diff --git a/srsue/hdr/mac/dl_harq.h b/srsue/hdr/mac/dl_harq.h
index 3b9c25e28..25677dd84 100644
--- a/srsue/hdr/mac/dl_harq.h
+++ b/srsue/hdr/mac/dl_harq.h
@@ -45,15 +45,15 @@
 
 
 namespace srsue {
-  
+
+template <std::size_t N, typename Tgrant, typename Taction, typename Tphygrant>
 class dl_harq_entity
 {
 public:
 
-  const static uint32_t NOF_HARQ_PROC = 8; 
-  const static uint32_t HARQ_BCCH_PID = NOF_HARQ_PROC; 
+  const static uint32_t HARQ_BCCH_PID = N;
   
-  dl_harq_entity()
+  dl_harq_entity() : proc(N+1)
   {
     pcap = NULL;
   }
@@ -65,7 +65,7 @@ public:
     mac_cfg    = mac_cfg_; 
     si_window_start = 0; 
     log_h = log_h_; 
-    for (uint32_t i=0;i<NOF_HARQ_PROC+1;i++) {
+    for (uint32_t i=0;i<N+1;i++) {
       if (!proc[i].init(i, this)) {
         return false; 
       }
@@ -74,7 +74,7 @@ public:
   }
 
   /***************** PHY->MAC interface for DL processes **************************/
-  void new_grant_dl(mac_interface_phy::mac_grant_t grant, mac_interface_phy::tb_action_dl_t *action)
+  void new_grant_dl(Tgrant grant, Taction *action)
   {
     if (grant.rnti_type != SRSLTE_RNTI_SPS) {
       uint32_t harq_pid; 
@@ -82,7 +82,7 @@ public:
       if (grant.rnti_type == SRSLTE_RNTI_SI) {
         harq_pid = HARQ_BCCH_PID; 
       } else {
-        harq_pid = grant.pid%NOF_HARQ_PROC; 
+        harq_pid = grant.pid%N;
       }
       if (grant.rnti_type == SRSLTE_RNTI_TEMP && last_temporal_crnti != grant.rnti) {
         grant.ndi = true;
@@ -96,7 +96,7 @@ public:
       proc[harq_pid].new_grant_dl(grant, action);
     } else {
       /* This is for SPS scheduling */
-      uint32_t harq_pid = get_harq_sps_pid(grant.tti)%NOF_HARQ_PROC; 
+      uint32_t harq_pid = get_harq_sps_pid(grant.tti)%N;
       if (grant.ndi) {
         grant.ndi = false; 
         proc[harq_pid].new_grant_dl(grant, action);
@@ -121,16 +121,16 @@ public:
   void tb_decoded(bool ack, srslte_rnti_type_t rnti_type, uint32_t harq_pid)
   {
     if (rnti_type == SRSLTE_RNTI_SI) {
-      proc[NOF_HARQ_PROC].tb_decoded(ack);    
+      proc[N].tb_decoded(ack);
     } else {
-      proc[harq_pid%NOF_HARQ_PROC].tb_decoded(ack);
+      proc[harq_pid%N].tb_decoded(ack);
     }
   }
 
 
   void reset()
   {
-    for (uint32_t i=0;i<NOF_HARQ_PROC+1;i++) {
+    for (uint32_t i=0;i<N+1;i++) {
       proc[i].reset();
     }
     dl_sps_assig.clear();
@@ -138,7 +138,7 @@ public:
 
   void start_pcap(srslte::mac_pcap* pcap_) { pcap = pcap_; }
 
-  int  get_current_tbs(uint32_t harq_pid) { return proc[harq_pid%NOF_HARQ_PROC].get_current_tbs(); }
+  int  get_current_tbs(uint32_t harq_pid) { return proc[harq_pid%N].get_current_tbs(); }
 
   void set_si_window_start(int si_window_start_) { si_window_start = si_window_start_; }
 
@@ -151,7 +151,7 @@ private:
     {
       is_initiated = false; 
       ack = false; 
-      bzero(&cur_grant, sizeof(mac_interface_phy::mac_grant_t));
+      bzero(&cur_grant, sizeof(Tgrant));
     }
 
     bool init(uint32_t pid_, dl_harq_entity *parent)
@@ -172,13 +172,13 @@ private:
     {
       ack = false; 
       payload_buffer_ptr = NULL; 
-      bzero(&cur_grant, sizeof(mac_interface_phy::mac_grant_t));
+      bzero(&cur_grant, sizeof(Tgrant));
       if (is_initiated) {
         srslte_softbuffer_rx_reset(&softbuffer);
       }
     }
     
