Shouldn't have PDSCH1 yet, come back later\n");
+          AssertFatal(1==0,"exiting");*/
+          break;
+          case PMCH:
+          /*LOG_E(PHY,"Shouldn't have PMCH here\n");
+          AssertFatal(1==0,"exiting");*/
+          break;
+        }
+      }
+
+      /*ue->total_TBS[eNB_id] =  ue->total_TBS[eNB_id] + dlsch0->harq_processes[dlsch0->current_harq_pid]->TBS;
+      ue->total_received_bits[eNB_id] = ue->total_TBS[eNB_id] + dlsch0->harq_processes[dlsch0->current_harq_pid]->TBS;
+    }*/
+
+    // TODO CRC check for CW1
+
+  }
 }
 
 
@@ -4132,6 +4207,8 @@ int phy_procedures_nrUE_RX(PHY_VARS_NR_UE *ue,
                            uint8_t do_pdcch_flag,
                            runmode_t mode)
 {
+  int l,l2;
+  int pilot1;
   int frame_rx = proc->frame_rx;
   int nr_tti_rx = proc->nr_tti_rx;
   int slot_pbch;
diff --git a/openair2/LAYER2/MAC/mac_extern.h b/openair2/LAYER2/MAC/mac_extern.h
index 3510e7e7ae..dbf5b57b6b 100644
--- a/openair2/LAYER2/MAC/mac_extern.h
+++ b/openair2/LAYER2/MAC/mac_extern.h
@@ -34,7 +34,6 @@
 
 //#include "PHY/defs_common.h"
 #include "mac.h"
-
 #include "RRC/LTE/rrc_defs.h"
 
 extern const uint32_t BSR_TABLE[BSR_TABLE_SIZE];
@@ -51,13 +50,9 @@ extern const uint8_t cqi2fmt2x_agg[MAX_SUPPORTED_BW][CQI_VALUE_RANGE];
 extern UE_RRC_INST *UE_rrc_inst;
 extern UE_MAC_INST *UE_mac_inst;
 
-
 extern eNB_ULSCH_INFO eNB_ulsch_info[NUMBER_OF_eNB_MAX][MAX_NUM_CCs][MAX_MOBILES_PER_ENB];	// eNBxUE = 8x8
 extern eNB_DLSCH_INFO eNB_dlsch_info[NUMBER_OF_eNB_MAX][MAX_NUM_CCs][MAX_MOBILES_PER_ENB];	// eNBxUE = 8x8
 
-
-
-
 extern unsigned char NB_INST;
 extern unsigned char NB_eNB_INST;
 extern uint16_t NB_UE_INST;
@@ -65,7 +60,6 @@ extern uint16_t NB_THREAD_INST;
 extern unsigned char NB_RN_INST;
 extern unsigned short NODE_ID[1];
 
-
 extern int cqi_to_mcs[16];
 
 extern uint32_t RRC_CONNECTION_FLAG;
diff --git a/openair2/LAYER2/NR_MAC/nr_mac.h b/openair2/LAYER2/NR_MAC_COMMON/nr_mac.h
similarity index 78%
rename from openair2/LAYER2/NR_MAC/nr_mac.h
rename to openair2/LAYER2/NR_MAC_COMMON/nr_mac.h
index ce15d88c0c..acb63ea4dc 100644
--- a/openair2/LAYER2/NR_MAC/nr_mac.h
+++ b/openair2/LAYER2/NR_MAC_COMMON/nr_mac.h
@@ -41,6 +41,31 @@
 
 #define NR_BCCH_BCH 5    // MIB
 
+//  For both DL/UL-SCH
+//  Except:
+//   - UL/DL-SCH: fixed-size MAC CE(known by LCID)
+//   - UL/DL-SCH: padding
+//   - UL-SCH:    MSG3 48-bits
+//  |0|1|2|3|4|5|6|7|  bit-wise
+//  |R|F|   LCID    |
+//  |       L       |
+//  |0|1|2|3|4|5|6|7|  bit-wise
+//  |R|F|   LCID    |
+//  |       L       |
+//  |       L       |
+
+//  For both DL/UL-SCH
+//  For:
+//   - UL/DL-SCH: fixed-size MAC CE(known by LCID)
+//   - UL/DL-SCH: padding, for single/multiple 1-oct padding CE(s)
+//   - UL-SCH:    MSG3 48-bits
+//  |0|1|2|3|4|5|6|7|  bit-wise
+//  |R|R|   LCID    |
+//  LCID: The Logical Channel ID field identifies the logical channel instance of the corresponding MAC SDU or the type of the corresponding MAC CE or padding as described in Tables 6.2.1-1 and 6.2.1-2 for the DL-SCH and UL-SCH respectively. There is one LCID field per MAC subheader. The LCID field size is 6 bits;
+//  L: The Length field indicates the length of the corresponding MAC SDU or variable-sized MAC CE in bytes. There is one L field per MAC subheader except for subheaders corresponding to fixed-sized MAC CEs and padding. The size of the L field is indicated by the F field;
+//  F: lenght of L is 0:8 or 1:16 bits wide
+//  R: Reserved bit, set to zero.
+
 typedef struct {
     uint8_t LCID:6;     // octet 1 [5:0]
     uint8_t F:1;        // octet 1 [6]
diff --git a/openair2/LAYER2/NR_MAC_gNB/nr_mac_common.c b/openair2/LAYER2/NR_MAC_COMMON/nr_mac_common.c
similarity index 100%
rename from openair2/LAYER2/NR_MAC_gNB/nr_mac_common.c
rename to openair2/LAYER2/NR_MAC_COMMON/nr_mac_common.c
diff --git a/openair2/LAYER2/NR_MAC_COMMON/nr_mac_extern.h b/openair2/LAYER2/NR_MAC_COMMON/nr_mac_extern.h
new file mode 100644
index 0000000000..10df4567c4
--- /dev/null
+++ b/openair2/LAYER2/NR_MAC_COMMON/nr_mac_extern.h
@@ -0,0 +1,73 @@
+/*
+ * Licensed to the OpenAirInterface (OAI) Software Alliance under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The OpenAirInterface Software Alliance licenses this file to You under
+ * the OAI Public License, Version 1.1  (the "License"); you may not use this file
+ * except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.openairinterface.org/?page_id=698
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *-------------------------------------------------------------------------------
+ * For more information about the OpenAirInterface (OAI) Software Alliance:
+ *      contact@openairinterface.org
+ */
+
+/*! \file extern.h
+* \brief NR mac externs
+* \author G. Casati
+* \date 2019
+* \version 1.0
+* \email guido.casati@iis.fraunhofer.de
+* @ingroup _mac
+
+*/
+
+#ifndef __NR_MAC_EXTERN_H__
+#define __NR_MAC_EXTERN_H__
+
+//#include "PHY/defs_common.h"
+#include "nr_mac.h"
+#include "RRC/LTE/rrc_defs.h"
+#include "common/ran_context.h"
+
+/* extern const uint32_t BSR_TABLE[BSR_TABLE_SIZE];
+extern const uint32_t Extended_BSR_TABLE[BSR_TABLE_SIZE];
+extern const uint8_t cqi2fmt0_agg[MAX_SUPPORTED_BW][CQI_VALUE_RANGE];
+extern const uint8_t cqi2fmt1x_agg[MAX_SUPPORTED_BW][CQI_VALUE_RANGE];
+extern const uint8_t cqi2fmt2x_agg[MAX_SUPPORTED_BW][CQI_VALUE_RANGE];
+extern UE_RRC_INST *UE_rrc_inst;
+extern eNB_ULSCH_INFO eNB_ulsch_info[NUMBER_OF_eNB_MAX][MAX_NUM_CCs][MAX_MOBILES_PER_ENB];	// eNBxUE = 8x8
+extern eNB_DLSCH_INFO eNB_dlsch_info[NUMBER_OF_eNB_MAX][MAX_NUM_CCs][MAX_MOBILES_PER_ENB];	// eNBxUE = 8x8
+extern int cqi_to_mcs[16];
+extern uint32_t RRC_CONNECTION_FLAG;
+extern uint8_t rb_table[34];
+extern mac_rlc_am_muilist_t rlc_am_mui;
+extern SCHEDULER_MODES global_scheduler_mode;
+extern unsigned char NB_UE_INST;*/
+
+extern unsigned char NB_INST;
+extern unsigned char NB_eNB_INST;
+extern unsigned char NB_RN_INST;
+extern unsigned short NODE_ID[1];
+
+/* Scheduler */
+extern RAN_CONTEXT_t RC;
+extern int phy_test;
+extern uint8_t nfapi_mode;
+
+/*#if defined(PRE_SCD_THREAD)
+extern uint16_t pre_nb_rbs_required[2][MAX_NUM_CCs][NUMBER_OF_UE_MAX];
+extern uint8_t dlsch_ue_select_tbl_in_use;
+extern uint8_t new_dlsch_ue_select_tbl_in_use;
+extern boolean_t pre_scd_activeUE[NUMBER_OF_UE_MAX];
+extern eNB_UE_STATS pre_scd_eNB_UE_stats[MAX_NUM_CCs][NUMBER_OF_UE_MAX];
+#endif*/
+
+#endif //DEF_H
diff --git a/openair2/LAYER2/NR_MAC_UE/mac_extern.h b/openair2/LAYER2/NR_MAC_UE/mac_extern.h
index 960b47e44a..26e0ea2667 100644
--- a/openair2/LAYER2/NR_MAC_UE/mac_extern.h
+++ b/openair2/LAYER2/NR_MAC_UE/mac_extern.h
@@ -30,6 +30,10 @@
  * \warning
  */
 
+#include "mac_defs.h"
+
+//extern NR_UE_MAC_INST_t *UE_mac_inst;
+
 //	Type0-PDCCH search space
 extern const int32_t table_38213_13_1_c2[16];
 extern const int32_t table_38213_13_1_c3[16];
diff --git a/openair2/LAYER2/NR_MAC_UE/mac_proto.h b/openair2/LAYER2/NR_MAC_UE/mac_proto.h
index 98389ddcfd..6cbe7b32c4 100755
--- a/openair2/LAYER2/NR_MAC_UE/mac_proto.h
+++ b/openair2/LAYER2/NR_MAC_UE/mac_proto.h
@@ -125,16 +125,28 @@ uint32_t get_ssb_slot(uint32_t ssb_index);
 uint32_t mr_ue_get_SR(module_id_t module_idP, int CC_id, frame_t frameP, uint8_t eNB_id, uint16_t rnti, sub_frame_t subframe);
 
 
+
+/* \brief Get payload (MAC PDU) from UE PHY
+@param module_idP Instance id of UE in machine
+@param CC_id Component Carrier index
+@param frameP Current Rx frame
+@param ttiP Current Rx tti subframe
+@param pdu Pointer to the MAC PDU
+@param pdu_len Length of the MAC PDU
+@param eNB_id Index of eNB that UE is attached to
+@returns void
+*/
+void nr_ue_send_sdu(module_id_t module_idP,uint8_t CC_id, frame_t frameP, uint8_t ttiP,
+                    uint8_t * pdu, uint16_t pdu_len, uint8_t eNB_index);
+
 void nr_ue_process_mac_pdu(
     module_id_t module_idP,
     uint8_t CC_id,
     uint8_t *pduP, 
-    uint16_t mac_pdu_len, 
+    uint16_t mac_pdu_len,
     uint8_t eNB_index);
 
 int8_t nr_ue_process_dlsch(module_id_t module_id, int cc_id, uint8_t gNB_index, fapi_nr_dci_indication_t *dci_ind, void *pduP, uint32_t pdu_len);
 
-void nr_ue_send_sdu(module_id_t module_idP, uint8_t CC_id, frame_t frameP, sub_frame_t subframeP, uint8_t * sdu, uint16_t sdu_len, uint8_t eNB_index);
-
 #endif
 /** @}*/
diff --git a/openair2/LAYER2/NR_MAC_UE/nr_ue_procedures.c b/openair2/LAYER2/NR_MAC_UE/nr_ue_procedures.c
index 5d7a2dca29..57b418f945 100644
--- a/openair2/LAYER2/NR_MAC_UE/nr_ue_procedures.c
+++ b/openair2/LAYER2/NR_MAC_UE/nr_ue_procedures.c
@@ -21,23 +21,41 @@
 
 /* \file ue_procedures.c
  * \brief procedures related to UE
- * \author R. Knopp, K.H. HSU
+ * \author R. Knopp, K.H. HSU, G. Casati
  * \date 2018
  * \version 0.1
  * \company Eurecom / NTUST
- * \email: knopp@eurecom.fr, kai-hsiang.hsu@eurecom.fr
+ * \email: knopp@eurecom.fr, kai-hsiang.hsu@eurecom.fr, guido.casati@iis.fraunhofer.de
  * \note
  * \warning
  */
 
+/* MAC related headers */
 #include "mac_proto.h"
-#include "LAYER2/NR_MAC/nr_mac.h"
+#include "LAYER2/NR_MAC_COMMON/nr_mac.h"
 #include "mac_extern.h"
+//#include "LAYER2/MAC/mac_vars.h" // TODO Note that mac_vars.h is not NR specific and this should be updated
+                                 // also, the use of the same should be updated in nr-softmodem and nr-uesoftmodem
+
+/* PHY UE related headers*/
+#include "SCHED_NR_UE/defs.h"
+
 #include "RRC/NR_UE/rrc_proto.h"
 #include "assertions.h"
 #include "PHY/defs_nr_UE.h"
+
+/*Openair Packet Tracer */
+#include "UTIL/OPT/opt.h"
+#include "OCG.h"
+
+/* log utils */
 #include "common/utils/LOG/log.h"
-#include "openair2/LAYER2/MAC/mac.h"
+#include "common/utils/LOG/vcd_signal_dumper.h"
+
+/* TODO remove this for debugging purpose
+#include "LAYER2/NR_MAC_gNB/nr_mac_gNB.h"
+#include "LAYER2/MAC/mac.h"
+*/
 