-    void new_grant_dl(mac_interface_phy::mac_grant_t grant, mac_interface_phy::tb_action_dl_t *action)
+    void new_grant_dl(Tgrant grant, Taction *action)
     {
       // Compute RV for BCCH when not specified in PDCCH format
       if (pid == HARQ_BCCH_PID && grant.rv == -1) {
@@ -201,10 +201,10 @@ private:
       // Save grant 
       grant.last_ndi = cur_grant.ndi; 
       grant.last_tti = cur_grant.tti; 
-      memcpy(&cur_grant, &grant, sizeof(mac_interface_phy::mac_grant_t)); 
+      memcpy(&cur_grant, &grant, sizeof(Tgrant));
       
       // Fill action structure 
-      bzero(action, sizeof(mac_interface_phy::tb_action_dl_t));
+      bzero(action, sizeof(Taction));
       action->default_ack = ack; 
       action->generate_ack = true; 
       action->decode_enabled = false; 
@@ -224,7 +224,7 @@ private:
         action->rv = cur_grant.rv; 
         action->rnti = cur_grant.rnti; 
         action->softbuffer = &softbuffer;     
-        memcpy(&action->phy_grant, &cur_grant.phy_grant, sizeof(srslte_phy_grant_t));
+        memcpy(&action->phy_grant, &cur_grant.phy_grant, sizeof(Tphygrant));
         n_retx++; 
         
       } else {
@@ -293,7 +293,7 @@ private:
     int get_current_tbs() { return cur_grant.n_bytes*8; }
     
   private: 
-    bool calc_is_new_transmission(mac_interface_phy::mac_grant_t grant)
+    bool calc_is_new_transmission(Tgrant grant)
     {
       bool is_new_tb = true; 
       if ((srslte_tti_interval(grant.tti, cur_grant.tti) <= 8 && (grant.n_bytes == cur_grant.n_bytes)) ||
@@ -328,7 +328,7 @@ private:
     
     uint32_t        n_retx; 
     
-    mac_interface_phy::mac_grant_t cur_grant;    
+    Tgrant                         cur_grant;
     srslte_softbuffer_rx_t         softbuffer; 
   };
   
@@ -344,7 +344,8 @@ private:
   
   dl_sps           dl_sps_assig;
   
-  dl_harq_process  proc[NOF_HARQ_PROC+1];
+
+  std::vector<dl_harq_process> proc;
   srslte::timers   *timers_db;
   mac_interface_rrc::mac_cfg_t *mac_cfg; 
   demux           *demux_unit; 
diff --git a/srsue/hdr/mac/mac.h b/srsue/hdr/mac/mac.h
index 82a7b1e76..660f7fbba 100644
--- a/srsue/hdr/mac/mac.h
+++ b/srsue/hdr/mac/mac.h
@@ -106,6 +106,7 @@ private:
   
   static const int MAC_MAIN_THREAD_PRIO = 5; 
   static const int MAC_PDU_THREAD_PRIO  = 6;
+  static const int MAC_NOF_HARQ_PROC    = 8;
 
   // Interaction with PHY 
   srslte::tti_sync_cv   ttisync; 
@@ -130,9 +131,9 @@ private:
   mux           mux_unit; 
   demux         demux_unit; 
   
-  /* DL/UL HARQ */  
-  dl_harq_entity dl_harq; 
-  ul_harq_entity ul_harq; 
+  /* DL/UL HARQ */
+  dl_harq_entity<MAC_NOF_HARQ_PROC, mac_grant_t, tb_action_dl_t, srslte_phy_grant_t> dl_harq;
+  ul_harq_entity<MAC_NOF_HARQ_PROC, mac_grant_t, tb_action_ul_t, srslte_phy_grant_t> ul_harq;
   