 #include <stdio.h>
 #include <math.h>
@@ -2025,21 +2043,88 @@ int8_t nr_ue_get_SR(module_id_t module_idP, int CC_id, frame_t frameP, uint8_t e
     return 0;
 }
 
+void nr_ue_send_sdu(module_id_t module_idP,
+                    uint8_t CC_id,
+                    frame_t frameP,
+                    uint8_t ttiP,
+                    uint8_t * pdu, uint16_t pdu_len, uint8_t eNB_index){
+
+  printf("nr_ue_send_sdu frame %d\n", frameP);
+
+  // Changes wrt LTE: replaced subframeP with ttiP
+  // TODO double check this and eventually create a type for TTI (tti_t)
+  // Note: pdu_len was previously named sdu and sdu_len
+
+  uint8_t * pduP = pdu;
+  NR_UE_MAC_INST_t *UE_mac_inst = get_mac_inst(module_idP);
+
+  /*
+  #if UE_TIMING_TRACE
+    start_meas(&UE_mac_inst[module_idP].rx_dlsch_sdu);
+  #endif
+  */
+
+  VCD_SIGNAL_DUMPER_DUMP_FUNCTION_BY_NAME(VCD_SIGNAL_DUMPER_FUNCTIONS_UE_SEND_SDU, VCD_FUNCTION_IN);
+
+  //LOG_D(MAC,"sdu: %x.%x.%x\n",sdu[0],sdu[1],sdu[2]);
+
+  if (opt_enabled) {
+    trace_pdu(DIRECTION_DOWNLINK, pduP, pdu_len, module_idP, WS_C_RNTI,
+    UE_mac_inst[module_idP].cs_RNTI, frameP, ttiP, 0, 0); //subframeP
+    LOG_D(OPT, "[UE %d][DLSCH] Frame %d trace pdu for rnti %x  with size %d\n",
+      module_idP, frameP, UE_mac_inst[module_idP].cs_RNTI, pdu_len);
+    }
+
+  /*
+  #ifdef DEBUG_HEADER_PARSING
+    LOG_D(MAC, "[UE %d] ue_send_sdu : Frame %d eNB_index %d : num_ce %d num_sdu %d\n",
+      module_idP, frameP, eNB_index, num_ce, num_sdu);
+  #endif
+  */
+
+  /*
+  #if defined(ENABLE_MAC_PAYLOAD_DEBUG)
+    LOG_T(MAC, "[UE %d] First 32 bytes of DLSCH : \n", module_idP);
+    for (i = 0; i < 32; i++) {
+      LOG_T(MAC, "%x.", sdu[i]);
+    }
+    LOG_T(MAC, "\n");
+  #endif
+  */
+
+  // Processing MAC PDU
+  // it parses MAC CEs subheaders, MAC CEs, SDU subheaderds and SDUs
+  nr_ue_process_mac_pdu(module_idP, CC_id, pduP, pdu_len, eNB_index);
+
+  VCD_SIGNAL_DUMPER_DUMP_FUNCTION_BY_NAME(VCD_SIGNAL_DUMPER_FUNCTIONS_UE_SEND_SDU, VCD_FUNCTION_OUT);
+
+  /*
+  #if UE_TIMING_TRACE
+    stop_meas(&UE_mac_inst[module_idP].rx_dlsch_sdu);
+  #endif
+  */
+}
 
 void nr_ue_process_mac_pdu(
     module_id_t module_idP,
     uint8_t CC_id,
     uint8_t *pduP, 
-    uint16_t mac_pdu_len, 
+    uint16_t mac_pdu_len,
     uint8_t eNB_index){
 
+    // This function is adapting code from the old
+    // parse_header(...) and ue_send_sdu(...) functions of OAI LTE
+
     uint8_t *pdu_ptr = pduP;
-    uint16_t pdu_len = mac_pdu_len;
+    int pdu_len = mac_pdu_len;
 
     uint16_t mac_ce_len;
     uint16_t mac_subheader_len;
     uint16_t mac_sdu_len;
 
+    NR_UE_MAC_INST_t *UE_mac_inst = get_mac_inst(module_idP);
+    uint8_t scs = UE_mac_inst->mib->subCarrierSpacingCommon;
+
     //  For both DL/UL-SCH
     //  Except:
     //   - UL/DL-SCH: fixed-size MAC CE(known by LCID)
@@ -2067,12 +2152,16 @@ void nr_ue_process_mac_pdu(
 
     uint8_t done = 0;
     
-    while (!done || pdu_len <= 0){
-        mac_ce_len = 0x0000;
-        mac_subheader_len = 0x0001; //  default to fixed-length subheader = 1-oct
-        mac_sdu_len = 0x0000;
+    while (!done && pdu_len > 0){
+        mac_ce_len = 0;
+        mac_subheader_len = 1; //  default to fixed-length subheader = 1-oct
+        mac_sdu_len = 0;
         switch(((NR_MAC_SUBHEADER_FIXED *)pdu_ptr)->LCID){
             //  MAC CE
+
+            /*#ifdef DEBUG_HEADER_PARSING
+              LOG_D(MAC, "[UE] LCID %d, PDU length %d\n", ((NR_MAC_SUBHEADER_FIXED *)pdu_ptr)->LCID, pdu_len);
+            #endif*/
             case DL_SCH_LCID_CCCH:
                 //  MSG4 RRC Connection Setup 38.331
                 //  varialbe length
@@ -2082,8 +2171,29 @@ void nr_ue_process_mac_pdu(
                     mac_ce_len |= (uint16_t)(((NR_MAC_SUBHEADER_LONG *)pdu_ptr)->L2)<<8;
                     mac_subheader_len = 3;
                 }
+
+                /*LOG_D(MAC, "[UE %d] rnti %x Frame %d : DLSCH -> DL-CCCH, RRC message (eNB %d, %d bytes)\n",
+                    module_idP, UE_mac_inst[module_idP].crnti, frameP, eNB_index, rx_lengths[i]);*/
+
+                /*#if defined(ENABLE_MAC_PAYLOAD_DEBUG)
+                  int j;
+                  for (j = 0; j < rx_lengths[i]; j++) {
+                    LOG_T(MAC, "%x.", (uint8_t) payload_ptr[j]);
+                  }
+                  LOG_T(MAC, "\n");
+                #endif*/
+
+                /*mac_rrc_data_ind_ue(module_idP,
+                            CC_id,
+                            frameP, subframeP,
+                            UE_mac_inst[module_idP].crnti,
+                            CCCH,
+                            (uint8_t *) payload_ptr,
+                            rx_lengths[i], eNB_index, 0);*/
                 break;
+
             case DL_SCH_LCID_TCI_STATE_ACT_UE_SPEC_PDSCH:
+
                 //  38.321 Ch6.1.3.14
                 //  varialbe length
                 mac_ce_len |= (uint16_t)((NR_MAC_SUBHEADER_SHORT *)pdu_ptr)->L;
@@ -2169,10 +2279,70 @@ void nr_ue_process_mac_pdu(
             case DL_SCH_LCID_TA_COMMAND:
                 //  38.321 Ch6.1.3.4
                 mac_ce_len = 1;
+
+                uint8_t ta_command = ((NR_MAC_CE_TA *)pdu_ptr)[1].TA_COMMAND;
+
+                uint8_t tag_id = ((NR_MAC_CE_TA *)pdu_ptr)[1].TAGID;
+
+                /*
+                #ifdef DEBUG_HEADER_PARSING
+                LOG_D(MAC, "[UE] CE %d : UE Timing Advance : %d\n", i, pdu_ptr[1]);
+                #endif
+                */
+
+                LOG_D(MAC, "Received TA_COMMAND %u TAGID %u CC_id %d\n", ta_command, tag_id, CC_id);
+
+                //if (nfapi_mode!=3){ // TODO check nfapi_mode
+                  nr_process_timing_advance(module_idP, CC_id, ta_command, scs);
+                //}
+
                 break;
             case DL_SCH_LCID_CON_RES_ID:
                 //  38.321 Ch6.1.3.3
                 mac_ce_len = 6;
+
+                // TODO index should be shifted by 1
+                // LOG_I(MAC,"[UE %d][RAPROC] Frame %d : received contention resolution msg: %x.%x.%x.%x.%x.%x, Terminating RA procedure\n", module_idP, frameP, payload_ptr[0], payload_ptr[1], payload_ptr[2], payload_ptr[3], payload_ptr[4], payload_ptr[5]);
+
+                // TODO RACH is missing
+
+                /*if (UE_mac_inst[module_idP].RA_active == 1) {
+                  LOG_I(MAC, "[UE %d][RAPROC] Frame %d : Clearing RA_active flag\n",
+                    module_idP, frameP);
+                    UE_mac_inst[module_idP].RA_active = 0;
+                    // check if RA procedure has finished completely (no contention)
+                    tx_sdu = &UE_mac_inst[module_idP].CCCH_pdu.payload[3];
+
+                  //Note: 3 assumes sizeof(SCH_SUBHEADER_SHORT) + PADDING CE, which is when UL-Grant has TBS >= 9 (64 bits)
+                  // (other possibility is 1 for TBS=7 (SCH_SUBHEADER_FIXED), or 2 for TBS=8 (SCH_SUBHEADER_FIXED+PADDING or SCH_SUBHEADER_SHORT)
+                  for (i = 0; i < 6; i++)
+                    if (tx_sdu[i] != payload_ptr[i]) {
+                      LOG_E(MAC, "[UE %d][RAPROC] Contention detected, RA failed\n", module_idP);
+                      if(nfapi_mode == 3) { // phy_stub mode
+                      //  Modification for phy_stub mode operation here. We only need to make sure that the ue_mode is back to
+                      // PRACH state.
+                        LOG_I(MAC, "nfapi_mode3: Setting UE_mode BACK to PRACH 1\n");
+                        UE_mac_inst[module_idP].UE_mode[eNB_index] = PRACH;
+                      //ra_failed(module_idP,CC_id,eNB_index);UE_mac_inst[module_idP].RA_contention_resolution_timer_active = 0;
+                      }
+                      else{
+                        ra_failed(module_idP, CC_id, eNB_index);
+                      }
+                    UE_mac_inst[module_idP].RA_contention_resolution_timer_active = 0;
+                    VCD_SIGNAL_DUMPER_DUMP_FUNCTION_BY_NAME(VCD_SIGNAL_DUMPER_FUNCTIONS_UE_SEND_SDU, VCD_FUNCTION_OUT);
+                    return;
+                    }
+                    LOG_I(MAC,"[UE %d][RAPROC] Frame %d : Clearing contention resolution timer\n", module_idP, frameP);
+                    UE_mac_inst[module_idP].RA_contention_resolution_timer_active = 0;
+                    if(nfapi_mode == 3){
+                      // phy_stub mode
+                      // Modification for phy_stub mode operation here. We only need to change the ue_mode to PUSCH
+                      UE_mac_inst[module_idP].UE_mode[eNB_index] = PUSCH;
+                  } else { // Full stack mode
+                    ra_succeeded(module_idP,CC_id,eNB_index);
+                  }
+                }*/
+
                 break;
             case DL_SCH_LCID_PADDING:
                 done = 1;
@@ -2180,25 +2350,62 @@ void nr_ue_process_mac_pdu(
                 break;
 
             //  MAC SDU
+            /* TODO double check SRBs 1-3 & DRB 1-3 */
+
             case DL_SCH_LCID_SRB1:
-                //  check if LCID is valid at current time.
+            //  check if LCID is valid at current time.
+
+              /*if ((rx_lcids[i] == DCCH) || (rx_lcids[i] == DCCH1)) {
+
+              LOG_D(MAC, "[UE %d] Frame %d : DLSCH -> DL-DCCH%d, RRC message (eNB %d, %d bytes)\n",
+              module_idP, frameP, rx_lcids[i], eNB_index, rx_lengths[i]);
+
+              mac_rlc_data_ind(module_idP, UE_mac_inst[module_idP].crnti, eNB_index, frameP, ENB_FLAG_NO,
+              MBMS_FLAG_NO, rx_lcids[i], (char *) payload_ptr, rx_lengths[i], 1, NULL);
+              } else if ((rx_lcids[i] < NB_RB_MAX) && (rx_lcids[i] > DCCH1)) {
+              LOG_D(MAC, "[UE %d] Frame %d : DLSCH -> DL-DTCH%d (eNB %d, %d bytes)\n",
+              module_idP, frameP, rx_lcids[i], eNB_index, rx_lengths[i]);
+
+              #if defined(ENABLE_MAC_PAYLOAD_DEBUG)
+                int j;
+                for (j = 0; j < rx_lengths[i]; j++)
+                LOG_T(MAC, "%x.", (unsigned char) payload_ptr[j]);
+                LOG_T(MAC, "\n");
+              #endif
+
+              mac_rlc_data_ind(module_idP,
+                         UE_mac_inst[module_idP].crnti,
+                         eNB_index,
+                         frameP,
+                         ENB_FLAG_NO,
+                         MBMS_FLAG_NO,
+                         rx_lcids[i],
+                         (char *) payload_ptr, rx_lengths[i], 1, NULL);
+            }*/
+
             case UL_SCH_LCID_SRB2:
                 //  check if LCID is valid at current time.
             case UL_SCH_LCID_SRB3:
                 //  check if LCID is valid at current time.
             default:
                 //  check if LCID is valid at current time.
-                mac_sdu_len |= (uint16_t)((NR_MAC_SUBHEADER_SHORT *)pdu_ptr)->L;
-                mac_subheader_len = 2;
                 if(((NR_MAC_SUBHEADER_SHORT *)pdu_ptr)->F){
-                    mac_sdu_len |= (uint16_t)(((NR_MAC_SUBHEADER_LONG *)pdu_ptr)->L2)<<8;
+                    //mac_sdu_len |= (uint16_t)(((NR_MAC_SUBHEADER_LONG *)pdu_ptr)->L2)<<8;
                     mac_subheader_len = 3;
+                    mac_sdu_len = ((uint16_t)(((NR_MAC_SUBHEADER_LONG *) pdu_ptr)->L1 & 0x7f) << 8)
+                    | ((uint16_t)((NR_MAC_SUBHEADER_LONG *) pdu_ptr)->L2 & 0xff);
+
+                } else {
+                  mac_sdu_len = (uint16_t)((NR_MAC_SUBHEADER_SHORT *)pdu_ptr)->L;
+                  mac_subheader_len = 2;
                 }
+
                 //  DRB LCID by RRC
                 break;
         }
         pdu_ptr += ( mac_subheader_len + mac_ce_len + mac_sdu_len );
         pdu_len -= ( mac_subheader_len + mac_ce_len + mac_sdu_len );
+
         AssertFatal(pdu_len >= 0, "[MAC] nr_ue_process_mac_pdu, residual mac pdu length < 0!\n");
     }
 }
diff --git a/openair2/LAYER2/NR_MAC_gNB/gNB_scheduler.c b/openair2/LAYER2/NR_MAC_gNB/gNB_scheduler.c
index e43f2633b1..fb5f9eccf1 100644
--- a/openair2/LAYER2/NR_MAC_gNB/gNB_scheduler.c
+++ b/openair2/LAYER2/NR_MAC_gNB/gNB_scheduler.c
@@ -33,9 +33,10 @@
 #include "assertions.h"
 