   /* MAC Uplink-related Procedures */
   ra_proc       ra_procedure;
diff --git a/srsue/hdr/mac/ul_harq.h b/srsue/hdr/mac/ul_harq.h
index 38046b099..21c4a9602 100644
--- a/srsue/hdr/mac/ul_harq.h
+++ b/srsue/hdr/mac/ul_harq.h
@@ -43,17 +43,18 @@
 
 /* Uplink HARQ entity as defined in 5.4.2 of 36.321 */
 namespace srsue {
-  
+
+template <std::size_t N, typename Tgrant, typename Taction, typename Tphygrant>
 class ul_harq_entity
 {
 public:
-  const static uint32_t NOF_HARQ_PROC = 8; 
   static uint32_t pidof(uint32_t tti)
   {
-    return (uint32_t) tti%NOF_HARQ_PROC;
+    return (uint32_t) tti%N;
   }
   
-  ul_harq_entity() {  
+  ul_harq_entity() : proc(N)
+  {
     pcap        = NULL; 
     timers_db   = NULL; 
     mux_unit    = NULL; 
@@ -61,7 +62,7 @@ public:
     mac_cfg     = NULL; 
     rntis       = NULL; 
     average_retx = 0; 
-    nof_pkts     = 0; 
+    nof_pkts     = 0;
   }
 
   bool init(srslte::log *log_h_, 
@@ -75,7 +76,7 @@ public:
     mac_cfg   = mac_cfg_;
     rntis     = rntis_;
     timers_db = timers_db_;
-    for (uint32_t i=0;i<NOF_HARQ_PROC;i++) {
+    for (uint32_t i=0;i<N;i++) {
       if (!proc[i].init(i, this)) {
         return false;
       }
@@ -85,7 +86,7 @@ public:
 
   void reset()
   {
-    for (uint32_t i=0;i<NOF_HARQ_PROC;i++) {
+    for (uint32_t i=0;i<N;i++) {
       proc[i].reset();
     }
     ul_sps_assig.clear();
@@ -93,7 +94,7 @@ public:
 
   void reset_ndi()
   {
-    for (uint32_t i=0;i<NOF_HARQ_PROC;i++) {
+    for (uint32_t i=0;i<N;i++) {
       proc[i].reset_ndi();
     }
   }
@@ -105,7 +106,7 @@ public:
 
   
   /***************** PHY->MAC interface for UL processes **************************/
-  void new_grant_ul(mac_interface_phy::mac_grant_t grant, mac_interface_phy::tb_action_ul_t *action)
+  void new_grant_ul(Tgrant grant, Taction *action)
   {
     if (grant.rnti_type == SRSLTE_RNTI_USER ||
       grant.rnti_type == SRSLTE_RNTI_TEMP ||
@@ -125,13 +126,13 @@ public:
     }
   }
 
-  void new_grant_ul_ack(mac_interface_phy::mac_grant_t grant, bool ack, mac_interface_phy::tb_action_ul_t *action)
+  void new_grant_ul_ack(Tgrant grant, bool ack, Taction *action)
   {
     set_ack(grant.tti, ack);
     new_grant_ul(grant, action);
   }
 
-  void harq_recv(uint32_t tti, bool ack, mac_interface_phy::tb_action_ul_t *action)
+  void harq_recv(uint32_t tti, bool ack, Taction *action)
   {
     set_ack(tti, ack);
     run_tti(tti, NULL, action);
@@ -162,7 +163,7 @@ private:
       is_initiated = false;
       is_grant_configured = false;
       tti_last_tx = 0;
-      bzero(&cur_grant, sizeof(mac_interface_phy::mac_grant_t));
+      bzero(&cur_grant, sizeof(Tgrant));
     }
 
     bool init(uint32_t pid_, ul_harq_entity *parent)
@@ -191,12 +192,12 @@ private:
       current_irv = 0;
       tti_last_tx = 0;
       is_grant_configured = false;
-      bzero(&cur_grant, sizeof(mac_interface_phy::mac_grant_t));
+      bzero(&cur_grant, sizeof(Tgrant));
     }
 
     void reset_ndi() { ndi = false; }
     
-    void run_tti(uint32_t tti_tx, mac_interface_phy::mac_grant_t *grant, mac_interface_phy::tb_action_ul_t* action)
+    void run_tti(uint32_t tti_tx, Tgrant *grant, Taction* action)
     {
       uint32_t max_retx;
       if (is_msg3) {
@@ -287,7 +288,7 @@ private:
     int get_current_tbs() { return cur_grant.n_bytes*8; }
    
   private: 
-    mac_interface_phy::mac_grant_t cur_grant;
+    Tgrant                      cur_grant;
     
     uint32_t                    pid;
     uint32_t                    current_tx_nb;
@@ -307,14 +308,14 @@ private:
     uint8_t *payload_buffer;
     uint8_t *pdu_ptr; 
     