 #include "LAYER2/MAC/mac.h"
-#include "LAYER2/MAC/mac_extern.h"
+#include "LAYER2/NR_MAC_COMMON/nr_mac_extern.h"
 #include "LAYER2/MAC/mac_proto.h"
 #include "LAYER2/NR_MAC_gNB/mac_proto.h"
+
 #include "common/utils/LOG/log.h"
 #include "common/utils/LOG/vcd_signal_dumper.h"
 #include "UTIL/OPT/opt.h"
@@ -64,10 +65,6 @@
 #define ENABLE_MAC_PAYLOAD_DEBUG
 #define DEBUG_eNB_SCHEDULER 1
 
-extern RAN_CONTEXT_t RC;
-extern int phy_test;
-extern uint8_t nfapi_mode;
-
 uint16_t nr_pdcch_order_table[6] = { 31, 31, 511, 2047, 2047, 8191 };
 
 void clear_nr_nfapi_information(gNB_MAC_INST * gNB,
@@ -375,11 +372,12 @@ void gNB_dlsch_ulsch_scheduler(module_id_t module_idP,
 
   // Phytest scheduling
  
-  if (slot_rxP==2){
+  if (slot_rxP == NR_UPLINK_SLOT){
     nr_schedule_uss_ulsch_phytest(&RC.nrmac[module_idP]->UL_tti_req[0], frame_rxP, slot_rxP);
   }
   
-  if (slot_txP==1){
+  if (slot_txP == NR_DOWNLINK_SLOT){
+    nr_schedule_ue_spec(module_idP, frame_txP, slot_txP);
     nr_schedule_uss_dlsch_phytest(module_idP, frame_txP, slot_txP,NULL);
   }
 
diff --git a/openair2/LAYER2/NR_MAC_gNB/gNB_scheduler_bch.c b/openair2/LAYER2/NR_MAC_gNB/gNB_scheduler_bch.c
index 8dbdbc93fa..df3e04dccf 100644
--- a/openair2/LAYER2/NR_MAC_gNB/gNB_scheduler_bch.c
+++ b/openair2/LAYER2/NR_MAC_gNB/gNB_scheduler_bch.c
@@ -33,7 +33,7 @@
 #include "assertions.h"
 #include "LAYER2/NR_MAC_gNB/nr_mac_gNB.h"
 #include "LAYER2/NR_MAC_gNB/mac_proto.h"
-#include "LAYER2/MAC/mac_extern.h"
+#include "LAYER2/NR_MAC_COMMON/nr_mac_extern.h"
 #include "common/utils/LOG/log.h"
 #include "common/utils/LOG/vcd_signal_dumper.h"
 #include "UTIL/OPT/opt.h"
diff --git a/openair2/LAYER2/NR_MAC_gNB/gNB_scheduler_dlsch.c b/openair2/LAYER2/NR_MAC_gNB/gNB_scheduler_dlsch.c
new file mode 100644
index 0000000000..a53f09939b
--- /dev/null
+++ b/openair2/LAYER2/NR_MAC_gNB/gNB_scheduler_dlsch.c
@@ -0,0 +1,330 @@
+/*
+ * Licensed to the OpenAirInterface (OAI) Software Alliance under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The OpenAirInterface Software Alliance licenses this file to You under
+ * the OAI Public License, Version 1.1  (the "License"); you may not use this file
+ * except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.openairinterface.org/?page_id=698
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *-------------------------------------------------------------------------------
+ * For more information about the OpenAirInterface (OAI) Software Alliance:
+ *      contact@openairinterface.org
+ */
+
+/*! \file       gNB_scheduler_dlsch.c
+ * \brief       procedures related to gNB for the DLSCH transport channel
+ * \author      Guido Casati
+ * \date        2019
+ * \email:      guido.casati@iis.fraunhofe.de
+ * \version     1.0
+ * @ingroup     _mac
+
+ */
+
+/*PHY*/
+#include "PHY/CODING/coding_defs.h"
+#include "PHY/defs_nr_common.h"
+#include "PHY/NR_TRANSPORT/nr_transport_common_proto.h"
+/*MAC*/
+#include "LAYER2/NR_MAC_COMMON/nr_mac.h"
+#include "LAYER2/NR_MAC_gNB/nr_mac_gNB.h"
+#include "LAYER2/NR_MAC_COMMON/nr_mac_extern.h"
+#include "LAYER2/MAC/mac.h"
+
+/*NFAPI*/
+#include "nfapi_nr_interface.h"
+/*TAG*/
+#include "NR_TAG-Id.h"
+
+
+int nr_generate_dlsch_pdu(unsigned char *sdus_payload, 
+	                        unsigned char *mac_pdu,
+                          unsigned char num_sdus,
+                          unsigned short *sdu_lengths,
+                          unsigned char *sdu_lcids,
+                          unsigned char drx_cmd,
+                          unsigned short timing_advance_cmd,
+                          NR_TAG_Id_t tag_id,
+                          unsigned char *ue_cont_res_id,
+                          unsigned short post_padding){
+
+  NR_MAC_SUBHEADER_FIXED *mac_pdu_ptr = (NR_MAC_SUBHEADER_FIXED *) mac_pdu;
+  unsigned char * dlsch_buffer_ptr = sdus_payload;
+  uint8_t last_size = 0;
+  int offset = 0, mac_ce_size, i;
+
+  // MAC CEs 
+  uint8_t mac_header_control_elements[16], *ce_ptr;
+  ce_ptr = &mac_header_control_elements[0];
+
+  // 1) Compute MAC CE and related subheaders 
+
+  // DRX command subheader (MAC CE size 0)
+  if (drx_cmd != 255) {
+    mac_pdu_ptr->R = 0;
+    mac_pdu_ptr->LCID = DL_SCH_LCID_DRX;
+    //last_size = 1;
+    mac_pdu_ptr++;
+  }
+
+  // Timing Advance subheader
+  if (timing_advance_cmd != 31) {
+    mac_pdu_ptr->R = 0;
+    mac_pdu_ptr->LCID = DL_SCH_LCID_TA_COMMAND;
+    //last_size = 1;
+    mac_pdu_ptr++;
+
+    // TA MAC CE (1 octet) 
+    AssertFatal(timing_advance_cmd < 64,"timing_advance_cmd %d > 63\n", timing_advance_cmd);
+    ((NR_MAC_CE_TA *) ce_ptr)->TA_COMMAND = timing_advance_cmd;    //(timing_advance_cmd+31)&0x3f;
+    ((NR_MAC_CE_TA *) ce_ptr)->TAGID = tag_id;
+
+    LOG_D(MAC, "NR MAC CE timing advance command =%d (%d) TAG ID =%d\n", timing_advance_cmd, ((NR_MAC_CE_TA *) ce_ptr)->TA_COMMAND, tag_id);
+    mac_ce_size = sizeof(NR_MAC_CE_TA);
+    
+    // Copying  bytes for MAC CEs to the mac pdu pointer
+    memcpy((void *) mac_pdu_ptr, (void *) ce_ptr, mac_ce_size);
+    ce_ptr += mac_ce_size;
+    mac_pdu_ptr += (unsigned char) mac_ce_size;  
+   }
+
+  // Contention resolution fixed subheader and MAC CE
+  if (ue_cont_res_id) {
+    mac_pdu_ptr->R = 0;
+  	mac_pdu_ptr->LCID = DL_SCH_LCID_CON_RES_ID;
+    mac_pdu_ptr++;
+    //last_size = 1;
+
+    // contention resolution identity MAC ce has a fixed 48 bit size
+    // this contains the UL CCCH SDU. If UL CCCH SDU is longer than 48 bits, 
+    // it contains the first 48 bits of the UL CCCH SDU
+    LOG_T(MAC, "[gNB ][RAPROC] Generate contention resolution msg: %x.%x.%x.%x.%x.%x\n",
+        ue_cont_res_id[0], ue_cont_res_id[1], ue_cont_res_id[2],
+        ue_cont_res_id[3], ue_cont_res_id[4], ue_cont_res_id[5]);
+
+    // Copying bytes (6 octects) to CEs pointer
+    mac_ce_size = 6;
+    memcpy(ce_ptr, ue_cont_res_id, mac_ce_size);
+    
+    // Copying bytes for MAC CEs to mac pdu pointer
+    memcpy((void *) mac_pdu_ptr, (void *) ce_ptr, mac_ce_size);
+    ce_ptr += mac_ce_size;
+    mac_pdu_ptr += (unsigned char) mac_ce_size;
+  }
+
+
+  // 2) Generation of DLSCH MAC SDU subheaders
+  for (i = 0; i < num_sdus; i++) {
+    LOG_D(MAC, "[gNB] Generate DLSCH header num sdu %d len sdu %d\n", num_sdus, sdu_lengths[i]);
+
+    if (sdu_lengths[i] < 128) {
+      ((NR_MAC_SUBHEADER_SHORT *) mac_pdu_ptr)->R = 0;
+      ((NR_MAC_SUBHEADER_SHORT *) mac_pdu_ptr)->F = 0;
+      ((NR_MAC_SUBHEADER_SHORT *) mac_pdu_ptr)->LCID = sdu_lcids[i];
+      ((NR_MAC_SUBHEADER_SHORT *) mac_pdu_ptr)->L = (unsigned char) sdu_lengths[i];
+      last_size = 2;
+    } else {
+      ((NR_MAC_SUBHEADER_LONG *) mac_pdu_ptr)->R = 0;
+      ((NR_MAC_SUBHEADER_LONG *) mac_pdu_ptr)->F = 1;
+      ((NR_MAC_SUBHEADER_LONG *) mac_pdu_ptr)->LCID = sdu_lcids[i];
+      ((NR_MAC_SUBHEADER_LONG *) mac_pdu_ptr)->L1 = ((unsigned short) sdu_lengths[i] >> 8) & 0x7f;
+      ((NR_MAC_SUBHEADER_LONG *) mac_pdu_ptr)->L2 = (unsigned short) sdu_lengths[i] & 0xff;
+      last_size = 3;
+    }
+
+    mac_pdu_ptr += last_size;
+
+    // 3) cycle through SDUs, compute each relevant and place dlsch_buffer in   
+    memcpy((void *) mac_pdu_ptr, (void *) dlsch_buffer_ptr, sdu_lengths[i]);
+    dlsch_buffer_ptr+= sdu_lengths[i]; 
+    mac_pdu_ptr += sdu_lengths[i];
+  }
+
+  // 4) Compute final offset for padding
+  if (post_padding > 0) {    
+    ((NR_MAC_SUBHEADER_FIXED *) mac_pdu_ptr)->R = 0;
+    ((NR_MAC_SUBHEADER_FIXED *) mac_pdu_ptr)->LCID = DL_SCH_LCID_PADDING;
+    mac_pdu_ptr++;
+
+ 	// compute final offset