-    void generate_retx(uint32_t tti_tx, mac_interface_phy::tb_action_ul_t *action)
+    void generate_retx(uint32_t tti_tx, Taction *action)
     {
       generate_retx(tti_tx, NULL, action);
     }
 
     // Retransmission with or w/o grant (Section 5.4.2.2)
-    void generate_retx(uint32_t tti_tx, mac_interface_phy::mac_grant_t *grant, 
-                                        mac_interface_phy::tb_action_ul_t *action)
+    void generate_retx(uint32_t tti_tx, Tgrant *grant,
+                                        Taction *action)
     {
       int irv_of_rv[4] = {0, 3, 1, 2};
       if (grant) {
@@ -322,7 +323,7 @@ private:
         if (grant->rv) {
           current_irv = irv_of_rv[grant->rv%4];
         }
-        memcpy(&cur_grant, grant, sizeof(mac_interface_phy::mac_grant_t));
+        memcpy(&cur_grant, grant, sizeof(Tgrant));
         harq_feedback = false;
         Info("UL %d:  Adaptive retx=%d, RV=%d, TBS=%d\n",
              pid, current_tx_nb, get_rv(), grant->n_bytes);
@@ -345,13 +346,12 @@ private:
     }
 
     // New transmission (Section 5.4.2.2)
-    void generate_new_tx(uint32_t tti_tx, bool is_msg3_, mac_interface_phy::mac_grant_t *grant,
-                         mac_interface_phy::tb_action_ul_t *action)
+    void generate_new_tx(uint32_t tti_tx, bool is_msg3_, Tgrant *grant, Taction *action)
     {
       if (grant) {
         // Compute average number of retransmissions per packet considering previous packet
         harq_entity->average_retx = SRSLTE_VEC_CMA((float) current_tx_nb, harq_entity->average_retx, harq_entity->nof_pkts++);
-        memcpy(&cur_grant, grant, sizeof(mac_interface_phy::mac_grant_t));
+        memcpy(&cur_grant, grant, sizeof(Tgrant));
         harq_feedback = false;
         is_grant_configured = true;
         current_tx_nb = 0;
@@ -364,7 +364,7 @@ private:
     }
 
     // Transmission of pending frame (Section 5.4.2.2)
-    void generate_tx(uint32_t tti_tx, mac_interface_phy::tb_action_ul_t *action)
+    void generate_tx(uint32_t tti_tx, Taction *action)
     {
       action->current_tx_nb = current_tx_nb;
       current_tx_nb++;
@@ -374,7 +374,7 @@ private:
       action->softbuffer = &softbuffer;
       action->tx_enabled = true;
       action->payload_ptr = pdu_ptr;
-      memcpy(&action->phy_grant, &cur_grant.phy_grant, sizeof(srslte_phy_grant_t));
+      memcpy(&action->phy_grant, &cur_grant.phy_grant, sizeof(Tphygrant));
 
       current_irv = (current_irv+1)%4;
       tti_last_tx = tti_tx;
@@ -383,7 +383,7 @@ private:
 
   // Implements Section 5.4.2.1
   // Called with UL grant
-  void run_tti(uint32_t tti, mac_interface_phy::mac_grant_t *grant, mac_interface_phy::tb_action_ul_t* action)
+  void run_tti(uint32_t tti, Tgrant *grant, Taction* action)
   {
     uint32_t tti_tx = (tti+4)%10240;
     proc[pidof(tti_tx)].run_tti(tti_tx, grant, action);
@@ -405,7 +405,7 @@ private:
 
   srslte::timers  *timers_db;
   mux             *mux_unit;
-  ul_harq_process proc[NOF_HARQ_PROC];
+  std::vector<ul_harq_process> proc;
   srslte::log     *log_h;
   srslte::mac_pcap *pcap;