+    offset = ((unsigned char *) mac_pdu_ptr - mac_pdu);
+    
+  } else {            
+    // no MAC subPDU with padding
+  }
+
+  //printf("Offset %d \n", ((unsigned char *) mac_pdu_ptr - mac_pdu));
+
+  return offset;
+}
+
+/*TODO expand the scheduling functionalities
+this function is just generating a dummy MAC PDU and is used to transmit the TA
+The structure of the algorithm is taken from the schedule_ue_spec function in LTE 
+and is preserved for future reference.*/
+void
+nr_schedule_ue_spec(module_id_t module_idP, frame_t frameP, sub_frame_t slotP){
+
+
+  gNB_MAC_INST *gNB = RC.nrmac[module_idP];
+  UE_list_t *UE_list = &gNB->UE_list;
+  nfapi_nr_dl_config_request_body_t *dl_req; 
+
+  // TODO size corretly the arrays
+  // at present, preserved the array length from lte code
+  // however not sure why NR_MAX_NB_RB was used here
+  unsigned char sdu_lcids[NR_MAX_NB_RB] = {0};
+  uint16_t sdu_lengths[NR_MAX_NB_RB] = {0};
+
+  int padding = 0, post_padding = 0, ta_len = 0, header_length_total = 0, sdu_length_total = 0, num_sdus = 0;
+  int CC_id, sub_pdu_id, lcid, offset, i, j=0, k=0;
+
+  // hardcoded parameters
+  // for DMRS configuration type 1
+  // sdus should come from RLC 
+  static unsigned char dlsch_buffer[MAX_NR_DLSCH_PAYLOAD_BYTES];
+  uint8_t Qm = 2;
+  uint16_t R = 697;
+  uint16_t nb_rb = 50 ;
+  uint32_t TBS = nr_compute_tbs(Qm, R, nb_rb, 12, 6, 0, 1)/8; // this is in bits TODO use nr_get_tbs
+  int ta_update = 17;
+  NR_TAG_Id_t tag_id = 0;
+  int UE_id = 0; // UE_list->head is -1 !
+
+  UE_sched_ctrl_t *ue_sched_ctl = &UE_list->UE_sched_ctrl[UE_id];
+  
+  for (CC_id = 0; CC_id < RC.nb_nr_mac_CC[module_idP] + 1; CC_id++) {
+    LOG_D(MAC, "doing nr_schedule_ue_spec for CC_id %d\n", CC_id);
+    dl_req = &gNB->DL_req[CC_id].dl_config_request_body;
+
+    //for (UE_id = UE_list->head; UE_id >= -1; UE_id = UE_list->next[UE_id]) {
+
+      /* 
+      //process retransmission
+      if (round != 8) {
+   
+      } else {	// This is a potentially new SDU opportunity */
+
+        if (gNB->tag->timeAlignmentTimer != NULL) {
+          if (gNB->tag->timeAlignmentTimer == 0) {
+            ta_update = ue_sched_ctl->ta_update;
+            /* if we send TA then set timer to not send it for a while */
+            if (ta_update != 31)
+              ue_sched_ctl->ta_timer = 20;
+            /* reset ta_update */
+            ue_sched_ctl->ta_update = 31;
+          } else {
+            ta_update = 31;
+          }
+        }
+
+        ta_len = (ta_update != 31) ? 2 : 0;
+
+        // retrieve TAG ID
+        if(gNB->tag->tag_Id != NULL ){
+          tag_id = gNB->tag->tag_Id;
+        }
+
+        // fill dlsch_buffer with random data
+        for (i = 0; i < MAX_NR_DLSCH_PAYLOAD_BYTES; i++){
+          dlsch_buffer[i] = (unsigned char) rand();
+        }
+
+        /*
+        //Sending SDUs with size 1
+        //Initialize elements of sdu_lcids and sdu_lengths
+        //TODO this will be eventually be removed 
+        for (j = 0; j < NB_RB_MAX; j++){
+          sdu_lcids[j] = 0x05; // DRB
+        }
+        
+        for (k = 0; k < NB_RB_MAX; k++){
+          sdu_lengths[k] = 1;
+          header_length_total += 2;
+          sdu_length_total += 1;
+        }*/
+
+        //Sending SDUs with size 1
+        //Initialize elements of sdu_lcids and sdu_lengths
+        //TODO this will be eventually be removed
+        while (TBS - header_length_total - sdu_length_total - ta_len >= 3){
+          if (k < NR_MAX_NB_RB && j < NR_MAX_NB_RB){
+            sdu_lcids[j] = 0x05; // DRB
+            sdu_lengths[k] = 1;
+            header_length_total += 2;
+            sdu_length_total += 1;
+            num_sdus +=1;
+            k++, j++;
+          }
+          else {
+            break;
+          }
+        }
+
+        /*
+        // RLC data on DCCH
+        if (TBS - ta_len - header_length_total - sdu_length_total - 3 > 0) {
+        }
+
+        // RLC data on DCCH1
+        if (TBS - ta_len - header_length_total - sdu_length_total - 3 > 0) {
+        }
+
+        // looping over lcid
+        for (lcid = NB_RB_MAX - 1; lcid >= DTCH; lcid--) {
+        // here sdu_lcids[num_sdus] is populated
+        }*/
+
+        // there is at least one SDU or TA command
+        // if (num_sdus > 0 ){
+        if (ta_len + sdu_length_total + header_length_total > 0) {
+
+          // Check if there is data from RLC or CE 
+          if (TBS - header_length_total - sdu_length_total - ta_len >= 2) {
+            // we have to consider padding
+	          // padding param currently not in use
+            padding = TBS - header_length_total - sdu_length_total - ta_len - 1;
+            post_padding = 1;
+          } else {
+            post_padding = 0;
+          }
+
+
+          offset = nr_generate_dlsch_pdu((unsigned char *) dlsch_buffer,
+          	                            (unsigned char *) UE_list->DLSCH_pdu[CC_id][0][UE_id].payload[0],
+          	                            num_sdus,    //num_sdus
+                                        sdu_lengths,
+                                        sdu_lcids,
+          	                            255,          // no drx
+          	                            ta_update,    // timing advance
+                                        tag_id,
+          	                            NULL,         // contention res id
+          	                            post_padding);
+          // Padding: fill remainder of DLSCH with 0 
+          if (post_padding > 0){
+            for (int j = 0; j < (TBS - offset); j++)
+              UE_list->DLSCH_pdu[CC_id][0][UE_id].payload[0][offset + j] = 0;
+          }    
+
+          // Printing bit by bit for debugging purpose 
+          /*for (int k = 0; k < TBS; k++){
+            printf("MAC PDU %u\n",((( UE_list->DLSCH_pdu[CC_id][0][UE_id].payload[0][k/8]) & (1 << (k & 7))) >> (k & 7)));     
+            if ((k+1)%8 == 0)
+              printf("\n");
+          }*/
+          
+	        }
+          else {  // There is no data from RLC or MAC header, so don't schedule
+          } 
+	      //}
+    //} // UE_id loop
+  } // CC_id loop
+}
diff --git a/openair2/LAYER2/NR_MAC_gNB/gNB_scheduler_primitives.c b/openair2/LAYER2/NR_MAC_gNB/gNB_scheduler_primitives.c
index d746756d65..92ba958519 100644
--- a/openair2/LAYER2/NR_MAC_gNB/gNB_scheduler_primitives.c
+++ b/openair2/LAYER2/NR_MAC_gNB/gNB_scheduler_primitives.c
@@ -34,7 +34,7 @@
 
 #include "LAYER2/MAC/mac.h"
 #include "LAYER2/NR_MAC_gNB/nr_mac_gNB.h"
-#include "LAYER2/MAC/mac_extern.h"
+#include "LAYER2/NR_MAC_COMMON/nr_mac_extern.h"
 
 #include "LAYER2/NR_MAC_gNB/mac_proto.h"
 #include "common/utils/LOG/log.h"
diff --git a/openair2/LAYER2/NR_MAC_gNB/mac_proto.h b/openair2/LAYER2/NR_MAC_gNB/mac_proto.h
index d56d5d28c1..451bac8042 100644
--- a/openair2/LAYER2/NR_MAC_gNB/mac_proto.h
+++ b/openair2/LAYER2/NR_MAC_gNB/mac_proto.h
@@ -33,6 +33,7 @@
 
 #include "nr_mac_gNB.h"
 #include "PHY/defs_gNB.h"
+#include "NR_TAG-Id.h"
 
 void set_cset_offset(uint16_t);
 
@@ -70,6 +71,19 @@ void gNB_dlsch_ulsch_scheduler(module_id_t module_idP,
 			       frame_t frame_txP, sub_frame_t slot_txP,
 			       frame_t frame_rxP, sub_frame_t slot_rxP);
 
+int nr_generate_dlsch_pdu(unsigned char *sdus_payload,
+                          unsigned char *mac_pdu,
+                          unsigned char num_sdus,
+                          unsigned short *sdu_lengths,
+                          unsigned char *sdu_lcids,
+                          unsigned char drx_cmd,
+                          unsigned short timing_advance_cmd,
+                          NR_TAG_Id_t tag_id,
+                          unsigned char *ue_cont_res_id,
+                          unsigned short post_padding);
+
+void nr_schedule_ue_spec(module_id_t module_idP, frame_t frameP, sub_frame_t slotP);
+
 void schedule_nr_mib(module_id_t module_idP, frame_t frameP, sub_frame_t subframeP);
 
 void nr_schedule_css_dlsch_phytest(module_id_t   module_idP,
diff --git a/openair2/LAYER2/NR_MAC_gNB/main.c b/openair2/LAYER2/NR_MAC_gNB/main.c
index 88f6c38758..1482f9bf35 100644
--- a/openair2/LAYER2/NR_MAC_gNB/main.c
+++ b/openair2/LAYER2/NR_MAC_gNB/main.c
@@ -31,7 +31,7 @@
  */
 
 #include "mac_proto.h"
-#include "LAYER2/MAC/mac_extern.h" //temporary
+#include "LAYER2/NR_MAC_COMMON/nr_mac_extern.h"
 #include "assertions.h"
 
 #include "LAYER2/PDCP_v10.1.0/pdcp.h"
@@ -106,6 +106,9 @@ void mac_top_init_gNB(void)
 
         RC.nrmac[i]->Mod_id = i;
 
+        RC.nrmac[i]->tag = (NR_TAG_t*)malloc(sizeof(NR_TAG_t));
+        memset((void*)RC.nrmac[i]->tag,0,sizeof(NR_TAG_t));
+
 
         for (j = 0; j < MAX_NUM_CCs; j++) {
           RC.nrmac[i]->DL_req[j].dl_config_request_body.dl_config_pdu_list = RC.nrmac[i]->dl_config_pdu_list[j];
diff --git a/openair2/LAYER2/NR_MAC_gNB/nr_mac_gNB.h b/openair2/LAYER2/NR_MAC_gNB/nr_mac_gNB.h
index 7633279579..170fb5d440 100644
--- a/openair2/LAYER2/NR_MAC_gNB/nr_mac_gNB.h
+++ b/openair2/LAYER2/NR_MAC_gNB/nr_mac_gNB.h
@@ -55,12 +55,14 @@
 #include "common/ran_context.h"
 #include "LAYER2/MAC/mac.h"
 #include "LAYER2/MAC/mac_proto.h"
-#include "LAYER2/MAC/mac_extern.h"
+#include "LAYER2/NR_MAC_COMMON/nr_mac_extern.h"
 #include "PHY/defs_gNB.h"
 #include "PHY/TOOLS/time_meas.h"
 #include "targets/ARCH/COMMON/common_lib.h"
 
 
+#include "NR_TAG.h"
+
 /*! \brief gNB common channels */
 typedef struct {
     int physCellId;
@@ -107,7 +109,9 @@ typedef struct gNB_MAC_INST_s {
   /// frame counter
   frame_t                         frame;
   /// slot counter
-  int                             slot;  
+  int                             slot;
+  /// timing advance group
+  NR_TAG_t                        *tag;
   /// Pointer to IF module instance for PHY
   NR_IF_Module_t                  *if_inst;
     /// Common cell resources
diff --git a/openair2/NR_PHY_INTERFACE/NR_IF_Module.c b/openair2/NR_PHY_INTERFACE/NR_IF_Module.c
index 4c9804bdc0..e446ab3a95 100644
--- a/openair2/NR_PHY_INTERFACE/NR_IF_Module.c
+++ b/openair2/NR_PHY_INTERFACE/NR_IF_Module.c
@@ -34,7 +34,7 @@
 #include "openair1/PHY/phy_extern.h"
 #include "openair1/SCHED_NR/fapi_nr_l1.h"
 #include "openair2/NR_PHY_INTERFACE/NR_IF_Module.h"
-#include "LAYER2/MAC/mac_extern.h"
+#include "LAYER2/NR_MAC_COMMON/nr_mac_extern.h"
 #include "LAYER2/MAC/mac_proto.h"
 #include "LAYER2/NR_MAC_gNB/mac_proto.h"
 #include "common/ran_context.h"
diff --git a/openair2/RRC/NR/nr_rrc_common.c b/openair2/RRC/NR/nr_rrc_common.c
index f5ab3f2366..daa9663ca8 100644
--- a/openair2/RRC/NR/nr_rrc_common.c
+++ b/openair2/RRC/NR/nr_rrc_common.c
@@ -29,7 +29,7 @@
  */
 
 #include "nr_rrc_extern.h"
-#include "LAYER2/MAC/mac_extern.h"
+#include "LAYER2/NR_MAC_COMMON/nr_mac_extern.h"
 #include "COMMON/openair_defs.h"
 #include "COMMON/platform_types.h"
 #include "RRC/L2_INTERFACE/openair_rrc_L2_interface.h"
diff --git a/openair2/RRC/NR_UE/rrc_defs.h b/openair2/RRC/NR_UE/rrc_defs.h
index ff4145ece3..e2b22ef243 100644
--- a/openair2/RRC/NR_UE/rrc_defs.h
+++ b/openair2/RRC/NR_UE/rrc_defs.h
@@ -40,7 +40,7 @@
 #include "platform_types.h"
 
 #include "LAYER2/NR_MAC_UE/mac.h"
-#include "LAYER2/NR_MAC/nr_mac.h"
+#include "LAYER2/NR_MAC_COMMON/nr_mac.h"
 #include "rrc_list.h"
 #include "NR_asn_constant.h"
 #include "NR_MeasConfig.h"